The assessment of regional microvascular myocardial blood flow is likely to predict the outcome of revascularization procedures. The problem has been the adequate assessment of flow. Furthermore, the lack of a suitable experimental model that mimics chronic human coronary disease has made the pathophysiology of dysfunctional myocardium more difficult to understand. In a series of experiments the application of myocardial contrast echocardiography (MCE) in the quantification of regional myocardial blood flow was examined. Using this method, the passage of intravenously injected microtubules can be imaged through the myocardium with echocardiography. The conditions allowing quantifiable assessment of myocardial opacification were identified in the preliminary studies. In experimental models of coronary disease, this method was used to both detect and judge the severity of epicardial coronary stenoses. Using MCE, the physiology of coronary autoregulation was studied and a method was proposed for the measurement of absolute regional myocardial blood flow. MCE - derived myocardial blood flow measurements were validated against radiolabelled microsphere-derived blood flow in these studies. These experiments have contributed to the development of non invasive and repeated assessment of regional myocardial blood flow in patients with coronary artery diseases. In a further series of studies, the first large animal model of multivessel coronary disease was developed. The relation between myocardial blood flow and function, both on a regional and global basis, were studied using this model. It is hoped that this model will make the further study of the pathophysiology of dysfunctional myocardium, its response to stress and the outcome of revascularization possible.