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Biomedical subjects

W A Pocock

Publications and source records attributed to W A Pocock.

At least 37 records · Page 2Linked to original sources
PubMed1980

Innocent murmurs and third heart sounds in Black schoolchildren.

Normal auscultatory findings were studied during a heart survey in which 12 050 Black schoolchildren, aged 2 to 18 years, were examined by cardiologists. Physiological third heart sounds were detected in 96 per cent of children, innocent systolic murmurs in 72 per cent, and innocent mid-diastolic murmurs in 0.27 per cent. The term 'innocent systolic murmur" was used for vibratory systolic murmurs (70%) and pulmonary ejection systolic murmurs (4.2%) but distinct separation of these two murmurs was often difficult. Vibratory systolic murmurs were present throughout the age range. Important features in differentiating innocent systolic murmurs from those caused by mild organic heart disease included the intonation, site of maximal intensity, timing in systole, and behaviour with postural change. Innocent mid-diastolic murmurs are short murmurs occurring immediately after the third heart sound in children, with no supportive evidence of organic heart disease.

Adolescent↗
PubMed1978

Four year follow-up of black schoolchildren with non-ejection systolic clicks and mitral systolic murmurs.

In 1972 we conducted a survey of 12,050 urban Black schoolchildren and detected 168 (prevalence rate of 14 per 1,000) with a non-ejection systolic click (NESC), a late systolic murmur, or both. The etiology of the mitral valve abnormality was unknown but we considered that a significant proportion might have early rheumatic heart disease. The auscultatory features four years later of 139 of the original 168 subjects as well as those of 139 age- and sex-matched controls are presented in this study. No cardiac abnormality was detected in as many as 55 of the subjects. Five children now had pansystolic murmurs but the mitral regurgitation was assessed as mild in four. Twenty-five (17.9 per cent) of the controls, 23 of whom had NESCs, had auscultatory features compatible with mitral valve prolapse. These findings do not support our earlier suggestion that a large number of the 1972 subjects have mild rheumatic heart disease. The results are in accord with other studies which have indicated that auscultatory features compatible with mitral valve prolapse are common in "normals" and also that the prognosis of the specific "billowing mitral leaflet syndrome" is generally benign.

Adolescent↗
PubMed1977

Billowing mitral valve syndrome in association with absent left pericardium: a case report.

A patient with congenital complete absence of the left pericardium had a late systolic murmur and an intermittent non-ejection systolic click. A post-exercise ECG showed ST-segment depression and T-wave inversion, compatible with that described in the billowing mitral leaflet syndrome. Left ventricular cine-angiography confirmed prolapse of the mitral valve. It is suggested that an associated billowing mitral leaflet syndrome may be responsible for chest pain, variable auscultatory features and abnormal ECGs in some patients with absent left pericardium.

Adult↗
PubMed1977

Mitral valve aneurysm after infective endocarditis in the billowing mitral leaflet syndrome.

Mitral valve aneurysm is an uncommon complication of infective endocarditis. This report describes a patient with severe regurgitation due to perforations in a mitral aneurysm who required mitral valve replacement 9 years after a staphylococcal infection was superimposed on a billowing mitral leaflet. The unusual auscultatory signs and angiographic appearance could have led to diagnosis of the aneurysm.

Adult↗
PubMed1976

Some metabolic relationships in young patients with ischemic heart disease.

The interrelationships between body weight, insulin secretion and serum lipids were studied in 40 young white patients (mean age 37 years) with established ischemic heart disease (IHD), living in Johannesburg. None was severely obese, hypertensive or overtly diabetic. In general, strong positive correlations were found between body weight and insulin concentrations and between insulin levels and fasting serum triglycerides. However, insulin levels were relatively low in 4 patients with marked hypertriglyceridemia (above 350 mg/dl). These data are consistent with the postulate that insulin promotes (hepatic) triglyceride synthesis, but when there is gross hypertriglyceridemia peripheral triglyceride clearance becomes defective. Insignificant correlations were observed between body weight and serum lipids and between cholesterol and other metabolic variables. We conclude that there is a sequential link between increasing body weight, insulin secretion and triglyceride levels in young patients with IHD, but that cholesterolemia is independent of this axis.

Adult↗
PubMed1976

Non-ejection systolic clicks and mitral systolic murmurs in black schoolchildren of Soweto, Johannesburg.

A survey was conducted on 12 050 Black schoolchildren, aged 2 to 18 years, in the South Western Townships of Johannesburg (Soweto), and the prevalence of non-ejection systolic clicks and late systolic murmurs was determined. One or both of these auscultatory findings were detected in 168 children, yielding a prevalence rate of 13-99 per 1000 in the school population. A female preponderance of 1-9:1 was present and there was a strong linear increase in prevalence with age, with a peak rate of 29-41 per 1000 in 17-year-old children. A non-ejection click was the only abnormal auscultatory finding in 123 children (73%) and a mitral systolic murmur in 8 (5%), whereas in 37 (22%) both these findings were present. Of the latter 37 children, the murmur was late systolic in 32; in 5 it was early systolic. Auscultation in different postures was important in the detection of both non-ejection clicks and mitral systolic murmurs. Experience in the detection of these auscultatory findings influenced the frequency with which they were heard. Electrocardiographic abnormalities compatible with those previously described in the billowing mitral leaflet syndrome were present in 11 of 158 children. The aetiology of these auscultatory findings in this community remains unknown. In the same survey, a high prevalence rate of rheumatic heart disease was recorded and the epidemiology of the non-ejection clicks and these mitral systolic murmurs showed similarties to that of rheumatic heart disease. Though the specific billowing mitral leaflet syndrome almost certainly accounts for some of these auscultatory findings, a significant proportion may have early rheumatic heart disease. Further elucidation of this problem is necessary.

