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Biomedical subjects

W C Roberts

Publications and source records attributed to W C Roberts.

At least 127 records · Page 7Linked to original sources
PubMed1993

Coexistence of sudden cardiac death and end-stage heart failure in familial hypertrophic cardiomyopathy.

OBJECTIVES: The purpose of this study was to determine the occurrence of sudden cardiac death or end-stage heart failure, two phases of the natural history of hypertrophic cardiomyopathy, in closely related relatives. BACKGROUND: Hypertrophic cardiomyopathy is a genetically transmitted cardiac disease with a particularly diverse clinical and morphologic spectrum. Premature death usually occurs either suddenly or as a result of progressive congestive heart failure. METHODS: We describe seven families with genetically transmitted hypertrophic cardiomyopathy that were studied with echocardiography or necropsy, or both, and were selected because they were known to include relatives who had incurred either premature sudden cardiac death or the end-stage phase of the disease. RESULTS: The seven families comprised 128 relatives; 26 died suddenly, and 9 developed end-stage heart failure (including 2 with heart transplantation) associated with left ventricular cavity enlargement, wall thinning or decreased contractility, alone or in combination, as well as loss of outflow obstruction. Patients who died suddenly did so at younger ages (23 +/- 10 years) than did patients who died or required heart transplantation in the end-stage phase of hypertrophic cardiomyopathy (42 +/- 8 years, p < 0.001). CONCLUSIONS: This study demonstrates that family members with hypertrophic cardiomyopathy, despite a common genetic substrate, may exhibit markedly diverse and distinct expressions of the natural history of their disease, which occur at widely separated periods of life.

Adolescent↗
PubMed1993

Comparison in women versus men of composition of atherosclerotic plaques in native coronary arteries and in saphenous veins used as aortocoronary conduits.

OBJECTIVES: This study quantifies and compares the components of atherosclerotic plaques in native coronary arteries and in saphenous vein grafts used for aortocoronary bypass surgery in women versus those in men. BACKGROUND: Plaque composition has been described in various manifestations of fatal coronary artery disease and after the bypass operation, but no reports have investigated this composition according to gender. METHODS: A total of 979 5-mm segments of native coronary arteries and 842 5-mm segments of saphenous vein grafts were examined by computerized planimetric technique in 11 women and 11 men who were matched for survival time after the bypass operation. RESULTS: Comparison of the plaque components revealed that atherosclerotic plaques in women, compared with those in men, contained significantly more cellular fibrous tissue, both in native coronary arteries (mean 38% vs. 4%, p < 0.001) and in saphenous vein grafts (mean 70% vs. 36%, p < 0.05). In contrast, the proportion of dense fibrous tissue was significantly less in the atherosclerotic plaques of women than in those of men, both in native coronary arteries (mean 50% vs. 85%, p < 0.001) and in saphenous vein grafts (mean 25% vs. 57%, p < 0.05). CONCLUSIONS: Cellular fibrous tissue is often found at an early stage of plaque development, whereas dense fibrous tissue is a major component in later stages. Thus, the plaque composition of the native coronary arteries and saphenous venous conduits differed in men and women, with the plaques of the women appearing younger than those of the men.

Adult↗
PubMed1993

Solitary coronary ostium in the aorta in the absence of other major congenital cardiovascular anomalies.

OBJECTIVES: This study examines the distribution patterns and the clinical significance of the "solitary coronary ostium" in the aorta in the absence of other major congenital cardiovascular anomalies. BACKGROUND: Ogden in 1970 classified "single coronary artery" into 14 basic distribution patterns. Since then, other patterns of distribution of single coronary artery have been recognized. Distinction has also been made between the cases with and without other major congenital cardiovascular anomalies or coronary artery atresia and those without these additional abnormalities. Single coronary artery has been generally considered to be a benign clinical entity. METHODS: This study describes 10 cases of single coronary artery at necropsy and reviews 87 previously reported cases, 35 diagnosed at necropsy and 52 by coronary angiography. RESULTS: We classified single coronary artery into 20 categories on the basis of the location of the solitary coronary ostium, the presence or absence of an aberrant-coursing coronary artery and the course taken by the aberrant-coursing coronary artery. When atherosclerotic coronary artery disease was absent, 15% (8 of 53) of the patients reviewed with single coronary artery had myocardial ischemia as a direct consequence of the coronary anomaly. CONCLUSIONS: The anatomic classification presented is useful from both clinical and surgical viewpoints. This comprehensive classification of this rare anomaly facilitates description of the various distribution patterns of single coronary artery and their clinical significance.

Adolescent↗
PubMed1993

Clinical, electrocardiographic and morphologic features of massive fatty deposits ("lipomatous hypertrophy") in the atrial septum.

