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Biomedical subjects

W C Roberts

Publications and source records attributed to W C Roberts.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of composition of atherosclerotic plaques in saphenous veins used as aortocoronary bypass conduits with plaques in native coronary arteries in the same men.

This study describes quantitatively the components of atherosclerotic plaques in saphenous vein grafts used for aortocoronary bypass and compares the findings with the plaques in the native coronary arteries in the same men. A total of 607 five-mm segments of saphenous veins and 797 five-mm segments of native coronary arteries were examined by computerized planimetric technique in 19 men, aged 39 to 82 years (mean 61), who had survived bypass operation for > 1 year. Comparison of the mean percentages of the plaque components in saphenous vein grafts in place for 14 to 26 months with those of the native coronary arteries revealed significant differences: cellular fibrous tissue, 86 vs 7%; dense fibrous tissue, 13 vs 82%; p < 0.05. As survival time after the bypass operation increased, composition of the plaques in the saphenous veins changed so that by approximately 80 months the amounts of cellular and dense fibrous tissue in both saphenous vein grafts and native coronary arteries were similar: 10 vs 16%, and 75 vs 71%; p = not significant. Thus, by about 7 years after a coronary bypass operation the composition of plaques in saphenous vein grafts is similar to that in the native coronary arteries of the same patients.

Adult↗
PubMed1992

Composition of atherosclerotic plaques in the epicardial coronary arteries in juvenile (type I) diabetes mellitus.

The composition of atherosclerotic plaques in 331 five-mm segments of the 4 major (left main, left anterior descending, left circumflex, and right) epicardial coronary arteries of 8 patients with juvenile (mean age at onset, 9 years; mean age at death, 29 years) diabetes mellitus was determined by computerized planimetric analysis. Analysis of all coronary segments disclosed that the plaques consisted primarily of dense (53%) and cellular (38%) fibrous tissue. Pultaceous debris (7%), foam cells (1.2%) and calcific deposits (0.7%) occupied a small percentage of the plaques. Thus, 91% of the coronary plaques in these young diabetic patients consisted of fibrous tissue and nearly all of the remaining 9% consisted of lipid deposits. Analysis of composition according to degrees of cross-sectional luminal narrowing revealed marked increases in dense fibrous tissue (from 31 to 74%), pultaceous debris (from 3 to 12%), and calcific deposits (from 0% to 3%) as the cross-sectional area narrowing increased from < or = 25% to > 75%. Compared with older patients with fatal coronary artery disease, the patients with juvenile diabetes had more dense fibrous tissue and pultaceous debris and less calcific deposits.

Adult↗
PubMed1992

Myocardial disarray at junction of ventricular septum and left and right ventricular free walls in hypertrophic cardiomyopathy.

The abnormality of the myocardium in hearts with hypertrophic cardiomyopathy (HC) was assessed regarding whether the muscle bundle in the mid-wall layer maintains its normal circular and continuous orientation surrounding the left ventricular (LV) cavity. Forty-seven autopsied hearts with HC were examined. The LV wall midway between the base and apex was divided into 6 segments in the transverse plane. Histologically, the circular orientation was destroyed largely or completely due to marked fascicle disarray in 77% of the anterior and posterior junctional segments. In 33% of the middle portion of the ventricular septum and in 34% of the anterior and posterior portions of the LV free wall, the midwall layer showed disarray of muscle fibers or small fascicles. In contrast, the lateral LV free wall was devoid of disarranged fibers in its midwall layer. Myocardial fibrosis usually was predominant in the portion where disarray was marked. There were deep tissue clefts often in the area of junction. In 11 hearts (7 from patients aged > 65 years), the circular unit was intact in almost every segment, as it was in 9 of 10 control hearts. The destruction of the circular unit in the area of septal-free wall junctions in most patients with HC is a previously undescribed morphologic feature of HC. This discontinuity may result from retention of an abnormal fetal myocardial architecture in which the septal latitudinal muscle was continuous with the right ventricular free wall.

Adolescent↗
PubMed1992

Degrees of coronary arterial narrowing at necropsy in men with large fusiform abdominal aortic aneurysm.

In 27 patients (mean age at death 72 +/- 9 years) with abdominal aortic aneurysm (AAA) > or = 5.0 cm in its widest transverse diameter, the amounts of narrowing at necropsy in the 4 major (left main, left anterior descending, left circumflex, and right) epicardial coronary arteries were determined. During life, 12 of the 27 patients (44%) had symptoms of myocardial ischemia: angina pectoris alone in 2, acute myocardial infarction alone in 3, angina pectoris and acute myocardial infarction in 5, and sudden coronary death in 2. Ten of the 27 patients (37%) died from consequences of myocardial ischemia. Six (22%) died from rupture of the AAA. Grossly visible left ventricular necrosis or fibrosis, or both, was present in 15 patients (56%). Of the 27 patients, 23 (85%) had narrowing 76 to 100% in cross-sectional area of 1 or more major coronary arteries by atherosclerotic plaque. The mean number of coronary arteries per patient severely (> 75%) narrowed was 2.0 +/- 1.3/4.0. Of the 108 major coronary arteries in the 27 patients, 55 (51%) were narrowed > 75% in cross-sectional area by plaque. The 4 major coronary arteries in the 27 patients were divided into 5-mm segments and a histologic section, stained by the Movat method, was prepared from each segment. The mean percentages of the resulting 1,475 five-mm segments narrowed in cross-sectional area 0 to 25%, 26 to 50%, 51 to 75%, 76 to 95% and 96 to 100% were 17, 37, 28, 15 and 3%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Amounts of coronary arterial narrowing by atherosclerotic plaque at necropsy in patients with lower extremity amputation.

