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 .
Pacemaker implantation and quality of life in the Mode Selection Trial (MOST).
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
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 .