Coronary Blood Flow and Myocardial Ischemia

The major factors determining myocardial perfusion and oxygen delivery have been elucidated over the past several decades, and this knowledge has been successfully incorporated into the management of patients with ischemic heart disease. The basic understanding of the fluid mechanical behavior of coronary stenoses also has been translated to the cardiac catheterization laboratory where measurements of coronary pressure distal to a stenosis and coronary flow are routinely obtained. The role of perturbations in coronary microvascular structure and function in ischemic heart disease is becoming increasingly recognized, but the microvascular mechanisms that control coronary blood flow and the underlying causes and mechanisms of coronary microvascular dysfunction, remain incompletely understood. Moreover, although our understanding of the acute and chronic sequelae of myocardial ischemia, including stunning, hibernation, and acute myocardial infarction, has been greatly advanced, attempts to limit ischemic damage to the myocardium have been rather disappointing, with the notable exception of revascularization.