Coronary artery disease (CAD) or ischemic heart disease (IHD) is any condition that leads to ischemia (tissue injury as a result of low oxygen availability) and related injuries to the heart. It covers the entire spectrum of ischemic diseases of the heart from angina to myocardial infarction. As the name suggests, the flow of blood through the coronary arteries, which supply oxygenated blood to the heart muscle, is compromised in CAD.