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. 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. Cross sectional comparative study. Armed Forces Institute of Cardiology [AFIC]/National Institute of Heart Diseases, Rawalpindi and Army Medical College, Rawalpindi, Pakistan 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. 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. Combined effects of high resolution ECG, holter monitoring and leaflet geometry identified the high risk subset, comprising of 2.7% of the study population