[Electrophysiologic effects of lorcainide (R 15889) in man]

The electrophysiological effects of lorcainide (R 15 899) were studied in 15 patients. Atrioventricular conduction was analysed by His bundle recording and cardiac refractory periods were determined by the extra stimulus method. The assessment of sino atrial function was performed by measuring sinus node recovery times and sino atrial conduction times. The electrophysiological data was recorded before and 10 minutes after a slow intravenous injection of 1,5 mg/Kg of lorcainide followed by a continuous infusion at 0,02 mg/Kg/min. The following results were obtained; 1) The HV interval increased in all cases (average : II ms) 2) The QRS and QT intervals were significantly prolonged 3) Lorcainide produced a slowing of conduction and an increase in the refractory periods at atrial level 4) AV nodal conduction was unaffected 5) The sinus rate slightly increased. There were no significant changes in sinus node recovery time or sino atrial conduction. It must be concluded that, in man, lorcainide produces electrophysiological effects of antiarrhythmic agents of the quinidine type.