Coronary heart disease (CHD) or coronary artery disease is narrowing of the coronary arteries, which supply blood to the heart, leading to damage or malfunction of the heart. The most common heart disorders due to coronary artery disease are angina pectoris (chest pain due to insufficient oxygen reaching the heart) and myocardial infarction (heart attack). Coronary heart disease was previously called ischaemic heart disease (IHD).
The usual cause is atherosclerosis,in which fatty plaques develop on artery linings. An affected vessel can become totally blocked if a blood clot forms or lodges in the narrowed area. Atherosclerosis has many interrelated causes, including smoking, a high-fat diet, lack of exercise, being overweight, and raised blood cholesterol levels. Other risk factors include a genetic predisposition and diseases such as diabetes mellitus and hypertension.
In its early stages, coronary artery disease often produces no symptoms. The first sign is frequently the chest pain of angina, or an actual heart attack. The disease may also cause cardiac arrhythmias (abnormalities in the heartbeat); in severe cases, arrhythmia can cause cardiac arrest (in which the heart stops beating). In elderly people, it may lead to heart failure, in which the heart gradually becomes less and less efficient.
Drugs are given to help the heart to function more efficiently and to relieve symptoms. These include glyceryl trinitrate (GTN) and other nitrate drugs (e.g. isosorbide mononitrate); calcium channel blockers (e.g. nifedipine); beta-blockers; potassium channel activators; and vasodilator drugs. If drug treatment fails to relieve the symptoms of coronary artery disease, or if there is extensive narrowing of the coronary arteries, blood flow may be improved by balloon angioplasty, stenting or coronary artery bypass surgery.