Rate adaptive pacing in sick sinus syndrome: effects of pacing modes and intrinsic conduction on physiological responses, arrhythmias, symptomatology and quality of life. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome. A randomized comparison of atrial and dual-chamber pacing in 177 consecutive patients with sick sinus syndrome: echocardiographic and clinical outcome. Quality of life and clinical outcomes in elderly patients treated with ventricular pacing as compared with dual-chamber pacing. Pacemaker Selection in the Elderly Investigators. Pacemaker dependency after transcatheter aortic valve implantation with the self-expanding Medtronic CoreValve System. The Drug And Pace Health cliNical Evaluation (DAPHNE) study: a randomized trial comparing sotalol versus beta-blockers to treat symptomatic atrial fibrillation in patients with brady-tachycardia syndrome implanted with an antitachycardia pacemaker. Long-term outcomes in patients with atrioventricular block undergoing septal ventricular lead implantation compared with standard apical pacing. Effects of physiologic pacing versus ventricular pacing on the risk of stroke and death due to cardiovascular causes. Canadian Trial of Physiologic Pacing Investigators. Incidence of atrial fibrillation and thromboembolism in a randomised trial of atrial versus dual chamber pacing in 177 patients with sick sinus syndrome High incidence of pacemaker syndrome in patients with sinus node dysfunction treated with ventricular-based pacing in the Mode Selection Trial (MOST). Ventricular pacing or dual-chamber pacing for sinus-node dysfunction. Diagnosis of paroxysmal atrial fibrillation in patients with implanted pacemakers: relationship to symptoms and other variables. Atrial fibrillation and quality of life after pacemaker implantation for sick sinus syndrome: data from the Mode Selection Trial (MOST). Early complications of permanent pacemaker implantation: no difference between dual and single chamber systems. Complications of Dual Chamber Pacemaker Implantation in the Elderly Pacemaker implantation and quality of life in the Mode Selection Trial (MOST). Atrial fibrillation after DDDR pacemaker implantation. Conversion of recent onset atrial fibrillation with single loading oral dose of propafenone: is in-hospital admission absolutely necessary? Sudden death after radiofrequency ablation of the atrioventricular node in patients with atrial fibrillation. Ventricular pacing vs dual chamber pacing in patients with persistent atrial fibrillation after atrioventricular node ablation: open randomized study. Effect of pacing mode on health-related quality of life in the Canadian Trial of Physiologic Pacing. Clinical characteristics of patients intolerant to VVIR pacing. Long-term follow-up of patients from a randomised trial of atrial versus ventricular pacing for sick-sinus syndrome Adverse Effect of Ventricular Pacing on Heart Failure and Atrial Fibrillation Among Patients With Normal Baseline QRS Duration in a Clinical Trial of Pacemaker Therapy for Sinus Node Dysfunction Comparison of ventricular function in atrial rate adaptive versus dual chamber rate adaptive pacing during exercise. Cost-Effectiveness of Dual-Chamber Pacing Compared With Ventricular Pacing for Sinus Node Dysfunction Minimizing ventricular pacing to reduce atrial fibrillation in sinus-node disease. Diastolic mitral and tricuspid regurgitation by Doppler echocardiography in patients with atrioventricular block: new insight into the mechanism of atrioventricular valve closure. Atorvastatin prevents atrial fibrillation in patients with bradyarrhythmias and implantation of an atrial-based or dual-chamber pacemaker: a prospective randomized trial. Effects of cardiac resynchronization therapy on heart rate variability in patients with chronic systolic heart failure and intraventricular conduction delay. Low incidence of cardiac events with beta-blocking therapy in children with long QT syndrome. Prevention of ventricular desynchronization by permanent para-Hisian pacing after atrioventricular node ablation in chronic atrial fibrillation: a crossover, blinded, randomized study versus apical right ventricular pacing. Long-term nonoutflow septal versus apical right ventricular pacing: relation to left ventricular dyssynchrony. Influence of atrioventricular junction radiofrequency ablation in patients with chronic atrial fibrillation and flutter on quality of life and cardiac performance. Importance of rate control or rate regulation for improving exercise capacity and quality of life in patients with permanent atrial fibrillation and normal left ventricular function: a randomised controlled study AAIR versus DDDR pacing in the bradycardia tachycardia syndrome: a prospective, randomized, double-blind, crossover trial. Predictors for permanent pacemaker implantation in patients undergoing transfemoral aortic valve implantation with the Edwards Sapien 3 valve
An atrial-based pacing mode is superior to ventricular constant rate dem and pacing ( VVI ) mode in patients with sick sinus syndrome ( SSS ) by providing both rate adaptation and atrioventricular ( AV ) synchrony . The use of a non-atrial sensor to overcome chronotropic incompetence and preserve normal intrinsic AV conduction in pacemaker therapy for SSS was investigated in 15 consecutive patients ( mean age 66 + /- 2 years ) . All had intact AV conduction ( ante grade conduction capacity > 100 beats.min-1 and an atrial paced to intrinsic R interval of < or = 220 ms ) .  DDDR pacemakers capable of being programmed into atrial rate adaptive ( AAIR ) , dual chamber rate adaptive ( DDDR ) and ventricular rate adaptive ( VVIR ) modes were used . Beginning with an acute study , arterial pressure was invasively assessed in each pacing mode during physiological stresses and low level exercise . In the ambulatory phase , the incidence of ventricular pacing and arrhythmias ( Holter recording ) , diurnal blood pressure changes ( ambulatory blood pressure recording ) , and symptom and quality of life level ( question naires and interviews ) were compared . Despite similar heart rate changes during acute physiological stresses , a higher blood pressure was recorded during AAIR or DDDR pacing compared with VVIR pacing . Systolic blood pressure over 24 h was lower in the VVIR mode ( 122 + /- 5 mmHg ) than AAIR/DDDR pacing ( 129 + /- 6/128 + /- 6 mmHg , P < 0.05 ) . VVIR pacing was associated with a higher frequency of atrial and ventricular ectopics , with two patients developing paroxysmal atrial fibrillation . Ventricular pacing was used in a higher percentage in the DDDR compared with the VVIR mode ( 64 + /- 11 and 39 + /- 7 % , P < 0.03 ) . VVIR pacing was associated with more palpitations , a lower level of general well being and depression . Despite the use of a sensor to overcome chronotropic incompetence , VVIR pacing is a less satisfactory pacing mode for SSS . Although AAIR/DDDR pacing may achieve similar haemodynamic and clinical status , in patients with intact AV conduction , AAIR pacing may be preferable by avoiding an abnormal ventricular activation pattern AIMS In patients with sick sinus syndrome , bradycardia can be treated with a single-lead pacemaker or a dual-chamber pacemaker . Previous trials have revealed that pacing modes preserving atrio-ventricular synchrony are superior to single-lead ventricular pacing , but it remains unclear if there is any difference between single-lead atrial pacing ( AAIR ) and dual-chamber pacing ( DDDR ) . METHODS AND RESULTS We r and omly assigned 1415 patients referred for first pacemaker implantation to AAIR ( n = 707 ) or DDDR ( n = 708 ) pacing and followed them for a mean of 5.4 ± 2.6 years . The primary outcome was death from any cause . Secondary outcomes included paroxysmal and chronic atrial fibrillation , stroke , heart failure , and need for pacemaker reoperation . In the AAIR group , 209 patients ( 29.6 % ) died during follow-up vs. 193 patients ( 27.3 % ) in the DDDR group , hazard ratio ( HR ) 1.06 , 95 % confidence interval ( CI ) 0.88 - 1.29 , P = 0.53 . Paroxysmal atrial fibrillation was observed in 201 patients ( 28.4 % ) in the AAIR group vs. 163 patients ( 23.0 % ) in the DDDR group , HR 1.27 , 95 % CI 1.03 - 1.56 , P = 0.024 . A total of 240 patients underwent one or more pacemaker reoperations during follow-up , 156 ( 22.1 % ) in the AAIR group vs. 84 ( 11.9 % ) in the DDDR group ( HR 1.99 , 95 % CI 1.53 - 2.59 , P < 0.001 ) . The incidence of chronic atrial fibrillation , stroke , and heart failure did not differ between treatment groups . CONCLUSION In patients with sick sinus syndrome , there is no statistically significant difference in death from any cause between AAIR pacing and DDDR pacing . AAIR pacing is associated with a higher incidence of paroxysmal atrial fibrillation and a two-fold increased risk of pacemaker reoperation . These findings support the routine use of DDDR pacing in these patients . CLINICAL TRIAL REGISTRATION URL http://www . clinical trials.gov . Unique identifier : NCT00236158 OBJECTIVES A r and omized trial was done to compare single-chamber atrial ( AAI ) and dual-chamber ( DDD ) pacing in patients with sick sinus syndrome ( SSS ) . Primary end points were changes in left atrial ( LA ) size and left ventricular ( LV ) size and function as measured by M-mode echocardiography . BACKGROUND In patients with SSS and normal atrioventricular conduction , it is still not clear whether the optimal pacing mode is AAI or DDD pacing . METHODS A total of 177 consecutive patients ( mean age 74 + /- 9 years , 73 men ) were r and omized to treatment with one of three rate-adaptive ( R ) pacemakers  : AAIR ( n = 54 ) , DDDR with a short atrioventricular delay ( n = 60 ) ( DDDR-s ) , or DDDR with a fixed long atrioventricular delay ( n = 63 ) ( DDDR-l ) . Before pacemaker implantation and at each follow-up , M-mode echocardiography was done to measure LA and LV diameters . Left ventricular fractional shortening ( LVFS ) was calculated . Analysis was on an intention-to-treat basis . RESULTS Mean follow-up was 2.9 + /- 1.1 years . In the AAIR group , no significant changes were observed in LA or LV diameters or LVFS from baseline to last follow-up . In both DDDR groups , LA diameter increased significantly ( p < 0.05 ) , and in the DDDR-s group , LVFS decreased significantly ( p < 0.01 ) . Atrial fibrillation was significantly less common in the AAIR group , 7.4 % versus 23.3 % in the DDDR-s group versus 17.5 % in the DDDR-l group ( p = 0.03 , log-rank test ) . Mortality , thromboembolism , and congestive heart failure did not differ between groups . CONCLUSIONS During a mean follow-up of 2.9 + /- 1.1 years , DDDR pacing causes increased LA diameter , and DDDR pacing with a short atrioventricular delay also causes decreased LVFS . No changes occur in LA or LV diameters or LVFS during AAIR pacing . Atrial fibrillation is significantly less common during AAIR pacing BACKGROUND St and ard clinical practice permits the use of either single-chamber ventricular pacemakers or dual-chamber pacemakers for most patients who require cardiac pacing .  