[Ventricular arrhythmias in the acute stage of experimental swine myocardial infarct; effect of the beta blocker pindolol and the calcium antagonist Ro 11-1781].

A study was designed to examine ventricular arrhythmias in the acute phase of experimental myocardial infarction in the pig and to evaluate possible antiarrhythmogenic influence of the beta-adrenergic blocking drug pindolol (Visken) and the calcium antagonist Ro 11-1781. Ventricular fibrillation (VF) occurred in 17 of 18 animals, in 4 almost immediately after coronary occlusion and in 12 with a delay of about 17 min. VF was almost always induced by episodes of ventricular tachycardia (VT) which were started by single ventricular premature beats (VPBs). VPBs occurred in 3 phases, whereas VT and VF coincided only with phase 1 and phase 3. The prematurity index QR/QT of single VPBs decreased significantly with time after coronary occlusion. The beta-adrenergic blocking drug pindolol and the calcium antagonist Ro 11-1781 did not prevent VT or VF.