In humans, the physiologic relation between myocardial blood flow and epicardial coronary artery anatomy remains poorly defined. With the recent development of sonicated microbubble contrast agents, it is now possible to use contrast echocardiography to assess myocardial perfusion and to correlate blood flow with angiographically identified coronary artery anatomy. The purpose of the current study was to determine myocardial perfusion patterns in patients without significant coronary artery disease. These results may be used as a reference to analyze myocardial blood flow in patients with coronary artery disease.
Sonicated meglumine sodium diatrizoate solution (Renografin-76), which contains microbubbles measuring 4.5 ± 2.8 μm in diameter by laser analysis, was used as the echocardiographic contrast agent during elective coronary arteriography in 14 patients without significant coronary artery disease. Patients received intracoronary injections of 1.5 to 2 ml of sonicated Renografin-76 without complications. Perfusion characteristics were studied by visual assessment of the two-dimensional echocardiographic images obtained after individual injections. In patients found to be free of significant coronary artery disease by arteriography, the left coronary system always supplied the anteroseptal, anterior, anterolateral and posterior regions of the left ventricle at the mid-papillary, cross-sectional level. The right coronary artery system perfused the inferior and inferoseptal regions in 89% of the patients identified with a right dominant system. The anterolateral papillary muscle was perfused from the left coronary system in all cases. The posteromedial papillary muscle was perfused from the left coronary system in 58% of the patients and from the right system in 42% of the patients. The mid portion of the intraventricular septum was variably perfused from both coronary systems.
These results indicate that in patients free of significant coronary artery disease, the general perfusion pattern may be anticipated from the epicardial vessel distribution. However, for a specific patient, individual regional perfusion patterns vary. Thus, data are now available in humans correlating normal myocardial perfusion and angiographically determined coronary anatomy. Contrast echocardiography, when used in conjunction with cardiac catheterization, provides a rapid, safe and effective method for the clinical evaluation of regional myocardial blood flow.
