CT of the extraperitoneal space: normal anatomy and fluid collections.

Knowledge of the appearance and location of the normal fascial structures surrounding the kidneys and the bladder is the key to proper CT analysis of extraperitoneal fluid collections. Recent studies have shown that the renal fascia and the perirenal space are more complex than previously recognized. An extracapsular renal hematoma, confined against the kidney by the posterior renorenal septum within the perirenal space, can entirely simulate a subcapsular hematoma. Pancreatitis fluid can dissect between the discrete layers that constitute the posterior renal fascia, allowing fluid in the anterior pararenal space to extend posterior to the kidney without directly involving the posterior pararenal space. The umbilicovesical fascia separates the small perivesical space from the potential large reservoir of the prevesical space in the extraperitoneal portion of the pelvis. Fluid in the prevesical space can communicate directly with the retroperitoneal spaces surrounding the kidney. In addition to compartmental localization, CT features of the fluid itself or the presence of ancillary findings such as aortic aneurysm, enlarged pancreas, renal mass, or hydronephrosis will frequently indicate the cause and the extent of most extraperitoneal fluid collections.


Color Doppler imaging of the hepatic vasculature.

Duplex sonography added a new dimension to real-time sonographic imaging and can be used to characterize flow dynamics. Unfortunately, duplex sonography also has significant drawbacks, most of which are the result of the limited sampling ability of pulse-gated technology and the inability to provide a global display of Doppler information. Sonographic imaging of intraabdominal vessels has improved markedly with the advent of color Doppler techniques. This article reviews the use of color Doppler sonography in the evaluation of hepatic vessels. The complementary role of Doppler spectral analysis is also considered.


MR imaging of the lungs: value of short TE spin-echo pulse sequences.

An experimental short echo delay (TE = 7 msec) T1-weighted spin-echo sequence was compared with a conventional (TE = 20 msec) T1-weighted spin-echo sequence in the assessment of normal and abnormal lung parenchyma. Comparison was also made with high-resolution CT of abnormal lung parenchyma. At 1.5 T, an experimental short echo delay T1-weighted multislice spin-echo sequence (TR = RR interval, TE = 7 msec) was compared with an optimal conventional T1-weighted spin-echo sequence (TR = RR interval, TE = 20 msec, spatial presaturation). Ten healthy volunteers were examined with both sequences. The mean signal intensity and signal-to-noise ratios were calculated in lung parenchyma for both sequences. Two radiologists compared the visualization of normal lung parenchymal structures with the two techniques. In 24 patients with diffuse lung disease, results with both MR sequences and with high-resolution CT were compared. The signal intensity was significantly greater (p < .001) with the TE of 7 msec than with the TE of 20 msec, resulting in a 3.5-fold improvement in the signal-to-noise ratio. The 7-msec TE improved visualization of lung parenchymal structures, including peripheral vessels, interlobular septa or veins, and centrilobular arteries. In the patients with diffuse lung disease, pulmonary parenchymal abnormalities were better visualized on the images with TEs of 7 msec than on images with TEs of 20 msec. When compared with high-resolution CT, the sequence with a TE of 7 msec provided comparable assessment of air-space opacification and dense consolidation, but it was inferior to high-resolution CT in the anatomic assessment of lung parenchyma. This experimental spin-echo sequence with a TE of 7 msec significantly improves the signal-to-noise ratio, allowing improved visualization of normal and abnormal pulmonary parenchyma when compared with conventional spin-echo images with a TE of 20 msec. Although anatomic detail remains inferior to that seen with high-resolution CT, the improved image quality with a TE of 7 msec suggests that assessment and follow-up of parenchymal lung disease might be possible with MR, thereby avoiding ionizing radiation.


Chronic hypersensitivity pneumonitis: use of CT in diagnosis.

In its subacute or chronic form, hypersensitivity pneumonitis is often difficult to distinguish clinically and physiologically from other idiopathic diffuse lung diseases. The aim of this study was to identify high-resolution CT features that allow distinction of chronic hypersensitivity pneumonitis from other chronic diffuse parenchymal lung diseases. Six patients with chronic hypersensitivity pneumonitis were examined with pulmonary function testing, bronchoalveolar lavage, lung biopsy, chest radiography, and high-resolution CT. The chest radiographs and high-resolution CT scans were reviewed independently by three observers without knowledge of the patients' clinical status. Discrepancies between the observers were resolved by consensus. The chest radiographs revealed normal lung volumes with a combination of abnormalities: a mixed alveolar/interstitial pattern in five cases, peribronchiolar thickening in three, a diffuse granular pattern in one, and a linear fibrotic pattern in one. In general, the high-resolution CT scans showed more abnormalities than were apparent on the plain chest radiographs. High-resolution CT revealed centrilobular, peribronchiolar, indistinct nodular opacities, of various numbers, in all cases. Four cases had areas of ground-glass density, three cases had lobular areas of hyperlucency, and one case had areas of pulmonary fibrosis and honeycombing. We confirm that high-resolution CT can most clearly show the type and distribution of parenchymal abnormalities in patients with hypersensitivity pneumonitis. Importantly, although not pathognomonic, the high-resolution CT finding of centrilobular, peribronchiolar, indistinct nodules should suggest the diagnosis of chronic hypersensitivity pneumonitis.


Malignant pleural mesothelioma: value of CT and MR imaging in predicting resectability.

Our objective was to determine if CT or MR imaging findings could be used to accurately predict resectability in patients with biopsy-proved malignant pleural mesotheliomas. CT and MR findings in 41 consecutive patients with malignant mesotheliomas who were referred to the thoracic surgery clinic for extrapleural pneumonectomy were studied by thoracic radiologists before surgery. Review of radiologic studies focused on local invasion of three separate regions: the diaphragm, chest wall, and mediastinum. Results of all imaging examinations were carefully correlated with intraoperative, gross, and microscopic pathologic findings. After radiologic and clinical evaluation, 34 patients (83%) had thoracotomy; 24 of these had tumors that were resectable. The sensitivity was high (> 90%) for both CT and MR in each region. Specificity, however, was low, probably because of the small number of patients with unresectable tumors. CT and MR provided similar information on resectability in most cases. Sensitivity was high for both procedures. Because CT is more widely available and used, we suggest it as the initial study when determining resectability. In difficult cases, important complementary anatomic information can be derived from MR images obtained before surgical intervention.


Radiographic appearance of bullet tracks in the lung.

Penetrating missile or bullet wounds to the lung result in a number of abnormalities visible on chest radiographs. One finding that is unique to pulmonary parenchyma is the bullet track, which occurs along the course of a bullet as it traverses the lung. A bullet track may occur in the lung because of this organ's low specific gravity and high elasticity. In other tissues, such as liver and brain, that have higher specific gravities and lower elastic content, bullet tracks are rarely, if ever, noted because widespread destruction usually occurs. Bullet tracks may have a delayed appearance on chest radiographs, and thus may cause confusion in interpretation if a history of injury is not elicited. With the increase in violet confrontations in the United States, it is more and more likely that radiologists will be asked to interpret chest radiographs of patients who have had penetrating bullet injuries to the thorax. In this pictorial essay, we illustrate the appearance of bullet tracks in lung on chest radiographs.


Bronchial stenosis due to endobronchial tuberculosis: successful treatment with self-expanding metallic stent.

Endobronchial tuberculosis is present in 10-40% of patients with active pulmonary tuberculosis, and more than 90% of the patients with endobronchial tuberculosis have some degree of bronchial stenosis. The primary treatment for tuberculous bronchial stenosis is antituberculous chemotherapy combined with steroids, but some patients do not respond well, and more aggressive treatment is needed to restore the patency of the involved bronchus. Balloon dilatation of tuberculous bronchial stenosis has been reported to be successful. However, in our experience, balloon dilatation of the stenotic segment has not significantly improved patients' clinical symptoms except in those with very short segmental stenosis. We describe a case of tuberculous bronchial stenosis that was successfully treated with Gianturco self-expanding metallic stents.


Screening mammography in 350 women with breast implants: prevalence and findings of implant complications.

A series of screening mammograms in asymptomatic women with breast implants was reviewed to determine the prevalence of clinically silent sequelae of breast augmentation and to analyze the mammographic findings. The screening mammograms of 350 consecutive women with implants were reviewed retrospectively by experienced mammographers. Any women who reported problems had a diagnostic examination and therefore were not included in our sample. Mammographic features of sequelae specific to implantation such as development of a fibrous capsule, periprosthetic calcification, implant herniation, and silicone leaks were tabulated. Additionally, modified compression (push-back) views, when obtained, were evaluated for their usefulness. Fibrous encapsulation of breast implants was seen in 257 (73%) of 350 women. Periprosthetic calcification was seen in 90 (26%), and 60 women (17%) had implant herniations. Sixteen women (5%) had implant failure as evidenced by silicone leak. Two of these women had bilateral implant failures. Surgical confirmation was attainable in only five of 16 women. Analysis of modified compression views demonstrated an overall improvement in visualization of breast tissue with this technique. Although the sample size is small, there was a significant increase in the amount of breast tissue seen with push-back views in women with submuscular implants. Our analysis revealed a wide range of mammographic findings in this group of asymptomatic women with breast augmentation. Especially worrisome is the 5% prevalence of unsuspected silicone extravasation. Additionally, we have demonstrated the usefulness of push-back views in this screening group, especially in women with submuscular implants.


Percutaneous obliteration of the cystic duct with a holmium:yttrium-aluminum-garnet laser: results of in vitro and animal experiments.

