Heart disease is the predominant cause of death in all industrialised nations, accounting for 40% of all mortality.
Ischaemic heart disease is the single biggest contributor to cardiac mortality.
Reduction in coronary blood flow is the cause of myocardial ischaemia in over 90% of cases.
The arterial supply of the heart is unique because blood flow is confined to diastole - the coronary arteries being compressed during systole. There is considerable overlap in the distribution of the individual coronary arteries and, in disease, collateral flow may develop.
Coronary artery disease which may or may not lead to ischaemia also includes coronary artery aneurysm.