a 72-year - old male patient visited smg - snu boramae medical center with exertional chest pain , which had been aggravated during the most recent 3 months .
the initial electrocardiogram revealed sinus bradycardia with a heart rate of 50 beat per minute , and there was no st segment elevation .
the serum cardiac enzyme level was within the normal range , and there were no abnormal findings except mild functional mitral regurgitation in transthoracic echocardiography , which showed a left ventricular ejection fraction of 67% and no regional wall motion abnormality .
myocardial single - photon emission computed tomography showed a reversible perfusion decrease at the basal inferior wall .
preoperative coronary angiography showed 70% to 80% stenosis of the left anterior descending coronary artery ( lad ) , 90% stenosis of the proximal ramus artery , 50% stenosis of the proximal left circumflex artery , 95% stenosis of the distal right coronary artery , and 90% stenosis of the posterolateral branch artery ( plb ) . according to the patient s past medical history
in addition , arteriosclerosis obliterans of both the lower extremities had been treated medically for 6 years .
diagnosed with unstable angina with three - vessel disease , the patient underwent off - pump coronary artery bypass graft surgery ( cabg ) . under general anesthesia , an advanced venous access catheter and a swan - ganz ( sg ) catheter
several premature ventricular contractions ( pvcs ) occurred during the insertion of the sg catheter .
we used the left internal mammary artery as a pedicled graft and anastomosed it to the mid - lad .
we also harvested the saphenous vein from the left lower leg and anastomosed it to the left internal mammary artery to make a y - shaped composite graft .
subsequently , the vein graft was anastomosed to the ramus artery and plb sequentially . during the operation
as soon as the patient was transferred to the intensive care unit , frequent ventricular tachyarrhythmia began to occur and the hemodynamics became unstable .
we tried our best to control the unstable ventricular arrhythmia with the administration of antiarrhythmic drugs like lidocaine and amiodar - one as well as a meticulous correction of the fluid and electrolyte imbalance , but none of the medical measures worked .
furthermore , ventricular fibrillation ( vf ) occurred three times at intervals of about 1 hour ( fig .
, we inserted an intra - aortic balloon pump to provide hemodynamic support , but failed to stop recurrent vf , and the patient s condition worsened considerably .
in fact , we did not notice the severely angulated sg catheter demonstrated by the serial chest radiographs until around 6 hours after the patient was brought to the intensive care unit .
we found that the sg catheter was located too deep in the right ventricle and relocated the catheter to remove the acute angulation ( fig .
however , the catheter still seemed to readily stimulate the ventricle ; thus , we decided to remove the catheter . during the removal of the sg catheter , vf occurred once again .
the removal of the catheter finally resulted in prompt and complete cessation of recurrent ventricular arrhythmia .
there were , in total , 5 events of vf and defibrillation was performed 9 times .
the myocardial contractility , which was shown to be good by trans - esophageal echocardiography at the end of the operation , worsened and led to a left ventricular ejection fraction of 43% .
the serum troponin - i level was also markedly elevated from an immediate postoperative value of 2.0 ng / ml to a peak value of 45.7 ng / ml on postoperative day 1 . despite this event , the patient recovered and was transferred to the general ward on postoperative day 6 without any significant complications .
myocardial function was fully recovered without any regional wall motion abnormality , but the saphenous vein harvest site was dehisced and the wound problem had to be addressed .
the first presentation of sustained ventricular arrhythmia in the recovery period after cabg is uncommon , and its incidence in the previous studies ranged from 1.6% to 3.1% .
the occurrence of ventricular tachycardia ( vt ) or vf after cabg has been reported to have a strong impact on in - hospital mortality , which ranged from 21.7% to 25% .
recurrent ventricular arrhythmia was not infrequent , observed in 33% of the patients , and was associated with a high mortality ; 75% of the patients with these characteristics did not survive to hospital discharge .
the known risk factors for ventricular arrhythmia after cabg are age under 65 years , female gender , body mass index under 25 kg / m , unstable angina , moderate or poor ejection fraction , and a need for pre - operative inotropic support or an intra - aortic balloon pump . as an sg catheter allows the measurement of hemodynamic variables that can not be assessed reliably or continuously by less invasive means , it is widely used in the perioperative monitoring of cardiac surgical procedures in many centers . however , a significant number of patients who undergo pulmonary artery catheterization experience catheter - related complications such as cardiac arrhythmia , pulmonary infarction , catheter knotting , catheter entanglement with other endovascular structures , pulmonary artery rupture , thrombosis , and tricuspid valve rupture .
various types of arrhythmia related to the sg catheter placement have been described and include premature atrial contraction , atrial and ventricular tachycardia , pvc , and conduction abnormalities .
the incidence of arrhythmia has been reported to range from 12.5% to more than 70% during sg catheter insertion .
some cite a 52% to 68% incidence of pvc , the most commonly seen type of arrhythmia .
these resolve either with the sg catheter advancement from the right ventricle into the pulmonary artery , or with the prompt sg catheter withdrawal into the right atrium or the superior vena cava .
fortunately , clinically significant vt or vf requiring treatment occurs in < 1% of the patients , although fatal vt has been observed .
the risk factors for ventricular arrhythmia during the insertion of an sg catheter include prolonged catheterization time , a predisposition to pvc , liver transplantation , myocardial infarction or ischemia , shock , acidosis , sepsis , electrolyte disturbances , and increased sympathetic tone .
baldwin and heland   reported a 2% incidence of vt associated with the removal of the sg catheter . in this report
, the onset of vt was associated with a brief period of hypotension , and the duration of vt and hypotension was longer than the period of catheter removal , which implies that the activity is triggered by the procedure and has the potential to be prolonged beyond an initial stimulus . in patients with the wolff - parkinson - white ( wpw )
syndrome , pre - excited atrial fibrillation with a rapid ventricular response can induce potentially life - threatening arrhythmia .
a previous prospective study reported that the incidence of vf with cardiac arrest among the wpw syndrome patients was 1.6% ( 3 of 184 patients ) .
although it is not relevant to our case , the wpw syndrome is thought to be one of the predisposing factors of vf . in our case
there was no risk factor for ventricular arrhythmia except unstable angina , and vf was thought to be triggered by the malpositioned sg catheter .
the inserted length of the sg catheter was within the usual range because the kinking of the catheter masked the malposition .
checking the pulmonary capillary wedge pressure could be helpful in detecting the malposition of the catheter , but we did not try it until we realized the cause of the vf . in conclusion , it is basic and imperative to check the position of the sg catheter and to keep in mind that life - threatening and otherwise intractable recurrent ventricular arrhythmia can be triggered by a malpositioned catheter .
 recurrent ventricular arrhythmia can be fatal and cause serious complications , particularly when it is caused immediately after an operation . 
 incorrect placement of a swan - ganz catheter can trigger life - threatening ventricular arrhythmia , but even intensive care specialists tend to miss this fact . here , we report a case of recurrent ventricular arrhythmia causing a severe hemodynamic compromise ; the arrhythmia was induced by a severely angulated swan - ganz catheter . 
 the recurrent ventricular arrhythmia was not controlled by any measures including repositioning of the catheter , until the complete removal of the swan - ganz catheter . 
 it is necessary to keep in mind that the position of the pulmonary artery catheter should be promptly checked if there is intractable recurrent ventricular arrhythmia . 
CASE REPORT
DISCUSSION