[Effects of lorcainide, a new antiarrhythmic agent, on experimental cardiac arrhythmias]

Antiarrhythmic actions of lorcainide were compared with those of disopyramide on different types of arrhythmias in animal models. It was shown in dogs that lorcainide and disopyramide were approximately equipotent against the arrhythmias following coronary occlusion. In guinea pigs, lorcainide was less effective than disopyramide against the ouabain-induced arrhythmia. Both drugs showed a weak protective action against the aconitine-induced ventricular arrhythmias, but had no effect on the cardiac arrest. In the arrhythmias induced by the application of acetylcholine on the right auricle of guinea pigs, the disappearance of P-waves and the disturbance of R-R intervals were inhibited by disopyramide, but lorcainide had no influence on these events; both prevented the atrial fibrillation induced by acetylcholine application. Both drugs by themselves induced ventricular arrhythmias in guinea pigs.