Human electropharmacology of the calcium antagonist dimeditiapramine (Ro 11-1781) in coronary patients.

The electrophysiological effect of dimeditiapramine (Ro 11-1781), a Ca2+ antagonist, was evaluated in 20 patients with coronary heart disease. Electrophysiological measurements, including sinus cycle length, sinoatrial conduction time, intra-atrial conduction time, atrial, atrioventricular, nodal and ventricular refractory periods and intraventricular conduction time were recorded before and after the intravenous administration of Ro 11-1781. At a dose which is effective against cardiac arrhythmias, Ro 11-1781 produced no statistical significant changes in the sinoatrial and intraventricular conduction time. Similarly, neither the sinoatrial nor the ventricular refractory period was affected. Ro 11-1781, however, increased the atrioventricular conduction time and decreased the systolic blood pressure to a statistically significant extent. The tolerance was very good.