The purpose of this study was to investigate the feasibility of using a holmium:yttrium-aluminum-garnet laser to permanently occlude the cystic duct in order to isolate the gallbladder from the biliary-enteric circulation and prevent gallstone formation. To determine the optimal laser parameters (power and pulsing rate) for cystic duct thermocoagulation, 20 freshly excised porcine gallbladders with intact cystic ducts underwent low-energy (0.075-0.085 J/pulse) or high-energy (0.20-0.25 J/pulse) thermocoagulation. Histopathologic examination was done to determine the extent of cystic duct injury. After in vitro experiments, percutaneous transcholecystic laser thermocoagulation of the cystic duct was performed on 23 anesthetized domestic pigs (four controls). Cholangiograms immediately after laser thermocoagulation were obtained to assess cystic duct occlusion. Animals were sacrificed for histopathologic correlation immediately after laser thermocoagulation (n = 4), 72 hr later (n = 4), and 6 weeks later (n = 15). In the in vitro studies, all 10 cystic ducts in the high-energy group were occluded, while only four in the low-energy group were occluded. At histology, all cases in both groups showed circumferential injury to the cystic duct wall without injury to the cystic artery or vein. In the in vitro experiments, the cystic duct was successfully cannulated in 21 (91%) of 23 animals. Cholangiography after thermocoagulation showed occlusion of the cystic duct in 16 (84%) of 19 cases. Immediately after laser thermocoagulation, the cystic duct mucosa was circumferentially destroyed, whereas after 72 hr necrosis of the cystic duct wall and periductal tissues had occurred. By 6 weeks, all pigs had complete cystic duct fibrosis without injury to the common bile duct. Holmium:yttrium-aluminum-garnet laser thermocoagulation of the cystic duct can be performed easily, results in immediate cystic duct occlusion, and leads to permanent fibrous ductal obliteration by 6 weeks.


Percutaneous chemical gallbladder sclerosis after laser-induced cystic duct obliteration: results in an experimental model.

Chemical gallbladder sclerosis has been attempted as a way to defunctionalize the gallbladder in patients who have undergone nonsurgical removal of gallstones and who are unable to undergo surgical/laparoscopic cholecystectomy. The purpose of this investigation was threefold: to study an animal model for chemical sclerosis of the gallbladder with 95% ethanol and 3% sodium tetradecyl sulfate, to attempt chemical sclerosis immediately after percutaneous cystic duct obliteration by laser thermocoagulation, and to assess histopathologic changes in the gallbladder after sclerosis. Percutaneous cholecystostomy and laser thermocoagulation of the cystic duct was performed in 13 pigs. Eight pigs underwent immediate gallbladder sclerosis with 95% ethanol and 3% sodium tetradecyl sulfate while two pigs received 95% ethanol only. The remaining three pigs served as controls. The cholecystostomy catheter was removed immediately after the procedure. All animals were sacrificed 6 weeks after laser thermocoagulation. Multiple sections through the gallbladder, which included the adjacent liver, the cystic duct, and the common bile duct, were obtained for histologic examination. At autopsy, the gallbladder in all 10 animals who underwent gallbladder sclerosis was reduced in size compared with controls. In all treated animals, the gallbladder mucosa was denuded; however, in nine of 10 cases reepithelialization had occurred. Complete sclerosis without reepithelialization was achieved in one pig who received both ethanol and sodium tetradecyl sulfate. In the two animals who received ethanol only, the depth of wall necrosis around the gallbladder lumen was less than in those pigs who received both ethanol and sodium tetradecyl sulfate. No pigs showed signs of hepatic necrosis or injury to the common bile duct. Cystic duct laser thermocoagulation allows immediate gallbladder sclerotherapy without injury to the common bile duct. Sclerosis with ethanol and sodium tetradecyl sulfate results in denudation of the gallbladder mucosa. However, a single therapeutic session with immediate removal of the cholecystostomy catheter was inadequate for gallbladder ablation in this model because of reepithelialization.


Use of T1-weighted MR imaging to differentiate between primary polydipsia and central diabetes insipidus.

To investigate the value of MR in differentiating patients with primary polydipsia, who have an intact neurohypophyseal system, from those with central diabetes insipidus, who have impaired synthesis and/or release of vasopressin. Eighteen patients with clinically significant hypotonic polyuria were diagnosed endocrinologically as having primary polydipsia or diabetes insipidus (central or nephrogenic). These patients, and 92 patients without sellar disease, were then imaged with 1.5-T, T1-weighted, thin sagittal sections without gadolinium contrast. Normal hyperintense signal of the neurohypophysis was present in 90 of 92 patients without sellar disease. The signal was also present in all six patients with primary polydipsia. In contrast, the hyperintense signal was absent in all eight patients with central diabetes insipidus. Three of the four patients with nephrogenic diabetes insipidus also had an absent hyperintense signal. T1-weighted MR may prove important in differentiating patients with central diabetes insipidus from those with primary polydipsia.


Macroprolactinomas: serial MR imaging in long-term bromocriptine therapy.

To study the changes in macroprolactinomas during long-term bromocriptine therapy by means of serial MR imaging, and to correlate the findings to the serum prolactin (S-PRL) levels. Thirteen patients with macroprolactinomas were studied before and during bromocriptine therapy; six to 11 MR examinations were performed with a duration of follow-up of 22 to 74 months. Tumor size, extension, relationship to adjacent structures, and signal intensity patterns were evaluated. Signal intensity ratios and T2 values were calculated in areas of apparently solid tumor tissue. Bromocriptine effectively reduced the size of all tumors; the size reduction was already significant at 1 week, but often continued for several years. Reenlargement during therapy was seen in three cases. The development of chiasmal herniation parallel to increasing cisternal invagination into the sella was a common finding, but was not correlated to visual symptoms. Signal intensity patterns corresponding to hemorrhage, cysts or necrosis were frequently observed, and transitions from one pattern to another were common. Hemorrhage occurred mainly in tumors corresponding to high initial serum prolactin levels. After 1 year of therapy, there was a significant increase in T2 values, indicating an increased water content in residual solid tumor tissue. MR is valuable for follow-up in bromocriptine therapy of macroprolactinomas, and provides new information on the tumor size changes, the inner structure of the tumors, and the optic chiasm.


MR assessment of pituitary gland morphology in healthy volunteers: age- and gender-related differences.

High-field MR images at 1.5 T were used to characterize the effects of age and gender on pituitary size and shape in a sample of 71 adult volunteers (40 females), aged 21 to 82 years. For all subjects, age was inversely correlated with pituitary height (r = -.43, P less than .0002) and cross-sectional area (r = -.35, P less than .0028). Age-specific gender differences were also present in pituitary height and area. A convex upper pituitary margin was more common in females (P = .002) and younger subjects (P = .009). This study confirms that aging is accompanied by gender-specific changes in pituitary size and shape, and provides normative data that may facilitate evaluation of the pituitary gland in neuroendocrine disorders.


Can nonenhancing white matter lesions in cancer patients be disregarded?

To assess the risks and implications of assuming that white matter lesions in cancer patients that do not enhance with gadopentetate dimeglumine (Gd-DTPA) can be considered to be benign. Gd-DTPA was administered prospectively to 131 consecutive patients with biopsy-proved extracranial malignancies referred for cranial MR imaging to exclude cerebral metastases over a 21/2-year period. From this initial group, 50 patients were identified who had focal nonenhancing lesions of the white matter on T2-weighted images, but no other findings to suggest metastatic disease. This cohort of 50 patients was then followed for at least 1 year to determine the risk and clinical implications of assuming these nonenhancing white matter lesions were benign. Thirty patients (60%) were alive and clinically free of cranial metastatic disease at least 1 year following their initial MR study (median follow-up time, 17 months). Twenty of the 50 patients (40%) died within 1 year of their study (median survival, 4.1 months). Review of clinic notes and hospital charts revealed no evidence for deterioration of neurologic status in any of these patients before death, and the cause of death in each case was ascribed to extracranial complications of their systemic malignancies. Eight of these 20 patients who expired had at least one follow-up cranial CT or MR scan before death showing no new cerebral metastases or change in the nonenhancing white matter lesions previously identified. In a single patient, however, follow-up MR scan revealed conversion of one of her several white matter lesions from nonenhancing to enhancing without appreciable change in its size on T2-weighted images. Unfortunately, this patient died 4 months later from surgical complications without interval change in her neurologic status nor pathologic proof of the nature of this lesion. White matter lesions in cancer patients that do not enhance with Gd-DTPA at the time of the initial MR study have a low probability of representing metastatic disease. Clinical management or final outcome will not likely be altered by assuming such lesions are benign.


Dysembryoplastic neuroepithelial tumors: MR appearance.

Dysembryoplastic neuroepithelial tumor (DNT) is a newly described, pathologically benign tumor arising within the supratentorial cortex and having a 100% association with partial complex seizures. We reviewed the MR appearance of the brains of six patients with DNT, without and with administration of gadolinium-DTPA, emphasizing the clinical and radiologic features. The MR images in six patients (five male, one female) with pathologically proved DNT were reviewed. Five had partial complex seizures and one had partial simple seizures. Age at onset of partial seizures ranged from 2 to 19 years. Scans were obtained with conventional T1 and T2 weighting without and with the administration of gadolinium-DTPA. All patients had craniotomies for medically refractory seizures and pathologic examination of all specimens was available for review. MR demonstrated a focal cortical mass in all patients. Five were located in the temporal lobe and one was located within the occipital lobe. Two showed enhancement with gadolinium-DTPA. Calcification occurred in one lesion. Common features included very low signal intensity on T1-weighted images and high signal on T2-weighted images, similar to cerebrospinal fluid. Proton density images demonstrated slightly higher signal intensity in the lesion than cerebrospinal fluid. The margin of the tumor is well-circumscribed and may remodel the adjacent calvarium. DNT, a newly described pathologic entity resulting in chronic, often medically, intractable seizures, has characteristic features on MR that allow it to be suggested in the differential diagnosis. These lesions may simulate benign cysts; however, increased signal intensity on proton density images should prompt further investigation in the proper clinical setting. Differentiation from low-grade astrocytomas and ganglioglioma is not possible by MR.


Magnetic susceptibility artifact in spin-echo MR imaging of the pituitary gland.

To evaluate the magnetic susceptibility effect on spin-echo MR images of the pituitary gland. Air-in-water phantom experiments and studies in normal volunteers were performed using various sampling bandwidth (8.3-33.3 kHz) spin-echo sequences with the polarity of the readout gradient normal or reversed. Attachment of a sphenoid septum to the sellar floor was the major factor in the appearance of the inferior surface of the pituitary gland. Patterns of distortion and/or artifactual signal intensities, related to the presence or absence of the attachment, were accentuated on the images with narrower bandwidth. A "spearhead shape" deformity of the sphenoid sinus was observed both in the air-in-water phantom experiment, and when no sphenoid septum was present. When a sphenoid septum was present, two spearhead shapes side by side were present. High-intensity artifacts were seen where the sellar floor was misplaced into the pituitary gland. Knowledge of the patterns of distortion and high-intensity artifact is important in the diagnosis of pituitary lesions.