Ventricular pacemakers are less expensive , but dual-chamber pacemakers are believed to be more physiologic . However , it is not known whether either type of pacemaker results in superior clinical outcomes . METHODS The Pacemaker Selection in the Elderly study was a 30-month , single-blind , r and omized , controlled comparison of ventricular pacing and dual-chamber pacing in 407 patients 65 years of age or older in 29 centers . Patients received a dual-chamber pacemaker that had been r and omly programmed to either ventricular pacing or dual-chamber pacing . The primary end point was health-related quality of life as measured by the 36-item Medical Outcomes Study Short-Form General Health Survey . RESULT The average age of the patients was 76 years ( range , 65 to 96 ) , and 60 percent were men .  Quality of life improved significantly after pacemaker implantation ( P<0.001 ) , but there were no differences between the two pacing modes in either the quality of life or prespecified clinical outcomes ( including cardiovascular events or death ) . However , 53 patients assigned to ventricular pacing ( 26 percent ) were crossed over to dual-chamber pacing because of symptoms related to the pacemaker syndrome . Patients with sinus-node dysfunction , but not those with atrioventricular block , had moderately better quality of life and cardiovascular functional status with dual-chamber pacing than with ventricular pacing . Trends of borderline statistical significance in clinical end points favoring dual-chamber pacing were observed in patients with sinus-node dysfunction , but not in those with atrioventricular block . CONCLUSION The implantation of a permanent pacemaker improves health-related quality of life . However , the quality -of-life benefits associated with dual-chamber pacing as compared with ventricular pacing are observed principally in the subgroup of patients with sinus-node dysfunction BACKGROUND / OBJECTIVES To determine pacemaker ( PM ) dependency at follow-up visit in patients who underwent new permanent pacemaker implantation ( PPI ) following transcatheter aortic valve implantation ( TAVI ) .  METHODS Single center prospect i ve observational study including 167 patients without previous PM implantation who underwent TAVI with the self-exp and ing Medtronic CoreValve System ( MCS ) between November 2005 and February 2011 . PM dependency was defined by the presence of a high degree atrioventricular block ( HDAVB ; second [ AV2 ] and third degree [ AV3B ] ) , or a slow ( < 30 bpm ) or absent ventricular escape rhythm during follow-up PM interrogation . RESULTS A total of 36 patients ( 21.6 % ) received a new PM following TAVI . The indication for PM was AV2B ( n=2 , 5.6 % ) , AV3B ( n=28 , 77.8 % ) , postoperative symptomatic bradycardia ( n=3 , 8.3 % ) , brady-tachy syndrome ( n=1 , 2.8 % ) , atrial fibrilation with slow response ( n=1 , 2.8 % ) and left bundle branch block ( n=1 , 2.8 % ) . Long term follow-up was complete for all patients and ranged from 1 to 40 months ( median ( IQR ) : 11.5 ( 5.0 - 18.0 months ) . Of those patients with a HDAVB , 16 out of the 30 patients ( 53.3 % ) were PM independent at follow-up visit ( complete or partial resolution of the AV conduction abnormality ) . Overall , 20 out of the 36 patients ( 55.6 % ) who received a new PM following TAVI were PM independent at follow-up . CONCLUSION Partial and even complete resolution of peri-operative AV conduction abnormalities after MCS valve implantation occurred in more than half of the patients BACKGROUND Atrial tachyarrhythmias ( ATAs ) are mainly treated by pharmacologic therapy for rate control or rhythm control . The aim of our study was to compare sotalol ( S ) versus beta-blocking agents ( BB ) in terms of prevention of ATA , cardioversions ( CVs ) , and cardiovascular hospitalizations ( H ) in patients paced for bradycardia-tachycardia form of sinus node disease ( BT-SND ) . METHODS One hundred thirty-five patients ( 67 males , aged 73 + /- 7 years ) were enrolled in a prospect i ve , parallel , r and omized , single-blind , multicenter study . All patients received a dual chamber rate adaptive pacemaker ; after 1 month , 66 patients were r and omly assigned to BB ( 62 + /- 26 and 104 + /- 47 mg/d for atenolol and metoprolol , respectively ) and 69 patients to S ( 167 + /- 66 mg/d ) . RESULTS After an observation period of 12 months , the percentage of patients free from ATA recurrences was 29 % in both BB and S group . Cardioversion and H were significantly ( P < .01 ) fewer in the 12 months after implantation than in the 12 months before both in patients treated with S ( CV 69.4 % vs 22.2 % , H 91.7 % vs 33.3 % ) and in patients treated with BB ( CV 58.5 % vs 17.1 % , H 82.9 % vs 26.8 % ) . Kaplan-Meier survival analysis showed a nonsignificant trend toward a lower incidence of the composite end point ( CV + H ) among BB patients . CONCLUSIONS In the complex context of " hybrid therapy " in patients with BT-SND implanted with a modern dual chamber rate adaptive pacemaker device delivering atrial antitachycardia pacing , no differences were found between the use of beta-blocker and the use of S , at the relatively low dose achieved after clinical titration , in terms of prevention of cardiovascular H or need for atrial CV AIMS Left ventricular function may be altered by right ventricular apical pacing . The aims of the study were to compare the long-term course of different parameters of left ventricular dysfunction in patients undergoing implantation of a dual-chamber pacemaker with the ventricular lead in a septal position vs. in a st and ard apical position . METHODS We r and omized 98 patients with atrioventricular block ( AV-block ) undergoing pacemaker implantation to positioning the ventricular lead in the high or mid septum ( n = 53 ) or in the apex ( n = 45 ) of the right ventricle . N-terminal pro-brain natriuetic peptide ( BNP ) levels , left ventricular ejection fraction ( LVEF ) , and exercise capacity were analysed 3 days , 3 months , and 18 months after the implantation . The primary endpoints were the changes of these parameters from baseline to 18 months . RESULTS Changes of BNP levels , LVEF , and exercise capacity from baseline to 18 months were statistically not different between septal and apical stimulation . The clinical occurrence or deterioration of overt heart failure was similar in both treatment arms . CONCLUSION With regard to different parameters of congestive heart failure , a septal stimulation site is not superior to conventional apical pacing in unselected patients undergoing pacemaker implantation for AV-block BACKGROUND Evidence suggests that physiologic pacing ( dual-chamber or atrial ) may be superior to single-chamber ( ventricular ) pacing because it is associated with lower risks of atrial fibrillation , stroke , and death . These benefits have not been evaluated in a large , r and omized , controlled trial . METHODS At 32 Canadian centers , patients without chronic atrial fibrillation who were scheduled for a first implantation of a pacemaker to treat symptomatic bradycardia were eligible for enrollment . We r and omly assigned patients to receive either a ventricular pacemaker or a physiologic pacemaker and followed them for an average of three years . The primary outcome was stroke or death due to cardiovascular causes . Secondary outcomes were death from any cause , atrial fibrillation , and hospitalization for heart failure . RESULTS A total of 1474 patients were r and omly assigned to receive a ventricular pacemaker and 1094 to receive a physiologic pacemaker .  