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Myocardial perfusion in the area at risk
Shintaro Beppu, M.D.
Osaka University Graduate School of Medicine,Division of Functional Diagnostic Science

Although the regional wall motion abnormalities are the important key findings of the coronary artery disease, the motion abnormality is the result of myocardial ischemia. Severity of myocardial ischemia does not always correlate with the severity of coronary artery stenosis. The crucial point is the myocardial perfusion abnormality. Myocardial contrast echocardiography (MCE) has unique and significant role for evaluating the myocardial perfusion, while it is a simple and safe method to perform. The normal myocardium is opacified clearly by the contrast agent injected into the peripheral vein. Appearance of microbubbles in the myocardium tells us two important data for the coronary circulation; blood flow speed and myocardial blood volume.

In this lecture, (1) tolerance of the myocardial perfusion in the area at risk having severe stenosis of the coronary artery, (2) significance of the collateral flow in the area at risk and (3) the influence of the perfusion pressure on the critical coronary flow are presented. These issues of coronary pathophysiology can be resolved by MCE.