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Biomedical subjects

A E Becker

Publications and source records attributed to A E Becker.

At least 181 records · Page 10Linked to original sources
PubMed1984

Left atrial isomerism associated with asplenia: prenatal echocardiographic detection of complex congenital cardiac malformations.

Complex congenital heart disease with suspected isomerism of the atria was diagnosed in two fetuses of 20 and 29 weeks' gestation using two-dimensional and M-mode scanning techniques. The first pregnancy was terminated at 21 weeks' gestation and stillbirth occurred at 31 weeks' gestation in the second pregnancy. At postmortem examination, a thoracoabdominal discordancy was found; the spleen was absent and the arrangement of the abdominal vessels was as anticipated for asplenia, but the thoracic situs revealed a bilateral right-sided arrangement with left isomerism of the atria. The heart, otherwise, showed complex abnormalities as anticipated for asplenia.

Abnormalities, Multiple↗
PubMed1984

Tachycardia caused by an accessory nodoventricular tract: a clinico-pathologic correlation.

Paroxysmal tachycardia with widened QRS complexes was recorded in an eleven-year old boy who had suffered from brain damage, which had resulted from an episode of ventricular fibrillation. Atrial stimulation produced an increased AV conduction, sudden disappearance of the His bundle deflection and a complete left bundle branch block pattern. Tachycardias of this morphology were initiated by early atrial and ventricular premature beats. The findings suggested the presence of a macro re-entry circuit, utilizing a slow AV node- nodoventricular bypass tract as the anterograde limb and the His-Purkinje system--fast AV node as the retrograde limb. This supposition found further support by serial sectioning of the AV junctional area of the heart, which revealed a nodoventricular tract, which originated from the posterior extension of the compact part of the atrioventricular node and inserted into the crest of the ventricular septum.

Brain Damage, Chronic↗
PubMed1984

The role of echocardiography in assessing the functional class of the patient with Ebstein's anomaly.

In 23 patients with Ebstein's anomaly of the tricuspid valve, the functional class of the patients has been related to the echocardiographic parameters generally used to diagnose this disorder. These are the extent of apical displacement of the tricuspid valve and the delay in tricuspid valve closure time related to that of the mitral valve. In addition, the functional class of the patients has also been evaluated in relation to the severity of tricuspid valve insufficiency and to the presence or absence of associated cardiac abnormalities. The study revealed that the echocardiographic parameters i.e. the degree of apical displacement of the tricuspid valve and the delayed closure time of the tricuspid valve have no predictive value for the patient's clinical condition. On the other hand, both tricuspid valve insufficiency and the presence of additional anomalies have a direct correlation with the well-being of the patient.

Adolescent↗
PubMed1984

Endocardial fibroelastosis and hypoplasia of the left ventricle in neonates without significant aortic stenosis.

Endocardial fibroelastosis in neonates with hypoplasia of the left ventricle is usually associated with severe aortic stenosis or atresia. In this study three hearts were examined, in which severe hypoplasia of the left ventricular cavity with myocardial hypertrophy and endocardial fibroelastosis were associated with small but non-stenotic subaortic outflow tracts and aortic valves. These features were contrasted with those of neonatal left heart hypoplasia in aortic stenosis and atresia. The index cases were examples of the very rare contracted form of endocardial fibroelastosis.

Aortic Valve↗
PubMed1984

Modification of the precise relationship of the atrioventricular conduction bundle to the margins of the ventricular septal defects by the trabecula septomarginalis.

There is a widely recognized relationship between the atrioventricular conduction bundle and the margins of the ventricular septal defects according to whether the defect is perimembranous or muscular. We have shown that this relationship may in turn be markedly influenced by the precise topography of the trabecula septomarginalis. Fifteen hearts, each with a ventricular septal defect, were studied by serial sectioning. Four hearts had an isolated ventricular septal defect in the setting of normal chamber connections and relations. One heart had a truncus arteriosus, seven hearts had Fallot's tetralogy, and three hearts exhibited complete transposition. In those hearts with outlet defects in which a bar of muscle separated the rim of the defect from the position of the conduction bundle, deficiency of the posterior limb of the trabecula septomarginalis permitted the right-sided margin of the conduction axis to "surface" in directly subendocardial position. Moreover, in some of these outlet defects, the conduction axis in the region of the branching bundle was exposed directly upon the crest of the muscular septum. The position of the medial papillary muscle complex was the best landmark to this potential danger area. In some of the examples of Fallot's tetralogy, we observed a firm muscle bar overlying the posteroinferior margin of the defect, which nonetheless was perimembranous. This protected the nonbranching component of the conduction axis in the anticipated danger area. Paradoxically, a deficiency in the trabecula septomarginatis then permitted the branching bundle to sit directly astride the septum along the inferior rim of the defect. We noted particularly marked variability of the atrioventricular conduction axis among the hearts with tetralogy. Our results suggest that close inspection during the operation may reveal whether or not a well-developed trabecula septomarginalis is present and permit conclusions to be drawn concerning the precise position of the atrioventricular conduction axis.