The annual rate of stroke or death due to cardiovascular causes was 5.5 percent with ventricular pacing , as compared with 4.9 percent with physiologic pacing ( reduction in relative risk , 9.4 percent ; 95 percent confidence interval , -10.5 to 25.7 percent [ the negative value indicates an increase in risk ] ; P=0.33 ) . The annual rate of atrial fibrillation was significantly lower among the patients in the physiologic-pacing group ( 5.3 percent ) than among those in the ventricular-pacing group ( 6.6 percent ) , for a reduction in relative risk of 18.0 percent ( 95 percent confidence interval , 0.3 to 32.6 percent ; P=0.05 ) . The effect on the rate of atrial fibrillation was not apparent until two years after implantation . The observed annual rates of death from all causes and of hospitalization for heart failure were lower among the patients with a physiologic pacemaker than among those with a ventricular pacemaker , but not significantly so ( annual rates of death , 6.6 percent with ventricular pacing and 6.3 percent with physiologic pacing ; annual rates of hospitalization for heart failure , 3.5 percent and 3.1 percent , respectively ) . There were significantly more perioperative complications with physiologic pacing than with ventricular pacing ( 9.0 percent vs. 3.8 percent , P<0.001 ) . CONCLUSIONS Physiologic pacing provides little benefit over ventricular pacing for the prevention of stroke or death due to cardiovascular causes Objective : To analyse the occurrence of atrial fibrillation ( AF ) and thromboembolism in a r and omised comparison of rate adaptive single chamber atrial pacing ( AAIR ) and dual chamber pacing ( DDDR ) in patients with sick sinus syndrome and normal atrioventricular ( AV ) conduction , in which left atrial dilatation and decreased left ventricular fractional shortening had been observed in the DDDR group . Methods : 177 consecutive patients with sick sinus syndrome ( mean ( SD ) age 74 ( 9 ) years , 104 women ) were r and omly assigned to treatment with one of three pacemakers : AAIR ( n = 54 ) , DDDR with a short rate adaptive AV delay ( n = 60 ) ( DDDR-s ) ; or DDDR with a fixed long AV delay ( n = 63 ) ( DDDR-l ) . Analysis was intention to treat . Results : Mean follow up was 2.9 ( 1.1 ) years . AF at one or more ambulatory visits was significantly less common in the AAIR group ( 4 ( 7.4 % ) v 14 ( 23.3 % ) in the DDDR-s group v 11 ( 17.5 % ) in the DDDR-l group ; p = 0.03 , log rank test ) . The risk of developing AF in the AAIR group compared with the DDDR-s group was significantly decreased after adjustment for brady-tachy syndrome in a Cox regression analysis ( relative risk 0.27 , 95 % confidence interval ( CI ) 0.09 to 0.83 , p = 0.02 ) . The benefit of AAIR was highest among patients with brady-tachy syndrome . Brady-tachy syndrome and a thromboembolic event before pacemaker implantation were independent predictors of thromboembolism during follow up ( relative risk 7.5 , 95 % CI 1.6 to 36.2 , p = 0.01 , and relative risk 4.7 , 95 % CI 1.2 to 17.9 , p = 0.02 , respectively ) . Conclusions : During a mean follow up of 2.9 years AAIR was associated with significantly less AF . The beneficial effect of AAIR was still significant after adjustment for brady-tachy syndrome . Brady-tachy syndrome was associated with an increased risk of thromboembolism OBJECTIVES We evaluated the incidence , predictors , and treatment of  pacemaker syndrome in patients with sinus node dysfunction treated with ventricular-based ( VVIR ) pacing in the Mode Selection Trial ( MOST ) . BACKGROUND Pacemaker syndrome , or intolerance to VVIR pacing , consists of cardiovascular signs and symptoms induced by VVIR pacing . METHODS The definition of pacemaker syndrome required that a patient with single-chamber VVIR pacing develop either congestive signs and symptoms associated with retro grade conduction during VVIR pacing or a > or=20 mm Hg reduction of systolic blood pressure during VVIR pacing , associated with reproducible symptoms of weakness , lightheadedness , or syncope . RESULTS Of 996 patients r and omized to VVIR pacing , 182 ( 18.3 % ) met criteria for pacemaker syndrome in follow-up . Pacemaker syndrome occurred early in most patients ( 13.8 % at 6 months , 16.0 % at 1 year , increasing to 19.7 % at 4 years ) . Baseline univariate predictors of pacemaker syndrome included a lower sinus rate and higher programmed pacemaker rate . Previous heart failure , ejection fraction , and drop in systolic blood pressure with VVIR pacing at implantation did not predict the development of pacemaker syndrome . Post-implantation predictors of pacemaker syndrome were a higher percentage of paced beats , higher programmed low rate , and slower underlying spontaneous sinus rate . Quality of life decreased at the time of diagnosis of pacemaker syndrome and improved with reprogramming to atrial-based pacing . CONCLUSIONS Severe pacemaker syndrome developed in nearly 20 % of VVIR-paced patients and improved with reprogramming to the dual-chamber pacing mode . Because prediction of pacemaker syndrome is difficult , the only way to prevent pacemaker syndrome is to implant atrial-based pacemakers in all patients BACKGROUND Dual-chamber ( atrioventricular ) and single-chamber ( ventricular ) pacing are alternative treatment approaches for sinus-node dysfunction that causes clinical ly significant bradycardia . However , it is unknown which type of pacing results in the better outcome . METHODS We r and omly assigned a total of 2010 patients with sinus-node dysfunction to dual-chamber pacing ( 1014 patients ) or ventricular pacing ( 996 patients ) and followed them for a median of 33.1 months . The primary end point was death from any cause or nonfatal stroke . Secondary end points included the composite of death , stroke , or hospitalization for heart failure ; atrial fibrillation ; heart-failure score ; the pacemaker syndrome ; and the quality of life . RESULTS The incidence of the primary end point did not differ significantly between the dual-chamber group ( 21.5 percent ) and the ventricular-paced group ( 23.0 percent , P=0.48 ) . In patients assigned to dual-chamber pacing , the risk of atrial fibrillation was lower ( hazard ratio , 0.79 ; 95 percent confidence interval , 0.66 to 0.94 ; P=0.008 ) , and heart-failure scores were better ( P<0.001 ) . The differences in the rates of hospitalization for heart failure and of death , stroke , or hospitalization for heart failure were not significant in unadjusted analyses but became marginally significant in adjusted analyses . Dual-chamber pacing result ed in a small but measurable increase in the quality of life , as compared with ventricular pacing . CONCLUSIONS In sinus-node dysfunction , dual-chamber pacing does not improve stroke-free survival , as compared with ventricular pacing . However , dual-chamber pacing reduces the risk of atrial fibrillation , reduces signs and symptoms of heart failure , and slightly improves the quality of life . Overall , dual-chamber pacing offers significant improvement as compared with ventricular pacing BACKGROUND Atrial fibrillation ( AF ) is not always accompanied by clear-cut symptoms and symptoms suggestive of AF may not correspond to a genuine AF episode . The study prospect ively evaluated the burden of asymptomatic AF episodes in pacemaker patients ( for sick sinus syndrome ) with a history of documented paroxysmal AF . METHODS Consecutive patients were enrolled and implanted with dual-chamber pacemakers equipped with diagnostic features for AF monitoring .  Each patient was instructed about typical AF symptoms and was asked to keep a detailed log of symptoms . Stored pacemaker data were analyzed using only AF episodes > 30 s. RESULTS The mean follow-up was 16 + /- 6 months and 102 patients were enrolled ( 73 + /- 7 years , 59 M ) . Thirteen patients ( 13 % ) dropped out with the development of permanent AF and their data were discarded . Twenty-three patients ( 26 % ) without device-stored AF episodes all reported at least one annotated AF episode . There were 1,245 device-stored AF episodes in 66 ( 74 % ) out of 89 patients . Patients reported 1,141 episodes of AF-related symptoms . Only 240 ( 21 % ) corresponded to a genuine device-stored AF event . The sensitivity and positive predictive value of symptoms to detect AF were respectively 19 % and 21 % . Episode duration , rate increase at the onset of the arrhythmia , heart disease , or antiarrhythmic drug therapy showed no statistically significant differences comparing symptomatic and asymptomatic episodes . CONCLUSIONS Many pacemaker patients with paroxysmal AF can develop AF-like symptoms in the absence of device-stored AF . AF-related symptoms have low sensitivity and low positive predictive value in patients with permanent pacemakers BACKGROUND In the Mode Selection Trial ( MOST ) of 2,010 patients with sinus node dysfunction , dual-chamber-paced patients had less atrial fibrillation ( AF ) and heart failure and had slightly improved health-related quality of life ( QOL ) compared with rate modulated right ventricular-paced patients . Our objective was to assess the impact of AF on QOL within MOST . METHODS We analyzed serial QOL measures ( Short Form-36 , Specific Activity Scale , time trade-off ) in 3 groups : ( 1 ) those without AF ; ( 2 ) those with paroxysmal AF ( PAF ) , but not chronic AF ( CAF ) ; and ( 3 ) those with CAF . We carried forward the last known QOL before crossover for all subsequent time points in patients r and omized to rate modulated right ventricular pacing who crossed over to dual-chamber pacing for severe pacemaker syndrome . RESULTS Three hundred seventeen patients ( 15.8 % ) had AF in the year after implantation , 206 patients within 3 months ( 191 PAF , 15 CAF ) , and another 159 ( 124 PAF , 35 CAF ) between 3 and 12 months . There were no significant differences among groups in individual Short Form-36 subscales or time trade-off scores at 12 months as compared with baseline or 3 months . Cardiovascular health status was better at 12 months as compared with baseline or 3 months in those without AF . CONCLUSIONS Atrial fibrillation after pacemaker implantation in elderly patients with sick sinus syndrome was not a major determinant of QOL . However , there was a trend toward better cardiovascular functional status in patients without AF OBJECTIVE --To evaluate the incidence of intraoperative and early postoperative complications ( up to two months after implant ) of endocardial permanent pacemaker insertion in all patients under-going a first implant at a referral centre . METHODS -- Prospect i ve evaluation of all  endocardial pacemaker implantation procedures performed from April 1992 to January 1994 carried out by completion of st and ard audit form at implant . Patients ' demographic data , medical history , details of pacemaker hardware used , and any complications were noted . Follow up information was also collected prospect ively