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Abnormalities of ventricular repolarization in mitral valve prolapse
Sophie Digeos-Hasnier1, Xavier Copie, Olivier Paziaud
1Department of Cardiology, Georges Pompidou Hospital, Pierre and Marie Curie University, Paris, France.
Summary
Mitral valve prolapse (MVP) is linked to increased QT intervals and altered nocturnal heart rate dependence, suggesting abnormal ventricular repolarization. These findings may explain the higher risk of arrhythmias in MVP patients.
Area of Science:
- Cardiology
- Electrophysiology
- Autonomic Nervous System
Background:
- Mitral valve prolapse (MVP) is associated with increased risk of arrhythmias and sudden cardiac death.
- Autonomic nervous system (ANS) abnormalities are suspected contributors to MVP-related arrhythmias.
Purpose of the Study:
- To investigate the autonomic profile of patients with MVP using Holter monitoring.
- To assess heart rate variability (HRV) and QT dynamicity in MVP patients and controls.
Main Methods:
- A 24-hour Holter ECG was performed on 30 MVP patients and two control groups (30 healthy relatives, 31 healthy volunteers).
- Analysis focused on heart rate variability (HRV) and QT interval dynamics, including rate dependence of ventricular repolarization (QT-RR slope).
Main Results:
- No significant differences in HRV (SDNN, rMSSD) were observed among the groups.
- Patients with MVP exhibited significantly increased QT interval duration compared to both control groups.
- Nocturnal ventricular repolarization showed increased rate dependence in MVP patients, indicating disturbed circadian modulation.
Conclusions:
- MVP is characterized by prolonged QT intervals and abnormal circadian modulation of ventricular repolarization, specifically increased nocturnal rate dependence.
- These repolarization abnormalities may underlie the increased risk of arrhythmic events observed in mitral valve prolapse.