Intracranial fetus-in-fetu: CT diagnosis.

The authors present a case of fetus-in-fetu in which the CT findings are compatible with an earlier description by Nocera et al., i.e., a "round or tubular collection of very low density fat surrounding a central bony structure (probably one of the legs)." Additionally, sonography showed a heterogeneous mass with limb-like structures in the left lateral ventricle. Plain films can confirm the presence of a vertebral column and identify specific bony structures, but CT is a valuable aid in cases where plain films were not obtained or are inconclusive.


Pleomorphic xanthoastrocytoma.

We report two cases of pleomorphic astrocytoma, a rare primary brain tumor with an unusually good prognosis. These lesions typically are peripherally located, partially cystic, temporal lobe masses. Dural attachment is frequent, calcifications are not. Angiography usually shows a hypovascular mass, although blood supply from the external carotid artery may be seen.


Subdural hygroma versus atrophy on MR brain scans: "the cortical vein sign".

To determine if the position of the superficial cerebral cortical veins can be used to distinguish subdural hygroma from atrophy on MR brain scans. Retrospective review of MR scans obtained in cases of extracerebral fluid collections, separating these into two groups, ie, subdural hygroma or atrophy. All cases of atrophy in this study showed cortical veins and their branches traversing widened cerebrospinal fluid spaces over the cerebral convexities. None of the subdural hygroma patients showed this finding. Cortical veins in hygroma patients were seen only at the margin of the displaced cortex, and did not traverse the fluid collections over the cerebral convexities. The authors call the visualization of cortical veins and their branches within fluid collections at the cerebral convexities "the cortical vein sign." They believe this sign to be prima facie evidence of atrophy; its presence rules out the diagnosis of subdural hygroma in the region of interest.


Systemic lupus erythematosus associated with marked intracranial calcification.

The authors describe a case of systemic lupus erythematosus associated with marked intracerebral calcification. The distribution of high signal on T1-weighted MR images was almost identical to the distribution of calcification on CT; however, the bodies of caudate nuclei with little calcification on CT also showed high intensities on T1-weighted images.


Primary meningeal tumors in children: correlation of clinical and CT findings with histologic type and prognosis.

To identify the radiologic features that might help in preoperative differentiation of the meningiomas from the remaining primary meningeal tumors, in particular the malignant tumors. The clinical and computed tomographic features of 21 children with histologically proved primary meningeal tumors were analyzed. Benign tumors (meningiomas) are more likely to occur in older children, to have longer symptom duration, and to have CT appearances similar to the "typical" adult meningioma. Atypical CT features suggest a malignant meningeal tumor, such as meningeal sarcoma, melanoma, or meningeal primitive neuroectodermal tumor. The recent identification of a new subtype of meningioma (a "sclerosing" group) is discussed. This is common in children and the CT and clinical features are similar to those seen in other meningiomas. It is frequently mistaken histologically for an intraaxial tumor, or for an atypical or malignant meningioma. These sclerosing meningiomas may also show brain invasion but despite this, in the short term, the prognosis is no different from other meningiomas. The bad reputation previously ascribed to childhood primary meningeal tumors should be confined to that small group that are malignant. Meningiomas have a more favorable outlook.


MR of the hypothalamic-pituitary axis in Langerhans cell histiocytosis.

To describe the MR findings in the hypothalamic pituitary area in children with Langerhans cell histiocytosis and to define those MR alterations especially associated with the risk of developing diabetes insipidus. The hypothalamic-neurohypophyseal axis was studied by sagittal and coronal 1.5 T1-weighted MR imaging in 14 children with Langerhans cell histiocytosis (five with diabetes insipidus) and in 28 low-stature controls, ages 6-14 years. The pituitary stalk was thicker in seven/14 patients (three with diabetes insipidus) than in controls (P less than .05). Bright posterior pituitary signal was undetectable in children with diabetes insipidus and in one/9 without diabetes insipidus. Thickening of the hypothalamus and/or the pituitary stalk in the absence of the posterior pituitary bright signal is seen in children with Langerhans cell histiocytosis with overt diabetes insipidus. Those Langerhans cell histiocytosis patients without diabetes insipidus but showing thickened stalk with or without posterior pituitary bright signal could be at high risk to develop diabetes insipidus.


Delayed neurologic deterioration in the patient with spinal trauma: role of MR imaging.

To 1) correlate spinal MR features and modes of clinical presentation associated with symptomatic neurologic deterioration following longstanding spinal trauma; 2) correlate degree of neurologic deficit with spinal MR appearance in these patients; and 3) determine the relationship between new symptoms and ongoing cord compression. Retrospective examination of MR images, and correlation with clinical data, in 94 consecutive patients. Sixty-seven patients presented with either an increase in degree of myelopathy or ascending neurologic level. Spinal cord atrophy (43%), syrinx (41%), and cord compression (24%) were found most frequently. Whereas in patients with complete motor and sensory deficit cord atrophy was the most frequent finding (52%), 75% of patients with useful motor function had normal spinal cords. There was a significant association (P less than .05) between cord compression and the MR findings of cord atrophy and myelomalacia, whereas a normal cord was over twice as frequent in patients without spinal cord compression. MR imaging led to an active change in management in 15% of patients, with improvement following surgery in all operated cases. Although syrinx is a frequent, and treatable cause of delayed neurologic deterioration, MR will frequently show other abnormalities such as ongoing cord compression. MR imaging should be performed urgently in all patients with new symptoms to enable early treatment to prevent irreversible loss of function.


Fast spin-echo imaging in the evaluation of intradural disease of the spine.

Fast spin echo (FSE) images were compared with conventional images in 46 patients with intradural spinal disease to determine their accuracy in the detection and delineation of lesions. The images were interpreted by two neuroradiologists, who read individually. A total of 720 blinded readings formed the basis for this evaluation. A gold standard for each patient was selected, based on the blinded readings of the conventional studies. In the sagittal plane, the FSE sequences were found to have an accuracy of 93% and 93% for the first reader and 93% and 85% for the second reader. For the axial plane, the corresponding figures were 86% and 82% for the first reader and 64% and 77% for the second reader. These figures compared favorably with conventional sequences. Similar delineation of lesions was noted in 78% of cases. In the remaining cases, there were no significant trends. Because of these findings, FSE sequences appear as accurate as conventional sequences. In this study, they were capable of supplanting conventional sequences in the evaluation of intradural pathology of the spine in the sagittal plane, although conventional sequences were still preferred in the axial plane.


MR of slow CSF flow in the spine.

To evaluate a slow-flow MR sequence in normal CSF flow and in CSF flow disturbance in cases of spinal stenosis. The method was tested for flow sensitivity and applied to 67 sites of spinal canal compromise. Phantom studies show that flow can be depicted at a velocity of 0.5-1 mm/sec. On clinical images, stagnant CSF is black, flowing CSF is bright. Typically, in high-grade (90%-100%) stenosis, CSF above and below the site of spinal canal compromise (SCC) is black. With intermediate stenosis (50%-89%), CSF above the SCC remains white but becomes black distal to the SCC. Low-grade stenosis shows only localized flow disturbances. This easy-to-use sequence can solidify the MR diagnosis of high-grade stenosis when a distinct flow pattern is recognized. Flow patterns for intermediate and low-grade stenosis are less reliable.


Herpes zoster myelitis: MR appearance.

The author describes a 71-year-old woman in whom cutaneous cervical herpes zoster was complicated by the development of cervical myelitis. T2-weighted MR showed two focal areas of hyperintensity in the cervical cord and suggested a slight enlargement at C2-C3 and C7.


Artifacts associated with MR neuroangiography.

Neurovascular MR angiography (MRA) is rapidly gaining greater clinical acceptance. To provide functional information, novel techniques of acquisition, information processing, and display are used, generating a new set of artifacts. The purpose of this paper is to outline the causes, provide examples, and note clinical problems associated with MRA artifacts by grouping them into six common types: 1) poor visualization of small vessels, 2) overestimation of stenosis, 3) view-to-view variations, 4) false positives, 5) false negatives, and 6) vessel overlap. This in turn will lead to four generalized solutions: 1) optimize acquisition parameters, 2) edit volume boundaries before performing maximum intensity projection reconstructions, 3) refer to the individual source images, and 4) use alternative image processing. By organizing and simplifying both clinical problems and solutions into major categories, a greater understanding of the current clinical indications and the overall goals of MRA can be achieved.


MR angiography of the extracranial carotid arteries using a two-slab oblique 3-D acquisition.

To describe an oblique, two-slab 3-D acquisition technique for MR angiography of the extracranial carotid arteries, an approach chosen to minimize saturation effects when the body coil is used as transmitter, as is often the situation when a dedicated neck coil is used as receiver. Five healthy subjects and 17 patients in whom carotid artery disease was suspected underwent MR angiography using the above technique. Flow contrast was much better than in direct sagittal acquisition. Comparisons between multislab transverse 3-D acquisition and the oblique approach showed that a greater length of the carotid arteries was depicted and scan time was less for oblique acquisitions. Use of oblique imaging is a simple and effective solution to the problem of coil-related saturation effects.


Fat suppression in combination with multiple overlapping thin-slab 3-D acquisition MR angiography: proposed technique for improved vessel visualization.

To study the parameters of the 1331 fat saturation pulse (saturation pulse flip angle (SPFA) and interpulse delay (tau)) in order to identify values that provide optimal vessel visibility. Carotid bifurcations of three healthy subjects were studied. The optimal values for the SPFA and tau were 60 degrees (7.5 degrees, -22.5 degrees, 22.5 degrees, -7.5 degrees) and 2.0-3.0 msec, respectively. At these values there was a 1.56-fold increase (SD = +/- .12, P less than .01) in the contrast-to-noise ratio between the left internal carotid artery and fat compared to the study without fat saturation. A 3.0-fold increase was noted for the smaller left occipital artery. Additionally, there was no statistically significant reduction in the vessel-muscle contrast-to-noise ratio nor in the absolute vessel signal-to-noise ratio at these values. Implementation of fat saturation into carotid MR angiography markedly improves visualization of vascular anatomy without increasing imaging time.


Determination of blood flow direction using velocity-phase image display with 3-D phase-contrast MR angiography.

The authors describe their use of phase-contrast MRA to depict vascular anatomy and to define the direction of blood flow. Documentation of flow reversal can provide information regarding prognosis and can facilitate surgical planning. The technique requires no additional scan-time.