onto st and ard forms at pacemaker outpatient clinic . SETTING --United Kingdom tertiary referral cardiothoracic centre . PATIENTS --1088 consecutive patients underwent implantation of their first endocardial permanent pacemaker from April 1992 to January 1994 . Implant and follow up data were available for 1059 ( 97.3 % ) patients at analysis . The median ( range ) age was 77 years ( 16 - 99 ) ; 51.2 % were male . RESULTS --Dual chamber units were implanted in 54.1 % of patients , single chamber atrial in 5.2 % , and ventricular in 40.7 % . A temporary pacing lead was present at implant in 22.9 % of patients . Most ( 93.6 % ) implants were performed via the subclavian vein . Immediate complications were rare : eight ( 0.8 % ) patients developed pneumothorax requiring medical treatment and 11 ( 1.0 % ) an insignificant pneumothorax . There was no significant difference in the pneumothorax rate for dual chamber ( DDD ) compared with single chamber systems . Arterial puncture without sequelae was documented in 2.7 % of attempts at subclavian vein cannulation . A total of 35 patients ( 3.3 % ) required reoperation ; the reoperation rate for dual chamber ( 3.5 % ) was similar to that for single chamber ( 3.1 % ) systems . Electrode displacement ( n = 15 , 1.4 % ) was the most common reason for reoperation . Atrial lead displacement ( n = 10 , 1.6 % of atrial leads ) was significantly more common than ventricular lead displacement ( n = 5 , 0.5 % of ventricular leads , P = 0.047 ) . There was no difference in electrode displacement rates for dual ( 1.6 % ) compared with single ( 1.2 % ) chamber systems . Pacemaker pocket infection led to reoperation in 10 patients ( six dual , four single chamber , P = not significant ) and was significantly more common in patients who had a temporary pacing lead in place at implant ( 2.9 % ) than in those who did not ( 0.4 % , P = 0.0014 ) . Five patients ( 0.5 % ) required reoperation for generator erosion ( two dual , three single chamber , P = not significant ) . and a further five for drainage of haematoma or a serous fluid collection ( three dual , two single chamber , P = not significant ) . Complications that did not require reoperation were also rare . Undersensing occurred in 10 patients ( 0.9 % ) . Atrial undersensing ( n = 8) was significantly more common than ventricular undersensing ( n = 2 , P = 0.017 ) . All patients were successfully treated by reprogramming of sensitivity . Superficial wound infection was treated successfully with antibiotics in nine patients ( six dual , three single chamber , P = not significant ) . Three patients with DDD generators developed sustained atrial fibrillation : two required reprogramming to VVI mode and one required cardioversion . CONCLUSIONS --Permanent pacing in a large tertiary referral centre with experienced operators carries a low risk . Infection rates are low , < 1 % overall but significantly higher in patients who undergo temporary pacing before implantation . Lead displacement and undersensing are more likely to occur with atrial than ventricular leads . The overall complication rate for dual chamber pacing , however , is no higher than for single chamber pacing Pacemakers are frequently implanted , yet accurate prospect i ve data on implant complications are limited . Elderly patients may be at increased risk of implant complications and are increasingly being referred for pacemaker implantation . The purpose of the present analysis was to define the incidence and possible predictors of serious complications of dual chamber permanent pacemaker implantation  in the elderly . Therefore , we sought to prospect ively identify the incidence and predictors of pacemaker implant complications in a large multicenter trial involving patients receiving a dual chamber pacemaker .  The Pacemaker Selection in the Elderly ( PASE ) study was a prospect i ve trial design ed to evaluate quality of life in  dual chamber pacemaker recipients age 65 years or older r and omized to DDDR versus VVIR programming . In addition to being age 65 years or older , patients enrolled in this study were in normal sinus rhythm , and had st and ard indications for permanent pacemaker implantation . All patients received dual chamber pacemakers and were r and omized to DDDR versus VVIR pacing . Pacemaker implant complications were collected on st and ardized forms which were completed at pacemaker implantation and during follow-up appointments . In this study of 407 patients , there were 26 complications occurring in 25 patients ( 6.1 % ) . The most frequent complication was lead dislodgment which occurred in 9 patients . This was followed by pneumothorax ( 8 patients ) and cardiac perforations ( 4 patients ) . In 18 patients ( 4.4 % ) repeat surgical procedures ( including chest tubes ) were required . Complications were noted prior to discharge in only 18 patients . There were no significant predictors of overall complications . Pneumothorax was more frequent in patients ≤75 years old , and was observed only in patients with subclavian venous access . In conclusion , complications from pacemaker implantation in the elderly are seen in 6.1 % of patients and 4.4 % of patients require a repeat surgical procedure . Other than advanced age and lower weight predicting for pneumothorax , there are no significant clinical predictors of BACKGROUND Dual-chamber pacemakers restore AV synchrony compared with ventricular pacemakers , but the effects on health-related quality of life ( QOL ) are uncertain . OBJECTIVES The purpose of this study was to assess the effect of pacemaker implantation , clinical factors , and pacing mode on QOL . METHODS The Mode Selection Trial ( MOST ) r and omized 2,010 patients with sinus node dysfunction to rate-modulated right ventricular ( VVIR ) or dual-chamber ( DDDR ) pacing .  A longitudinal analysis of serial QOL measures ( Short Form-36 [ SF-36 ] , Specific Activity Scale , and time trade-off utility ) was performed . In patients who crossed over from VVIR to DDDR because of severe pacemaker syndrome , the last known QOL prior to crossover was carried forward . RESULTS Pacemaker implantation result ed in substantial improvement in almost all QOL measures .  Subjects 75 years or older experienced significantly less improvement in functional status and physical component summary scores than did younger subjects . In longitudinal analyses of the effect of pacing mode on QOL , significant improvement in three SF-36 subscales was observed with DDDR pacing compared with VVIR pacing : role physical [ 62.8 points ( 95 % confidence interval [ CI ] 60.2 , 65.5 ) vs 56.4 ( 95 % CI 53.7 , 59.1 ) ] , role emotional [ 85.0 ( 95 % CI 82.9 , 87.0 ) vs 81.9 ( 95 % CI 79.9 , 84.0 ) ] , and vitality [ 51.8 ( 95 % CI 50.3 , 53.3 ) vs 49.3 ( 95 % CI 47.8 , 50.7 ) ] , but not in other SF-36 subscales , the Specific Activity Scale , or utilities . The gains in QOL were larger than the declines associated with 1 year of aging but smaller than those associated with heart failure . CONCLUSION Pacemaker implantation improved health-related QOL . The mode selected was associated with much smaller , but significant , improvements in several domains , particularly role physical function INTRODUCTION Newer implantable pulse generators have data storage capabilities that permit detection of multiple episodes of atrial fibrillation ( AF ) . This study evaluated the clinical predictors and time course of AF development in a general pacemaker population . METHODS AND RESULTS Patients ( n = 231 ) received DDDR pacemakers with features that permit detection and storage of information about the date , time of onset , and duration of multiple , sequential episodes of AF . Patients were followed for 718+/-383 days . Time to first occurrence of AF , interval between first and second episode of AF , and total AF burden were determined at each follow-up visit . AF occurred more often in patients ( 68 % ) with sinus node disease than in patients with AV block ( 37 % ; P < 0.001 ) . Time to first occurrence of AF was 21.2 days ( 95 % confidence interval [ CI ] 14.7 to 30.6 days ) after pacemaker implantation . AF burden initially decreased significantly in patients ( 0.8 hours/day , 95 % CI 0.7 to 0.9 at 8 weeks after implant vs 0.6 hours/day , 95 % CI 0.4 to 0.8 at 12 months after implant ; P = 0.005 ) but then increased significantly during long-term follow-up ( 2.0 hours/day , 95 % CI 1.0 to 3.7 at 48 months after implant ; P = 0.008 ) . The long-term increase in AF burden was seen predominantly in patients with sinus node disease . A prior history of AF and the duration of follow-up were independent predictors of AF occurrence . CONCLUSION AF develops frequently after dual-chamber pacemaker implantation . AF burden increases progressively over the long term A population of 283 patients with recent onset ( < 72 hours ) AF , without heart failure , who received a single 450- or 600-mg oral dose of propafenone , or digoxin 1 mg , or placebo for conversion to sinus rhythm ( SR ) , was studied to determine whether a routine admission to the hospital for drug administration is justified . Previous bradyarrhythmias or sick sinus syndrome ( SSS ) , and concomitant use of antiarrhythmic drugs were exclusion criteria . None of the 283 patients studied experienced VT or VF and none of them needed implantation of a temporary pacemaker . Periods of atrial tachyarrhythmias with regularization of atrial waves and 1:1 AV conduction were observed in only two cases , both receiving placebo . No predictor of proarrhythmia was found among the clinical variables considered ( age , etiology , arrhythmia duration , atrial dimension , and blood potassium ) . No serious hemodynamic adverse effects were noted in either group . The rates of conversion to SR after 4 hours were : 80 ( 57 % ) of 141 patients who received propafenone and 35 ( 25 % ) of 142 patients who received digoxin or placebo ( P < 0.001 ) . Acute oral treatment with propafenone is simple and effective for the conversion of recent onset AF to SR in patients without clinical signs of heart failure . The routine admission of these patients to the hospital is not necessary . Home-based administration of oral propafenone to a selected group of patients could significantly increase the cost effectiveness of this treatment OBJECTIVES We evaluated the incidence and predictors of sudden death after  atrioventricular ( AV ) node ablation and pacemaker implantation .  