Effects of prostaglandin E2, propranolol and nitroglycerine with halothane, pethidine or pentobarbitone anaesthesia on arrhythmias and other responses to ligation of a coronary artery in rats.

The effects of various cardiovascular drugs (prostaglandin E2 (PGE2), propranolol and nitroglycerine) and anaesthetic regimens (halothane, pethidine and pentobarbitone), upon the outcome of coronary artery ligation in acutely prepared rats were determined. Effects upon arrhythmias, blood pressure, heart rate, mortality, ECG and the size of the occluded zone were determined for each drug in the presence of each anaesthetic. PGE2 and nitroglycerine had no statistically significant effects on the outcome of ligation whatever the anaesthetic. Propranolol had limited antiarrhythmic actions. The anaesthetic used had major effects upon the outcome of ligation, regardless of the cardiovascular drugs administered. Pentobarbitone anaesthesia resulted in the highest mortality, and most arrhythmias. Pethidine-N2O anaesthesia was associated with fewer arrhythmias. Halothane-N2O anaesthesia markedly decreased the incidence and severity of arrhythmias, independent of the cardiovascular drug. It was concluded that the anaesthetic used can have a major influence on ligation-induced arrhythmias in acutely prepared anaesthetized rats.