Repolarization abnormalities in mitral valve prolapse.

Inferolateral ST depression, T wave inversion, and QT prolongation have been frequently described in reports of largely symptomatic mitral valve prolapse (MVP) patients, but not in a recent population-based survey of mainly asymptomatic subjects with MVP. To learn if there is a relationship between these ECG changes and symptoms, physical findings or hemodynamic sequelae, we reviewed ECGs from 119 patients, ages 18 to 60 years who had MVP diagnosed by echocardiography. Seventy-four percent had symptoms characteristic of MVP. ST-T changes were found as frequently in asymptomatic patients (29%) as in those symptomatic (27%), and did not identify those with hemodynamic sequelae of MVP (apical systolic murmurs, Doppler-defined mitral regurgitation, or left atrial enlargement). QT prolongation was found more frequently in the symptomatic group (25% vs 10%) but did not predict syncope. When compared to the expected 0.9% prevalence of ST abnormalities in a normal population, ST-T changes and QT prolongation are indeed frequent in MVP, but are not useful in identifying clinically important subsets.