Search PubMed⌕ Search

Biomedical subjects

A E Becker

Publications and source records attributed to A E Becker.

At least 271 records · Page 15Linked to original sources
PubMed1976

Morphogenesis of univentricular hearts.

Two main theories exist for the explanation of univentricular hearts. One states that the bulboventricular septum becomes realigned to form the interventricular septum, and that univentricular hearts are a consequence of failure of this realignment. The other states that bulboventricular and interventricular septa are different structures, and that the univentricular heart results from failure of formation of the posterior interventricular septum. Four hearts are described in which both the posterior septum and an anterior bulboventricular septum are present. In each heart, therefore, the right ventricular sinus is separated both from the left ventricular sinus and from a discrete outlet chamber which supports the pulmonary artery. It is argued that these findings militate strongly against theories proposing reorientation of the bulboventricular septum to form the definitive interventricular septum. They support strongly the concept that the definitive right ventricle is formed in part from the bulbus and in part from the primitive ventricle. On the basis of these findings, it is suggested that the distinctive feature of the univentricular heart is absence of the posterior septum. Such hearts can properly be termed 'primitive ventricle'. It is also suggested that hearts with atretic or straddling valves should be included within this category.

Heart Defects, Congenital↗
PubMed1976

Coronary artery disease in patients dying from cardiogenic shock or congestive heart failure in the setting of acute myocardial infarction.

Pathological findings in the heart and particularly in the coronary arteries are reported from 70 patients dying from pump failure after acute myocardial infarction. Fifty of the patients had died in cardiogenic shock, the remainder from refractory congestive heart failure. Three-vessel disease (greater than or equal to 75% occlusion) was present in 68 per cent of the group with cardiogenic shock but in only 35 per cent of those with fatal congestive heart failure (P less than 0-02). In both groups there was an almost equal incidence (84% for cardiogenic shock and 80% for congestive heart failure) of severe disease (greater than or equal to 75% occlusion) over a long segment of the left anterior descending artery. However, there were differences between the two groups regarding the involvement of the other coronary arteries. Whereas patients with cardiogenic shock generally showed severe disease over a long segment in all coronary arteries, in 60 per cent of those with congestive heart failure there was only local severe narrowing of the right coronary artery with little or no narrowing of the peripheral part. Similarly, 60 per cent of those with congestive heart failure had less than 75 per cent narrowing in the left circumflex artery. These anatomical findings may be of relevance with regard to desirability of acute coronary bypass surgery in patients with pump failure after acute myocardial infarction.

Acute Disease↗
PubMed1976

Focal myocytolysis mimicking the electrocardiographic pattern of transmural anteroseptal myocardial infarction.

Two patients are documented, one with a cerebral infarct and one with a primary brain tumor, both of whom initially had a normal electrocardiogram but subsequently developed the classic pattern of transmural anteroseptal myocardial infarction; however, in both cases the autopsy proved the electrocardiograph pattern to be related to "focal myocytolysis" of the myocardium. Both patients also exhibited coronary arterial disease of the localized type and to a maximal luminal narrowing of 75 percent without a history of anginal complaints. It is of interest that the intensity of the lesions of focal myocytolysis was greatest in the areas supplied by the affected arteries. This peculiarity suggests that ischemia, though not primarily involved in inducing the lesions, could be of additional significance.

Adult↗
PubMed1975

Tetralogy of Fallot: a morphometric and geometric study.

Fourteen examples of tetralogy of Fallot were studied by morphometric and geometric methods, and the findings compared with results from 10 normal hearts. The data show that in Fallot's tetralogy the conal septum is deviated anteriorly. The infundibulum, although narrow, is similar to, or of greater length than, that of the normal heart. This finding is not in agreement with the recent observations suggesting that the anomaly represents lack of growth of the pulmonary conus. Our results further demonstrate that the aorta is dextroposed in Fallot's tetralogy and that in the majority of cases absorption of the right extremity of the conoventricular flange has led to aortic-tricuspid fibrous continuity. The overall findings indicate that conal rotation has occurred in addition to anterior deviation. The data are interpreted as supporting a hypothesis of "lack of conal inversion" and conal malseptation as the morphogenetic mechanisms in tetralogy of Fallot.

Adolescent↗
PubMed1975

Cardiac manifestations of Fabry's disease. Report of a case with mitral insufficiency and electrocardiographic evidence of myocardial infarction.

The light and electron microscopic findings in the heart of a patient with Fabry's disease are described. The study revealed that all cardiac tissues, including the conducting tissues and the valves, were involved. The latter finding was of particular interest since the patient was known to have mitral insufficiency. The findings of diffuse ballooning of the mitral valve with localized "overshoot" and massive glycolipid storage in the valve substance suggest that the abnormal storage process was itself responsible for the valvular insufficiency. The widespread involvement of the myocardium and conducting tissues is consistent with the elelctrocardiographic changes indicating infarction, although myocardial necrosis was not observed. The findings in this case suggest that the cardiac manifestations in Fabry's disease can be either primary, that is, directly related to the enzyme deficiency, or secondary, that is, evolving with time as a consequence of the disease.