Adolescent↗
PubMed1976

Acute myocardial infarction with normal coronary arteries: a possible manifestation of the billowing mitral leaflet syndrome.

The findings in four young patients with the billowing mitral leaflet syndrome who presented with evidence of acute myocardial infarction are reported. Because technically adequate coronary arteriograms demonstrated patent vessels and the electrocardiograms initially showed pronounced elevation of the ST segments as occurs in Prinzmetal's angina, it is postulated that spasm of normal coronary arteries was the operative factor. Scrutiny of those cases of clinically apparent ischemic heart disease with normal coronary angiograms is suggested to establish whether there is in fact a causal relationship with the billowing mitral leaflet syndrome.

Adult↗
PubMed1975

Epidemiology of rheumatic heart disease in black shcoolchildren of Soweto, Johannesburg.

A survey to determine the prevalence of rheumatic heart disease (R.H.D.) in Black children was conducted in the creeches and primary schools of the South Western Townships of Johannesburg (Soweto). A total of 12 050 Black children were examined by 10 cardiologists in May to October 1972. The overal prevalence rate of R.H.D. was 6.9 per 1000, with a peak rate of 19.2 per 1000 in children of the seventh school grade. The maximal age incidence was 15-18 years and there was a female preponderance of 1 6:1. A rise in prevalence occurred with increasing family size. Most children (92%) were asymptomatic, and in 82.5% R.H.D. was diagnosed for the first time during the school survey. The commonest valve lesion was mitral regurgitation, which was present in 93% and occurred as an isolated lesion in 47.5%. Lancefield's group A beta-haemolytic streptococcus was isolated from the throats of 52 per 1000 Soweto children. The auscultatory features of a non-ejection systolic click and late systolic murmur were prevalent (13.9 per 1000) and had several epidemiological factors in common with R.H.D. A comprehensive preventative campaign is urgently needed in South Africa, directed at both primary and secondary prophylaxis of R.H.D. The socioeconomic status of the community must be improved if optimal prevention is to be achieved.

Adolescent↗
PubMed1975

Auscultatory features of hypertrophic obstructive cardiomyopathy. A study of 90 patients.

The auscultatory signs in 90 subjects with hypertrophic obstructive cardiomyopathy are described. The late-onset ejection systolic murmur and its responses to vaso-active manoeuvres reflect a volume-dependent outflow tract obstruction. Late vibrations of the systolic murmur, not uncommonly recorded at the apex, are due to associated mitral incompetence. Non-ejection systolic clicks may occur, and the likely explanation is inequality of the functional length of the mitral chordae tendineae secondary to asymmetrical myocardial hypertrophy. The second heart sound is often abnormal, usually with delay in the aortic component. Some correlation was demonstrated between the relative degrees of left and right ventricular outflow obstruction and the pattern of splitting of the second heart sound. Reversed or partially reversed splitting is usually associated with a more severe left ventricular outflow obstruction. Ejection systolic clicks and early diastolic murmurs occur infrequently, but are not incompatible with the diagnosis of hypertrophic obstructive cardiomyopathy.

Adolescent↗
PubMed1975

The problem of nonejection systolic clicks and associated mitral systolic murmurs: emphasis on the billowing mitral leaflet syndrome.

Nonejection clicks and associated mitral systolic murmurs are common in routine cardiologic practice and can result from multiple etiologic factors affecting the complex mitral valve mechanism. Such factors include a specific syndrome the essential feature of which is that the mitral leaflets or part thereof, primarily the posterior one, are voluminous. The syndrome has stimulated widespread interest and study during the last decade and various descriptive terms, including the "billowing mitral leaflet syndrome" (BMLS), have been applied to it. A familial occurrence of the BMLS may be detected and symptoms include chest pain, palpitations, syncope, and anxiety. Arrhythmias, conduction defects, and ECG abnormalities which mimic occlusive coronary artery disease are important features which remain ill understood. It is suggested that there is a possible relationship between the so-called "athlete's heart" and the BMLS. We also postulate that the entity of acute myocardial infarction without demonstrable occlusive coronary artery disease is, in at least some instances, a complication of the BMLS-possibly on the basis of coronary spasm. More severe mitral regurgitation, infective endocarditis, or, rarely, sudden death may supervene in the BMLS but we conclude, from published data and our own experience, that the prognosis is generally good.

Adolescent↗
PubMed1975

Infective endocarditis in the billowing mitral leaflet syndrome.

Ten patients with the billowing mitral leaflet syndrome complicated by infective endocarditis are reported. Two patients had a non-ejection systolic click and 8 had both a non-ejection systolic click and a late systolic murmur. These auscultatory features were difficult to detect in 4 instances in that they were intermittent, soft, or brought out only with postural change. Seven patients were unaware of their cardiac lesions. A low grade pyrexia was present in all 10 patients. Four patients presented with clinical features caused by reversible neurological lesions. Blood cultures were positive in all patients, with Staphylococcus albus the infecting organism in 6. Antibiotic therapy was successful with significant mitral regurgitation supervening in only one instance. The importance of the billowing leaflet as a potential site of infective endocarditis is emphasized. It seems that antibiotic prophylaxis is indicated at times of increased risk of infection in subjects with a non-ejection systolic click or a late systolic murmur.

Adolescent↗