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
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
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 .