ARRHYTHMOGENESIS IN MITRAL VALVE PROLAPSE

RISK STRATIFICATION – ROLE OF HIGH RESOLUTION ECG, HOLTER MONITORING AND MITRAL LEAFLET GEOMETRY

Abstract

Mitral valve prolapse is generally considered a benign condition, however, a
subset of patients remains at high risk of arrhythmogenesis which may lead to sudden cardiac
death. Objective: To stratify risk of arrhythmogenesis in patients with mitral valve prolapse
on the basis of high resolution ECG, Holter monitoring, resting heart rate and mitral leaflet
geometry. Study Design: Cross sectional comparative study. Place of study: Armed Forces
Institute of Cardiology (AFIC)/National Institute of Heart Diseases, Rawalpindi and Army Medical
College, Rawalpindi, Pakistan Methodology: Mitral leaflet displacement and thickness were
measured on echocardiography in 37 patients with mitral valve prolapse. Resting heart rate
and time domain indices of heart rate variability of each patient were recorded from 24 hours
Holter monitoring. High resolution ECG of all the patients was carried out to record ventricular
late potentials. Statistical analysis was performed using SPSS and the alpha value was set at
<0.05 for significance. Results: The mean values for resting heart rate, leaflet displacement and
leaflet thickness were 77.19±6.29 per minute, 3.64±0.92 mm and 4.96±0.79 mm respectively.
Ventricular late potentials were present in 8 (21.62%) whereas heart rate variability was reduced
in 5 (13.51%) patients. Leaflet thickness was significantly greater in patients with ventricular
late potentials as compared to those without (p-value 0.004). Patients with reduced heart rate
variability had significantly higher resting heart rate as compared to those with normal variability
(p-value 0.02). One patient (2.7%) had ventricular late potentials, reduced heart rate variability,
resting heat rate of 88 beats per minute and leaflet thickness over 5 mm. Conclusions:
Combined effects of high resolution ECG, holter monitoring and leaflet geometry identified the
high risk subset, comprising of 2.7% of the study population.