Biomedical subjects
Publications and source records attributed to R H Anderson.
Quantitative studies of visceral nociception have been limited due to the lack of an easily controlled, reproducible stimulus. Distension of hollow viscera is painful in humans. The device described here allows control over a phasic distending stimulus satisfactory for quantitative neurophysiologic, behavioral or pharmacologic studies.
Fifty-seven heart specimens with complete transposition (concordant atrioventricular and discordant ventriculo-arterial connections) and ventricular septal defect were reviewed to establish the spectrum of morphology of the ventricular septal deficiency and to correlate the type of defect with presence of subarterial and aortic arch obstruction. The ventricular septal defect was single in 52 cases (27 perimembranous and 25 muscular) and multiple in five. A normal alignment between the outlet component and the rest of the muscular septum was present in 18 cases (10 perimembranous, five muscular, and three multiple). The defect was the consequence of septal malalignment in the other 39 specimens; 29 with rightward and 10 with leftward displacement of the outlet septum. Rightward displacement led to perimembranous defects in 16 cases and muscular defects in 12. In another instance, a perimembranous malalignment defect was associated with a muscular inlet defect. Subaortic stenosis due to either deviation of the outlet septum or prominence of the ventriculo-infundibular fold and septoparietal trabeculations was observed in 14 cases. Leftward displacement of the outlet septum was associated with one perimembranous and eight muscular defects and with multiple (muscular outlet plus muscular inlet) defects in another case. Of these, five cases showed subpulmonary stenosis. Aortic arch obstructions were present in 19 cases; 14 showed rightward malalignment of the outlet septum, which produced subaortic stenosis. These findings suggest two things: Unlike the situation in hearts with "normally related" great arteries, most defects in complete transposition result from malalignment of the outlet septum, with many being of the muscular type. Rightward or leftward displacement of the outlet septum frequently results in subaortic or subpulmonary stenosis, respectively. Aortic arch obstructions, although frequent, are not always associated with subaortic stenosis.
Two congenitally malformed hearts are described, one studied in life and the other at autopsy, in which the topology of the ventricular mass was not as expected for the atrioventricular (AV) connection present. In Case 1, studied at autopsy, there was the usual atrial arrangement with a concordant AV connection. The morphologically right ventricle, however, was left-sided and the ventricular mass was of left-hand topology (l loop) rather than the expected right-hand pattern (d loop). In Case 2, studied during life, there was the usual atrial arrangement and a discordant AV connection. Rather than the anticipated left-hand topology (l loop), the ventricular mass was arranged in right-hand fashion (d loop) and the morphologically right ventricle was right-sided. The cases emphasize that for a full description of a congenitally malformed heart, it is often necessary to account for the topology of each segment as well as the connections (or alignment) among the segments.
Ebstein's anomaly of the tricuspid valve is characterised by downstream displacement of the tricuspid leaflets. In the case of the septal leaflet, the result is exaggerated offsetting of the atrioventricular valves. Thus it might be supposed that in Ebstein's anomaly of the mitral valve, downstream displacement of the aortic (septal) leaflet of the mitral valve could move its attachment beyond that of the tricuspid valve, resulting in reversed offsetting. To examine this hypothesis three patients each with a concordant atrioventricular connection were studied. The first, with Marfan's syndrome and without an abnormal mitral valve, had reversed offsetting shown by echocardiography. The second, without Marfan's syndrome and with Ebstein's anomaly of the mitral valve, showed echocardiographically normal offsetting but a displaced mural leaflet. The third, in whom Ebstein's anomaly of the mitral valve was confirmed at necropsy, showed all the features of the second case, with normal offsetting of the atrioventricular valves. Thus reversed offsetting is not a feature of Ebstein's anomaly of the mitral valve and in the first case this feature was caused by upward displacement of the tricuspid valve secondary to dilation of the aortic root.
