ELECTROCARDIOGRAPHIC ABNORMALITIES IN MITRAL-VALVE PROLAPSE

A number of electrocardiographic findings associated with mitral valve prolapse (MVP) have been reported. The most frequent finding is inversion of T waves in the inferior leads,1-7 which was first described by Humphries and McKusick7 in patients with late systolic murmurs. The association with MVP was not yet known, and they suggested the term "auscultatory-electrocardiographic syndrome." Other electrocardiographic abnormalities have been reported to consist of ST abnormalities8 and variable degrees of intraventricular conduction delay, including frank bundle branch block (BBB).3,4 Jeresaty4 found a 6% incidence of incomplete right BBB in the absence of atrial septal defects. The incidence of incomplete right BBB was 8% in another study3; 3% had associated atrial septal defect. Prolongation of the QT interval in MVP was also noted in several studies.3,5,8-11 Meyers et al9 described an increased frequency of QT prolongation in symptomatic patients with MVP compared with in asymptomatic patients, but this difference was not statistically significant. The diagnosis of MVP in many of these studies was primarily obtained by auscultation or based on clinical grounds, or both. Furthermore, in no study that described electrocardiographic findings was a comparison performed with a group of normal subjects. In the present study, we quantify the frequently described electrocardiographic abnormalities in patients in whom the diagnosis of MVP was documented by 2-dimensional echocardiography. These results were compared with those of a control group of patients with completely normal echocardiograms. © 1992.