Effect of nisoldipine on electrophysiological parameters in patients pretreated with beta-blockers

The effect of the new 1,4-dihydropyridine calcium antagonist nisoldipine on electrophysiological parameters was investigated in 10 patients who were pretreated with a beta-blocker. 9 patients received atenolol (75 mg/d) and 1 patient pindolol (15 mg/d) at least for three days prior to the electro-physiological study. Before and after the intravenous injection of nisoldipine (1.5 micrograms/kg body weight) the sinus node function (spontaneous sinus node cycle length, sinus node recovery time, rate corrected sinus node recovery time), the conduction times from the high right atrium to the apex of the right ventricle, and the refractoriness of the different compartments of the heart were assessed. Arterial blood pressure was measured with the cuff method. Nisoldipine induced a slight but significant increase of the heart rate without effecting the blood pressure significantly. All other measured electrophysiological parameters remained unaltered, especially the conduction time of the av node. It is concluded that concerning electrophysiology nisoldipine can safely be combined with beta-blockers because this calcium antagonist does not exert an electrophysiological effect.