Pathophysiologic Mechanisms in Unstable Angina

UNDERSTANDING the pathophysiology of unstable angina has been a major research effort for over two decades. Over the years our understanding of this syndrome has changed as different causes for the syndrome were identified. Initially, it was thought that increased myocardial oxygen demand was responsible for rest ischemia in patients with unstable angina. Later, it seemed that decreased supply caused by coronary vasospasm may have been responsible for the symptoms in these patients. More recently, by pathologic, angiographic, and angioscopic studies, we find that atherosclerotic plaque disruption with thrombus formation is the primary cause of this and other acute syndromes. In this paper, I hope to present a clear understanding of the pathophysiology of unstable angina.