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Biomedical subjects

M M Webb-Peploe

Publications and source records attributed to M M Webb-Peploe.

At least 91 records · Page 5Linked to original sources
PubMed1977

Visual complications of mitral leaflet prolapse.

Four young women and six older men with mitral leaflet prolapse presented with visual disturbances consistent with embolism in the ophthalmic or posterior cerebral circulation. Cardiac arrhythmias were common, but these are rarely associated with focal ischaemia. The evidence that mitral leaflet prolapse caused the embolism in these patients is suggestive but not conclusive. Further studies are needed. All patients with acute cerebral or ocular ischaemia should undergo through cardiovascular assessment, which should include routine echocardiography.

Adolescent↗
PubMed1977

Systolic and diastolic ventricular function in cardiac amyloidosis. Studies in six cases diagnosed with endomyocardial biopsy.

Five cases of cardiac amyloidosis diagnosed after endomyocardial biopsy are described. Systolic function was normal in three cases as assessed by cardiac index, ejection fraction and maximal velocity of contractile element shortening at zero developed pressure. The diastolic dip and plateau wave form was a characteristic but not an invariable finding. Increased ventricular end-diastolic pressure but normal end-diastolic volume indexes in all cases implied a disorder of diastolic compliance. The diastolic pressure-volume plots suggested a sudden decrease in distensibility after normal early filling of the ventricle. The functional defect did not necessarily differ from that of other diseases of heart muscle. Therefore, hemodynamic data should not be relied upon for diagnostic purposes. Electron microscopy was the most reliable aid in making the diagnosis from the endomyocardial biopsy specimens especially in the presence of fibrosis. It may not be valid to assume a diagnosis of cardiac amyloidosis from the finding of amyloid in other organs.

Adult↗
PubMed1977

Left ventricular endomycardial biopsy. I: description and evaluation of the technique.

The results of left ventricular endomyocardial biopsy by means of a long sheath technique in 154 patients are reported. The risks of left ventricular biopsy are those of left heart catheterisation. In 30 of these patients the results of left and right ventricular biopsy were compared, and in further 10 patients the right ventricle only was biopsied. Biopsy from the left ventricle carries less risk of cardiac perforation, gives a higher incidence of successful biopsy, and with the exception of hypertrophic obstructive cardiomyopathy yields more diagnostic information.

Biopsy↗
PubMed1977

Left ventricular endomyocardial biopsy. II: the value of light microscopy.

Histological sections of left ventricular endomyocardial biopsies have been examined by light microscopy. The biopsies were taken from patients with congestive, hypertrophic, or restrictive cardiomyopathy and from patients with either aortic stenosis or regurgitation. In congestive cardiomyopathy no specific features were found and similar abnormalities were seen in aortic valve disease. In only one of six cases of asymmetric septal hypertrophy were the characteristic histological appearances noted. In four out of five patients with a restrictive type of cardiomyopathy, amyloid was demonstrated. The muscle fibres in aortic stenosis had a greater cross-sectional area than those in aortic regurgitation. A greater degree of fibrosis was present in aortic stenosis than in aortic regurgitation. In aortic stenosis the amount of fibrous tissue was inversely related to function.

Aortic Stenosis, Subvalvular↗
PubMed1977

Left ventricular endomyocardial biopsy. III: ultrastructural characteristics of cardiomyopathy and cardiac hypertrophy with good or poor ventricular function.

Left ventricular endomyocardial biopsies have been obtained from patients with cardiomyopathy and hypertrophy due to aortic valve disease. These biopsies have been examined by electron microscopy and the ultrastructural abnormalities compared. In congestive cardiomyopathy no specific abnormalities were found although myofibrillary degeneration and membrane-bound vacuoles were more commonly present. Crossing of whole groups of sarcomeres was found only in asymmetric septal hypertrophy, but was not present in all cases. Amyloid deposits were demonstrated easily by electron microscopy in patients with restrictive cardiomyopathy. In the patients with hypertrophy due to aortic valve disease, no specific features were found and ultrastructural abnormalities did not differentiate between normal and impaired left ventricular functions.

Aortic Stenosis, Subvalvular↗
PubMed1977

Enzymic analysis of endomyocardial biopsy specimens from patients with cardiomyopathies.