Fabry Disease↗
PubMed1975

The coronary arteries in Marfan's syndrome. A morphologic study.

The coronary arteries of five hearts of patients known to have had Marfan's syndrome were studied microscopically. In four of the five cases the extramural coronary arteries showed structural changes consisting of accumulations of acid mucopolysaccharides and a concomitant disruption of the connective tissue elements. These changes closely resembled the changes that frequently occur in the aorta and that are generally described as "cystic medial necrosis". They are considered to be an important expression of wall weakening. In one case a laceration, probably traumatic, of a coronary artery led to formation of an "incomplete dissecting aneurysm." "Cystic medial necrosis" was found once in the proximal segment of the sinus nodal artery and once in the musculoelastic layer of a coronary artery that reached the atrioventricular node from the ventricular septum by perforating the anulus fibrosus. However, in contrast to findings in a previous report, the intramural coronary arteries were otherwise unaffected. The clinical significance of these data is as yet unknown particularly since these alterations are intramural and initially do not cause narrowing of the lumen. Nevertheless, the possibility of coronary arterial involvement by the metabolic disorder of Marfan's syndrome should always be considered during clinical assessment of this lesion.

Adult↗
PubMed1975

Coagulopathy in Ruptured or Dissecting Aortic Aneurysms.

A consumption coagulopathy was demonstrated in each of four patients with either ruptured aneurysm of the aorta or a dissecting aortic aneurysm. The most prominent features of this disorder were (1) a prolonged prothrombine time due to a decrease of one or more clotting factors, and (2) formation of fibrin and fibrinogen degradation products. Recognition of this coagulation disorder could be a valuable diagnostic tool to differentiate a ruptured or dissecting aortic aneurysm from other conditions with a similar acute onset. The coagulation disorder could be due to liberation of coagulant material from the aortic wall into the circulation or to an accumulation of clotting factors at the site of the lesion, secondary to the local exposition of tissue factors from the torn arterial wall. The probability of the latter mechanism is suggested by the local increase of radioactivity after the injection of 125I-fibrinogen.

Aged↗
PubMed1975

Anatomically corrected malposition of great arteries.

Four anomalous hearts are described in which the great arteries arise in unusual fashion from their morphologically appropriate ventricles. This malformation, previously termed anatomically corrected transposition, is now termed anatomically corrected malposition. This is because, following the precedent of Van Praagh and his associates, we now reserve the term 'transposition' to describe the situation in which both great arteries arise from separate morphologically inappropriate ventricles. All the hearts examined exhibited atrioventricular concordance, I with viscero-atrial situs inversus, and 3 with situs solitus. However, there were considerable variations in ventricular morphology between the cases. Thus, 2 cases exhibited atresia of the right atrioventricular valve, and in the remaining 2 cases right and levt ventricular sinuses were both identified. Two of the cases also had pulmonary atresia, and coronary artery anomalies were present in all 4. The cases emphasize the fact that the term anatomically corrected malposition describes not a discrete anomaly but only a ventriculo-arterial relation, which is one of ventriculo-arterial concordance. Doubt has previously been cast upon the existence of this as an anatomical entity. It is concluded that the relation does indeed exist, and furthermore can coexist with all varieties of atrioventricular relations. It is suggested that the differing atrioventricular relations can be distinguished by usage of the terms 'concordant' or 'discordant' anatomically corrected malposition. Finally, it is emphasized that it is necessary to distinguish this anomaly, which in most cases presents with left-sided anterior aorta, from the left-sided anterior aorta more frequently encountered in classically corrected transposition'.

Aorta, Thoracic↗
PubMed1975

Complete heart block as a consequence of atriondal discontinuity.

We have recently studied a case of complete heart block in which there was considerable difficulty in deciding whether it was of congenital or acquired origin. This was because the heart block was first discovered at the age of 2 years in the course of acute diphtheria. Though diphtheritic infections are known to affect the cardiac conduction system, authenticated cases of post-diphtheritic block persisting after the infection are rare, and, furthermore, histopathological study in this case revealed discontinuity between the atrial tissues and the more peripheral parts of the atrioventricular conduction tissues. This has been more commonly observed in congenital cases of complete heart block and it has been postulated on theoretical grounds that this could be thebasis for congenital heart block; on the other hand, it has been noted in a single casethought to be of acquired origin. Review of the evidence available failed to allow accurate classification of the case into either congenital or acquired categories. Thenormal, segmental development of the atrioventricular node, each segment being of different embryological origin, is discussed and the case presented is understandable in thelight of this.

