Effects of carbocromene on ventricular fibrillation during acute myocardial ischemia in anesthetized dogs.
The effects of carbocromene, 4 mg/kg intravenously, prior to coronary artery occlusion plus 40 microgram/kg/min during coronary artery occlusion and reperfusion on ventricular fibrillation threshold (VFT) were studied in pentobarbital-anesthetized open-chest dogs and compared to controls receiving saline. Coronary artery occlusion decreased VFT by 46 +/- 4% (mean +/- SEM, p less than 0.02) in controls and by 22+/-3% in drug-treated animals. Reperfusion of the occluded artery decreased VFT by 83+/-7% (p less than 0.01) in controls and by 47+/-5% in carbocromene-treated hearts (p less than 0.02). Hemodynamics did not change in the drug group during coronary artery occlusion. In controls, blood pressure and dP/dtmax decreased while heart rate, end-diastolic pressure and ST-T segments increased significantly during both coronary artery occlusion and reperfusion. The underperfused, ischemic region was assessed by staining with Evans blue and involved 34+/-3% of the left ventricular mass in controls but only 27+/-3% in carbocromene-treated hearts (p less than 0.05). These results indicate protective effects of carbocromene on ventricular vulnerability in canine hearts during coronary artery occlusion and subsequent reperfusion.
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002866:Chromonar / Q000494:pharmacology*; D003327:Coronary Disease / Q000503:physiopathology*; D003374:Coumarins / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000503:physiopathology*
D003374:Coumarins; D002866:Chromonar