Differentiation between late potentials of right ventricular and of left ventricular origin

Abstract

The aim of this study was to determine whether late potentials of right and left ventricular origin could be differentiated with the use of a signal-averaging technique. Nineteen patients with both late potentials and recurrent sustained ventricular tachycardia were divided into 2 groups according to the origin of their late potentials. Group I consisted of 10 patients with late potentials that originated from the right ventricle. Group II consisted of 9 patients with late potentials originating from the left ventricle. Signal-averaged electrocardiograms (Marquette Electronics MAC I unit) were recorded using 3 bipolar and 3 augmented unipolar leads (the electrode positions were V 1, V 5 and V 6R) with a band-pass filter of 100 to 300 Hz. The augmented unipolar V 5 lead (aV 5) was used for left-side recording and the augmented unipolar V 1 lead (aV 1) was used for right-side recording. In group I, the mean maximal late potential amplitude was larger in lead aV 1 than in lead aV 5 (5.1 ± 2.5 vs 3.7 ± 1.8 μV, p < 0.005) and the maximal late potential amplitude was larger in lead aV 1 in all except 1 patient. In group II, however, the mean maximal late potential amplitude was smaller in lead aV 1 than in lead aV 5 (4.0 ± 3.0 vs 5.7 ± 3.2 μV, p <0.005) and the maximal late potential amplitude was smaller in lead aV 1 in all patients. Thus, the origin of late potentials (right ventricular vs left ventricular origin) can be determined by comparing the maximal amplitudes of late potentials in the right- and left-sided leads. This method might be useful in determining ventricular tachycardia origins.