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 .
Clinical and quality of life comparison of accelerometer, piezoelectric crystal, and blended sensors in DDDR-paced patients with sinus node dysfunction in the mode selection trial (MOST).
INTRODUCTION Permanent pacemakers are capable of increasing heart rate in response to physical activity by a variety of sensors including accelerometers , piezoelectric crystals , or blended sensors . The impact of these different physiologic sensors on cardiovascular events and quality of life is not known . METHODS Of 2,010 patients r and omized in the Mode Selection Trial , 1,245 patients were selected with the most commonly used pacemakers with these three sensors .  Clinical characteristics and quality of life were compared between groups at baseline , 3 months , and then yearly . RESULTS There were 449 patients with an accelerometer sensor device  , 682 with a piezoelectric sensor  , and 114 with a blended sensor . The groups were similar in terms of age ( mean 74 years ) , gender , and cardiac risk factors but differences existed in weight , heart rate , mitral regurgitation , revascularization history , and drug therapy . The median ventricular pacing frequency was 80 % ( 25th , 75th percentiles 42 , 97 ) . After a median follow-up of 33.1 months , the risk of death , heart failure hospitalization , atrial fibrillation , and the combined endpoint of mortality and stroke was not significantly different between the sensor types , after adjustment for baseline differences . Quality of life analyses demonstrated that patients with blended sensors had significantly worse ( P < 0.01 ) physical function than did patients with the other two sensor systems . Moreover , patients receiving blended sensors had the poorest absolute scores , without reaching statistical significance , on 9 of 13 quality of life measures after adjusting for differences in the groups . CONCLUSION We found no significant differences among the three most utilized sensors in clinical endpoints . Those patients who received blended sensors had worse physical function quality of life scores . However , clinical selection of the most sophisticated sensor for the most ill patients can not be excluded as an explanation of these results
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 .