[Effect of propranolol on the fibrillation threshold and the period of vulnerability of cardiac ventricles under normal conditions and during acute coronary occlusion].
Experiments on anesthetized dogs have shown that intravenous infusion of 1 mg/kg of propranolol has no essential effect on the threshold of ventricular fibrillation, but considerably reduces the duration of the vulnerable period. Ligation of the coronary artery during propranolol infusion does not cause a reduction in the fibrillation threshold or prolongation of the period of vulnerability; propranolol inhibits the fibrillatory effect of ligation of the vessel. Infusion of propranolol after ligation of the coronary artery leads to the return of the fibrillation threshold and the duration of the period of vulnerability to the initial values. Prolongation of the period of vulnerability after ligation of the coronary artery and its reduction after propranolol infusion occur due to shifts in the internal boundary of the period. There is a direct correlative relationship between the duration of the vulnerable period and the body mass of the dogs: the greater the mass of the animal, the longer the duration of the period of vulnerability.
D000818:Animals; D003331:Coronary Vessels / Q000601:surgery; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D007263:Infusions, Parenteral; D008026:Ligation; D009203:Myocardial Infarction / Q000188:drug therapy*; D011433:Propranolol / Q000008:administration & dosage*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000188:drug therapy*
D011433:Propranolol
Vliianie propranolola na porog fibrilliatsii i dlitel'nost' uiazvimogo perioda zheludochkov serdtsa v norm i v techenie ostroĭ koronarnoĭ okkliuzii.