Repolarization alternans (RPA) and late potentials (LP) predict arrhythmic events following myocardial infarction

In a study of 102 patients with a prior myocardial infarction (MI) followed for 13 months, the combination of repolarization alternans (RPA) and late potentials (LP) on a signal averaged ECG had a specificity and negative predictive value for an arrhythmic event of 91 and 92 percent, respectively. However, the positive predictive value was only 50 percent. The very low event rate in the group "RPA negative and LP positive" may be due to the small number of patients in this subset (n = 5).