To assess the potential of coronary collateral circulation to protect myocardium after occlusion of a coronary vessel, the mean coronary wedge pressure, the angiographic grade of Experimentally, the coronary collateral circulation has been studied mainly in the dog heart. Because collaterals are more developed in dogs than in healthy humans, the results can not necessarily be extrapolated to the human coronary circulation. The hemodynamics of coronary collaterals have been studied directly in humans during aortocoronary bypass surgery,17 and, more recently, the From the Cardiology Center, University Hospital, Geneva, Switzerland.Address for correspondence: B. Meier, MD, Cardiology Center, University Hospital, 1211 Geneva 4, Switzerland.Received November 20, 1987; revision accepted April 28, 1988. pressure distally to coronary lesions was measured during percutaneous angioplasty18-22 and the relation of the coronary wedge pressure (pressure in the distal part of the occluded artery) to spontaneously visible and recruitable collaterals has been established.22 To evaluate the protective role of the coronary collateral circulation, we studied the relation between the mean coronary wedge pressure measured during percutaneous transluminal coronary angioplasty and the left ventricular function in patients with occlusion of a major coronary vessel.
Patients and Methods PatientsCoronary wedge pressure measurements were done in 53 of 108 consecutive patients with attempted recanalization of a total coronary occlusion. Four patients with a previous myocardial infarction in a region other than that supplied by the attempted vessel were excluded. Two additional patients were excluded because of unsatisfactory quality of the left ventriculogram. The remaining 47 patients constituted the study population. Among them, 13 patients underwent mechanical recanalization during the acute phase of a myocardial infarction. The remaining 34 underwent an elective procedure for a