Coronary heart disease (CHD) is the most common form of heart disease. An estimated 330 000 people have a myocardial infarct each year. Approximately 1.3 million people have angina each year. Disease of the coronary arteries is almost always due to atheroma and its complications, particularly thrombosis. Myocardial Ischemia results when there is an imbalance between myocardial oxygen supply and demand. Most occurs because of atherosclerotic plaque within one or more coronary arteries, limiting normal rise in coronary blood flow in response to an increase in myocardial oxygen demand.