Non-heme mechanisms for T1 shortening: pathologic, CT, and MR elucidation.

To further elucidate the nonparamagnetic effects of T1-relaxation mechanisms in MR imaging. In 12 patients with lesions having hyperintense signal on T1-weighted spin-echo MR, findings were correlated with autopsy/surgical biopsy in seven cases and/or noncontrast CT scans in 10 cases. Eight of the 10 CT scans demonstrated hyperattenuation in the lesions, indicating mineralization, which correlated with the areas of hyperintense signal on MR. Histologic characterization of the mineralization was accomplished in three cases using four stains; hematoxylineosin, alizarin red S, von Kassa stains for calcium and Perls' iron. The areas of mineralization were homogeneously strongly positive with the calcium stains and only focally weakly positive with the Perls' iron stain. The mineralization was further characterized in all three cases as containing calcium and phosphorus using energy-dispersive x-ray analysis. Four of the 12 cases had either no correlating CT scans (two cases) or the CT showed no hyperattenuating properties to the lesions (two cases). In all four of these cases, microscopic examination showed that the gyriform configuration of the cortical hyperintense signal on T1-weighted images correlated with linear zones of nonhemorrhagic laminar necrosis (cerebral infarction). No mineralization, except for an occasional ferruginated neuron, could be demonstrated with the four histologic stains. Specimen MR imaging of formalin-fixed brain sections in one case demonstrated in vitro the gyriform hyperintense signal seen in vivo. Our studies describe and pathologically characterize two associations with T1 shortening in neuroimaging unrelated to the presence of heme: 1) calcification and 2) laminar necrosis in cerebral infarction.


Angiographic findings in two cases of aneurysmal malformation of vein of Galen prior to spontaneous thrombosis: therapeutic implications.

Two cases of aneurysmal malformations of the vein of Galen with later spontaneous thrombosis are reported. Angiograms before thrombosis in both cases showed mural type aneurysmal malformations of the vein of Galen with slow arteriovenous shunts and associated stagnation of contrast in the venous sac secondary to severe outflow restriction. Based on these angiographic findings, the patients were managed conservatively and the arteriovenous malformations of the vein of Galen thrombosed with good clinical outcomes. Twenty cases of spontaneous thrombosis previously reported in the literature are reviewed.


MR angiography of cervical fibromuscular dysplasia.

The authors present examples of cephalic fibromuscular dysplasia (involving five vessels in two patients) using 2-D time-of-flight MR angiography and conventional angiography. Artifacts that can mimic the MR appearance of fibromuscular dysplasia will tend to decrease the sensitivity and specificity of MRA in its detection.


Gd-DTPA enhancement of the cisternal portion of the oculomotor nerve on MR imaging.

To describe a radiographic finding--enhancement of the cisternal portion of the third cranial nerve on postcontrast MR--and to correlate it with patients' clinical symptoms and ultimate diagnosis. Thirteen consecutive patients with enhancement of the cisternal portion of the third cranial nerve on postcontrast MR were retrospectively identified; 50 control patients referred for pituitary microadenomas were also retrospectively reviewed. The enhancement was bilateral in six patients and unilateral in seven patients. Four of the six patients with bilateral enhancement had unilateral oculomotor nerve palsies; none had bilateral third cranial nerve palsy. Five of the seven patients with unilateral enhancement had ipsilateral third nerve palsies. Of the nine patients with third nerve palsies, the pupil was involved in four patients. Follow-up studies were available in six patients, four of whom had third nerve palsy. Resolution of the enhancement correlated with resolution of the symptoms in two patients. The patients' underlying diagnoses were lymphoma (four), leukemia (one), viral meningitis (one), neurofibromatosis (two), inflammatory polyneuropathy-HIV related (one), ophthalmoplegic migraine (one), Tolosa-Hunt syndrome (one), coccidioidomycosis (one), and diabetes (one). No enhancement was seen in any of the controls. Enhancement of the cisternal segment of the third cranial nerve is always abnormal, revealing an underlying inflammatory or neoplastic process. However, it is not always associated with clinically apparent oculomotor nerve dysfunction.


Cerebral aspergillosis: MR imaging and histopathologic correlation.

The authors report a case of intracranial aspergillosis secondary to immunosuppression. Signal intensity changes in the lesion on brain MR are compared with gross and histopathologic findings at autopsy. A peripheral ring of low signal intensity relates to a dense population of Aspergillus hyphal elements and small areas of hemorrhage. CT findings are included for comparison.


Prefrontal sonic treatment: MR findings.

The authors describe the use of MR in a patient who underwent prefrontal sonic treatment for relief of intractable headaches. MR demonstrated well-demarcated regions of encephalomalacia within the white matter of the frontal lobe (with relative sparing of cortex) in a characteristic conical volume that corresponded to the insonified regions.


Proboscis lateralis with associated orbital cyst: detailed MR and CT imaging and correlative embryopathy.

Proboscis lateralis is a rare craniofacial malformation. We present a case in a 1-week-old male infant, describe the clinical and imaging findings, and discuss the pertinent embryology. MR and CT proved to be complementary: CT provided anatomic detail in bone, defined the nasal cavity, and aided in determining the relationship of the proboscis and orbit; MR clarified the relationship of the proboscis to the orbit and skull base, and the relationships of normal brain to the dysplastic ethmoid centers.


AIDS-related CNS cryptococcosis: radiologic-pathologic correlation.

This study evaluates the effectiveness of cranial CT and MR in detecting autopsy findings of AIDS-related CNS cryptococcosis. Final imaging studies compared with pathology were CT in eight patients (five with contrast) and MR in five patients (all with Gd-DTPA). Neither modality effectively identified cryptococcal meningitis. Punctate hyperintensities were seen in all patients with MR and corresponded pathologically to both perivascular spaces dilated by cryptococcal infection and cryptococcomas. Pathologically, cryptococcomas were more common than dilated perivascular spaces. MR detected more cryptococcomas than did CT, but both modalities underestimated the number of lesions seen at autopsy. Contrast enhancement of cryptococcomas and cryptococcal meningitis was uncommon. CNS cryptococcosis was more effectively demonstrated by MR than by CT, but both modalities underestimated the pathologic extent of the disease. Cryptococcal lesion contrast enhancement was unusual possibly because of the immunocompromised state of our patients and the unique characteristics of the organism itself.


Primary causes of medical instability of Medicare patients at discharge 1990-1991.

HCFA-sponsored Peer Review Organizations nationwide have been criticized by organized medicine, Medicare beneficiaries and interested Congressional parties for being punitive without exploiting educational opportunities garnered through their massive data collection capabilities. Until now this data has been poorly analyzed and has not been adequately utilized as a positive motivational tool. HCFA has developed, with the cooperation of the medical community, six generic screens for Peer Review Organizations to utilize when evaluating quality care provided Medicare beneficiaries in an acute care setting. Through the sheer volume of cases seen, significant inpatient information can be obtained that cannot be duplicated in any other epidemiological endeavor. Line item discrepancies can be further studied through small-area-analysis to determine "who" as well as "what" may be the problem. By compiling and reviewing data in a systematic manner over two years (1990-1991), the Alabama Quality Assurance Foundation (AQAF) has singled out problems with patient medical stability at discharge as the predominant concern for care providers and reviewers alike. Having determined the primary problem in rendering quality care in a Prospective Payment System to Medicare beneficiaries lies in premature discharges, subsequent small-area-analysis further narrows the focus of concerned individuals. Hopefully, practitioners and providers alike will act on their own initiative in correcting this problem. Follow-up review will be utilized to assure this self-corrective action.


Topical flunisolide treatment of perennial rhinitis: clinical and immunological effects.

We studied the clinical and immunological effects of three months' treatment with intranasal flunisolide (100 micrograms daily) in 18 allergic patients with perennial rhinitis. 17 were hypersensitive to house dust mite and one to Parietaria pollen only. We found no significant changes in white blood cell count, serum levels of IgE and nasal IgA. However the treatment induced a marked improvement of clinical symptoms in all cases, and we observed a significant reduction of total IgE in nasal secretion. Flunisolide seems to exert this effect through its antiinflammatory action on the nasal mucosa.


IgG4-anti-IgE antibodies in Chinese allergic children.

IgG4-anti-IgE antibodies have been identified in normal nonatopic subjects, as well as in allergic patients. Their potential role remains controversial. We studied 44 Chinese children with allergic symptoms, and measured their IgG4-anti-IgE serum levels using a modified IgG4 FAST assay. The levels of IgG4-anti-IgE antibodies did not correlate with clinical status. The usefulness and relevance of these measurements remain questionable in allergic patients.


Improvements in the signing skills of hearing parents of deaf children.

Most deaf children are born to hearing parents. Yet, many hearing parents are unable to communicate clearly and unambiguously with their deaf offspring. This study looked at changes in the number of parents of deaf offspring who learn sign language, and the signing skills of those parents. It found that over the years the signing skills of these parents have been improving. Of the younger deaf offspring in this study, 73% reported that their parents knew some sign language. Younger offspring rated their parents' signing skills higher than did older offspring. These results may indicate that more parents are now learning sign language.


Interleukin 2 proliferative response by cord blood mononuclear cells of term and preterm neonates.

The results of previous studies on the proliferative response of resting cord blood mononuclear cells (CBMC) of term neonates to human recombinant interleukin 2 (hrIL-2) are contrasting. Some authors have reported a good and others a poor response. In our study we have obtained a significant reactivity, compared with the response of resting peripheral blood mononuclear cells (PBMC) of adult subjects, of resting CBMC to varying quantities of hrIL-2 in the absence of any known mitogenic or antigenic stimuli. Most responding cells was CD3 positive. Both CD4-positive and CD8-positive cells responded. However, we observed a more marked increase of the percentage of the CD4-positive T cells and a clear reduction of the percentage of the CD21-positive cells (B-lymphocytes) testing CBMC rather than PBMC of the adult subjects. The percentage of the NK cells was reduced in both the categories of subjects. Moreover, we have examined the reactivity to hrIL-2 of CBMC of preterm neonates. The results showed that this response is low. The peculiar level and kinetic of CBMC proliferative response to hrIL-2 are discussed.


How successful deaf teenagers experience and cope with isolation.

