ARRHYTHMOGENESIS IN MITRAL VALVE PROLAPSE

Abstract

Mitral valve prolapse is generally considered a benign condition, however, asubset of patients remains at high risk of arrhythmogenesis which may lead to sudden cardiacdeath. Objective: To stratify risk of arrhythmogenesis in patients with mitral valve prolapseon the basis of high resolution ECG, Holter monitoring, resting heart rate and mitral leafletgeometry. Study Design: Cross sectional comparative study. Place of study: Armed ForcesInstitute of Cardiology (AFIC)/National Institute of Heart Diseases, Rawalpindi and Army MedicalCollege, Rawalpindi, Pakistan Methodology: Mitral leaflet displacement and thickness weremeasured on echocardiography in 37 patients with mitral valve prolapse. Resting heart rateand time domain indices of heart rate variability of each patient were recorded from 24 hoursHolter monitoring. High resolution ECG of all the patients was carried out to record ventricularlate 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 andleaflet 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 reducedin 5 (13.51%) patients. Leaflet thickness was significantly greater in patients with ventricularlate potentials as compared to those without (p-value 0.004). Patients with reduced heart ratevariability 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 thehigh risk subset, comprising of 2.7% of the study population.