Acute Myocardial Infarction in Man

Abstract

It has become evident that the immediate and long-term prognosis of patients with acute myocardial infarction largely depends on the extent of the infarcted myocardium. Although some information can be obtained from the M-mode echocardiogram by measurements of left ventricular internal dimensions and an abnormality in mitral valve closure (B bump) [1], or by mapping the extent of left ventricular asynergy using multiple transducer positions [2], M-mode echocardiography remains a poor method for quantitating the involved myocardium due to the restricted field of vision. Two-dimensional echocardiography is capable of displaying the contractile behavior of the entire left ventricle, however. Infarcted areas can be recognized and localized by two-dimensional echocardiography [3, 4], even in nontransmural infarction [5]. The correlative two-dimensional echocardio-graphic-pathologic study by Weiss et al. has shown that quantification of infarcted tissue is possible [6]. Other studies have correlated two-dimensional echocardiographic infarct size with scintigraphy [7] (both thallium 201 and technetium 99m-pyrophosphate) and peak CK-MB values [8, 9]. The results are summarized in table 10–1.