Effects of tetrodotoxin and verapamil on abnormal ventricular activity at the late stage of experimental myocardial infarction in dogs
Aniukhovskiĭ, E.P.; Ivanovich, T.; Beloshapko, G.G.; Rozenshtraukh, L.V.
Kardiologiia 29(5): 66-71
1989
ISSN/ISBN: 0022-9040 PMID: 2770089 Document Number: 332281
An in situ experimental study of the heart has demonstrated that verapamil++ (0.3 mg/kg), administered intravenously to dogs with complete transverse heart block one day after two-step occlusion of the left descending coronary artery either produced a 15-30% drop in the incidence of abnormal ventricular activity (AVA) in some experiments, or had no effect on the latter in others. Tetrodotoxin (3 micrograms/kg) produced a 20-44% drop in AVA in all experiments. Combined administration of 0.2 mg/kg verapamil++ and 2 micrograms/kg tetrodotoxin completely suppressed AVA. At an early phase of its development (5-10 hours after the occlusion of the left descending artery), AVA was completely suppressed both by 0.3 mg/kg verapamil and 3 micrograms/kg tetrodotoxin. Mechanisms of AVA and its progress following coronary-artery occlusion in dogs are discussed.