BACKGROUND Sudden death may occur after radiofrequency catheter ablation of the AV node and pacemaker implantation in patients with atrial fibrillation ( AF ) . Whether it is related to the procedure or to pre-existing heart disease remains unclear . METHODS All patients who had radiofrequency catheter ablation of the AV node and pacemaker implantation for rate control of medically refractory AF were identified retrospectively and observed prospect ively . All patients with sudden death after ablation were identified . The relationship between the procedure and sudden death was defined on the basis of the time between the two as " likely , " " possibly " or " unlikely . " RESULTS Of 334 consecutive patients with AF who underwent AV node ablation  , nine had sudden death after the ablation . Four patients ( 1.2 % ) had sudden death likely related to the procedure : in 3 patients , arrest occurred within 48 h after the procedure ; in one patient , arrest occurred four days after the procedure . In three other patients ( 0.9 % ) , sudden death was possibly related to the procedure because the event occurred within three months afterward . The remaining two deaths were unrelated to the procedure . Diabetes , New York Heart Association functional class ( > or = II ) , preprocedure ventricular arrhythmia , mitral or aortic stenosis , aortic regurgitation and chronic obstructive pulmonary disease were independent predictors for sudden death . CONCLUSIONS Sudden death likely or possibly related to catheter ablation occurred in 7 of 334 patients ( 2.1 % ) . Risk of sudden death is highest within two days after the procedure AIM To compare ventricular rate responsive ( VVIR ) pacing with dual chamber rate responsive ( DDDR ) pacing and antiarrhythmic drugs for the treatment of patients with persistent atrial fibrillation after atrioventricular node ablation . METHODS One hundred two patients with persistent atrial fibrillation eligible for the atrioventricular node ablation were r and omly assigned to the therapy with either VVIR pacemaker ( n=52 ) or DDDR pacemaker and antiarrhythmic drugs ( n=50 ) . After ablation , patients in both pacing groups were assigned to take anticoagulant therapy . The primary end point was stroke or death from cardiovascular causes . RESULTS After a mean follow-up of 26.6+/-9.5 months , there was no difference in the stroke or death rates between patients with VVIR pacing ( 6 or 5.2 % per year ) and those with DDDR pacing and antiarrhythmic drugs ( 6 or 5.9 % per year , P=0.930 ) . The observed rates of death from all causes , hospitalization for heart failure , and myocardial ischemia were similar in the two patient groups . There was a significantly lower rate of development of permanent atrial fibrillation in patients with DDDR pacing and antiarrhythmic drugs , with a reduction in absolute risk by 56 % and relative risk by 64 % ( 32 % vs 88 % ; P<0.001 ) . CONCLUSION With respect to cardiovascular death and morbidity , VVIR pacing is not inferior to DDDR pacing and antiarrhythmic drugs for the treatment of patients with persistent atrial fibrillation after atrioventricular node ablation and may be considered as an appropriate therapy for such patients BACKGROUND Both " physiologic " ( dual-chamber or atrial only ) or ventricular-pacing-only permanent pacemakers provide chronotropic competence , with unknown health-related quality of life ( QOL ) differences between these options . The QOL studies within the Canadian Trial of Physiologic Pacing were performed to assess whether QOL differences exist in patients r and omized to these 2 pacing modes . METHODS Two QOL protocol s were performed : 1 ) a sub study of 269 patients with detailed QOL measures ( The Medical Outcomes Study , Short-Form [ SF-36 ] , the Pacemaker Syndrome Scale , an activity scale , and a pacemaker-specific scale ) at baseline and 6 months after implantation ; and 2 ) a parent study assessment of QOL in 1721 patients with a 12-item QOL instrument package ( SF-6 , " ladder of life , " and pacemaker syndrome scale ) given 6 months after implantation only . RESULTS In the sub study , pacing was associated with an average significant ( P < .05 ) 0.36 SD unit improvement in QOL across all domains ( SF-36 : 38 + /- 9 to 41 + /- 11 for physical scores , 47 + /- 11 to 52 + /- 9 for mental health scores , both P < .001 ) . Similar improvements were seen with the pacemaker-specific scales . There were no significant differences in the absolute or relative improvement in QOL between assigned pacing modes . The parent study similarly showed no differences in QOL between pacing modalities . Presyncope occurred in 31 % of patients in the physiological pacing group , compared with 38 % of the patients in the ventricular pacing group ( P < .01 ) . No other symptoms were different between the 2 groups . Pacemaker dependency , defined as an escape heart rate < 50 beats per minute , did not influence the lack of difference in QOL scores between the 2 assigned pacing modes . CONCLUSION In this largest r and omized assessment of QOL in patients with pacemakers , with the instruments used , there was no significant health-related QOL difference seen between " physiologic " pacing and ventricular pacing The incidence and clinical predictors of the development of intolerance to VVIR pacing have not been extensively studied in prospect i ve long-term r and omized trials comparing different pacing modes . The frequency and clinical factors predicting intolerance to ventricular pacing are controversial . The Pacemaker Selection in the Elderly ( PASE ) Trial enrolled 407 patients aged > /=65 years in a 30-month , single-blind , r and omized , controlled comparison of quality of life and clinical outcomes with ventricular pacing and dual-chamber pacing in patients undergoing dual-chamber pacemaker implantation for st and ard clinical ly accepted indications . We review ed the clinical , hemodynamic , and electrophysiologic variables at the time of pacemaker implantation  in 204 patients enrolled in the PASE trial and r and omized to the VVIR mode , some of whom subsequently required crossover ( reprogramming ) to DDDR pacing . During a median follow-up of 555 days , 53 patients ( 26 % ) crossed over from VVIR to DDDR pacing . A decrease in systolic blood pressure during ventricular pacing at the time of pacemaker implantation ( p = 0.001 ) , use of beta blockers at the time of r and omization ( p = 0.01 ) , and nonischemic cardiomyopathy ( p = 0.04 ) were the only variables that predicted crossover in the Cox multivariate regression model . After reprogramming to the dual-chamber mode , patients showed improvement in all aspects of quality of life , with significant improvements in physical and emotional role . The high incidence of crossover from VVIR to DDDR pacing along with significant improvements in quality of life after crossover to DDDR pacing strongly favors dual-chamber pacing compared with single-chamber ventricular pacing in elderly patients requiring permanent pacing BACKGROUND In a previous study of 225 patients with sick-sinus syndrome r and omised to either single-chamber atrial pacing ( n=110 ) or single-chamber ventricular pacing ( n=115 ) , we found that after a mean follow-up of 3.3 years , atrial pacing was associated with significantly less atrial fibrillation and thromboembolism whereas there was no significant difference in mortality and heart failure between the two groups . We aim ed to find out whether this beneficial effect of atrial pacing is maintained during extended follow-up of up to 8 years . METHODS Follow-up visits for all patients were at 3 months , 12 months , then once a year at which patients had a physical examination , ECG recording , and pacemaker check-up . Endpoints were mortality , cardiovascular death , atrial fibrillation , thromboembolic events , heart failure , and atrioventricular block . Data was analysed on Dec 31 , 1996 . FINDINGS At long-term follow-up , 39 patients from the atrial group had died versus 57 from the ventricular group ( relative risk 0.66 [ 95 % CI 0.44 - 0.99 ] ; p=0.045 ) . 19 patients from the atrial group and 39 patients from the ventricular group died from a cardiovascular cause ( 0.47 [ 0.27 - 0.82 ] ; p=0.0065 ) . The cumulative incidences of atrial fibrillation and chronic atrial fibrillation were also significantly lower in the atrial group than in the ventricular group ( 0.54 [ 0.33 - 0.89 ] , p=0.012 and 0.35 [ 0.16 - 0.76 ] , p=0.004 , respectively ) . Thromboembolic events occurred in 13 patients in the atrial group and 26 in the ventricular group ( 0.47 [ 0.24 - 0.92 ] , p=0.023 ) . Heart failure was less severe in the atrial group than in the ventricular group ( p<0.05 ) . In multivariate analysis , atrial pacing was significantly associated with freedom from thromboembolic events ( 0.47 [ 0.24 - 0.92 ] , p=0.028 ) and survival from cardiovascular death ( 0.52 [ 0.30 - 0.91 ] , p=0.022 ) , but no longer with overall survival ( 0.71 [ 0.46 - 1.08 ] , p=0.11 ) or chronic atrial fibrillation ( 0.45 [ 0.20 - 1.05 ] , p=0.063 ) . Atrioventricular block occurred in four patients in the atrial group ( 0.6 % annual risk ) . INTERPRETATION The beneficial effect of atrial pacing found in our previous study is enhanced substantially over time . Patients with sick-sinus syndrome should be treated with an atrial rather than ventricular-pacing system because after long-term follow-up , atrial pacing is associated with a significantly higher survival , less atrial fibrillation , fewer thromboembolic complications , less heart failure , and a low-risk of atrioventricular block Background Dual‐chamber ( DDDR ) pacing preserves AV synchrony and may reduce heart failure ( HF ) and atrial fibrillation ( AF ) compared with ventricular ( VVIR ) pacing in sinus node dysfunction ( SND ) . However , DDDR pacing often results in prolonged QRS duration s ( QRSd ) as the result of right ventricular stimulation , and ventricular desynchronization may result . The effect of pacing‐induced ventricular desynchronization in patients with normal baseline QRSd is unknown . Methods and Results Baseline QRSd was obtained from 12‐lead ECGs before pacemaker implantation in MOST , a 2010‐patient , 6‐year , r and omized trial of DDDR versus VVIR pacing in SND .  