Effects of vagotomy and drugs on the ventricular fibrillation threshold of normal and ischemic hearts in the anesthetized rat.
The ventricular fibrillation threshold (VFT) was determined by the electrical stimulation of the normal and the coronary artery-ligated myocardium in situ in anesthetized rats. A bilateral vagotomy lowered the VFT of the normal myocardium. After the coronary artery ligation in the vagotomized rats, VFT fell to a greater extent. Bretylium 20-40 mg/kg i.v. produced an elevation of VFT, hypotension and a decrease of the heart rate of rats with the normal or the ischemic myocardium. Lidocaine 10 mg/kg i.v. insignificantly affected the VFT of the normal and the ischemic myocardium. Nitroprusside 4 mg/kg i.v. elevated the VFT of the normal myocardium, and prevented a fall in the VFT of the ischemic myocardium. Adenosine 10 mg/kg or aspirin 20 mg/kg i.v. had no remarkable effect on the VFT of the normal myocardium, but prevented a fall in the VFT of the ischemic myocardium.
D000241:Adenosine / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D001949:Bretylium Compounds / Q000494:pharmacology; D003327:Coronary Disease / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D014628:Vagotomy; D014693:Ventricular Fibrillation / Q000503:physiopathology*
D001949:Bretylium Compounds; D009599:Nitroprusside; D008012:Lidocaine; D000241:Adenosine; D001241:Aspirin