Myocardial contrast echocardiography: a new method for the evaluation of regional myocardial blood flow.

Abstract

Myocardial contrast echocardiography is a new method enabling detailed evaluation of blood flow distribution within the myocardium. It is performed by means of intracoronary injection of small volumes of carrier solutions containing small microbubbles of a size similar to that of red blood cells. The perfused myocardium opacifies densely, while the ultrasonic backscatter of nonperfused areas does not change. This method enables evaluation of the physiologic impact of coronary stenosis, diagnosis of "small vessel disease", collateral blood flow assessment, infarct size measurement and, with the help of videomemory and a computer, also regional myocardial blood quantification. This paper reviews all hitherto published studies with myocardial contrast echocardiography in humans including some studies only recently submitted for publication. These studies examined a total of 169 patients. No complications of intracoronary injection of microbubbles were described. Transient ECG and haemodynamic changes of less than 30 seconds' duration are less pronounced than during routine coronary arteriography. This paper describes the methodology, safety, physiology and potential clinical usefulness of myocardial contrast echocardiography.