[New antiarrhythmia agents: propafenone and flecainide].

The electrophysiological and antiarrhythmic properties of two new drugs, propafenone and flecainide, are distinctly different from those of known products of the same therapeutic category. Compared with other class I (membrane-stabilising) antiarrhythmic agents, propafenone exerts a beta-adrenergic inhibitory effect which may be clinically useful, and flecainide has a stronger depressant effect on intraventricular conduction. There is no prolongation of Q-T nor any risk of wave burst arrhythmia with either of these drugs. Their antiarrhythmic activities are superior to those of class I compounds currently available and they can be combined with amiodarone, which considerably potentializes these activities. Their extracardiac side-effects are rarely limitating. However, their intracardiac side-effects on the sinus node an on distal conduction may result in disorders of conduction or severe drug induced arrhythmia in patients with fragile conduction system or cardiac failure.