Analysis of the proarrhythmic action of lidoflazine (Clinium).

The mechanism of the proarrhythmic action of the Na+ and Ca++ channel blocking agent lidoflazine (Clinium) in animal experiments was analysed. Lidoflazine pretreatment was found to increase the electrically induced atrial fibrillatory threshold in the intact cat, but to decrease this parameter in the ventricular heart muscle. The changes induced by lidoflazine in the ventricular repolarization of the normoxic dog heart (T wave flattening, appearance of prominent U waves, T-U fusion, QT/QTU prolongation) are considered to be proarrhythmic ECG signs.