Spontaneous heart rate, propranolol, and ischaemia-induced ventricular fibrillation in the dog.
Abrupt coronary occlusion was performed in anaesthetised, open-chest dogs with pre-occlusion arterial blood PO2 ranging from 8.0 to 10.7 kPa (60 to mmHg). Ventricular fibrillation occurred in 15/19 dogs with high spontaneous heart rate (less than 155 beats.min-1) and in 0/8 dogs with low spontaneous heart rate (less than 155 beats.min-1). Dogs with low spontaneous heart rate fibrillated when paced at a fast rate (200.min-1) (4/5). In dogs with high spontaneous heart rate fibrillation occurred in 0/5 dogs when propranolol reduced spontaneous heart rate, but in 3/5 dogs when reduction in spontaneous heart rate in response to propranolol was prevented by pacing.
D000818:Animals; D003327:Coronary Disease / Q000150:complications; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D011433:Propranolol / Q000494:pharmacology*; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology
D011433:Propranolol