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Biomedical subjects

R H Anderson

Publications and source records attributed to R H Anderson.

At least 19 recordsLinked to original sources
PubMed1992

Morphological study of defects of the atrial septum within the oval fossa: implications for transcatheter closure of left-to-right shunt.

OBJECTIVE: To determine the anatomical variability of the oval fossa in cases of atrial septal defect and to find out which factors might make such defects suitable or unsuitable for closure by umbrella or clamshell devices. DESIGN: 100 specimens with defects of the atrial septum within the oval fossa were studied, especially the position of the defects within the fossa; the area of the defect in relation to the total area of the oval fossa; the shape of the rims and flap valve of the oval fossa; and the anatomical variability in the eustachian and thebesian valves. RESULTS: The oval fossa was displaced to the mouth of the inferior caval vein in four cases; displaced to the mouth of superior caval vein in two cases; placed on the middle of the interatrial wall in 43; or placed slightly towards the inferior caval vein in 51. Because of their shape 29 of the hearts were considered to be unsuitable for transcatheter closure of the defect. This was because the defect was too large (16 hearts); the oval fossa was displaced to the mouth of the inferior caval vein (four hearts) or to the superior caval vein (two hearts); lacked its anterior rim (two hearts); lacked the posteroinferior rim (one heart); because a thick eustachian valve was displaced posteriorly forming a false posteroinferior rim (one heart); or because the strand of insertion of the floor of the oval fossa was too distant from the left atrial aspect (three hearts). CONCLUSION: 68 hearts appeared to be ideal candidates for transcatheter closure; 3 would probably have been suitable; but 29 were unsuitable. These morphological variations might explain why the procedure has been unsuccessful in so many cases. Patients should be screened before any attempt is made at transcatheter closure.

Adolescent↗
PubMed1992

Correlation between echocardiographic and morphological investigations of lesions of the tricuspid valve diagnosed during fetal life.

OBJECTIVE: To assess the degree of agreement between the fetal echocardiographic and postmortem examination of hearts from fetuses with severe malformations of the tricuspid valve. DESIGN: A retrospective study to analyse echocardiographic recordings and make comparisons with postmortem findings. SETTING: Tertiary referral centre for fetal echocardiography. Institute for cardiac morphology. PATIENTS: 19 cases shown to have severe malformation of the tricuspid valve by fetal echocardiography that died in the prenatal or neonatal period. MAIN OUTCOME MEASURES: Correlations between morphology and measurements made at echocardiography and necropsy. RESULTS: The echocardiographic diagnosis was Ebstein's malformation in seven and tricuspid valvar dysplasia in 12 fetuses. These findings were confirmed in six and eight cases at necropsy. In one false positive diagnosis of Ebstein's malformation, necropsy showed dysplasia of the leaflets of the tricuspid valve without displacement. In four cases with the echocardiographic diagnosis of valvar dysplasia, necropsy showed displacement, the hallmark of Ebstein's malformation. Associated malformations that are known to worsen prognosis were predicted correctly by echocardiography. Taking the mean duration of four weeks between echocardiographic and postmortem investigations, both methods showed cardiomegaly causing lung hypoplasia, right atrial dilatation, and relative hypoplasia of the pulmonary trunk, morphometric factors that may be responsible for the poor outcome. Mostly good agreement existed between the echocardiographic and postmortem measurements if cases with an interval of more than eight weeks between the measurements were excluded. CONCLUSION: Fetal echocardiography was proved to be a reliable technique in differentiating the variants of tricuspid valvar disease, in diagnosing associated cardiac lesions, and in predicting quantitative factors that can define the subsequent outcome.

Ebstein Anomaly↗
PubMed1992

New findings concerning ventricular septation in the human heart. Implications for maldevelopment.

BACKGROUND: The mechanics involved in development of the inlet component of the morphologically right ventricle are, as yet, undecided. Some argue that this component is derived from the descending limb of the ventricular loop, and that the inlet and apical trabecular components of the muscular ventricular septum have separate developmental origins. Others state that the entirety of the right ventricle grows from the ascending limb of the loop, and that the muscular septum, apart from its outer component, has a unitary origin. We now have material from human embryos at our disposal, which, we believe, solves this conundrum. METHODS AND RESULTS: We used a monoclonal antibody against an antigen to neural tissue from the chick to demarcate a ring of cells separating the descending (inlet) and ascending (outlet) limbs of the developing ventricular loop of the human heart. Preparation of serial sections of graded human embryos enabled us to trace the fate of this ring, and hence the formation of the inlet of the right ventricle, to the completion of cardiac septation. Eight embryos were studied, encompassing stages 14-23 of the Carnegie classification. The ring of cells initially separating the ascending and descending limbs of the ventricular loop were, at the conclusion of ventricular septation, located within the atrioventricular junction, sequestrated for the most part in the terminal segment of atrial myocardium. CONCLUSIONS: Our study conclusively shows that the inlet component of the morphologically right ventricle is derived from the ascending limb of the embryonic ventricular loop, and that the inlet and apical trabecular components of the muscular septum are derived from the same primary ventricular septum.

