QT Variables of Isolated Mitral Valve Prolapse

Purpose: It is thought that arrhythmias are responsible for sudden deaths in patients with mitral valve prolapse (MVP). QT intervals may predict malignant arrhythmia potential in these patients. The aim of the present study is to assess QT variables in patients with MVP. Methods : We studied 46 patients with non-rheumatic, uncomplicated and isolated MVP and 25 healthy control subjects. All individuals underwent full M-mode; two -dimensional and color-Doppler examinations. MVP was defined as superior displacement of the mitral leaflets of more than 2 mm during systole and as a maximal leaflet thickness of at least 5 mm during diastole. Maximum (QTmax), minimum (QTmin) durations, corrected QT intervals and QT dispersion were measured in every case. The results of MVP patients were compared with the data gathered from the control cases. Results: Demographic and clinical variables were similar between the two groups. Anterior mitral leaflet thickness (AMLD), maximal leaflet displacement (DMR) and degree of mitral regurgitation (DMR) were found to be significantly higher in the patient group. QTc max, QT dispersion (QTd) and corrected QT dispersion (QTcD) were also significantly higher in MVP patients. A significant and fairly strong correlation was found between QTc max, QTcD and AMLT, MLD and DMR. Conclusion: QT durations were significantly increased in patients with isolated MVP, which may explain increased incidence of ventricular arrhythmias and sudden death in this population. Furthermore QT variables were related with the mitral leaflet thickness and degree of mitral regurgitation; which means QT variables increases with the the severity of the disease.