Myocardial biopsies have been obtained from patients with hypertrophic or congestive cardiomyopathies. Marker enzymes for the principal subcellular organelles of the myocardium were estimated using highly sensitive assay procedures. The results were compared with those obtained in tissue from patients with valvular heart disease with good or poor left ventricular function. Left ventricular myocardial tissue from patients with hypertrophic cardiomyopathy showed essentially normal levels of enzymic activities. In congestive cardiomyopathy, right ventricular tissue showed reduced levels of mitochondrial enzymes with increased levels of lactate dehydrogenase. Left ventricular tissue from patients with congestive cardiomyopathy showed reduced levels of mitochondrial and myofibril enzymes but high levels of lactate dehydrogenase. The reduced levels of myofibril Ca++-activated ATP in congestive cardiomyopathy is similar to that found in patients with impaired left ventricular function secondary to valvular disease. It is suggested that defective mitochondrial function is a characteristic feature of congestive cardiomyopathy and that the increased levels of lactate dehydrogenase reflect a compensatory response.

Cardiomyopathies↗
PubMed1976

Enzymic analysis of cardiac biopsy material from patients with valvular heart-disease.

Cardiac tissue obtained by left-ventricular endomyocardial biopsy from patients with valvular heart-disease was assayed for marker enzyme activities of subcellular organelles and these were correlated with left ventricular function as assessed by haemodynamic studies. In patients with poor left ventricular function, calcium-dependent adenosine-triphosphatase (A.T.P.ase) activity, predominantly localised to the myofibrils, was strikingly reduced. Activity of lactate dehydrongenase, a cytosol enzyme, was significantly increased in tissue from patients with poor left ventricular function. The activity of enzymes associated with sarcolemma (5'-nucleotidase), mitochondria (glutamate dehydrogenase and monoamine oxidase), microsomes (neutral alpha-glucosidase), and lysosomes (acid phosphatase, N-acetyl-beta-glucosaminidase) was no different in patients with good or poor left ventricular function. It is suggested that reduced myofibrillary A.T.P.ase concentration is the biochemical basis for the impaired ventricular function.

Acid Phosphatase↗
PubMed1976

Assessment of left ventricular function by indices derived from aortic flow velocity.

The velocity and acceleration of aortic blood flow were measured by means of a catheter velocity probe in 40 patients during routine diagnostic cardiac catheterization. Ten different variables were derived from the aortic velocity measurements, and their ability to discriminate between good and bad left ventricular (LV) function was tested. By means of eight conventional indices of LV function derived from pressure, mean flow, and quantitative cineangiography, the patients were divided into 3 groups: group 1, good LV function; group 2, moderate LV function; group 3, poor LV function. Aortic peak velocity and maximal acceleration correlated well with stroke volume and were thus indices of LV pump function. Aortic peak velocity also showed a significant correlation with LV stroke work. Both aortic peak velocity and maximal acceleration failed to discriminate between the three groups of patients, and correlated poorly with conventional indices of LV function. The mean values of stroke volume differed significantly between groups 1 and 2, and between groups 1 and 3, and also correlated better with the conventional functional indices. The best discrimination between normal and abnormal LV function was provided by dividing stroke volume by maximal acceleration, but stroke volume divided by peak velocity discriminated better than stroke volume alone. Stroke volume divided by maximal acceleration also gave more significant individual correlations with the conventional functional indices than did any other variable derived from aortic velocity.

Adult↗
PubMed1976

Clinical, haemodynamic, and angiographic findings in Löffler's eosinophilic endocarditis.

Detailed haemodynamic and angiographic findings in Löffler's endocarditis are presented for the first time in a report of 3 cases of this rare disease. In 2 of the cases the right ventricular cavity was obliterated; in one of them this was shown by biopsy to be caused by organized thrombus. In the third case, there was progressive mitral regurgitation.

Blood Pressure↗
PubMed1976

An analysis of pulsus alternans in aortic stenosis.

Pulsus alternans was studied hemodynamically in 5 patients with calcific aortic stenosis. Left ventricular function was assessed by angiographic volume analysis and by force-velocity analysis. All cases showed alternation of max and min dP/dt and kVmax. Inconsistent factors were an alternating left ventricular enddiastolic pressure, alternating left ventricular enddiastolic volume, alternating left ventricular endsystolic volume, ejection fraction, enddiastolic wall stress and wall stiffness. All cases had a high ventricular mass, but the critical value of ventricular mass or the ratio of mass to left ventricular enddiastolic volume were also inconsistent. Pulses alternans is primarily due to alternating contractility.

Angiocardiography↗
PubMed1975

Anomalous origin of left coronary artery from pulmonary artery. Surgical considerations in the adult.

The usually recommended treatment for anomalous origin of a left coronary artery from the pulmonary artery is proximal ligation of the anomalous artery with a saphenous vein bypass graft to restore aortocoronary continuity. In an adult patient with large collateral vessels and with the left coronary artery arising from the back of the pulmonary artery, the technical surgical problems associated with this procedure are formidable. Closure of the orifice of the anomalous left coronary artery from inside the pulmonary artery is suggested as the treatment of choice in such a case.

Adult↗