Antibodies, Monoclonal↗
PubMed1992

Morphology of ventricular septal defects in complete transposition. Surgical implications.

Postmortem examination of 62 hearts with complete transposition (concordant atrioventricular and discordant ventriculoarterial connections) and an accompanying ventricular septal defect was performed to determine the morphologic variability of ventricular septal defects and to explore the surgical implications of these defects. Particular attention was directed toward assessing alignment of the outlet septum relative to the muscular septum. Coronary arterial distributions were also evaluated, but specific patterns of distribution did not correlate with morphology of the defect. Of 49 hearts with a normally aligned outlet septum, there were 24 perimembranous, 21 muscular, and 2 doubly committed and juxtaarterial defects. Two hearts had both perimembranous and muscular defects. Twelve of the 21 muscular defects were "central," being surrounded entirely by muscle and located just below the leaflets of the pulmonary valve, and 9 were located in the inlet or apical trabecular septum. There were 13 hearts with malalignment of the outlet septum, anteriorly in 11 and posteriorly in 2. All with anterior malalignment had a subpulmonary defect that was perimembranous in 7 and muscular in 4. Both defects with posterior malalignment had a subaortic perimembranous defect. Because variations in morphology of a ventricular septal defect have a direct impact on selection of the most suitable surgical repair, specific operative approaches are discussed.

Abnormalities, Multiple↗
PubMed1979

Prolonged QT interval and cardiac arrhythmias in two neonates: sudden infant death syndrome in one case.

Two neonates with arrhythmias and the long QT syndrome are described. The arrhythmias were detected in utero and both infants were apparently well after birth. The first infant, although well, had a bradycardia for the first 9 days of life. A normal heart rate was documented at 10 days but a prolonged QT interval was not appreciated on the ECG. He was discharged from hospital but died suddenly and unexpectedly 3 days later. A post-mortem examination failed to find a cause for his death which therefore fell into the category of the sudden infant death syndrome (SIDS). A retrospective analysis of the perinatal electrocardiogram showed a probable junctional rhythm with 2:1 conduction to the ventricle; the QT interval was prolonged at 0.52 seconds (QTC = 0.63). The second infant had a QT interval of 0.52 seconds (QTC = 0.54) and frequent ventricular premature beats on a 24-hour electrocardiogram. She was treated with propranolol and remains well 2 years later. Sudden infant death has often been described in the siblings of children with the long QT syndrome and one other report described a case of SIDS which was said to have had a prolonged QT interval on the perinatal ECG. This report, however, provides unquestionable evidence, in one case, of an association between the long QT syndrome and SIDS.

Arrhythmias, Cardiac↗
PubMed1979

Location and vascular supply of sinus node in human heart.

The exact location of the sinus node was determined in 25 infant hearts using reconstructive techniques. The sinus node was found to lie on the lateral aspect of the superior cavo-atrial junction in the great majority (22 hearts). In only 3 hearts was it found to straddle the summit of the crest of the right atrial appendage where it is popularly believed to be located. In the majority of instances a single artery supplied the node (in 11 hearts the artery approached posteriorly, and in 10 the artery approached anteriorly), though there was considerable variation in the exact anatomy of the arterial supply. Connections between the sinus node and atrial myocardium were diffuse and abundant but in no instances were tracts of specialised cells observed leaving the node and traversing any distance through the atrial wall. These findings are relevant to the sinus node dysfunction that may follow cardiac surgical procedures.

Arteries↗
PubMed1979

Disposition of the sinus node in left-sided juxtaposition of the atrial appendages.

In view of the complex cardiac anomalies frequently associated with left-sided juxtaposition of the atrial appendages the disposition of the sinus node has been studied in 6 of these hearts. While the sulcus terminalis still provides a landmark to the position of the node, the nodes were in an anterior position in all 5 hearts with complete juxtaposition, 2 being inferior to the crista terminalis. The node was in a more normal, lateral position in the sixth case with partial juxtaposition.

Heart Atria↗
PubMed1979

Coarctation, tubular hypoplasia, and the ductus arteriosus. Histological study of 35 specimens.

A histological study has been made in an attempt to study further the relation between the ductus arteriosus, coarctation, and tubular hypoplasia of the aortic arch. Thirty-five aortic arch systems were studied using serial sectioning techniques. Twelve were from patients with coarctation and/or tubular hypoplasia. The other 23 hearts were from patients without aortic obstructive lesions, 7 from anatomically normal hearts, and the others from malformed hearts with anomalies elsewhere from the aortic arch. The anatomical study of the hearts with obstructive aortic lesions emphasised the necessity of distinguishing 'coarctation' from 'tubular hypoplasia', since the curtain lesion of coarctation was found to coexist with tubular hypoplasia in some cases. The histological study showed that the ductus was easily distinguished from the walls of the aorta or pulmonary artery. In all these cases with coarctation or tubular hypoplasia a sling of ductal tissue was located around the aortic isthmal orifice. In 6 hearts a diaphragm of ductal tissue was seen to form the coarctation lesion.

