Late potentials and ventricular enlargement after myocardial infarction: A new role for high-resolution electrocardiography?

Abstract

Background. Arrhythmias are common in patients who have developed ventricular enlargement after myocardial infarction. Methods and Results. A prospective study was undertaken to assess the relation between ventricular dilatation and the development of late potentials after myocardial infarction. Echocardiograms and signal-averaged ECGs were recorded on days 1, 3, 7, and 42 in 52 patients with a first anterior myocardial infarction. Twenty-nine percent of patients were late potential-positive on their initial signal-averaged ECG recorded on the day of admission. The incidence of late potentials rose during the next week to a peak of 42% at day 7, declining to 13% by day 42. The presence of late potentials on the day of admission was associated with an increase in end-diastolic volume index of 16.1±6.0 mL/m2 (mean±SEM), compared with a decrease of 4.7±2.7 mL/m2 among late potential-negative patients (P