This study examined isolation among a group of deaf high school students who were nominated as "outstandingly successful" by their schools in a stratified random sampling from across the United States. From the data contained in 23 case studies, we determined that most of the students, whether from mainstream or residential programs, experienced some degree of isolation from peers or family or both. Nevertheless, most of the students had developed, or had at their disposal, positive strategies for coping with their isolation. These strategies are discussed and implications are drawn for teachers and parents.


Cross-sectional area of nasal airways during the nasal provocation tests.

Eighteen patients with allergic rhinitis were studied using nasal challenge tests to allergens. The Rivron algorithm was used to evaluate results. We calculated the dose-area correlation and changes in the cross-sectional area of the nasal airway during the test.


Recall performance on a central-incidental memory task by profoundly deaf children.

Bebko (1984) reported that deaf children tend not to use spontaneously active memory strategies such as rehearsal in tasks requiring recall of ordered, temporal information. The present study investigated whether this tendency is task specific or generalized to other experimental paradigms. A central-incidental paradigm was used with profoundly deaf children and hearing children 6 to 13 years of age. The results for the hearing students replicated previous studies: central recall increased with age, but incidental recall changed little. For the deaf children, the results initially appeared very similar to those of the hearing children. However, on closer examination, the rehearsal strategies of the deaf students seemed less effective in mediating their recall. They apparently compensated for these difficulties by capitalizing on unique spatial features of the task, leading to recall levels comparable to those of the hearing students. Therefore, similar performance may not have been the result of equal strategy use but, rather, of the use of additional strategies by the deaf students. This study reinforced the need to provide additional training for deaf students in the use of memory strategies such as rehearsal when information is to be remembered in a sequential manner.


Comparison of in-house reference extracts of Dermatophagoides pteronyssinus and Phleum pratense with the WHO International Standards.

Two of the WHO First International Standards (IS) of allergenic extracts, the corresponding to Dermatophagoides pteronyssinus (House dust mite) and phleum pratense (Thymothy grass), have been used to assess the quality of our in-house reference preparations (IHR) and to calibrate their relative potency. The qualitative comparison was achieved by SDS-PAGE, Agarose-IEF and their respective enzime immunoblottings (Western blot and immunoprinting). The band patterns obtained were fairly similar for both Phleum pratense extracts. With the exception of two basic IgE binding proteins not detected in the IEF-blotting of the International Standard. However, several differences were noted between IS and IHR Dermatophagoides pteronyssinus extracts, indicating so the higher raw material heterogeneity. The difference was specially remarkable at the level of SDS-PAGE Immunoblotting since while our IHR extract showed similar ratio of Der p I to Der p II major allergens, the IS exhibited a large preponderance of Der p I, with Der p II allergen scarcely detected by our chromogenic method. Calibration of potency was done by means of RAST inhibition, therefore allowing the expression of our extract concentrations in International Units. The higher degree of homogeneity between Phleum pratense extracts was corroborated by the comparison of slopes from the RAST-inhibition plots.


Some concerns about using whole language approaches with deaf children.

The whole language philosophy is having an impact not only in general education but in the education of deaf children as well. Many of the practices derived from this philosophy are beneficial for all children. Yet, because most deaf children have tremendous difficulty in acquiring English literacy, a more direct approach to teaching them may be warranted in many cases. The field of deaf education would be better served if, rather than moving from one trend in general education to another, we first took into account the special needs of deaf learners and then worked systematically and deliberately to build a knowledge base of the most effective practices for promoting literacy.


The Garden Cafe. An experiment in vocational education in the Philippines.

The author visited Bohol, a picturesque island in the Philippines 350 miles south of Manila, in 1986 and 1990 to observe and record the emerging deaf culture. Before the Peace Corps started a school program on the island some eight years ago, deaf children grew up functionally illiterate. Those who have not been found and are not enrolled in the fledgling school program still do, as they are completely isolated from the deaf community. This article describes heroic efforts to teach vocational skills to the deaf in Bohol. The project not only succeeded but led to the island's best restaurant, The Garden Cafe.


Cumulative trauma disorders among educational interpreters. Contributing factors and intervention.

Upper extremity cumulative trauma disorders became a potentially significant occupational hazard among sign language interpreters at the National Technical Institute for the Deaf in the 1988-89 academic year. The following case control study was conducted to identify factors that might play a role in developing, exacerbating, and maintaining upper extremity cumulative trauma disorders among interpreters. Investigations were conducted to determine whether medical status, physical capacities, interpreting styles, pain, fatigue, and job stress differed among NTID's sign language interpreters. This report provides a general summary of selected findings as well as a conceptual framework that should help clarify the factors associated with upper extremity cumulative trauma disorders in sign language interpreters. The results indicated that the upper extremity cumulative trauma disorder diagnosed most often is tendinitis rather than a nerve entrapment syndrome (e.g., carpal tunnel syndrome). Analysis of the frequency of potential biomechanical risk factors indicated that those reporting pain demonstrated higher frequency of hand and wrist deviations from the neutral position, higher frequency of the upper extremities leaving a predefined work space, fewer rest breaks during interpreting sessions, and higher evaluator ratings of pace of finger and hand movements. Specific features of interpreting styles were associated with increased pain and fatigue.


Deaf adolescents who drop out of local public schools.

This paper looks at correlates of school attrition in local public school programs. A preliminary survey of attrition and background data on a national sample of 451 deaf adolescents concluded that many of the same factors, including individual ability, local educational values, and certain demographic traits, that predict attrition in general education also apply to deaf education. The movement of students out of their original programs for whatever reason was primarily a regional phenomenon. Programs in the Southeast and the Southwest lost more of their original groups of students than did programs in the Northeast, Midwest, or Far West. The regional variations noted in our data suggest that local values about schooling will influence school attrition in local public school programs for the deaf.


Attitudes toward deafness. A collegiate perspective.

The Rochester Institute of Technology is a unique environment; a large number of hearing-impaired students are enrolled on a predominately hearing campus. The authors of this article explored the integration of deaf and hearing students on the campus and the attitudes surrounding deaf-hearing relationships. The major factors that hearing students identified as contributors to positive interaction between the two groups included awareness of cultural diversity, communication sensitivity and development of effective communication skills, structured opportunities for interaction, and mutual accommodation and respect.


No-scalpel vasectomy: a technique for family physicians.

Family physicians frequently perform outpatient vasectomies. A new approach to exposing the vas deferens, called the no-scalpel vasectomy, results in fewer complications and, the authors believe, improved patient acceptance. This technique, which calls for two specialized instruments, is described, along with patient selection and education issues, vasal occlusion techniques and post-vasectomy follow-up.


Erythema multiforme.

Erythema multiforme is a cutaneous reaction pattern manifested by well-demarcated plaques on the trunk and extremities. Target, or "iris," lesions, with central clearing, are characteristic of this disorder. Erythema multiforme may be a mild condition (erythema multiforme minor), or it may be a severe, possibly life-threatening condition (erythema multiforme major or Stevens-Johnson syndrome). Toxic epidermal necrolysis, manifested by widespread epidermal desquamation, is the most severe form of this disorder. The three most common triggers for erythema multiforme are herpes simplex infection, mycoplasma infection and drug reactions. Drugs that can precipitate erythema multiforme include sulfonamides, penicillins, phenylbutazone and phenytoin. The appearance of the characteristic lesion is usually diagnostic. However, conditions such as tinea corporis, lupus erythematosus, herpetic gingivostomatitis, Behçet's disease and erosive lichen planus, among others, may mimic erythema multiforme. For mild cases, treatment is supportive, with antibiotics used for secondary skin infections. For severe causes, many physicians use systemic corticosteroids, although this treatment is not universally endorsed.


Growth plate injuries: Salter-Harris classification.

Fracture of the growth plate is an injury unique to childhood. Most such fractures heal without permanent deformity. A small percentage, however, are complicated by growth arrest and subsequent deformity. The Salter-Harris classification of growth plate injuries aids in estimating both the prognosis and the potential for growth disturbance. The Salter-Harris system classifies growth plate fractures into five groups: type I, fracture through the growth plate; type II, fracture through the growth plate and metaphysis; type III, fracture through the growth plate and epiphysis; type IV, fracture through the growth plate, epiphysis and metaphysis, and type V, crush or compression injury of the growth plate.


Cleft lip and cleft palate.

The birth of a child with a cleft lip or a cleft palate, or both, can be traumatic to the family. Although referral to a multidisciplinary team experienced in craniofacial abnormalities is essential, the family physician can reduce the impact on the family by providing antenatal diagnosis and continued care of the entire family after diagnosis, during initial feeding and bonding difficulties and throughout the many years of surgical and speech therapy.


Effects of angiotensin-converting enzyme inhibitors on tissue renin-angiotensin systems.

The renin-angiotensin system (RAS) plays a major role in the control of blood pressure and cardiovascular homeostasis and is involved in the pathogenesis of a number of cardiovascular disorders. The efficacy of angiotensin-converting enzyme (ACE) inhibitors in the treatment of hypertension and congestive heart failure has led to the widespread clinical use of ACE inhibitors in primary or secondary prevention of heart disease. The demonstration of the expression of the components of the RAS in several extrarenal tissues, as well as local generation of angiotensin II, has confirmed the existence of a tissue RAS that may serve organ-specific functions and act independently from the plasma RAS. The concept of paracrine/autocrine functions of the local RAS has changed our understanding of the functions of the RAS and suggests that tissue ACE inhibition may be of greater importance than inhibition of circulating ACE in the treatment of congestive heart failure and other cardiovascular disorders. Whereas the circulating endocrine RAS appears to be responsible for mediation of acute effects, the tissue RAS seems to be involved in more chronic situations, such as secondary structural changes of the cardiovascular system, and therefore could contribute to the pathogenesis of hypertension as well as other cardiovascular disorders, such as cardiac hypertrophy, coronary artery disease, and atherosclerosis. Several experimental and clinical findings suggest that reversal of cardiovascular structural changes secondary to cardiovascular disease and enhancement of renal sodium excretion by ACE inhibitors are important long-term antihypertensive actions possibly mediated by inhibition of the tissue RAS.


Heart failure in 2001: a prophecy.