Adult↗
PubMed1979

Developmental anatomy of the membranous part of the ventricular septum in the human heart.

The anatomy of the membranous part of the ventricular septum is described in 25 hearts from patients ranging in age from 15 weeks of gestation to the ninth decade of adult life. Both atrioventricular and interventricular components were recognised in all the adult subjects, and the atrioventricular component was evident in all 25. The interventricular membranous septum was present in only 1 of the fetal hearts and 4 of the infant subjects. We consider that these findings indicate that the transformation of the membranous septum into atrioventricular and interventricular components occurs in the late fetal and early postnatal period rather than during closure of the embryonic interventricular foramen. It is associated with the liberation of the medial leaflet of the tricuspid valve from the muscular ventricular septum.

Adolescent↗
PubMed1979

Morphological variations in pulmonary atresia with intact ventricular septum.

The morphological features of a series of 37 specimens of pulmonary atresia with intact ventricular septum were reviewed with particular emphasis on features which might influence the results of pulmonary valvotomy. The degree of right heart hypoplasia was quantified by measuring right and left heart dimensions and comparing them with 20 normal infant hearts. Right ventricular cavity size was usually smaller than normal but constituted a spectrum ranging from tiny to a dilated ventricle larger than normal. There was a positive correlation between triscuspid annular size and right ventricular size but no correlation between the size of the pulmonary artery and the right ventricle. Successful pulmonary valvotomy with subsequent adequate right ventricular function would have been precluded by a tiny right ventricular cavity or infundibular atresia in 14 specimens and by severe tricuspid stenosis or regurgitation in an additional 4. Severe right or left ventricular endocardial fibroelastosis may have adversely affected ventricular function in several others. Ten specimens displayed convex bulging of the left ventricular septal surface. If these these anatomical findings are representative for the condition as a whole, they provide a good explanation for its disastrous prognosis.

Ebstein Anomaly↗
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↗
PubMed1979

Two-chambered right ventricle: simulating two-chambered left ventricle.

Two cases are described of a most unusual variant of two-chambered right ventricle. In both the ventricular septal defect was between the distal chamber of the right ventricle and the left ventricle. However the extensive dividing 'septum' between proximal and distal parts of the right ventricle converted the latter, haemodynamically, into part of the left ventricle. In the first case the distal chamber supported the aorta in the left anterior position, the pulmonary artery arising from the proximal part of the right ventricle. In the second the pulmonary artery arose from the distal chamber and the aorta from the proximal chamber. Though in both the ventriculoarterial connection was double outlet right ventricle, functionally there was arterial concordance in case 1 and discordance in case 2. A further disconcerting feature was the resemblance of the distal right ventricular chamber to the rudimentary chamber of a univentricular heart of left ventricular type.

Angiocardiography↗
PubMed1979

Atresia of the right atrioventricular orifice with atrioventricular concordance.

Three hearts are described in which a fibrous membrane was interposed between the right atrium and a formed but hypoplastic right ventricle, which possessed recognisable inlet, trabecular, and infundibular components. In these hearts the distribution of the conducting tissue was as expected for concordant atrioventricular connections, and contrasts with that seen in the classical type of 'tricuspid atresia'. The distinctive morphological and histological features of these specimens lend further support to our view that the majority of cases of atresia of the right atrioventricular orifice should be regarded as coming within the designation of 'the univentricular heart'.

Heart↗
PubMed1979

Dextrocardia--value of segmental analysis in its categorisation.

Dextrocardia can be defined as a heart in the right chest with the major axis to the right. This definition, however, conveys no information regarding the chamber arrangements and internal anatomy of the heart. Of 40 patients satisfying this definition in the files of the Brompton Hospital, 33 had angiocardiographic data adequate for complete analysis in terms of connections, relations, and morphology of cardiac segments. They form the subject of this report. There were 16 (48%) patients with situs solitus, 11 (33%) with situs inversus, and six (18%) with situs ambiguus. Of the cases of situs ambiguus, four exhibited laevoisomerism and two dextroisomerism. Of the 16 patients with situs solitus, six had two ventricles and 10 had univentricular hearts; two patients had concordant and three discordant ventriculoarterial connections, seven had double outlet ventricle, and four a single outlet heart. Of the 11 patients with situs inversus, nine had two ventricles and two a univentricular heart of right ventricular type; the arterial connection was concordant in two, discordant in two, double outlet in six, and single outlet in one. Of the six patients with situs ambiguus and laevo or dextroisomerism, four had two ventricles, and two univentricular hearts; the arterial connection was concordant in one, double outlet in three, and single outlet in two. Segmental analysis and the use of basic descriptive terms are essential to define the complex anatomy of such hearts.

Angiocardiography↗