Heart rate turbulence after ventricular pacing trains during programmed ventricular stimulation
Stepan Havranek1, Petr Stovicek, Miroslav Psenicka
12nd Department of Internal Medicine, 1st Medical School, Charles University, Prague, Czech Republic. shavr@volny.cz
Pacing and Clinical Electrophysiology : PACE
|February 17, 2007
Summary
Heart rate turbulence (HRT) after ventricular pacing is influenced by ventriculoatrial (VA) conduction and left ventricular (LV) function. Reduced vagal modulation was observed in patients with LV dysfunction.
Area of Science:
- Cardiology
- Electrophysiology
- Autonomic Nervous System
Background:
- Heart rate turbulence (HRT) is a measure of autonomic regulation.
- Ventricular pacing can influence HRT through various mechanisms.
Purpose of the Study:
- To investigate the impact of ventricular pacing train characteristics on HRT.
- To determine the role of ventriculoatrial (VA) conduction and left ventricular (LV) function in modulating HRT.
Main Methods:
- Analysis of programmed ventricular stimulation (PVS) in 82 patients.
- Measurement of sinus RR intervals and heart rate turbulence slope (HRTS) after 8-beat ventricular pacing trains (600-ms and 400-ms).
- Correlation of HRT parameters with VA conduction and LV ejection fraction (LVEF).
Main Results:
- RR interval dynamics differed based on the presence of VA conduction.
- HRT was less pronounced with 600-ms pacing compared to 400-ms pacing.
- HRTS was significantly shallower in patients with LVEF ≤ 40% compared to those with LVEF > 40% after 400-ms pacing.
Conclusions:
- HRT following ventricular pacing in patients with VA conduction involves vagal withdrawal and sinus node suppression.
- LV dysfunction is associated with attenuated vagal modulation during PVS.
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