Understanding of heart failure has developed through 3 paradigms involving organ, cell, and gene. The first views heart failure as an abnormality of organ (pump) function leading to salt and water retention and vasoconstriction. Therapy to correct these circulatory abnormalities is well accepted and effective. The second considers heart failure as a disordered cellular function, mainly impaired contraction and relaxation. Efforts to correct the biochemical and biophysical abnormalities responsible for these disorders of myocardial performance have, however, been less successful. Recent emphasis on efforts to improve prognosis as well as symptoms in patients with chronic heart failure demonstrates that it is a lethal disease with problems of survival similar to those in malignancies. The third paradigm of abnormal gene expression, which in the failing heart represents a cardiomyopathy of overload, appears to be a major cause of poor prognosis in these patients. Evidence that the angiotensin-converting enzyme inhibitors have important effects on cell growth, as well as on vascular tone, suggests that their ability to prolong survival in patients with heart failure may be due largely to the inhibition of detrimental effects of angiotensin II on cardiac gene expression. Thus, it seems likely that work focused on the third paradigm will uncover specific abnormalities of gene expression that are responsible for poor survival of patients with heart failure. By 2001, I predict that heart failure will be viewed as an abnormality of cell growth and this will lead to the development of therapies to retard, if not reverse, the clinical deterioration.(ABSTRACT TRUNCATED AT 250 WORDS)


Ventricular remodeling following myocardial infarction.

Ventricular remodeling denotes structural changes that occur in ventricular chamber size, wall thickness, and composition following myocardial damage. Following acute coronary occlusion, there are various factors to consider at different times that may contribute to subsequent ventricular dilation. Early infarct expansion and later healing may be accompanied by compensatory hypertrophy in the noninfarcted region and progressive global dilation, that may progress long term, the major stimulus being increased wall stress. The 2 major factors influencing ventricular remodeling following myocardial infarction are infarct artery patency and the ventricular loading conditions. Thrombolytic therapy may produce coronary reperfusion and limit infarct size. Patency of the infarct-related artery may also provide later benefits for ventricular remodeling. Following infarct evolution, pharmacologic intervention provides the potential to minimize the sequelae of infarct expansion and ventricular dilation. Clinical studies indicate that treatment of symptomless left ventricular dysfunction with angiotensin-converting enzyme inhibition at greater than or equal to 1 week following myocardial infarction may prevent further ventricular dilation and reduce the probability of progression to heart failure. Earlier intervention, at 24-48 hours following Q-wave myocardial infarction, is also practicable and effective. Even earlier intervention, in combination with or immediately following thrombolysis, is being assessed in other studies. The timing of treatment is of considerable importance because blockade of compensatory mechanisms activated at the time of infarction may not be desirable immediately, even though these mechanisms may be deleterious later. The results of large-scale mortality studies are awaited to indicate the benefit of this type of treatment in terms of heart failure prevention and survival long term.


Prospects for cardioreparation.

The structure of the myocardium has 2 principal components, a myocytic compartment and a non-myocytic compartment that consists primarily of interstitial tissue. It appears that increased collagen production is mainly responsible for the functional consequences of structural remodelling. The concept of cardioreparation implies both a restoration of structural abnormalities and a return of cardiac function to or toward normal. In spontaneously hypertensive rats with left ventricular hypertrophy and adverse structural remodeling of the cardiac interstitium, angiotensin-converting enzyme inhibition has resulted in restoration of myocardial integrity and stiffness toward normal. Further research needs to be undertaken to identify the molecular mechanisms involved in the development of interstitial myocardial fibrosis, and reliable methods for assessing the interstitium and the changes that occur within it in clinical practice need to be developed.


Ventricular arrhythmias in heart failure.

Heart failure is an increasingly common disorder leading to reduced quality and expectancy of life. Asymptomatic and symptomatic ventricular arrhythmias are a frequent complication and have been found to be independent prognostic predictors for sudden cardiac death in patients with heart failure. Unfortunately, the positive predictive failure for this finding is low, but in patients with sustained ventricular arrhythmias, variables indicating impaired pump function are the most important predictors of sudden and of nonsudden cardiac death. Arrhythmias in heart failure may have many different underlying mechanisms. Indications for, and mode of treatment of, arrhythmias in heart failure depend on the symptoms and prognostic significance of the arrhythmia. Primarily, pump function should be optimized and antiarrhythmic drug therapy instituted only when the arrhythmia persists. In poorly tolerated and life-threatening arrhythmias, implantable devices allowing pacing and defibrillation must be considered. No data are presently available indicating a protective role of antiarrhythmic drugs in the prevention of sudden cardiac death in heart failure. Future directions should concentrate on the development of better stratification of risk for sudden death, better delineation of mechanisms of arrhythmias in heart failure (allowing the development of mechanism-specific antiarrhythmic drugs), and research into new nonpharmacologic techniques such as cardiomyoplasty and molecular biologic techniques to rebuild the failing heart muscles.


Electrolyte balance in heart failure and the role for magnesium ions.

It is well established that clinically significant changes in a number of electrolytes occur in patients with congestive heart failure (CHF). Magnesium ions are an essential requirement for many enzyme systems, and evidence is rapidly emerging that magnesium deficiency is a major risk factor for survival of CHF patients. In animal experiments, magnesium has been shown to be involved in several steps of the atherosclerotic process and, although in humans the situation is somewhat more complex, magnesium ions play an extremely important role in CHF and various cardiac arrhythmias. A number of drugs commonly used to treat CHF can significantly affect not only cellular magnesium ion homeostasis, but potassium as well. These include mercurial, thiazide, and loop diuretics. It has also been reported that hypomagnesemia is common in digitalis intoxication. In contrast, a number of agents have been shown to have either a magnesium-conserving effect (potassium-sparing diuretics) or not to affect magnesium ion balance (angiotensin-converting enzyme inhibitors). The clinical consequences of magnesium deficiency include the development of various cardiac arrhythmias, all of which respond well to magnesium treatment. Thus, it is more than apparent that magnesium ion homeostasis is of major importance in CHF. Future studies should address the complex role of magnesium ions in electrolyte imbalance, particularly in relation to heart failure.


Effect of angiotensin-converting enzyme inhibitors on the peripheral circulation in heart failure.

In patients with chronic heart failure, the increase in blood flow to working muscle is attenuated and oxygen consumption is lower for any given workload of exercise, compared with normal subjects. This impaired metabolic vasodilation during exercise cannot be restored with short-term administration of angiotensin-converting enzyme (ACE) inhibitors. However, long-term ACE inhibition increases blood flow to skeletal muscle, and this increase is closely correlated with improvement in systemic oxygen consumption. The delayed effect of ACE inhibitors may be related to an interference with the vascular tissue renin-angiotensin system and remodeling of the vascular wall. In addition, endothelial-dependent dilation in response to acetylcholine is blunted in the forearm of patients with chronic heart failure, indicating an impaired endothelial function in this setting. There is experimental evidence that long-term ACE inhibition improves endothelial dysfunction; thus, one might speculate that the beneficial long-term effect of ACE inhibitors on peripheral flow may be, in part, related to its ability to restore normal endothelial function. Vasodilators such as hydralazine that improve blood flow to working muscle after acute administration do not increase skeletal muscle oxygen consumption, indicating that oxygen utilization is not improved. Ultrastructural analysis of skeletal muscle revealed that intrinsic alterations of skeletal muscle exist in patients with chronic heart failure; that is, the oxidative capacity of skeletal muscle is impaired in severe heart failure and contributes to the reduced exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)


Comparison of coronary responses to intracoronary and intraaortic ergonovine and isosorbide dinitrate in patients with atypical chest pain.

Fifty patients with atypical chest pain were studied to compare coronary responses to intracoronary and intraaortic ergonovine. The diameters of the proximal, middle (1) and (2) (proximal segments of segments 2 and 3 [AHA classification], respectively), and distal segments of the right coronary artery were measured before and after intracoronary ergonovine (4 micrograms/minute over 4 minutes) and isosorbide dinitrate (ISDN) (2 mg) in 24 patients, and before and after intraaortic ergonovine (0.2 mg) and ISDN (5 mg) in 26. Mean vasoconstriction by intracoronary and intraaortic ergonovine were 13 +/- 1.5% and 9 +/- 0.8%, respectively (p < 0.02). Irrespective of the methods of administration, the responses to ergonovine were similar in the 4 segments. Mean vasodilation by intracoronary and intraaortic ISDN, which were used to quantify the degree of basal coronary tone, were 25 +/- 2.2% and 27 +/- 1.5%, respectively (p = not significant [NS]). There were significant negative linear correlations between the responses to ergonovine and ISDN in the middle (2) (r = -0.51; p < 0.05) and distal (r = -0.53; p < 0.01) segments in patients with intracoronary injection, and the proximal (r = -0.41; p < 0.05), middle (1) (r = -0.66; p < 0.01) and middle (2) (r = -0.69; p < 0.01) segments in patients with intraaortic injection. These observations indicate that low-dose administration of intracoronary ergonovine produces sufficient coronary vasoconstriction, similar to or slightly greater than that of intraaortic ergonovine in patients with atypical chest pain, but basal coronary tone may influence the vasoreactivity to ergonovine.


Treatment of refractory familial hypercholesterolemia by low-density lipoprotein apheresis using an automated dextran sulfate cellulose adsorption system. The Liposorber Study Group.

A subgroup of patients with familial hypercholesterolemia (FH) respond inadequately to standard diet and drug therapy, and are therefore at high risk for the premature development or progression of coronary artery disease. This study evaluated low-density lipoprotein (LDL) cholesterol and lipoprotein (a) removal in a multicenter, controlled trial with a new LDL apheresis procedure (Liposorber LA-15 System). The study comprised patients with FH who had not responded adequately to diet and maximal drug therapy. There were 54 patients with heterozygous FH (45 randomized to treatment and 9 control subjects) and 10 with homozygous FH (all of whom received LDL apheresis). The study included three 6-week treatment phases and a 4-week rebound phase. Treatments were administered at 7- to 14-day intervals. Mean acute reductions in LDL cholesterol were 76% in heterozygous FH patients and 81% in homozygous ones. Time-averaged levels of LDL cholesterol were reduced 41% (243 to 143 mg/dl) in heterozygous FH patients and 53% (447 to 210 mg/dl) in homozygous ones. The substantial acute reduction of lipoprotein (a) (means: 65%, heterozygous FH; 68%, homozygous FH) has not been reported with other therapies. The Liposorber LA-15 System represents an important therapeutic option in FH patients who respond inadequately to diet and drug therapy.


