Clinical significance of noninvasive recordings of micropotentials of the heart--experience over a two years' period.

To assess the risk of malignant ventricular tachycardia (VT) and sudden cardiac death, clinical data including Holter monitoring, programmed ventricular stimulation and highly amplified signal averaged ECG were employed. Among 394 patients, 175 had late potentials. Close correlations were demonstrated between the presence, duration and voltage of late potentials and left ventricular function disturbances, arrhythmia profile, presence and frequency of VT. Signal averaging contributes to better identification of patients at risk. During a mean follow-up of two years 32 patients died, 20 suddenly. 17 of the latter had late potentials of long duration and 12 previous ventricular tachycardia. The predictive value of LP is superior to the other methods used.