Ischemia Testing for Stable Coronary Artery Disease

Abstract

Coronary artery disease (CAD) is a disorder that causes myocardial ischemia, where the blood flow to the myocardium is inhibited by obstruction and stenosis of the coronary artery, and the balance of supply and demand of oxygen in the myocardium is disturbed. In general, it is used almost synonymous with ischemic heart disease. Based on the condition of ischemia, it is roughly classified into angina, silent myocardial ischemia (SMI), and myocardial infarction. The development of myocardial ischemia, whether silent or painful, represents the cumulative impact of a sequence of pathophysiologic events over time and this sequence of events can be termed the ischemic cascade (Fig. 1). Specifically, these events include diminished left ventricular compliance, decreased myocardial contractility, increased left ventricular end-diastolic pressure, ST-segment changes and, occasionally, angina pectoris. Cardiac rhythm disturbances and breathlessness as a consequence of ischemic left ventricular dysfunction may also be recognized. There are three types of mechanism causing ischemia in coronary artery ; obstruction of epicardial coronary artery, coronary microvascular dysfunction (MVA: microvascular angina), and coronary spasm (CSA: coronary spastic angina), but the mechanisms are often overlapped. II. Initial assessment