QRS complex abnormalities in subjects with idiopathic ventricular fibrillation.

Recent data point to a high incidence of early repolarization abnormalities among patients with idiopathic ventricular fibrillation (IVF). ECG data from 11 patients with idiopathic IVF were evaluated for the presence of initial (slurring or notching of the ascending limb of the R-wave that resembles a "pseudo" delta-wave) and terminal (slurring or notching of the descending limb of the R-wave resembling the early repolarization pattern) QRS complex abnormalities in at least two contiguous leads. The control group comprised 101 age- and gender-matched healthy individuals without structural heart disease in whom the presence of an accessory pathway was excluded during electrophysiological study. Initial QRS complex abnormalities in the setting of a normal PR interval were more frequent in subjects with IVF than in control population (36.4% vs. 8.9%, p=0.023). Although not statistically significant, an early repolarization pattern was also more common among patients with IVF (27.3% vs. 12.9%, p=0.192). Among patients with IVF, there is an increased prevalence of initial and terminal QRS complex abnormalities.