[Intraoperative contrast echocardiography using sonicated iopromide (Ultravist 370) for imaging the post-bypass myocardial region].

In order to minimize the rate of inadequate myocardial revascularizations, an intraoperative evaluation of regional myocardial perfusion could have practical impact. Current bypass flow measurements have inherent limitations and can determine only epicardial blood flow. To analyze regional graft-dependent myocardial blood flow an echocardiographic short-axis view of the left ventricle was performed intraoperatively in 11 patients undergoing elective coronary artery bypass surgery. After injection of 2 ml of sonicated lopromid (Ultravist 370) into 14 vein grafts, contrast enhancement in the corresponding myocardial regions was clearly visible, no side-effects occurred. Contrast decay halftimes (T/2) were determined by computer-assisted videodensitometry and compared to electromagnetic flow (EMF) rates, which were measured immediately before. T/2 ranged from 2.1 to 6.9 (mean 4.1 +/- 1.5) s and did not correlate to the EMF-rates of 55 to 100 (mean 80 +/- 16) ml/min. Thus intraoperative myocardial echocardiography is a safe and feasible method which allows on-line visualization and off-line quantitation of regional myocardial perfusion intraoperatively.