Effects of left ventricular hypertrophy on the signal-averaged electrocardiogram

Abstract

Signal-averaged electrocardiography (SAECG) has made possible the identification of late potentials in patients at risk of developing malignant ventricular arrhythmias. 1–9 Late potentials have been shown to predict sudden cardiac death, 3,4 clinical ventricular tachycardia, 1,3–6 and ventricular tachycardia that is inducible with programmed electrical stimulation. 8–10 Sudden cardiac death 11,12 and ventricular arrhythmias 13–19 are more prevalent in patients with echocardiographic left ventricular (LV) hypertrophy. Late potentials might be useful in identifying a subgroup of patients with LV hypertrophy who are at high risk to experience clinical ventricular tachycardia or sudden cardiac death. However, patients with LV hypertrophy may have intraventricular conduction disturbances and repolarization abnormalities that may interfere with the ability of SAECG to accurately detect late potentials. To evaluate the use of SAECG in patients with LV hypertrophy, we examined 58 patients with SAECG, echocardiography and programmed electrical stimulation. In this study, we compare the clinical characteristics, SAECG findings and electrophysiology results of a group of patients with echocardiographic LV hypertrophy to a group of patients without echocardiographic LV hypertrophy.