Search PubMed⌕ Search

Biomedical subjects

L M Shapiro

Publications and source records attributed to L M Shapiro.

At least 127 records · Page 7Linked to original sources
PubMed1982

Echocardiographic features of impaired ventricular function in diabetes mellitus.

In order to study left ventricular diastolic function in diabetes mellitus, simultaneous echo- and phonocardiograms were recorded in 142 diabetics (free from heart disease), 20 normal subjects, and 16 patients with coronary artery disease. The resultant traces were digitised, and left ventricular relaxation and the rate and duration of cavity dimension increase and wall thinning were determined. Diastolic variables of left ventricular function were normal in 12 young diabetics with no complications. Significantly delayed mitral valve opening relative to minimum dimension and aortic valve closure was found in all other groups of diabetics. Forty-four diabetics with severe microvascular complications had significantly reduced peak rate and prolonged duration of wall thinning and dimension increase. The abnormalities were unlike those found in subjects with coronary artery disease. The extent of microvascular complications was significantly correlated to most variables of diastolic function. This relation was maintained in 31 diabetics with significant cavity dimension increase during isovolumic relaxation (incoordinate relaxation). In 42 juvenile onset patients there was good correlation between the duration of diabetes and most variables of diastolic function. These studies show that the primary cardiac abnormality in diabetic micro-angiography is a prolonged duration and reduced rate of posterior wall thinning with impaired left ventricular dimension increase, reflecting abnormal myocardial properties.

Adolescent↗
PubMed1982

The mortality and morbidity of young survivors of myocardial infarction.

The mortality and morbidity of 150 young (less than 45 years) survivors of myocardial infarction was studied prospectively over a 10-year period. Thirty-seven deaths (36 due to coronary artery disease) occurred from one month to 10 years after myocardial infarction and the cumulative 10-year mortality was 27 per cent compared with 5 per cent in the general population. High initial lactate dehydrogenase levels and continued cigarette smoking after infarction were associated with a poor long-term survival. Angina was present at some time during follow-up in 60 per cent of patients. Severe limitation of exercise tolerance was present in 18 per cent, and 16 per cent had radiological evidence of cardiomegaly. Left ventricular failure occurred in 13 patients and carried a very poor prognosis. Unemployment in 95 men who survived 10 years was 32 per cent, half of whom had never returned to work following infarction, compared with a regional value of 7 per cent. We have shown that there is a prolonged and persistent mortality and morbidity in young survivors of myocardial infarction with a high level of male unemployment. Careful rehabilitation should reduce the economic loss to the community together with persuasive advice against cigarette smoking.

Actuarial Analysis↗
PubMed1981

Left ventricular function in diabetes mellitus. I: Methodology, and prevalence and spectrum of abnormalities.

Frequent abnormalities of left ventricular function were detected in 212 established diabetic patients using non-invasive techniques. Diabetics without angina or heart failure (n = 185) were significantly different from normal subjects (n = 50) in beat-to-beat variation, ratio of pre-ejection period to left ventricular ejection time, pre-ejection period index, isovolumic relaxation time, and interval from minimal dimension to mitral valve opening. Diabetics with angina (n = 18) were similar to control subjects with angina (n = 25); they showed a significant dimension change during the isovolumic period as compared with other diabetics and normals. Sixteen diabetics without angina also showed outward motion during the isovolumic period (incoordinate relaxation) and 13 had abnormal systolic time intervals. Four diabetics suffered a myocardial infarction during the study period; all had previously shown incoordination. Comparison of diabetics with a diastolic blood pressure below 100 mmHg and between 100 and 125 mmHg showed that the latter had a thicker posterior wall; the enlarged systolic dimension and reduced fractional shortening were the result of the inclusion of five of the 11 diabetic subjects with heart failure in the hypertensive group. Insulin-dependent diabetics tend to have more pronounced abnormalities of left ventricular function than those not requiring insulin. Patients selected from a diabetic clinic frequently have impaired left ventricular function, and ventricular hypertrophy, when present, in primarily caused by hypertension.