Adult↗
PubMed1983

Surgical anatomy of double-outlet right ventricle--a reappraisal.

In light of the recent developments in surgical treatment of double-outlet right ventricle, the anatomic observations on this lesion were reevaluated. For this review, double-outlet right ventricle was diagnosed when more than half of both arterial valves were connected to the same ventricle, although appreciating the reasons for using, in a clinical context, a "90% rule" rather than the "50% rule" used in this review. Although this ventriculo-arterial connection can exist with any segmental combination, most often it is found in the setting of usually arranged atrial chambers (solitus) and atrioventricular concordance. Categorization of this subset is then done on the basis of the relationships of the arterial trunks. Three main groups stand out: intertwining arterial trunks and "normally related" arterial valves, and parallel trunks, but with the aortic valve to the right side or left side. These groupings give information concerning the site of the ventricular septal defect, which in any group may be perimembranous, muscular or be doubly committed and subarterial. Infundibular morphology is also variable, and the proximity of the arterial valves to the roof of the defect is largely determined by the extent of the ventriculo-infundibular fold.

Heart Defects, Congenital↗
PubMed1983

The definition of myocardial infarction during aortocoronary bypass surgery.

In a study of 392 aortocoronary bypass (CABG) patients, we found 16 patients with a postoperative new Q wave, 29 patients with new intraventricular conduction disturbance, 17 patients with cardiogenic shock, and 14 patients with excessive CK-MB activity. Those criteria were considered as diagnostic of perioperative acute myocardial infarction (AMI). Listing the 392 patients in a Venn diagram: five patients had three positive criteria, eight had two, 43 had one, and 336 had none. Ventricular arrhythmia, supraventricular arrhythmia, or ST-T changes occurred in decreasing frequency in patients with a decreasing number of positive criteria. Five patients died postoperatively and in four a postmortem examination was available. Diagnostic criteria partly predicted autopsy findings. We conclude that the diagnostic criteria of perioperative myocardial infarction have a low diagnostic performance.

Adult↗
PubMed1983

Right and left isomerism: the cardiac surgeon's view.

We have treated by palliative or corrective surgery 12 patients with the complex cardiovascular anomalies associated with right isomerism (asplenia syndrome) or left isomerism (polysplenia syndrome). A systemic-pulmonary artery shunt was performed in 4 patients, with 2 early deaths. Anatomical intracardiac repair was successfully done in 2 patients, while an orthoterminal repair using a modified Fontan procedure was attempted in 5 patients, only 1 of whom survived. A 1-year-old girl with diffuse pulmonary arteriovenous fistulas associated with left isomerism was not considered a good candidate for operation after an exploratory sternotomy. The surgical options and technical problems related to the complex intracardiac morphology of these developmental syndromes are presented.

Adolescent↗
PubMed1983

Transluminal coronary angioplasty and early restenosis. Fibrocellular occlusion after wall laceration.

Transluminal coronary angioplasty was performed in a 51 year old man with a localised narrowing of the proximal segment of the left anterior descending coronary artery. Initial inflations with a small size balloon catheter were unsuccessful. A second attempt, during the same procedure, using a larger calibre catheter relieved the obstruction but produced a dissection. Angina pectoris reappeared approximately three months later. Another attempt to relieve the obstruction by angioplasty, five months after the initial procedure, induced ST segment elevation before angioplasty, followed by ventricular fibrillation and death. The necropsy showed a split in the pre-existent sclerotic plaque and a dissecting aneurysm of the media. A proliferation of fibrocellular tissue filled the false channel and almost totally occluded the pre-existent arterial lumen. The observation suggests that wall laceration with exposure of smooth muscle cells to blood may have initiated the excessive fibrocellular tissue response. This event may be the underlying pathogenetic mechanism for the occurrence of early restenosis after transluminal coronary angioplasty.

Angioplasty, Balloon↗
PubMed1983

The surgical anatomy of the conduction tissues.

