Intercoronary Reflex

Abstract

The effect of coronary embolization on the coronary vascular bed was studied in the intact anesthetized dog utilizing the technique of coronary artery catheterization without opening the thorax. Two coronary arterial catheters were inserted via the carotids, one into the anterior descending branch and the other into the circumflex branch of the left coronary artery. Coronary vascular visualization was accomplished by routine roentgenography and by cinefluorography (using an image intensifier and 16- and 35-mm. motion picture film at 48 to 60 frames/sec.) of the heart after injection of a radiopaque dye into a coronary vessel. The results following coronary embolization showed that in both the embolized and nonembolized coronary vessels there was: (1) marked decrease in the size of the coronary vascular bed, (2) reflux of the injected contrast substance into the other coronary artery or into the aorta, (3) considerable delay in the disappearance time of the injected radiopaque material. Under the conditions of our experiments, these results can be interpreted as evidence of a generalized left coronary vasoconstriction following embolization of a branch of the left coronary artery. This was prevented to a great extent by the prior injection of atropine.