Longitudinal study of heart disease in a Jamaican rural population. 2. Factors influencing mortality.

The relationship between cardiovascular characteristics and mortality was investigated in an epidemiological study of heart disease in a representative adult rural community in Jamaica. Of 449 men and 469 women followed up for 5 years, 36 men and 28 women died and the data concerning their status as regards arterial pressure, electrocardiographic abnormalities, and histories of effort pain at the intial survey have been analysed. Cardiovascular disease, and heart disease in particular, was the major cause of death in this population. Blood pressure levels exceeding 160/95 mm Hg had been recorded in about one third of the men and half the women who died and a clear trend was found between overall mortality and arterial pressure. Symptoms of effort pain and ECG abnormalities compatible with myocardial ischaemia, both of which were unexpectedly common, appeared to have independent prognostic significance. The prognosis of each was worse when associated with hypertension; hypertension unaccompanied by either effort pain or ECG "ischaemic" abnormality, on the other hand, caused no excess mortality in either sex within the period of follow-up. Although classical myocardial infarction was confirmed to be relatively infrequent, myocardial disorders with many of the features of ischaemic heart disease are an important cause of death in rural Jamaicans.