CORONARY CIRCULATORY DYNAMICS IN AN ISCHEMIC BED DURING CORONARY SINUS OCCLUSION.

Coronary sinus occlusion (CSO) during acute ischemia has been shown to increase myocardial washout of radioactive tracers and to have a salvaging effect on ischemic myocardium. A model is proposed of the coronary circulation which predicts the related flow pattern. The coronary circulation is divided into normal and ischemic beds between which arterial and venous collaterals exist. The arterial and venous systems are represented by epicardial and intramyocardial capacitances and proximal resistances. Coronary artery occlusion leads to a marked decrease in flow to the ischemic zone. CSO leads to bidirectional flow across the microvascular bed in the ischemic zone, suggesting a mechanism for the observed increased washout of tracers.