Cumulative percent ventricular paced ( Cum%VP ) was determined from stored pacemaker data . Baseline QRSd < 120 ms was observed in 1339 patients ( 707 DDDR , 632 VVIR ) . Cum%VP was greater in DDDR versus VVIR ( 90 % versus 58 % , P=0.001 ) . Cox models demonstrated that the time‐dependent covariate Cum%VP was a strong predictor of HF hospitalization in DDDR ( hazard ratio [ HR ] , 2.99 [ 95 % CI , 1.15 to 7.75 ] for Cum%VP > 40 % ) and VVIR ( HR 2.56 [ 95 % CI , 1.48 to 4.43 ] for Cum%VP > 80 % ) . The risk of AF increased linearly with Cum%VP from 0 % to 85 % in both groups ( DDDR , HR 1.36 [ 95 % CI , 1.09 , 1.69 ] ; VVIR , HR 1.21 [ 95 % CI 1.02 , 1.43 ] , for each 25 % increase in Cum%VP ) . Model results were unaffected by adjustment for known baseline predictors of HF hospitalization and AF . Conclusions Ventricular desynchronization imposed by ventricular pacing even when AV synchrony is preserved increases the risk of HF hospitalization and AF in SND with normal baseline QRSd . ( Circulation . 2003;107:2932‐2937 . The hemodynamic effects of two different pacing modes -- rate adaptive atrial ( AAIR ) versus dual chamber ( DDDR ) pacing -- were assessed in 12 patients with DDDR pacemakers during upright bicycle exercise first-pass radionuclide angiography using a multiwire gamma camera with tantalum-178 as a tracer . All patients had sinus node disease with intact AV conduction . Patients exercised to the same heart rate in r and om order in these two different pacing modes , AAIR and DDDR with AV delay ( of 100 msec ) selected to maintain 100 % ventricular capture . Cardiac output increased significantly above baseline values during exercise in both pacing modes : 154 + /- 41 % ( mean + /- SEM , P = 0.002 ) with AAIR , versus 95 + /- 24 % ( P = 0.004 ) with DDDR ( P = NS between the two modes ) . The peak filling rate , likewise , increased in both pacing modes ( 2.3 + /- 0.21 end-diastolic volumes/sec to 3.8 + /- 0.31 end-diastolic volumes/sec in AAIR [ P = 0.0004 ] and 2.2 + /- 0.18 end-diastolic volumes/sec to 3.4 + /- 0.27 end-diastolic volumes/sec in DDDR [ P = 0.0008 ] ) . LV ejection fraction was normal at rest ( 60 + /- 4 % , SEM ) and did not significantly change with submaximal exercise in either pacing mode ( both 56 % , P = NS ) . No significant changes in end-diastolic volume or stroke volume indexes occurred with exercise in either pacing mode . Our study demonstrates that in patients with normal resting LV function , AAIR and DDDR pacing are equally effective in attaining appropriate increases in cardiac output and LV filling during exercise Background —Compared with single-chamber ventricular pacing , dual-chamber pacing can reduce adverse events and , as a result , improve quality of life in patients paced for sick sinus syndrome . It is not clear , however , how these benefits compare with the increased cost of dual-chamber pacemakers . Methods and Results —We used 4-year data from a 2010-patient , r and omized trial to estimate the incremental cost-effectiveness of dual-chamber pacing compared with ventricular pacing and then projected these findings over the patients ’ lifetimes by using a Markov model that was calibrated to the first 5 years of in-trial data . To assess the stability of the findings , we performed 1000 bootstrap analyses and multiple sensitivity analyses . During the first 4 years of the trial , dual-chamber pacemakers  increased quality -adjusted life expectancy by 0.013 year per subject at an incremental cost-effectiveness ratio of $ 53 000 per quality -adjusted year of life gained . Over a lifetime , dual-chamber pacing was projected to increase quality -adjusted life expectancy by 0.14 year with an incremental cost-effectiveness ratio of ≈$6800 per quality -adjusted year of life gained . In bootstrap analyses , dual-chamber pacing was cost-effective in 91.9 % of simulations at a threshold of $ 50 000 per quality -adjusted year of life and in 93.2 % of simulations at a threshold of $ 100 000 . Its cost-effectiveness ratio was also below this threshold in numerous sensitivity analyses that varied key estimates . Conclusions —For patients with sick sinus syndrome requiring pacing  , dual-chamber pacing  increases quality -adjusted life expectancy at a cost that is generally considered acceptable BACKGROUND Conventional dual-chamber pacing maintains atrioventricular synchrony but results in high percentages of ventricular pacing , which causes ventricular desynchronization and has been linked to an increased risk of atrial fibrillation in patients with sinus-node disease . METHODS We r and omly assigned 1065 patients with sinus-node disease , intact atrioventricular conduction , and a normal QRS interval to receive  conventional dual-chamber pacing ( 535 patients ) or dual-chamber minimal ventricular pacing with the use of new pacemaker features design ed to promote atrioventricular conduction , preserve ventricular conduction , and prevent ventricular desynchronization ( 530 patients ) . The primary end point was time to persistent atrial fibrillation . RESULTS The mean ( + /-SD ) follow-up period was 1.7+/-1.0 years when the trial was stopped because it had met the primary end point . The median percentage of ventricular beats that were paced was lower in dual-chamber minimal ventricular pacing than in conventional dual-chamber pacing ( 9.1 % vs. 99.0 % , P<0.001 ) , whereas the percentage of atrial beats that were paced was similar in the two groups ( 71.4 % vs. 70.4 % , P=0.96 ) . Persistent atrial fibrillation developed in 110 patients , 68 ( 12.7 % ) in the group assigned to conventional dual-chamber pacing and 42 ( 7.9 % ) in the group assigned to dual-chamber minimal ventricular pacing . The hazard ratio for development of persistent atrial fibrillation in patients with dual-chamber minimal ventricular pacing as compared with those with conventional dual-chamber pacing was 0.60 ( 95 % confidence interval , 0.41 to 0.88 ; P=0.009 ) , indicating a 40 % reduction in relative risk . The absolute reduction in risk was 4.8 % . The mortality rate was similar in the two groups ( 4.9 % in the group receiving dual-chamber minimal ventricular pacing vs. 5.4 % in the group receiving conventional dual-chamber pacing , P=0.54 ) . CONCLUSIONS Dual-chamber minimal ventricular pacing , as compared with conventional dual-chamber pacing , prevents ventricular desynchronization and moderately reduces the risk of persistent atrial fibrillation in patients with sinus-node disease . ( Clinical Trials.gov number , NCT00284830 [ Clinical Trials.gov ] . ) The purpose of this study was to prospect ively determine the incidence of diastolic mitral and tricuspid regurgitation in atrioventricular ( AV ) block using Doppler echocardiography . The temporal relation between mitral and tricuspid diastolic insufficiency and the diastolic murmur recorded in patients with complete heart block was also investigated . Twenty-two consecutive patients with AV block ( referred to the Echo-Doppler laboratory for routine clinical studies ) , aged 18 to 87 years , were enrolled in the study . Eleven patients had third degree AV block and a ventricular-inhibited ( VVI ) pacemaker , two patients had second degree AV block , seven patients had first degree AV block , one patient had blocked premature atrial complexes and one patient had atrial flutter with 4:1 AV block .  Diastolic mitral regurgitation was detected in 20 patients , and diastolic tricuspid regurgitation in 21 . A mid-diastolic murmur was detected in all patients except in the three youngest . The murmur occurred before diastolic regurgitation and coincided with peak forward flow through the AV valve after atrial contraction . M-mode mitral valve echocardiograms obtained in nine patients demonstrated near closure of some portions of the mitral valve after atrial contraction . Effective closure of the valve , however , did not occur unless ventricular systole supervened . In conclusion , diastolic mitral and tricuspid regurgitation are almost universally present in patients with AV block and are associated with a diastolic murmur . The murmur coincides with forward AV valve flow . Diastolic regurgitation is silent . Effective AV valve closure is not established until ventricular systole occurs , as demonstrated by M-mode echocardiographic recording of the mitral valve BACKGROUND Increasing evidence suggests that atrial fibrillation ( AF ) is an inflammatory disease . Statins is an anti-inflammatory agent . The present study was conducted to test the efficacy of atorvastatin in preventing paroxysmal AF or atrial high rate episodes ( AHEs ) in patients with bradyarrhythmias and implantation of an atrial-based or dual-chamber pacemaker . METHODS The effect of atorvastatin on time to the first attack of AF or AHE ( > or = 180 per minute and > or = 1 or 10 minutes ) , which was accurately detected by pacemaker interrogation , was evaluated