On the basis of our collective experience we have reviewed the disposition of the cardiac conduction tissues as they might be observed by the surgeon in both normal and abnormal hearts. The sinus node lies subepicardially in the terminal sulcus; because of its variable blood supply the entire superior cavoatrial junction is a potential danger area. There are no morphologically discrete tracts extending through the atrial tissues between sinus and atrioventricular nodes. The atrioventricular node, the atrial extent of the atrioventricular conduction axis, is contained exclusively within the triangle of Koch. The axis penetrates through the central fibrous body and branches on the muscular ventricular septum immediately beneath the interventricular component of the membranous septum. The landmarks to these structures are described as they might be seen through the right atrium, left atrium, and aorta. Consideration is then given to the surgical anatomy of the abnormal muscular atrioventricular connections that underscore the ventricular pre-excitation syndromes. Finally, rules are developed whereby the disposition of the conduction tissues can be predicted with accuracy in congenitally malformed hearts, in the settings of both normal and abnormal chamber connections. The most important variables in this respect are alignment between the atrial and ventricular septal structures and the pattern of ventricular architecture present.

Atrioventricular Node↗
PubMed1983

The Fontan procedure in the absence of the interatrial septum. Failure of its principle?

The Fontan principle, defined as a procedure in which the right ventricle is bypassed in order to convey desaturated venous blood from the right atrium to the lungs, is presently applied for a wide variety of congenital heart malformations including those in which there is no suitable ventricular pumping chamber. Recently, the procedure has also been advocated for complex malformations that require atrial septation or intra-atrial rerouting. The present report evaluates our experience in four patients with such complex malformations. Three had a complete form of atrioventricular septal defect with double-outlet right ventricle and one patient had left atrioventricular valve atresia. The common atrium was morphologically right in two patients and morphologically left in one. In each of these instances anomalous pulmonary venous connections were present, together with abnormal systemic venous connections. The results were unsatisfactory. Three of the four patients died. The only survivor had no pulmonary or systemic venous abnormalities. Severe impairment of pulmonary blood flow was one of the most important postoperative complications. The findings suggest that the complexities of rerouting the blood within the atria play an important role. The excess proportion of prosthetic material to atrial myocardium may result in excessive loss of contractile atrial myocardium and, probably equally significant, in a complex intra-atrial geometry of pathways that may cause a critical pressure gradient. The results clearly show that with an expanding horizon of the application of the Fontan principle, new pitfalls may arise which presently appear to be the prevailing factors limiting its success.

Adolescent↗
PubMed1982

Univentricular heart: can we alter the natural history?

Surgical treatment must be considered for patients with univentricular heart in view of their poor natural history. Since one of the major factors influencing the natural history of this malformation is the amount of pulmonary blood flow, we discuss the potential surgical options by separately considering the two main pathophysiological situations: univentricular heart with restricted pulmonary blood flow, and univentricular heart with unrestricted pulmonary blood flow. We have reviewed the early and late results of surgical treatment based on our experience with 19 patients and the data from the literature. Temporary relief of symptoms can be provided by palliative operations (systemic-pulmonary shunt, atrioseptectomy, enlargement of the outlet foramen, pulmonary artery banding, or palliative Mustard or Senning procedure). "Corrective" surgery, by means of either a modified Fontan operation or ventricular septation, carries a high early mortality (about 30%) and a high early and late morbidity, with only 50% of survivors enjoying an asymptomatic life. Studies of the long-term efficacy of palliative operations as well as our experience and that of others with "corrective" operations, which have a relatively short follow-up, do not yet indicate whether presently available surgical procedures can alter the natural history of patients with univentricular heart.

Adolescent↗
PubMed1982

Apex two dimensional echocardiography. Alternative approach to quantification of acute myocardial infarction.

Apex echocardiography has been chosen as an approach to detect and quantify acute myocardial infarction because the usual parasternal acoustic windows are often occluded. Fifty-three patients were studied, all within 12 hours after the onset of symptoms of their first myocardial infarction. Three apical long axis views were obtained, that is the two and four chamber views, and the right anterior oblique equivalent or three chamber view. Satisfactory echocardiograms were obtained in 48 patients (91%). The individual apical views were divided into equal segments and the area of asynergy was estimated in each view. Left ventricular asynergy was present in all 48 patients. In 46 patients a positive correlation between the electrocardiogram and the echocardiogram was obtained, as far as infarct localisation was concerned. The estimated asynergic area correlated well with the peak value of the isoenzyme of creatine kinase (CK MB). Apex echocardiography is a reliable alternative method of detecting and quantifying myocardial infarction soon after the onset of symptoms.

Adult↗