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[Chronotropic competence in patients with the sick sinus syndrome wearing AAI or DDD pacemakers]
A Goicolea de Oro1, L Márquez, M López Gil
1Servicio de Cardiología, Hospital Universitario de Getafe, Madrid.
Insights
Most patients with sinus node disease (SND) and pacemakers can increase heart rate during exercise. Rate-responsive pacing is only needed for a few patients with true chronotropic incompetence.
Area of Science:
- Cardiology
- Electrophysiology
- Pacemaker Technology
Background:
- Sinus node disease (SND) is common, but the prevalence of chronotropic incompetence in these patients is not well-defined.
- Patients with SND often receive permanent pacemakers (AAI/DDD).
Purpose of the Study:
- To assess the prevalence of chronotropic incompetence in patients with SND and permanent pacemakers.
- To determine the appropriateness of rate-responsive pacing in this population.
Main Methods:
- Evaluated 18 patients with SND and permanent pacemakers (AAI/DDD) using Holter monitoring and treadmill stress tests.
- Compared results with a control group of 33 individuals without organic heart disease.
- Assessed maximal heart rate, heart rate response during activity, and exercise tolerance (METs).
Main Results:
- Most pacemaker patients increased their heart rate above the basic programmed rate during ambulatory activity.
- Maximal heart rate during treadmill testing was similar between pacemaker patients (131 +/- 25 bpm) and controls (138 +/- 14 bpm).
- Exercise tolerance (METs) was also comparable between groups (pacemakers: 5.2 +/- 2.6; controls: 5.8 +/- 1.2).
- Only 12% of pacemaker patients failed to reach 100 bpm during stress testing.
Conclusions:
- The majority of patients with SND and permanent pacemakers can adequately increase their heart rate during exercise.
- Rate-responsive pacing (AAIR/DDDR) should be reserved for a small subset of patients with genuine chronotropic incompetence.
Abstract:
The prevalence of chronotropic incompetence in patients with sinus node disease (SND) is not well defined. To assess this, we evaluated 18 patients (7 men, 11 women; mean age: 64 +/- 11) with SND and permanent pacemakers (AAI/DDD) with Holter monitoring and treadmill stress test. Only 2 patients received active cardiac drugs (1, L-dopa an 1 propafenone). The treadmill tests results were compared with a control group of 15 men and 18 women (mean age: 66 +/- 5, p = NS) without organic heart disease. During ambulatory activity all pacemaker patients increased their own cardiac rate to a value higher than the programmed basic pacemaker rate. In 8 patients the maximal rate attained was over 100/min (mean 95 +/- 19/min). The maximal rate during treadmill test in pacemaker patients was 131 +/- 25 (control group 138 +/- 14, p = NS). Exercise tolerance in METs was similar in pacemaker patients (5.2 +/- 2.6) and in controls (5.8 +/- 1.2) (p = NS). Two pacemaker patients (12%) didn't reach 100/min during stress test. Most patients with SND and permanent pacemakers (AAI/DDD) are able to increase cardiac rate during exercise. Rate responsive pacing (AAIR/DDDR) should be limited to a minority of patients with true chronotropic incompetence.