The changing pattern of heart disease in South African Blacks.

All autopsies on Black patients who died of heart disease at Baragwanath Hospital were examined for the years 1959, 1960 and 1976. The commonest form of heart disease encountered in South African Blacks is undoubtedly hypertensive heart disease and by far the majority of these cases are of essential hypertension. There appears to have been a slight rise in the incidence of hypertension. Rheumatic heart disease is extremely common, and affects young people, who often have advanced valvular lesions by puberty. The incidence of idiopathic cardiomyopathy does not seem to have altered materially, although there has perhaps been a slight drop, which may be accounted for by the tendency of clinicians to place cases of congestive cardiac failure with mild hypertension in the hypertensive group rather than in the idiopathic cardiomyopathy group. There was a significant alteration in the incidence of myocardial infarction; in 1959 and 1960 these cases comprised less than 1% of all cardiac deaths but in 1976 they comprised nearly 12%. There has also been a dramatic fall in the incidence of cardiovascular syphilis.