Measurement of ventricular electrogram amplitude during intraoperative induction of ventricular tachyarrhythmias.

Adequate sensing of ventricular tachycardia (VT) and ventricular fibrillation (VF) is necessary for proper functioning of an implantable cardioverter defibrillator (ICD). Several ICDs currently undergoing investigation have programmable fixed gain sensitivity for tachycardia detection. If intracardiac electrogram amplitude decreases below the programmed sensitivity during VT or VF, detection of a ventricular arrhythmia may be delayed or missed. The mean amplitude of intracardiac electrograms (ICEGM) recorded with bipolar epicardial or transvenous sensing leads was measured in 63 patients during induced VT and VF recorded in the operating room at the time of ICD implantation. The mean amplitude of the ICEGM during 41 episodes of VF in 15 patients decreased from 14.9 +/- 0.9 mV during sinus rhythm to 8.8 +/- 0.7 mV at 1 second, 9.7 +/- 0.7 mV at 5 seconds, and 9.4 +/- 0.7 mV at 10 seconds (p < 0.0001 vs sinus rhythm ICEGM) with endocardial leads. The mean amplitude of the ICEGM recorded during 173 episodes of VF in 43 patients with epicardial leads decreased from 10.4 +/- 0.3 mV in sinus rhythm to 7.8 +/- 0.3 mV at 1 second, 8.3 +/- 0.3 mV at 5 seconds and 8 mV at 10 seconds (p <0.0001 vs sinus rhythm ICEGM). The mean amplitude of epicardial and transvenous ICEGMs recorded during 34 episodes of monomorphic VT decreased from 18.5 +/- 1.8 mV (epicardial) and 14.4 +/- 2.0 mV (transvenous) during sinus rhythm (p = 0.15, epicardial vs transvenous) to 16.0 +/- 1.7 mV (epicardial) and 13.7 +/- 1.9 mV (transvenous) at 10 seconds (< 10% of baseline amplitude).(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of chronic amiodarone therapy on defibrillation threshold.

In a prospective and parallel, randomized study, the long-term stability of epicardial defibrillation threshold was evaluated in 22 patients, using a patch-patch lead configuration at the time of implantation and generator replacement. The concomitant antiarrhythmic drug treatment consisted of either mexiletine (720 mg/day) or amiodarone (400 mg/day) and was administered to patients in a randomized and parallel manner. During a mean follow-up of 24 +/- 6 months, the defibrillation threshold increased significantly from 14.3 +/- 2.8 to 17.9 +/- 5.3 J (p < 0.05) for the entire patient group. The increase in the chronic defibrillation threshold was due to a marked increase in defibrillation energy needs in the subgroup of patients receiving amiodarone. Whereas no significant change in the defibrillation threshold was documented in the subgroup of patients receiving mexiletine, the mean defibrillation threshold increased from 14.1 +/- 3.0 to 20.9 +/- 5.4 J (p < 0.001) in those receiving amiodarone. In all patients with increased defibrillation thresholds, reevaluation showed a reduction in the defibrillation threshold after discontinuation of antiarrhythmic drug therapy. The only variable associated with an increase in the chronic defibrillation threshold was amiodarone treatment. These findings suggest that the defibrillation threshold should be measured at each generator replacement and in case of a change in antiarrhythmic drug treatment. In particular, if amiodarone treatment is initiated, it is recommended that the defibrillation threshold should be reevaluated to ensure an adequate margin of safety.


Stress response pattern in obesity and systemic hypertension.

Under resting conditions obese hypertensive patients have been described as having a greater cardiac output and lower total peripheral resistance than lean hypertensive patients. To evaluate the hemodynamic patterns under stress conditions, we determined the hemodynamic response to mental stress (first study) and during isometric exercise (second study) in hypertensive patients with a body mass index > 27 kg/m2 (obese) and < 27 kg/m2 (lean). The cohort exposed to mental stress comprised 54 white male patients (30 were lean, 24 were obese) with untreated stage I or II essential hypertension according to the World Health Organization. Obese subjects responded with a higher increase in total peripheral resistance (p < 0.02) and lower increases in heart rate (p < 0.01), cardiac output (p < 0.01) and stroke volume (p < 0.02) when compared with their lean counterparts. This was independent of any differences in chemical or baseline hemodynamic characteristics at rest. The cohort exposed to isometric stress consisted of 57 patients (30 were lean, 27 were obese) with World Health Organization stage I or II essential hypertension. Obese subjects responded with exaggerated increases in systolic (p < 0.04) and diastolic (p < 0.01) pressures, and heart rate (p < 0.04) when compared with lean patients. Body mass index emerged as an independent determinant of the increase in systolic (r = 0.03) and diastolic (r = 0.01) pressure as well as of heart rate (r = 0.03). These results indicate that obese hypertensive patients respond to (1) mental stress with vasoconstriction instead of the expected vasodilation, and to (2) isometric stress with an exaggerated increase in arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)


Transesophageal echocardiographic monitoring of percutaneous mitral balloon valvulotomy.

This study was designed to evaluate the usefulness of performing transesophageal echocardiography (TEE) during percutaneous mitral balloon valvulotomy (PMBV). TEE was performed in 35 consecutive patients with symptomatic severe mitral stenosis during PMBV (group A). Another group of 27 patients with mitral stenosis who underwent PMBV without TEE was used for comparison (group B). TEE was most helpful in guiding transseptal puncture, aiding in proper positioning of the balloon during the dilatation procedure and enabling early detection of complications. The results show that PMBV when aided by TEE has a tendency to decrease the frequency of significant mitral regurgitation without compromising the final mitral valve area. TEE decreased the x-ray exposure time and was well-tolerated. Thus, TEE provides information that makes this interventional catheterization procedure safer and easier to perform.


Quantitative dynamics of left ventricular emptying and filling as a function of heart size and stroke volume in pure aortic regurgitation and in normal subjects.

Quantitative understanding of the dynamics of left ventricular (LV) emptying and filling as the left ventricle dilates but maintains ejection fraction is limited. Cine computed tomography was used to quantify peak LV emptying and filling characteristics in 30 patients with normal ejection fraction but variable end-diastolic and stroke volumes. Group I consisted of 15 normal male patients and group II of 15 male patients with chronic, well-compensated, isolated aortic regurgitation. For each patient global LV volumes, absolute peak emptying and peak early diastolic filling rates and the timing of these maximal slopes were quantified. Mean arterial pressure and heart rate were within the normal range and ejection fraction and ages similar between groups I and II. Between-group analyses showed significantly increased end-diastolic and stroke volumes in group II compared with group I but nearly identical end-systolic volumes. Likewise, absolute peak emptying and filling rates were significantly greater in group II than in group I patients. The ratio of peak emptying rate to peak filling rate remained constant between groups. Timing of peak emptying and filling were similar in both groups. Absolute LV peak emptying and filling rates were found to vary linearly with end-diastolic and stroke volumes in all subjects examined. However, referencing peak emptying or peak filling rates to end-diastolic or total stroke volumes eliminated intergroup differences. Thus, in the presence of preserved ejection fraction and normal arterial pressure, the dynamic rates of LV emptying and early diastolic filling increase in direct proportion to absolute end-diastolic and stroke volumes, but the ratio of peak emptying to peak filling rate remains constant.


Effects on platelet aggregation and fibrinolytic activity during upright posture and exercise in healthy men.

The circadian variation of acute myocardial infarction suggests that daily activities such as assuming the upright posture and performing different daily activities may trigger the onset of coronary thrombosis. Such triggering may result from unfavorable alterations in the balance between the prothrombotic and antithrombotic properties of the blood. The present study compares the effects of 2 common daily activities, assuming the upright posture and exercise, on platelet aggregation and fibrinolytic activity. In healthy male subjects, assuming the upright posture in the morning significantly increased platelet aggregation and produced only a moderate increase in fibrinolytic activity within 10 minutes. These changes were still present after 90 minutes in the upright posture. Supine posture for 45 minutes resulted in levels of fibrinolytic activity and platelet aggregation comparable to that observed before initially assuming the upright posture in the morning. Return to the supine posture for 45 minutes resulted in levels of fibrinolytic activity and platelet aggregation comparable to that observed before the initial assumption of upright posture. The changes recurred when upright posture was taken later in the day. Exercise did not increase platelet aggregation to levels beyond that produced by the upright posture, but was associated with a marked increase in fibrinolytic activity. Thus, exercise and upright posture produce distinctive alterations in the thrombogenic potential of the blood that may influence the timing of clinical vascular events.


Transesophageal echocardiography to assess mitral valve function and flow during cardiopulmonary resuscitation.

This study further defines the mechanism of blood flow during closed-chest compression using transesophageal Doppler echocardiography. Although the echocardiographic demonstration of mitral valve closure during closed-chest compression has been used as evidence of direct cardiac compression, mitral valve closure has also been documented to occur during resuscitation by selectively increasing intrathoracic pressure. Transesophageal Doppler echocardiography was used to assess mitral valve position and flow in 17 adult patients undergoing cardiopulmonary resuscitation with a mechanical piston compression device. Left and right ventricular fractional shortening, mitral valve position with chest compression, timing and magnitude of transmitral flow, and anteroposterior chest diameter were recorded. In 12 patients (group I), the mitral valve closed during the down-stroke of chest compression; in the remaining 5 (group II), it opened further. Peak transmitral flow occurred during the release phase and was significantly higher (p < 0.05) in group I (39.5 +/- 9.3 cm/s) than the peak flow in group II (21.3 +/- 5.9 cm/s), which occurred during the downstroke of chest compression. Left ventricular fractional shortening inversely correlated (r = -0.68; p = 0.02) with the anteroposterior chest diameter, but did not correlate with peak transmitral flow (r = 0.34; p = not significant). It is concluded that the mitral valve closes during the downstroke of chest compression in most adult patients during resuscitation. The absence of a relation between mitral valve flow and left ventricular fractional shortening supports the hypothesis that other factors such as nonuniform increases in intrathoracic pressure cause the mitral valve to open or close during chest compression.


A new technique for simultaneous monitoring of electrocardiogram and walking cadence.

