Hypertension and Coronary Artery Disease

Abstract

Hypertension is very common in Blacks and occurs at a younger age than in Whites. It behaves in an explosive manner with death occurring frequently from cerebral haemorrhage, uraemia or congestive cardiac failure. In a study of urban Zulus, Seedat et al. (1978) found that the mean arterial pressure according to age and sex was not as high as in the American Negro, West Indian or Nigerian, but certainly higher than in most Caucasian populations. In the clinical series of Schwartz et al. (1958) hypertension was third in the frequency of cardiac disorders after idiopathic heart failure and chronic rheumatic heart disease and comprised 19.6% of all their cardiac cases. Recent authors have however, stressed that with increasing urbanization and associated stress, the incidence of hypertension in Blacks has increased and will probably rise even further. Wyndham (1979) has stated that the pattern of mortality from diseases of the circulatory system of Blacks in South Africa is that of high mortality rate for cerebral vascular disease and hypertensive heart disease and very low mortality rate for ischaemic heart disease. The current accepted view is that, in Johannesburg, the second most common cause of death in the adult Black population (after violence) is hypertension and its complications (Seftel 1973). There has been dispute as to whether hypertension in Blacks is essential or secondary to underlying renal disease. Isaacson and Kincaid-Smith (1962) examined the autopsy records of patients over the age of fifty years who had died of natural causes. Patients who had had a blood pressure of 200/100 mm Hg or more and had died of the effects of hypertension such as heart failure, uraemia or cerebral haemorrhage, were selected for study.