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 .
Comparison of ventricular function in atrial rate adaptive versus dual chamber rate adaptive pacing during exercise.
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
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 .