A new technique for simultaneously recording continuous electrocardiographic (ECG) data and walking step rate (cadence) is described. The ECG and gait signals are recorded on 2 channels of an ambulatory Holter monitor. Footfall is detected using ultrathin, force-sensitive foot switches and is frequency modulated. The footfall signal provides an indication of the subject's activity (walking or standing), as well as the instantaneous walking rate. Twenty-three young and elderly subjects were studied to demonstrate the use of this ECG and gait recorder. High-quality gait signals were obtained in all subjects, and the effects of walking on the electrocardiogram were assessed. Initial investigation revealed the following findings: (1) Although walking rates were similar in young and elderly subjects, the elderly had both decreased heart rate (HR) variability (p < 0.005) and increased cadence variability (p < 0.0001). (2) Overall, there was an inverse relation between HR and cadence variability (r = -0.73). Three elderly subjects with no known cardiac disease had HR and cadence variability similar to those of the young, whereas elderly subjects with history of congestive heart failure were among those with the lowest HR variability and the highest cadence variability. (3) Low-frequency (approximately equal to 0.1 Hz) HR oscillations (frequently observed during standing) persisted during walking in all young subjects. (4) In some subjects, both step rate and HR oscillated at the same low frequency (approximately equal to 0.1 Hz) previously identified with autonomic control of the baroreflex.(ABSTRACT TRUNCATED AT 250 WORDS)


Impact of food on the pharmacokinetics and electrocardiographic effects of sustained release verapamil in normal subjects.

To evaluate the impact of food on the pharmacokinetics and electrocardiographic effects of sustained release (SR) verapamil tablets, 9 healthy men each received 3 single doses of verapamil in a randomized, crossover manner: 10 mg of intravenous verapamil, 240 mg SR verapamil on an empty stomach, and 240 mg SR verapamil with a standardized meal. PR intervals and racemic verapamil serum concentrations were measured serially over 30 hours after administration. The time to peak concentration was longer (7.5 +/- 3.0 vs 4.4 +/- 2.3 hours), resulting in a lower peak verapamil serum concentration (118 +/- 43 vs 175 +/- 50 ng/ml) when SR verapamil was administered with food (p < 0.05). Food tended to decrease the bioavailability of SR verapamil (34 +/- 12 vs 49 +/- 14%), although this difference did not reach statistical significance (p = 0.065). Precipitous or exaggerated release of verapamil from the SR tablet was not observed in any subject during the fasting state. Prolongation of the PR interval paralleled these alterations in serum concentration. The maximal change in the PR interval was greater (21 +/- 8 vs 14 +/- 5%; p < 0.05) when SR verapamil was given in the fasting state. Although an exaggerated verapamil release or effect was not observed, food significantly altered the absorption and electrocardiographic effects of a single dose of SR verapamil. Manipulation of the administration condition may be helpful in achieving desired outcomes.


Differences in men and women in coronary artery disease, systemic hypertension and their treatment.

Various studies have shown that women with coronary artery diseases are treated quite differently from men, although the reasons for these differences are not easily discernible and may be based on misconceptions. Furthermore, although the attributable risk percentage for cardiovascular complications of hypertension is higher in women than in men, little information on treating hypertension in women is available. There is cause for concern owing to some findings that white women may be harmed by antihypertensive treatment unless that treatment differs from that of men. Consensus on the importance of this finding has not been reached.


Echocardiographic determinants of clinical outcome in subjects with coronary artery disease (the Framingham Heart Study).

Echocardiographic predictors of clinical outcome were examined in subjects from the Framingham Heart Study with overt coronary artery disease. The study population consisted of 185 men and 147 women with coronary artery disease who underwent M-mode echocardiography and were followed for a mean of 3.90 years. At baseline, 37 men (18.4%) and 16 women (10.9%) had reduced fractional shortening, 43 men (23.2%) and 28 women (19%) had left ventricular (LV) dilatation, and 76 men (41%) and 76 women (51.7%) had LV hypertrophy. During the follow-up period new cardiovascular disease events (coronary disease, stroke, transient ischemic attack, claudication, heart failure and deaths from cardiovascular disease) occurred in 60 men (32%) and 58 women (39%). With use of age-adjusted proportional hazards analyses, LV mass/height in men (relative risk [RR] = 1.25/50 g/m increment, 95% confidence interval [CI] 1.01 to 1.55) and LV end-diastolic diameter in women (RR = 1.36/5 mm increment, 95% CI 1.05 to 1.76) were predictors of new cardiovascular disease events. Cardiovascular risk was also associated with LV end-systolic diameter in both sexes (in men RR = 1.28/1 SD increment, 95% CI 1.02 to 1.63; in women RR = 1.40/1 standard deviation increment, 95% CI 1.09 to 1.82). Reduced fractional shortening alone (RR = 1.91, 95% CI 1.11 to 3.31) and in combination with LV dilatation (RR = 2.13, 95% CI 1.13 to 4.02) was associated with the incidence of new cardiovascular disease outcomes in men.(ABSTRACT TRUNCATED AT 250 WORDS)


Risk factor correlates of coronary calcium as evaluated by ultrafast computed tomography.

Coronary artery calcium is invariably associated with atherosclerosis and has been linked to an increased risk of coronary events. Ultrafast computed tomography (CT) was recently used to document the presence and relative quantity of coronary calcium. The use of the self-reported coronary risk factors to identify persons with coronary calcium as documented by ultrafast CT screening was examined in 458 men and 139 women aged 26 to 81 years (88% asymptomatic). All subjects underwent ultrafast CT scanning, and received a questionnaire and underwent an interview regarding medical and risk factor history. Total calcium score was calculated as the sum of lesion-specific scores, each calculated as the product of density > or = 130 Hounsfield units and area > or = 0.51 mm2. The prevalence of coronary calcium increased significantly (p < 0.01) by age group, and the greater the number of risk factors present, the greater the likelihood of calcium. From multiple logistic regression, age (p < 0.01), male sex (relative risk [RR] 3.03; p < 0.01), and history of smoking (RR 1.85; p < 0.01) and hypertension (RR 1.65; p < 0.05) were independently associated with the probability of detectable calcium. Among asymptomatic subjects, an association with hypercholesterolemia was also seen (RR 1.56; p < 0.05). The results demonstrate that cardiovascular risk factors can help in identifying the likelihood of coronary calcium.


Circulating aggregated platelets, number of platelets per aggregate, and platelet size during acute myocardial infarction.

Circulating aggregated platelets (total, reversibly and irreversibly aggregated), the number of platelets per aggregate and "big" platelets were measured by a modification of the Wu and Hoak method in 42 patients on the first, second and fifth day of acute myocardial infarction (AMI). Among them, 30 had an uncomplicated course and 12 patients had complications that occurred between the 5th and 10th day of hospitalization (7 patients had reinfarction and 5 died). In all patients the measured parameters were elevated compared with those of control subjects. There was a significant increase, especially after the first observation day, in the values of total aggregated platelets (37 +/- 11% vs 26 +/- 12%, p < 0.001), reversibly aggregated platelets (27 +/- 9% vs 17 +/- 8%, p < 0.001) and the average platelets per aggregate (8.6 +/- 0.3 vs. 2.3 +/- 0.4) in patients with versus without complications. In considering the role of platelets in the development of AMI, these findings may add information to the role of platelets in determining the course of AMI.


Effects of simulated left bundle branch block on QRST time-integral values of 12-lead electrocardiograms in patients with and without prior anterior wall myocardial infarction.

The effects of right ventricular pacing, which simulated left bundle branch block (BBB), on QRST time-integral values of 12-lead electrocardiograms (ECGs) were examined, and the clinical usefulness of QRST values for estimating the severity of left ventricular wall motion abnormalities due to a prior anterior wall myocardial infarction (MI) in the setting of left BBB were evaluated. Digitized ECGs were recorded during normal sinus rhythm and simulated left BBB in 38 patients (24 with and 14 without prior anterior wall MI). QRST values were calculated in each lead point of 12-lead ECGs. Data from 608 normal subjects were used as control values; the mean +/- 2 SD of these values was regarded as the normal range. The parameter sigma DE was defined as the sum of the differences between the normal mean QRST value and the QRST values of a given patient in leads where the QRST value was less than the normal range. The correlation coefficient of sigma DE for the 2 activation sequences was highly significant. Although small but significant changes were seen in QRST values in leads I, II, III, aVR, aVF and V1 during simulated left BBB, left precordial leads showed no significant changes in QRST values. A criterion of sigma DE > 40 mV.ms for detecting an anterior wall MI showed a sensitivity of 88%, a specificity of 93%, and a diagnostic accuracy of 89%. The sigma DE was significantly (p < 0.001) correlated with the asynergy index calculated from left ventriculograms.(ABSTRACT TRUNCATED AT 250 WORDS)


Acute hemodynamic and electrophysiologic effects and safety of high-dose intravenous diltiazem in patients receiving metoprolol.

The anti-ischemic efficacy of diltiazem may improve with increments in dosage and with additional beta-blocking therapy. However, the combined administration could lead to adverse effects through amplification of negative inotropic and chronotropic properties. To evaluate hemodynamic tolerability and safety of high-dose intravenous diltiazem in patients with coronary artery disease receiving long-term metoprolol treatment, 9 such patients were studied for 30 minutes after onset of intravenous diltiazem administration (0.5 mg/kg for 5 minutes, followed by 15 mg/hour). Diltiazem plasma levels peaked at 5 minutes (641 +/- 74 micrograms/liter), decreasing to 177 micrograms/liter at 30 minutes. Average metoprolol levels (43 +/- 12 micrograms/liter) did not change. Diltiazem immediately decreased systemic vascular resistance, left ventricular systolic and mean aortic pressures (29, 21 and 20%, respectively, at 5 minutes), and they remained significantly reduced at 30 minutes. Heart rate initially increased by 11% during the bolus infusion (p < 0.05). Concomitantly, contractility indexes Vmax and Vce40, measured at fixed heart rates, also increased significantly by 11%. Both heart rate and contractility indexes returned to baseline levels thereafter. Cardiac output increased by 10% (p = not significant), stroke index remained unchanged, but stroke work decreased significantly by 20%. Also, the tension-time index was significantly reduced (23%). Diltiazem induced moderate negative lusitropic effects, the first derivative of negative left ventricular pressure decline decreased by 12% and Tau 2 lengthened by 13%. Concomitantly, left ventricular filling pressure increased from 19 +/- 2 to 23 +/- 3 mm Hg, but only at 5 and 15 minutes. PQ, QRS and QTc intervals were not affected.(ABSTRACT TRUNCATED AT 250 WORDS)