Electrophysiological Effect of Falipamil (AQA-39), A New Bradycardic Agent.

The electrophysiological properties of falipamil (AQA-39), a new antiarrhythmic agent with bradycardic effect, were evaluated in 12 patients. Intravenous falipamil (1.5 mg/kg within 20 minutes) significantly prolonged sinus cycle length (control, 862 ± 148 msec; Falipamil, 941 ± 170 msec). The PR interval was significantly shorter due to AH interval shortening (P < 0.004). The antegrade Wenckebach point occurred at a higher rate. These findings were ascribed to an anticholinergic effect. The major electrophysiological findings included significant prolongation of the refractory periods of atrium and ventricle, whereas those of the AV node were not affected. Retrograde ventriculoatrial conduction present in 8 patients was not altered. In conclusion falipamil prolongs sinus cycle length and depresses atrial and ventricular functions, which is suggestive of antiarrhythmic properties at the atrial and ventricular levels. [ABSTRACT FROM AUTHOR]