Alteration of Ventricular Fibrillation by Flecainide, Verapamil, and Sotalol

Background—The purpose of this study was to determine whether the myocardial electrophysiological properties are useful for predicting changes in the ventricular fibrillatory pattern. Methods and Results—Thirty-two Langendorff-perfused rabbit hearts were used to record ventricular fibrillatory activity with an epicardial multiple electrode. Under control conditions and after flecainide, verapamil, or d,l-sotalol, the dominant frequency (FrD), type of activation maps, conduction velocity, functional refractory period, and wavelength (WL) of excitation were determined during ventricular fibrillation (VF). Flecainide (1.9±0.3 versus 2.4±0.6 cm, P<0.05) and sotalol (2.1±0.3 versus 2.5±0.5 cm, P…