The following points highlight the three major syndromes of coronary heart disease. The syndromes are: 1. Myocardial Infarction 2. Angina Pectoris (Pain in the Chest) 3. Sudden Death.

Coronary Heart Disease: Syndrome # 1. Myocardial Infarction:

a. This is necrosis or destruction of part of the heart muscle due to failure of the blood supply (ischaemia).

b. It may lead to sudden death or heal leav­ing a scar.

c. Patients with healed lesions may be se­verely disabled or may be able to return to their normal life with little or no restric­tion of their physical activities, but they carry an increased risk of a second infarct.

d. The infarction is usually due to a throm­bus forming in an atherosclerotic coronary artery and blocking the lumen.

e. Sometimes there is no thrombus and the infarct arises because the lumen of a coro­nary artery has been so narrowed by atherosclerosis that the blood flow is in­sufficient to supply the oxygen needed to maintain the cardiac muscle.

f. Occasional cases of myocardial infarction are seen in which neither thrombosis nor significant narrowing of the lumen can be recognised.

Coronary Heart Disease: Syndrome # 2. Angina Pectoris (Pain in the Chest):

a. In this condition exercise or excitement causes severe chest pain.

b. Patients may live for many years and re­main free of further disability, so long as they keep within the limits of their exer­cise tolerance.

c. The patients carry an increased risk of sud­den death or myocardial infarction, espe­cially if they undertake any unusual exer­tion.

d. Emotional stress may also bring on angina.

Coronary Heart Disease: Syndrome # 3. Sudden Death:

a. A proportion of sudden death results from angina pectoris or myocardial infarction.

b. The death is presumed to be due to CHD.

c. The most death is unexpected but autopsy shows evidence of old myocardial infarc­tion or extensive atheroma of the coro­nary arteries.