Experimental Study Of Two-dimensional Echocardiography And Doppler Echocardiography In Dogs With Quantitative Myocardial Ischemia

With the introduction of clinical two- dimensional echocardiography (2DE) in the late 1970s, the ability to visualize ail regions of left ventricle and to detect regional wall motion abnormalities ( RWMA) associated with myocardial ischemia or infarction was augmented tremendously. 2DE now offers an unparalleled view of left ventricular (LV) anatomy and provides a simultaneous assessment of endocardial wall motion and myocardial thickening. Its tremendous versatility, relatively low cost, portability, and high degree of accuracy, make it an ideal tool in experienced hands for evaluating patients with known or suspected coronary disease. The effects of complete coronary occlusion on cardiac wall thickening and RWMA have been quantitatively assessed by 2DE. Now some investigators have also begun to use 2DE to detect RWMA during stressful interventions such as'exercise when no abnormalities are apparent at rest. However, coronary artery disease (CAD) in the absence of myocardial infarction may not be associated with resting abnormalities. Indeed, contraction abnormalities may occur only transiently, such as during stress-induced ischemia. But, how much coronary blood flow (CBF) can be reduced without apparent RWMA of left ventricle, at what level of CBF reduction, the regional LV myocardial function (RLVF) is impaired...