An Analysis of Coronary Flow and Related Factors Following Vagotomy, Atropine, and Sympathectomy

Coronary blood flow in the dog has been measured by the nitrous oxide desaturation method before and after acute bilateral cervical vagotomy, intravenous injection of atropine, and chronie sympathectomy. Vagotomy and atropine markedly increased coronary flow, myocardial oxygen consumption, and heart rate, but decreased left ventricular efficiency. Chronic sympathectomy resulted in the following smaller but statistically significant changes: a decrease in coronary flow, myocardial oxygen consumption, and heart rate, but an increase in left ventricular efficiency. Increasing the oxygen content of the arterial blood decreased the coronary flow. A comparison of diallylbarbiturate acid and urethane with morphine and chloralose anesthesia gave similar flow values, but cardiac efficiency was increased in the latter case. An analysis of the relationships between coronary flow, left ventricular oxygen consumption, and the arteriovenous oxygen difference is presented.