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Biomedical subjects

A E Becker

Publications and source records attributed to A E Becker.

At least 217 records · Page 12Linked to original sources
PubMed1980

Classification of ventricular septal defects.

A classification with clinical significance is proposed for ventricular septal defect based on the study of 220 hearts with defects of the ventricular septum. All had atrioventricular and ventriculoarterial concordance with normal relations of cardiac structure. For the purpose of classification, the ventricular septum was considered as possessing muscular and membranous portions, the muscular septum itself being divided into inlet, trabecular, and outlet (or infundibular) components. Defects were observed in the area of the membranous septum, termed perimembranous defects; within the muscular septum, termed muscular defects; or in the area of septum subjacent to the arterial valves, termed subarterial infundibular defects. Perimembranous defects were found extending either into the inlet, trabecular, or infundibular septa. Muscular defects were found in or between the inlet septum, trabecular septum, or infundibular septum. Review of the angiograms showed that the classification was easy to use in the catheterisation laboratory, and our observations suggest that the precision thus obtained has considerable surgical significance.

Heart Septal Defects, Ventricular↗
PubMed1980

Straddling right atrioventricular valves in atrioventricular discordance.

Four hearts are described in which the right atrioventricular valve, draining a morphologically right atrium, straddled and overrode a septum between a right-sided chamber of left ventricular morphology and a left-sided chamber of right ventricular morphology. The degree of override varied between the straddling valve and was committed by 20-45% to the morphologically right ventricle. The ventriculoarterial connections in the hearts were discordant in one, double outlet from the morphologically right ventricle in two and single outlet via an aorta from the morphologically right ventricle with pulmonary atresia in the other. The straddling valve in one of the cases with double outlet had a dual orifice. Pulmonary stenosis was present in three cases, and pulmonary atresia in the fourth. Study of the conduction system in three of the hearts revealed subtle but important differences from the pattern expected in atrioventricular discordance. Each case had an anterior atrioventricular node and penetrating bundle, but the connection thus formed was more lateral than usual, and in the case with ventriculoarterial discordance, the nonbranching bundle was unrelated to the pulmonary outflow tract. A sling of conduction tissue between the anterior node and the regular node was found in the case with single outlet and pulmonary atresia.

Adult↗
PubMed1980

Functional and morphological organization of the rabbit sinus node.

In isolated right atria of the rabbit heart, we studied the activation pattern within the sinus node, using the microelectrode technique. After the electrophysiological experiments, the preparations were subjected to a correlative morphological investigation, using light or electron microscopy. Different criteria for defining the dominant pacemaker were compared. A group of at least 5000 cells, located within the central part of the node where the most characteristic tissue architecture was found, was considered to be responsible for generation of the impulse. At the ultrastructural level, this leading cell group appeared to be part of a larger uniform cell group. The number of gap junctions observed suggests that all nodal cells are coupled by these structures. Toward the periphery, the excitation wave was propagated preferentially in an oblique cranial direction toward the crista terminalis. Neither morphologically nor electrophysiologically specific pathways were found for the conduction, but the preferential direction could be explained by the tissue architecture.

Action Potentials↗
PubMed1980

Fontan's operation for Ebstein's anomaly.

Reported herein is the case of a patient with an almost imperforate form of Ebstein's anomaly of the tricuspid valve and a small muscular ventricular septal defect through which the left ventricle communicated with the right ventricular outflow tract. This particular anatomy facilitated the successful execution of a Fontan operation. We are of the opinion that this operation could find its place among the surgical options for Ebstein's anomaly.

Adult↗
PubMed1980

Fontan's operation: an expanded horizon.

The Fontan principle of redirecting systemic venous blood into the pulmonary arteries via a conduit has now gained a much wider application than initially intended. We have applied this type of operation in a series of 15 patients, five of whom had "classical" tricuspid atresia with concordant arterial connections. The other 10 patients showed a variety of congenital malformations, such as double-inlet univentricular heart with discordant arterial connections, double-outlet right ventricle with common atrioventricular canal. Ebstein's anomaly with almost imperforate tricuspid valve, hypoplasia of right ventricular inflow, and a crisscross heart with straddling right atrioventricular valve. Important associated anomalies, such as common atrium and anomalous pulmonary and/or systemic drainage, required particular adaptation of the technique. Thirteen of the 15 patients survived operation and are presently alive. One death occurred in a patient in whom the preoperative diagnosis had to be adjusted during operation because of unexpected total anomalous pulmonary venous connections. The other death occurred in a patient suffering from the "asplenic syndrome." The autopsy in this patient suggested that the large baffle used for atrial septation and ventricular exclusion had obstructed pulmonary venous return. Our experience thus supports the opinion that Fontan's operation has a place in the treatment of otherwise anatomically uncorrectable lesions.

Adolescent↗
PubMed1979

Nomenclature and classification of congenital heart disease.

At present there is no universally accepted nomenclature for congenital cardiac malformations. Much of the controversy results from failure to distinguish the structural connections of the heart from the morphology and spatial relations of its components. The confusion is compounded by an abundance of individual definitions, many of them speculative. The present article proposes a totally descriptive nomenclature. It describes in turn the connections of the cardiac segments, their morphology, their relations, and additional anomalies in any segment. Each step in the segmental approach is discrete. The overall effect is to force a succinct and comprehensive description of any cardiac malformation, no matter how complex.

Coronary Vessels↗