Adult↗
PubMed1981

Left ventricular function in diabetes mellitus. II: Relation between clinical features and left ventricular function.

We have shown a close relation between clinical microvascular complications and abnormalities of left ventricular function in 185 established diabetics without clinical heart disease. In 50 insulin-dependent diabetics who presented at under 20 years of age there was a correlation between the duration of diabetes and the isovolumic relaxation time, minimal dimension to mitral valve opening, and ratio of pre-ejection period to left ventricular ejection time. Diabetics with mild microvascular complications were similar to diabetics with no complications except for minor prolongation of the diastolic time intervals. Those with severe complications were significantly different from diabetes with milder complications and normal controls in all variables of left ventricular function. A close relation between left ventricular function and the microvascular complications index (code 0 when no complications to code 7 when all present and severe) was found for the following variables: isovolumic relaxation time, the interval from minimal dimension to mitral valve opening, ratio of pre-ejection period to left ventricular ejection time, and pre-ejection period index. It is concluded that in diabetes abnormalities of left ventricular function are related to duration of disease and complications; and that a diabetic specific heart muscle disorder occurs frequently in patients with severe microvascular complications.

Adult↗
PubMed1981

Echocardiographic features of malignant hypertension.

Computerised apex- and echocardiography was used to study left ventricular dimensions and function in 13 patients with untreated malignant hypertension and eight with severe benign hypertension. All patients had normal left ventricular cavity dimensions. Five benign hypertensives and malignant hypertensives with a previous history of hypertension had significant thickening of the septum and posterior wall. In eight malignant hypertensives without a previous history wall thicknesses were normal. The absence of ventricular hypertrophy in some cases of malignant hypertension suggests that it is sometimes of rapid onset and not preceded by a non-malignant phase. although fractional shortening and peak Vcf were normal in all the hypertensives, diastolic left ventricular function was frequently abnormal with delayed mitral valve opening, reduced peak rate of filling, and outward endocardial motion during isovolumic relaxation. Malignant hypertensives showed a cavity shape change during isovolumic contraction, and in those without a previous history the aortic second heart sound occurred earlier. The abnormalities of function are probably the result of a combination of factors including pressure overload, abnormal myocardial properties, and myocardial ischaemia, either regional or generalized and secondary to arteriolitis.

Adult↗
PubMed1976

Heterogeneity of chondrocyte mitochondria. A study of the Ca2+ concentration and density banding characteristics of normal and rachitic cartilage.

Previous morphological studies of the mineralizing epiphysis suggested that some mitochondria were concerned with Ca2+ accumulation while others were associated with cellular energetics and metabolism. To determine if there was mitochondrial heterogeneity in chondrocytes of the epiphyseal growth plate, mitochondria were isolated from four different regions of the plate and subjected to continuous sucrose gradient centrifugation. Centrifugation of the organelles in a narrow density sucrose gradient (1.5--2.0 M) in the presence of inhibitors of Ca2+ transport (ruthenium red and 5,5'-dithiobis-(2-nitrobenzoic acid)) revealed that considerable heterogeneity existed. In the least calcified zone 20% of the mitochondria formed a low density band of low Ca2+ concentration (309 nmol/mg protein). Organelles isolated from more calcified tissue zones showed a concomitant increase in Ca2+ concentration (up to 5700 nmol/mg protein) as well as an increase in the total percentage of mitochondria sedimenting in 2.0 M sucrose. The banding patterns of mitochondria isolated from rachitic and hypertrophic cartilage were similar. In addition, similarities were also noted in the Ca2+ concentration and the cytochrome oxidase activities of mitochondria of these tissues. During recovery from the rachitic condition, there was a change in the density centrifugation characteristics of this tissue and a substantial increase was noted in the proportion of mitochondria sedimenting in 2.0 M sucrose. The Ca2+ concentration of mitochondria of this rapidly calcifying tissue suggested that the critical Ca2+ concentration necessary for initiation of the calcification mechanism was 4 mumol/mg protein.

Animals↗