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Effects of pacing modes on cardiac baroreflex function in permanently paced patients with sinus node dysfunction
Takuo Tsurugi1, Haruhiko Abe, Yasushi Oginosawa
1The Second Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Journal of Cardiovascular Electrophysiology
|February 21, 2008
Summary
In sick sinus syndrome patients, VVI pacing significantly reduces baroreceptor-stroke volume reflex sensitivity compared to AAI or DDD pacing. Maintaining atrioventricular synchrony is crucial for preserving this reflex in pacemaker recipients.
Area of Science:
- Cardiology
- Autonomic Nervous System Function
- Medical Device Technology
Background:
- Impaired autonomic function, indicated by reduced baroreceptor-heart rate reflex sensitivity, is linked to sudden cardiac death.
- The impact of different pacemaker pacing modes on autonomic function in sick sinus syndrome (SSS) patients remains unclear.
- Chronotropic incompetence in SSS patients complicates direct evaluation of baroreceptor-heart rate reflex sensitivity.
Purpose of the Study:
- To compare the effects of AAI, DDD, and VVI pacing modes on baroreceptor-stroke volume (BR-SV) reflex sensitivity in patients with sick sinus syndrome.
- To assess the correlation between BR-SV reflex sensitivity and baroreceptor-heart rate (BR-HR) reflex sensitivity.
Main Methods:
- Twelve dual-chamber pacemaker recipients with sick sinus syndrome were studied.
- Beat-by-beat blood pressure and stroke volume were measured during 5-minute intervals of AAI, DDD, and VVI pacing.
- Spectral analysis was employed to evaluate baroreceptor-stroke volume reflex sensitivity.
Main Results:
- Systolic blood pressure was significantly lower during VVI pacing (109 +/- 24 mmHg) compared to DDD (124 +/- 22 mmHg) and AAI (125 +/- 41 mmHg) pacing.
- Stroke volume was significantly reduced with VVI pacing (36 +/- 23 mL) versus DDD pacing (49 +/- 31 mL).
- Baroreceptor-stroke volume reflex sensitivity was significantly lower during VVI pacing (9.3 +/- 5.7% per mmHg) compared to DDD (15.0 +/- 6.5% per mmHg) and AAI (15.5 +/- 6.2% per mmHg) pacing.
Conclusions:
- VVI pacing significantly diminishes baroreceptor-stroke volume reflex sensitivity in pacemaker recipients with sick sinus syndrome.
- AAI and DDD pacing modes preserve baroreceptor-stroke volume reflex sensitivity better than VVI pacing.
- Atrioventricular synchrony is identified as a critical factor in maintaining baroreceptor-stroke volume reflex sensitivity in pacemaker recipients.
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