in an open-label prospect i ve r and omized design for 1 year of follow-up . RESULTS Fifty-two patients ( 23 males , 70 + /- 13 years old ) were r and omized to the  statin group ( atorvastatin 20 mg/d ) and 54 ( 25 males , 72 + /- 13 years old ) to the  nonstatin group . Event-free survivals from AHE > or = 1 minute were not significantly different between the 2 groups ( log-rank P = .410 ) . However , patients in the nonstatin group were more likely to develop AHE > or = 10 minutes than those in the statin group ( log-rank P = .028 ) . Atrial high rate episode > or = 10 minutes occurred in 3 ( 5.8 % ) of 51 patients in the statin group after 1 year of follow-up , and 10 ( 19.2 % ) of 52 patients ( odds ratio 0.26 , P = .041 ) in the nonstatin group . The mean left atrial volume of the statin group was significantly lower than that of the nonstatin group at the end of follow-up ( 39.7 + /- 1.7 vs 43.7 + /- 1.9 mL , P < .0001 ) . CONCLUSIONS The present study demonstrated the efficacy of atorvastatin in preventing significant AF ( > or = 10 minutes ) and left atrial enlargement in patients with bradyarrhythmias and implantation of a pacemaker C resynchronization therapy ( CRT ) by atriobiventricular pacing has been proposed to treat severe heart failure in patients with intraventricular conduction delay result ing in ventricular mechanical discoordination . The clinical efficacy of CRT was recently demonstrated in a single-blind , r and omized , crossover trial , namely the MUltisite STimulation In Cardiomyopathies ( MUSTIC ) study .1 The purpose of this sub study was to assess the effect of CRT on heart rate variability ( HRV ) and to analyze its correlation with clinical efficacy . • • • All patients provided written informed consent before enrollment . All had severe heart failure due to idiopathic or ischemic left ventricular systolic dysfunction , left ventricular ejection fraction 35 % , and end-diastolic diameter 60 mm . All patients were in sinus rhythm with a QRS interval 150 ms and no classic indication for pacemaker implantation.2 Patients had been in New York Heart Association ( NYHA ) class III for 1 month before inclusion while receiving individually optimized treatment , including diuretics and angiotensin-converting enzyme inhibitors at the maximum tolerated dose . Exclusion criteria have been already reported.1 The study included a 6-month r and omized crossover phase during which atriobiventricular ( active ) pacing was compared with inhibited ( inactive ) ventricular pacing at the basic rate of 40 beats/min , each for a period of 3 months in r and om order ( Figure 1 ) . Implantation was performed after a 1-month observation period to verify the stability of heart failure .  Pacemakers were programmed as inactive after implantation . Patients were r and omly assigned to experimental groups within the following 2 weeks after verification of pacemaker proper performance . Treatment order r and omization followed a block design with stratification according to center . The single-blind , crossover phase was followed by a complementary 6-month period during which the pacing system was programmed according to patients ’ preferences . All leads were implanted transvenously . The left ventricular lead was placed in a tributary of the coronary sinus according to a previously described method .3 Specially design ed electrodes were used . The preferred target site was the lateral wall . The pacemakers were triple-output devices using st and ard dual-chamber technology , with built-in adapters to synchronize pacing in both ventricles . Pacemakers were programmed as either active or inactive at r and omization . The baseline pacing rate was set at 40 beats/min and the upper rate limit at 85 % of the highest predictable heart rate according to patients ’ age and gender . Each patient underwent Doppler echocardiography to determine their optimal atrioventricular delay ( electrical delay between atrial and ventricular excitation ) during atriobiventricular pacing . No modification of medical treatment except diuretic dose adjustment was permitted between enrollment and the end of the crossover phase of the study . Twenty-four-hour ambulatory electrocardiograms with a 2-channel recorder ( ELA Medical , le PlessisRobinson , France ) were obtained in all subjects during normal activity at baseline , at r and omization , at the end of each of the 2 crossover periods , and at the end of each longitudinal follow-up period ( 9 and 12 months ) . Tapes were replayed through a Elatec analyzer ( ELA Medical ) . HRV analysis used specifically vali date d software.4 Ambulatory electrocardiographic recordings  that lasted 16 hours and whose analyzable proportion was 90 % were excluded to avoid bias linked to HRV circadian variations . After initial arrhythmia analysis and editing , the remaining normal-to-normal RR intervals in suitable recordings were measured and HRV time-domain analyses were performed according to published guidelines .5 For the purpose s of this study , 4 different time-domain HRV indexes were measured : ( 1 ) the SD of the normal-to-normal ( NN ) interval over the recording duration ( SDNN ) ; ( 2 ) the SD of the 5-minute mean NN interval over the entire recording ( SDANN [ milliseconds ] ) . Because SDANN values are obtained from successive 5-minute periods , they reflect heart rate changes caused by 5-minute cycles . They reflect long-term variations but provide no short-term variability data ; ( 3 ) the square root of the mean squared successive differences between adjacent RR intervals over the entire recording ( rMSSD [ milliseconds ] ) . This correlates more with the parasympathetic ( vagal ) activity ; ( 4 ) proportion of successive interval differences 50 ms as computed over the entire recording ( pNN50 [ percent ] ) . This also reflects parasympathetic activity . From the Departement de Cardiologie et Maladies Vasculaires , Centre Cardio-Pneumologique , Hopital Pontchaillou-CHU , Rennes , France . Dr. Daubert ’s address is : Departement de Cardiologie et Maladies Vasculaires , Centre Cardio-Pneumologique , Hopital PontchaillouCHU , 35033 Rennes Cedex , France . E-mail : jean-claude . daubert@chu-rennes.fr . Manuscript received August 23 , 2002 ; revised manuscript received and accepted January 23 , 2003 AIMS To evaluate the effect of beta-blockers in children with long QT syndrome ( LQTS ) we review ed the outcome of 122 patients ( pts ) . METHODS LQTS was diagnosed in 24 neonates and in 98 pts aged 0.5 - 15 years . Diagnosis was made because of syncope in 51 pts , bradycardia in 10 neonates and family history in 61 pts . The longest QTc ranged from 400 to 700 ms . Thirteen pts had 2:1 atrioventricular block and /or ventricular arrhythmias . Screening for mutations was performed in 118 pts . All children were treated with beta-blockers , annually checked by exercise testing and /or 24 h ECG monitoring . RESULTS Four pts died . Survivors were followed-up for 1 - 18 years ( 7.5 + /- 5.3 years ) . Five neonates and 3 older pts received a  prophylactic pacemaker  ( 1 death ) so that only 111/122 pts survived and were followed-up with beta-blockers alone . None of them died and five experienced a non-fatal cardiac event . There was no cardiac event among pts who were diagnosed because of familial history and among symptomatic KCNQ1 pts who were effectively treated with beta-blockers . CONCLUSION The outcome of children with LQTS under effective beta-blockers is favourable . Persisting arrhythmia or symptoms despite beta-blockers should aim at identifying other genotypes than KCNQ1 OBJECTIVES The aim of our study was to evaluate the feasibility , the safety , and hemodynamic improvements induced by permanent para-Hisian pacing in patients with chronic atrial fibrillation and narrow QRS who underwent atrioventricular ( AV ) node ablation . BACKGROUND Right ventricular apical pacing , inducing asynchronous ventricular contraction , may impair cardiac function ; permanent para-Hisian pacing could preserve interventricular synchrony and improve left ventricular function . METHODS After AV node ablation , 16 patients were implanted with a dual-chamber pacemaker  connected to a screw-in lead positioned in close proximity to the His bundle and to a right ventricular apical lead . Clinical and echocardiographic data were collected at baseline and after two r and omized six-month periods ( with para-Hisian and conventional pacing ) . RESULTS During para-Hisian pacing , the interventricular electromechanical delay improved as well ( 34 + /- 18 ms ) as during right apical pacing ( 47 + /- 19 ms ) , p < 0.05 . Para-Hisian pacing allowed an improvement in New York Heart Association functional class ( 1.75 + /- 0.4 vs. 2.33 + /- 0.6 at baseline and 2.5 + /- 0.4 during apical pacing , p < 0.05 for both ) , in quality -of-life score ( 16.2 + /- 8.7 vs. 32.5 + /- 15.0 at baseline , p < 0.05 ) , and in the 6-min walk test ( 431 + /- 73 m vs. 378 + /- 60 m at baseline and 360 + /- 71 m during apical pacing , p < 0.5 for both ) . Mitral and tricuspid regurgitation improved during para-Hisian pacing ( 1.22 + /- 0.8 and 1.46 + /- 0.5 index , respectively , vs. 1.68 + /- 0.6 [ p < 0.05 ] and 1.62 + /- 0.7 [ p = NS ] index at baseline , respectively ) , with a slight worsening during apical pacing ( 1.93 + /- 1 and 1.93 + /- 0.7 index , respectively , p < 0.05 for both ) . CONCLUSIONS Permanent para-Hisian pacing is feasible and safe . Compared with conventional right apical pacing , it allows an improvement in functional and hemodynamic parameters over long-term follow-up BACKGROUND Right ventricular ( RV ) apical pacing deteriorates left ventricular ( LV ) function . RV nonoutflow ( low ) septal pacing may better preserve ventricular performance , but this has not been systematic ally tested . Our aim was to assess ( 1 ) whether long-term RV lower septal pacing is superior to