Coronary artery disease (CAD) also known as atherosclerotic heart disease, coronary heart disease, or ischemic heart disease (IHD), is the most common type of heart disease and cause of heart attacks. The disease is caused by plaque building up along the inner walls of the arteries of the heart, which narrows the arteries and reduces blood flow to the heart.<br />While the symptoms and signs of coronary artery disease are noted in the advanced state of disease, most individuals with coronary artery disease show no evidence of disease for decades as the disease progresses before the first onset of symptoms, often a “sudden” heart attack, finally arises. Symptoms of stable ischaemic heart disease include angina (characteristic chest pain on exertion) and decreased exercise tolerance. Unstable IHD presents itself as chest pain or other symptoms at rest, or rapidly worsening angina. The risk of artery narrowing increases with age, smoking, high blood cholesterol, diabetes, high blood pressure, and is more common in men and those who have close relatives with CAD. Other causes include coronary vasospasm, a spasm of the blood vessels of the heart, it is usually called Prinzmetal’s angina.