OBJECTIVES: This study examined the morphologic features and the clinical significance of massive fatty deposits in the atrial septum of the heart. BACKGROUND: Large deposits of adipose tissue in the atrial septum were first described in 1964 and have been referred to as "lipomatous hypertrophy" of the atrial septum. A relation between these fatty deposits and atrial arrhythmias has been suggested. METHODS: The thickness of the atrial septum cephalad to the fossa ovalis ranged from 1.5 to 6 cm in 91 patients and was > or = 2 cm in 80 patients. This report focuses primarily on the latter 80 patients. RESULTS: The thickness of the atrial septum in the 80 patients correlated with body weight and the thickness of the adipose tissue in the atrioventricular groove and that covering the right ventricle. In 53 patients (67%), one or more of the four major epicardial coronary arteries were narrowed > 75% in cross-sectional area by atherosclerotic plaque. Atrial arrhythmias were present in 31 patients (40%). Patients with larger deposits of fat (atrial septal thickness > or = 3 cm) had a higher frequency of atrial arrhythmias (60% vs. 34%, p < 0.01). The atrial septum was significantly thicker in patients with atrial arrhythmia compared with those without atrial arrhythmias (2.9 vs. 2.3 cm, p < 0.01). Of the 28 patients with available electrocardiograms, 20 (71%) showed atrial arrhythmias (nine atrial premature complexes, seven atrial fibrillation, three atrial tachycardia, one ectopic atrial rhythm and one junctional rhythm). CONCLUSIONS: Massive fatty deposits in the atrial septum are associated with large deposits of fat elsewhere in the body and other parts of the heart. They are frequently associated with atrial arrhythmias and atherosclerotic coronary artery disease.

Aged↗
PubMed1993

Morphological determinants of echocardiographic patterns of mitral valve systolic anterior motion in obstructive hypertrophic cardiomyopathy.

BACKGROUND: The morphological determinants of mitral valve systolic anterior motion (SAM) and obstruction to left ventricular outflow in patients within the broad clinical spectrum of hypertrophic cardiomyopathy (HCM) are not completely understood, particularly the contribution of mitral leaflet length and size. METHODS AND RESULTS: To clarify this issue, mitral valve specimens from 43 patients with HCM and basal outflow obstruction were used to relate morphometric measurements of leaflet area to certain morphological and functional assessments of left ventricular outflow tract geometry and valvular motion obtained from echocardiograms in the same patients. Twenty-four patients (56%) had mitral valves of normal size (leaflet area < 12.0 cm2) and 19 patients (44%) had enlarged and elongated valves (area > or = 12.0 cm2). Compared with normal-sized mitral valves, the enlarged valves were situated more posteriorly in a larger left ventricular outflow tract (cross-sectional area, 3.3 +/- 1.0 versus 1.9 +/- 0.7 cm2 for normal-sized valves; p < 0.001) and also had greater systolic excursion of the anterior leaflet (16.2 +/- 4.5 versus 13.3 +/- 3.3 mm, p < 0.02), usually with a distinctive sharp-angled bend and localized contact of the leaflet tip with ventricular septum ("typical" SAM); this pattern of SAM was possible because the central and distal portions of the leaflet were relatively free of fibrous thickening. In contrast, normal-sized mitral valves were situated more anteriorally in a smaller left ventricular outflow tract and frequently showed a different mechanism of SAM and subaortic obstruction with relatively limited leaflet motion, absence of a sharp bend, and septal contact involving more substantial portions of the anterior leaflet and contiguous chordae ("atypical" SAM); mitral-septal apposition was effected in large measure by posterior ventricular septal motion. This pattern of SAM was invariably associated with a more diffuse pattern of fibrous thickening. CONCLUSIONS: Patients with obstructive HCM show patterns of mitral valve SAM that are diverse and determined largely by the interrelation of left ventricular outflow tract geometry, the size and mobility of the mitral leaflets, and the presence and distribution of fibrous thickening.

Adolescent↗
PubMed1993

Echocardiographic assessment of mitral valve size in obstructive hypertrophic cardiomyopathy. Anatomic validation from mitral valve specimen.

BACKGROUND: In patients with hypertrophic cardiomyopathy, obstruction to left ventricular outflow is produced by systolic anterior motion of the mitral valve. In many of these patients, the mitral leaflets are elongated and increased in overall size. Mitral valve size may be responsible, in part, for the presence and magnitude of the outflow gradient and the pattern of systolic anterior motion of the leaflets. It may also influence the effectiveness of ventricular septal myotomy-myectomy in relieving subaortic obstruction. Therefore, the present study was undertaken to determine whether mitral valve dimensions could be assessed in quantitative terms from the echocardiogram in patients with hypertrophic cardiomyopathy. METHODS AND RESULTS: A group of 37 patients with hypertrophic cardiomyopathy was selected for this study by virtue of having a high-quality transthoracic or intraoperative echocardiogram suitable for certain quantitative measurements from stop-frame images as well as a morphologically intact mitral valve specimen (removed during surgery). Seven measurements of mitral valve dimensions were obtained from the two-dimensional and M-mode echocardiograms. A univariate regression analysis identified the mitral valve opening area as the best single predictor of actual mitral leaflet area measured from the specimen (r2 = .75; r = .87). The linear relation between mitral valve opening area as assessed by two-dimensional echocardiography and actual mitral leaflet area measured from the mitral valve specimen accounted for approximately 75% of the variability in mitral leaflet area. With such statistical models, it was possible to reliably identify from the echocardiogram enlarged mitral valves (> or = 12.0 cm2) in 16 of 19 patients (84%) and normal-sized valves in 15 of 18 patients (83%). CONCLUSIONS: In a selected group of patients with obstructive hypertrophic cardiomyopathy, a model derived from a regression analysis of quantitative echocardiographic measurements permitted (with good precision) estimation of actual mitral leaflet area and consequently overall mitral valve size and the discrimination of enlarged from normal-sized mitral valves.

Adolescent↗
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↗