RV apical pacing regarding LV volumes and ejection fraction ( EF ) , and ( 2 ) if the changes in LV dyssynchrony imposed by pacing are related to the long-term changes in LV volumes and EF . METHODS In thirty-six patients with atrioventricular ( AV ) block , a dual-chamber pacemaker was implanted . The ventricular electrode was placed either at the apex or at the lower septum , in a r and omized sequence . Twenty-four to 48 hours following implantation , we measured LV volumes , EF , and LV dyssynchrony ( by tissue Doppler imaging ) , both with and without pacing . Patients were reassessed echocardiographically after 12 months . RESULTS Lower septal pacing induced a more synchronized pattern of LV contraction changes ( P < 0.05 ) . Following 12 months , differences were observed between groups regarding LV volumes and EF . EF increased within the septal group ( from 52 + /- 3.3 % to 59 + /- 3.0 % , P < 0.05 ) . A significant inverse relation was documented between changes in LV dyssynchrony and changes in EF ( r = -0.64 , P < 0.05 ) . CONCLUSIONS In patients with AV block , RV nonoutflow septal pacing represents an attractive alternative , since it preserves better and may even improve LV volumes and EF . Late changes in EF are associated with the changes in LV dyssynchrony imposed by pacing The purpose of this study was to evaluate the effects of atrioventricular junction radiofrequency ablation on the quality of life , exercise performance , and echocardiographic parameters in 23 patients with chronic , severely symptomatic , drug-refractory atrial fibrillation or flutter . Initially , patients were r and omized to receive ablation plus pacemaker therapy ( n = 12 ) or pacemaker therapy alone ( n = 11 ) . After 15 days , palpitations decreased by 92 % and 37 % ( p = 0.004 ) , rest dyspnea by 79 % and 40 % ( p = NS ) , effort dyspnea by 65 % and 30 % ( p = 0.03 ) , exercise intolerance by 54 % and 17 % ( p = 0.005 ) , and asthenia by 67 % and 31 % ( p = 0.02 ) in the 2 groups , respectively . At the end of this short-term study , control patients also underwent ablation therapy , and a 3-month intrapatient follow-up study was performed in 22 patients . New York Heart Association functional class > or = 3 was present in 14 patients ( 64 % ) before , but in only 3 patients ( 14 % ) after ablation therapy ( p = 0.002 ) ; specific activity scale functional class > or = 3 was present in 9 patients ( 41 % ) before , but in only 5 ( 23 % ) after ablation therapy ( p = NS ) . Exercise duration during st and ardized stress testing increased by a mean of 63 + /- 93 seconds ( 15 % increase ) ( p = 0.001 ) . In the 9 patients with depressed left ventricular systolic function , echocardiographic fractional shortening increased by 34 % ( from 23 + /- 5 % to 31 + /- 9 % ) ( p = 0.003 ) . In the remaining 13 patients with normal systolic function , fractional shortening decreased by 10 % ( from 40 + /- 5 % to 36 + /- 6 % ) ( p = 0.05 ) . ( ABSTRACT TRUNCATED AT 250 WORDS OBJECTIVE To determine the importance of rhythm regulation or rate control in patients with permanent atrial fibrillation ( AF ) and normal left ventricular function . PATIENTS AND INTERVENTIONS Thirty six patients with a mixed fast and slow ventricular response rate to their AF were  r and omised to either His bundle ablation ( HBA ) and VVIR pacemaker ( HBA group ) or VVI pacemaker and atrioventricular modifying drugs ( Med group ) . Outcomes assessed at one , three , six , and 12 months included exercise duration and quality of life . RESULTS Exercise duration significantly improved from baseline in both groups . There was no difference in outcome between the groups ( Med + 40%v HBA + 20 % , p = NS ) . The heart rate profile on exercise was similarly slowed in both groups compared to baseline . Quality of life significantly improved in both treatment arms for the modified Karolinska question naire ( KQ ) ( Med + 50%v HBA + 50 % , p = NS ) and the Nottingham health profile ( NHP ) ( Med + 40 % v HBA + 20 % , p = NS ) . However , for the individual symptom scores of each question naire more were improved in the Med group ( KQ-Med 6 improvedv HBA 4 , NHP-Med 3 vHBA 1 ) . Left ventricular function was equally preserved by both treatments during follow up . CONCLUSION In these patients control of ventricular response rate with either HBA + VVIR pacemaker or atrioventricular modifying drugs + VVI pacemaker will lead to a significant improvement in exercise duration and quality of life . Rhythm regulation by HBA did not confer additional benefit , suggesting rate control alone is necessary for the successful symptomatic treatment of these patients in permanent AF In 19 patients paced and medicated for bradycardia tachycardia syndrome ( BTS ) , AAIR and DDDR pacing were compared with regard to quality of life ( QoL ) , atrial tachyarrhythmia ( AFib ) , exercise tolerance , and left ventricular (LV)function .  Patients had a PQ interval < or = 240 ms during sinus rhythm , no second or third degree AV block , no bundle branch block , or bifascicular block . In DDDR mode , AV delay was optimized using the aortic time velocity integral . After 3 months , QoL was assessed by question naires , patients were investigated by 24-hour Holter , cardiopulmonary exercise testing ( CPX ) was performed , and LV function was determined by echocardiography .  QoL was similar in all dimensions , except dizziness , showing a significantly lower prevalence in AAIR mode . The incidence of AFib was 12 episodes in 2 patients with AAIR versus 22 episodes in 7 patients with DDDR pacing ( P = 0.072 ) . In AAIR mode , 164 events of second and third degree AV block were detected in 7 patients ( 37 % ) with pauses between 1 and 4 seconds . During CPX , exercise duration and work load were higher in AAIR than in DDDR mode ( 423+/-127 vs 402+/-102 s and 103+/-31 vs 96+/-27 Watt , P < 0.05 ) . Oxygen consumption ( VO2 ) , was similar in both modes . During echocardiography , only deceleration of early diastolic flow velocity and early diastolic closure rate of the anterior mitral valve leaflet were higher in DDD than in AAI pacing ( 5.16+/-1.35 vs 3.56+/-0.95 m/s2 and 69.2+/-23 vs 54.1+/-26 mm/s , P < 0.05 ) . As preferred pacing mode , 11 patients chose DDDR , 8 patients chose AAIR . Hence , AAIR and DDDR pacing seem to be equally effective in  BTS patients . In view of a considerable rate of high degree AV block during AAIR pacing , DDDR mode should be preferred for safety reasons Background Predictors for the need of  permanent pacemaker implantation  ( PPMI ) in the context of transcatheter aortic valve implantation ( TAVI ) are not well defined yet . We evaluated the impact of conduction disturbances , calcium volume of the device l and ing zone , oversizing and implantation depth on PPMI after TAVI with the balloon-exp and able Edwards Sapien 3 ( ES3 ) . Methods and results 335 consecutive patients undergoing transfemoral TAVI with the ES3 for the treatment of symptomatic severe aortic stenosis were included ( clinical trials NCT02162069 ) . Rate of PPMI after TAVI was 18.4 % , excluding patients with permanent pacemakers prior to TAVI or valve-in-valve implantations . Patients requiring PPMI more often had first degree atrioventricular block ( AVB ) at baseline ( 48.7 vs. 16.5 % , p < 0.01 ) , preprocedural complete right bundle branch block ( RBBB ; 25.0 vs. 3.9 % , p < 0.01 ) and higher calcium volume of the aortic valve ( 258.5 ± 317.3 vs. 163.6 ± 178.8 mm³ , p < 0.01 ) . There was a trend towards higher rate of PPMI in patients with new-onset left bundle branch block after TAVI ( 32.7 vs. 20.7 % , p = 0.06 ) . Multivariate logistic regression analysis showed that baseline first degree AVB ( odds ratio 3.9 , 95 % confidence interval 1.73–9.10 , p < 0.01 ) and preprocedural complete RBBB ( odds ratio 4.5 , 95 % confidence interval 1.50–13.21 , p < 0.01 ) were independent predictors of PPMI . Of note , neither oversizing nor implantation depth were independent predictors for need of PPMI with the ES3 . Conclusions In patients treated with the ES3 for symptomatic severe aortic stenosis first degree AVB and complete RBBB at baseline were independently associated with higher rates of postprocedural PPMI , whereas implantation depth and oversizing did not have an impact on PPMI
No statistically significant difference was found between the pacing modes for mortality , heart failure , stroke , chronic atrial fibrillation or quality of life .
However , the risk of developing heart failure may vary with age and device .
The risk of heart failure may have an impact on the decision to use dual-chamber or single-chamber atrial pacemakers .
Results from an analysis based on age ( > 75 years or ≤ 75 years ) and risk of heart failure indicate that dual-chamber pacemakers dominate single-chamber atrial pacemakers ( i.e. are less expensive and more effective ) in older patients , whereas dual-chamber pacemakers are dominated by ( i.e. more expensive and less effective ) single-chamber atrial pacemakers in younger patients .
In patients with SSS without evidence of impaired AV conduction , dual-chamber pacemakers appear to be cost-effective compared with single-chamber atrial pacemakers .
BACKGROUND Bradycardia [ resting heart rate below 60 beats per minute ( b.p.m . ) ]
can be caused by conditions affecting the natural pacemakers of the heart , such as sick sinus syndrome ( SSS ) and atrioventricular ( AV ) blocks .
People suffering from bradycardia may present with palpitations , exercise intolerance and fainting .
The only effective treatment for patients suffering from symptomatic bradycardia is implantation of a permanent pacemaker .
OBJECTIVE To appraise the clinical effectiveness and cost-effectiveness of dual-chamber pacemakers compared with single-chamber atrial pacemakers for treating symptomatic bradycardia in people with SSS and no evidence of AV block .