Longitudinal study of heart disease in a Jamaican rural population. I. Prevalence, with special reference to ECG findings.

A long-term epidemiological study of heart disease in a representative rural community in Jamaica was started in 1962-63 and the first follow-up survey was carried out in 1967-68. This report describes the prevalence of several cardiovascular characteristics at each survey, and their associations with other measurements. The nature of the electrocardiographic abnormalities and their relationship with symptoms of effort pain and prolonged chest pain suggests that much of the disease seen in this population is ultimately ischaemic in origin despite evidence that classical myocardial infarction and severe coronary atheroma are relatively infrequent. Nevertheless both the symptoms and the electrocardiographic abnormalities had features that were not completely typical of occlusive disease of extramural coronary arteries. These findings are discussed in terms of the four conditions-hypertension, conventional coronary heart disease, small artery disease, and cardiomyopathy-that are believed to account for most cases of heart disease in this community, and it is concluded that the overall pattern of disease cannot be explained by any single disorder of overriding importance. The evidence suggests that all may be important contributors.

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.

Longitudinal study of heart disease in a Jamaican rural population. 3. Factors influencing changes in serial electrocardiograms.

A longitudinal survey of heart disease in adults in a representative rural population in Jamaica provided an opportunity to study factors influencing the progression and incidence of electrocardiographic abnormalities in serial tracings taken at a 5-year interval. An analysis of changes occurring in those with ECG abnormalities compatible with ischaemia at the first survey showed that progression from a less severe to a more severe category was greater in men than in women, in hypertensive than in normotensive subjects, and, among men, in those with the amplitude criteria of left ventricular hypertrophy. The incidence of abnormal Q/QS patterns was greater in men than in women, and that of all abnormalities suggesting ischaemia was greater in hypertensive than in normotensive persons; in men, it was greater in those with high amplitude R waves. The incidence cases showed S-T and T wave abnormalities, the great majority of which were classified as showing features compatible with ischaemia rather than with strain secondary to hypertrophy. These findings, which are discussed in terms of their possible causes, seem to confirm that much of the heart disease in this Jamaican community has features of myocardial ischaemia despite other evidence that extramural coronary vessels tend to be spared from such severe occlusive atheromatous disease as is found in many other populations.

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 initial 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 and important cause of death in rural Jamaicans.(AU)

Longitudinal study of heart disease in a Jamaican rural population. 3. Factors influencing changes in serial electrocardiograms

A longitudinal survey of heart disease in adults in a representative rural population in Jamaica provided an opportunity to study factors influencing the progression and incidence of electrocardiographic abnormalities in serial tracings taken at a 5-year interval. An analysis of changes occurring in those with ECG abnormalities compatible with ischaemia at the first survey showed that progression from a less severe to a more severe category was greater in men than in women, in hypertensive than in normotensive subjects, and, among men, in those with the amplitude criteria of left ventricular hypertrophy, The incidence of abnormal Q/QS patterns was greater in men than in women, and that of all abnormalities suggesting ischaemia was greater in hypertensive than in normotensive persons; in men , it was greater in those with high amplitude R waves. The incidence cases showed S-T and T wave abnormalities, the great majority of which were classified as showing features compatible with ischaemia rather than with strain secondary to hypertrophy, These findings, which are discussed in terms of their possible causes, seem to confirm that much of the heart disease in this Jamaican community has features of myocardial ischaemia despite other evidence that extramural coronary vessels tend to be spared from such severe oclusive atheromatous disease as is found in many other populations.(AU)

Cuatro años de estudio longitudinal de una comunidad rural con endemicidad chagásica / A 4-year follow-up study of a rural community with endemic chagas'disease

The four-year follow-up study reported herein represents the continuation of a previous cross-sectional study carried out in a rural community (Belen, Venezuela). The earlier study included 1,210 persons out of a total of 1,656 inhabitants, all over five years of age, and demonstrated a high prevalence of Chagas' infection (47.3 per cent) and a high rate of Chagas' disease seropositivity among those with chronic myocardial heart disease (84.8 per cent); heart disease was found in 17.3 per cent of persons studied. It included clinical, electrocardiographic and radiological analyses

The present report describes the results of the four-year follow-up study performed in 812 persons, which permitted to establish the incidence of Chagas' infection (16.3 per cent) and that of chagasic heart disease (2.2 per cent) in four years. The report also included the clinical, electrocardiographic and radiological analyses of cases with previous heart disease as well as new cases. Different evolutive electrocardiographic patterns have been found, including serial electrocardiographic variations ranging from normal to definitely abnormal. The mortality occurred in the sample during the observation period is reported(AU)

A 4-year follow-up study of a rural community with endemic Chagas' disease.

The paper reports on a 4-year follow-up study that represents the continuation of a previous cross-sectional study on Chagas' disease carried out in a rural community (Belén) in Venezuela. The earlier study included 1210 persons all over 5 years of age out of a total of 1656 inhabitants and demonstrated a high prevalence of Chagas' infection (47.3%) and a high rate of Chagas' disease seropositivity among those with chronic myocardial heart disease (84.8%); heart disease was found in 17.3% of persons studied. The follow-up study was based on 812 persons and established that in the sample the frequency of Chagas' infection was 16.3% and that of heart disease 2.2%. Clinical, electrocardiographic and radiological analyses were made on patients with previous heart disease as well as on new patients. Different evolutive electrocardiographic patterns have been found, including variations ranging from normal to definitively abnormal.

Clinical and epidemiological study of chronic heart involvement in Chagas' disease.

It has been estimated that, in vast areas of the American continent, there is a high prevalence of human infection by Trypanosoma cruzi. Such infection can lead to a variety of heart diseases, predominantly with involvement of the myocardium. The aim of the present work was to determine the prevalence of heart disease in two rural areas of Venezuela with a high endemicity of Chagas' disease and to try to determine the natural history of the disease. It is shown that a form of chronic myocardial disease in patients with positive specific serology and good functional capacity is highly prevalent. Electrocardiographic patterns typical of the initial and developing stages of the disease, as well as early abnormalities of the cardiac rhythm, are described and illustrated. The present work forms part of a longitudinal study still in progress.