In 26 patients (mean age at death 68 +/- 9 years) who had undergone amputation (at mean age 63 +/- 12 years) of 1 or both lower extremities due to severe peripheral arterial atherosclerosis, the amounts of narrowing at necropsy in the 4 major (left main, left anterior descending, left circumflex, and right) epicardial coronary arteries were determined. During life, 15 of the 26 patients (58%) had symptoms of myocardial ischemia: angina pectoris alone in 1, acute myocardial infarction alone in 5, and angina and/or infarction plus congestive heart failure or sudden coronary death in 9. Twelve of the 26 patients (42%) died from consequences of myocardial ischemia: acute myocardial infarction in 5, sudden coronary death in 3, chronic congestive heart failure in 3, and shortly after coronary bypass surgery in 1. Grossly visible left ventricular necrosis or fibrosis, or both, was present in 21 patients (81%). Of the 26 patients, 24 (92%) had narrowing 76 to 100% in cross-sectional area of 1 or more major coronary arteries by atherosclerotic plaque. The mean number of coronary arteries per patient severely (> 75%) narrowed was 2.3 +/- 1.0/4.0. Of the 104 major coronary arteries in the 26 patients, 60 (58%) were narrowed > 75% in cross-sectional area by plaque. The 4 major coronary arteries in the 26 patients were divided into 5-mm segments and a histologic section, stained by the Movat method, was prepared from each segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Relation between extent of cardiac muscle cell disorganization and left ventricular wall thickness in hypertrophic cardiomyopathy.

The presence of numerous, abnormally arranged, cardiac muscle cells distributed widely throughout the hypertrophied left ventricular (LV) wall has been considered a characteristic, morphologic feature of patients dying of hypertrophic cardiomyopathy (HC) and also probably a determinant of impaired LV compliance. However, the relation between such regions of myocardial cell disarray and the magnitude of wall thickness in the same areas of the left ventricle has not been defined. Therefore, the present study was undertaken in which LV wall thickness and the percent area of myocardium disorganized were systematically compared in the same tissue section. No correlation was identified between wall thickness and the amount of myocardium disorganized in the same tissue sections, either when calculated separately for the ventricular septum, and anterolateral and posterior free walls, or when expressed for all 3 regions combined. Therefore, in patients with HC: (1) disorganized myocardial architecture is not confined to greatly thickened portions of the LV wall, but regions of the left ventricle with normal or only mildly increased thickness may also be disordered; and (2) whereas both LV wall thickening and cellular disorganization are manifestations of the primary cardiomyopathic process, these 2 morphologic features do not appear to be directly related with regard to their extent and distribution within the LV wall. These observations will potentially enhance understanding of the relation between LV structure and compliance in HC.

Adult↗
PubMed1992

Severe mitral or aortic valve regurgitation, or both, requiring valve replacement for infective endocarditis complicating hypertrophic cardiomyopathy.

Certain clinical and morphologic findings are described in 11 patients with hypertrophic cardiomyopathy complicated by infective endocarditis that produced severe mitral or aortic valve regurgitation, or both, necessitating valve replacement. All 11 patients had changes in the operatively excised valve or valves characteristic of healed infective endocarditis. The infection involved only the mitral valve in seven patients, only the aortic valve in three patients and both valves in one patient. Study of the operatively excised mitral valves indicated that the healed vegetations were located most commonly on the left ventricular aspects of the anterior mitral leaflet, indicating that vegetation had formed at contact points of this leaflet with mural endocardium of the left ventricular outflow tract. In all 11 patients, the infective endocarditis either worsened preexisting valve regurgitation or initiated valve regurgitation and led to worsened signs and symptoms of cardiac dysfunction, necessitating valve replacement. Functional class improved in the nine patients who survived 7 to 101 months after valve replacement. Hypertrophic cardiomyopathy appears to be a factor predisposing to infective endocarditis. Patients with hypertrophic cardiomyopathy should receive prophylactic antibiotic therapy during procedures that predispose to infective endocarditis.

Adult↗
PubMed1992

The heart in Tangier disease. Severe coronary atherosclerosis with near absence of high-density lipoprotein cholesterol.

Cardiac necropsy findings are described in a 72-year-old man with Tangier disease whose plasma total cholesterol levels averaged 70 mg/dL, low-density lipoprotein cholesterol level was 45 mg/dL, and high-density lipoprotein cholesterol level was 1.4 mg/dL, and who had coronary artery bypass grafting for severe atherosclerotic coronary artery disease. At necropsy, 24 of the 72 (33%) 5-mm segments of the 4 major (right, left main, left anterior descending, and left circumflex) native coronary arteries and 4 of the 27 (15%) 5-mm segments of the saphenous vein aortocoronary bypass conduits were narrowed by more than 75% in cross-sectional area by atherosclerotic plaques. The plaques were composed primarily (91% to 97%) of fibrous tissue. Oil red O staining, polarized light microscopy, and electron microscopy revealed cholesterol deposits in the plaques and in the walls of coronary arteries, saphenous vein grafts, and aorta. Such deposits also were found in foam cells of histiocytic origin, fibroblasts in all four cardiac valves, and in Schwann cells of cardiac nerves.

Aged↗