Adult↗
PubMed1975

Aberrant origin of left pulmonary artery (vascular sling). Report of the clinical and anatomic features in three patients.

The clinical and anatomical findings in 3 patients with aberrant origin of the left pulmonary artery from the right pulmonary artery ("vascular sling") are presented. All 3 children symptoms of severe respiratory distress shortly after birth. In 2 children the correct diagnosis was suggested from the roentgenogram of the thorax, because of an indentation in the anterior wall of the esophagus. The diagnosis was further endorsed by selective angiography of the aberrant left pulmonary artery. The second patient is of particular interest, since the correct diagnosis was missed because of the presence of a multitude of associated anomalies. These included a tracheobronchial anomaly, a ventricular septal defect with a dilated pulmonary trunk, and a left-ward shift of the heart secondary to pulmonary emphysema on the right. Therefore, the indentation in the esophagus was absent, while the shift and rotation of the heart led to a misinterpretation of the exact course of the left pulmonary artery on the angiocardiogram. These cases are presented to reemphasize that "vascular sling", although rare, is indeed a serious cause of respiratory distress in infancy. Early recognition is of vital importance, since surgical repair of the vascular anomaly seems to be the only benificial procedure in these patients.

Angiocardiography↗
PubMed1975

The pulmonary outflow tract in classically corrected transposition.

Twenty-one specimens of classically corrected transposition have been studied in order to elucidate the morphology of the pulmonary outflow tract and the nature and origin of structures which obstruct it. The tract is an oblique channel wedged deeply between the inverted mitral and tricuspid valves. As a consequence of septal malalignment, the pulmonary valve ring overrides the muscular ventricular septum. In most specimens, the left wall of the tract is patent owing to incomplete formation of the interventricular portion of the membranous septum. This permits communication of the pulmonary artery with the left-sided morphologic right ventricle. Obstruction to the pulmonary outflow tract may be valvular or muscular or may result from the presence of fibrous tissue tags. Obstruction or atresia was present in 12 specimens (57 per cent). Fibrous tags were the most common cause, and these originated from the intact or perforated membranous septum, the inverted tricuspid valve, or the pulmonary valve. The unusual anterior relationship of the cardiac conducting tissue to the outflow tract in the anomaly is emphasized.

Heart Septal Defects, Ventricular↗
PubMed1975

The human atrioventricular junctional area. A morphological study of the A-V node and bundle.

A study has been conducted into the morphological arrangement of the atrioventricular junctional area of human heart. The area was investigated in infantile, child, young adult, middle-aged, and old nodes. Although marked individual and ageing variations were observed, a general pattern of nodal architecture could be distinguished. The junctional area was therefore divided into four areas: (1) a transitional zone, (2) the compact node, (3) the penetrating bundle, and (4) the branching bundle. The transitional zone was intermediate between atrial myocardium and compact nodal specialized myocardium, but itself exhibited specialized characteristics. An important connection of the zone was to the myocardium of the left side of the interatrial septum. The compact node was itself composed of two segments which approached each other anteriorly from the mitral and tricuspid extremities of the septal anulus fibrosus. The junction of compact node and penetrating bundle could not be distinguished using cytological criteria. It was arbitrarily defined as the last point to make contact with transitional cells. Tissue distal to this was considered as penetrating bundle. A bypass tract was defined as any fiber contacting the bundle distal to this point, but such tracts were not observed in normal hearts. The branching bundle originated at the point of bifurcation of the penetrating bundle.

Adult↗
PubMed1975

Ventricular preexcitation. A proposed nomenclature for its substrates.

The working party on ventricular preexcitation of the European Society of Cardiology has debated nomenclature of the syndrome at several meetings. This communication presents the terminology proposed by the morphologists within the study group on behalf of the other members. It is suggested that the problem should be approached on the basis of possibilities of avoiding the delay-producing area of the atrioventricular junctional region or short-circuiting the specialized ventricular conduction pathways. Thus we propose that the following pathways or contingencies are relevant to preexcitation: (1) accessory atrioventricular muscle bundles; (2) accessory nodoventricular muscle bundles, (3) atriofasicular bypass fibers, (4) fasciculoventricular accessory connections, (5) intranodal bypass fibers, and (6) nodal malformations. Each of these possibilities is defined, or, where only hypothetical, is discussed. In the case of the first two definitions, anatomical variations are indicated which satisfy the basic definition. Thus accessory atrioventricular bundles can be either septal or parietal, and can be composed of either specialized or nonspecialized myocardium. Nodoventricular bundles can connect either the transitional cell zone or the compact nodal region of the junctional area to the ventricular septum. Comparison is made of the new nomenclature with terms in present usage.

Angina Pectoris↗