The effect of potassium on the coronary circulation

Abstract

The influence of potassium on the coronary circulation was studied. Experiments were carried out on dogs under morphine-urethane anesthesia with the use of thermoelectric recording of the coronary circulation volume velocity, and with the resistography method with perfusion through the coronary artery at constant blood volume. Intracoronary and intravenous injections of different doses of potassium chloride caused coronary dilatation. Large doses led to cardiac arrest. In most of the cases there was a reduction of the cardiac blood supply after application of concentrated potassium chloride solution to the epicardium. However, it·increased in rare cases when the blood pressure was greatly elevated, thus compensating a slight rise of the coronary vessel tone. The coronary tone rose to a greater degree at the place of K application than in the remote zone. In these experiments the EKG changes seen were similar to those observed in myocardial infraction. They did not correlate with changes of coronary circulation.