A 13 day old baby was admitted to hospital with multiple abnormalities, increasing cyanosis, and cardiac failure. Cardiac catheterisation was performed on the day of admission and he died shortly after the procedure. A rare variant of common arterial trunk, in which the pulmonary arteries arose directly from the underside of the aortic arch, was found at necropsy.
Eight cases of absent right superior caval vein (vena cava) with normal atrial arrangement from the Great Ormond Street database were reviewed. In each case the right subclavian vein and jugular vein drained into a persistent left superior caval vein through a bridging vein. In six cases the left superior caval vein drained into the right atrium by way of the coronary sinus, and in two cases it drained into the left atrium directly because of the complete unroofing of the coronary sinus. The frontal plane P wave axis was displaced leftwards and upwards in four out of seven cases in which an electrocardiogram was available. No case showed arrhythmia on a standard electrocardiogram preoperatively. Echocardiograms were available in four cases and in each case diagnosis of the anomalous connections of the systemic vein was possible. Only one third of the cases showed a crescentic shadow of the persistent left superior caval vein on chest x ray. A chest x ray and electrocardiogram do not provide the means of reliable diagnosis of this condition, though they may suggest the possibility of its existence. Definitive diagnosis requires cross sectional echocardiography or angiocardiography or both.
Three cases of twins conjoined across the chest were examined. In one set, one twin showed right atrial isomerism and the other showed the usual atrial arrangement. The other two sets showed the usual atrial arrangement in both twins. The associated cardiac anomalies were diverse, ranging from atrioventricular septal defects to absent atrioventricular connections. Sequential segmental analysis was used successfully in each case to classify the complex cardiac anomalies. The first step was the recognition of the atrial arrangement. This was easily achieved despite the complexity of the intracardiac morphology.
MR was used to differentiate the classical form of tricuspid atresia, in which the atrioventricular connection is absent, from a rare type of right atrioventricular obstruction, in which the valve is imperforate, and from some Ebstein's malformations in which atrioventricular flow is obstructed by a displaced tricuspid valve. ECG-gated, T1-weighted spin-echo MR imaging was performed at 0.3 or 1.0 T in six patients with classical tricuspid atresia, in one patient with tricuspid atresia due to an imperforate tricuspid valve, and in two with Ebstein's malformation. In the patients with classical tricuspid atresia, epicardial fat within the atrioventricular sulcus that was interposed between the right atrium and the ventricular mass caused increased intensity. This finding was not present in the patients with imperforate tricuspid valve or Ebstein's malformation in whom the sulcus appeared normal. Postmortem examination of five other hearts with classical tricuspid atresia revealed epicardial fat extending into the atrioventricular sulcus, which separated the right atrium and the ventricular mass. In three hearts with Ebstein's malformation, the sulcus extended only to the level of the atrioventricular junction. The characteristic MR appearance of fat adjacent to the muscular floor of the right atrium, therefore, serves to identify the atrioventricular sulcus and allows differentiation of the types of right atrioventricular valve atresia.
There is no consensus as to the most appropriate definition of the use of the term Taussig-Bing malformation. In this study, we endorse the suggestion that the lesion be considered a spectrum of anomalies, unified by a juxtapulmonary ventricular septal defect with malalignment of the infundibular septum. The ends of the spectrum are hearts with, on the one hand, double-outlet right ventricle and, on the other hand, a discordant ventriculoarterial connection. We studied 10 hearts within this spectrum, eight with a double outlet and two with discordant ventriculoarterial connection. We found that the same basic morphology could exist with a bilaterally complete infundibulum or in the presence of fibrous continuity between the mitral and the pulmonary valves. Features of most significance for surgical correction were the arrangement of the outlet septum (particularly the presence or absence of chordal attachments from the atrioventricular valves), the morphology of the coronary arteries, and the state of the subaortic infundibulum. The options for surgical correction are determined by the internal morphology of the lesions rather than by the precise ventriculoarterial connection.
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The anatomy of the conduction system was studied in 8 patients who had isolated congenital complete heart block. Atrial-axis discontinuity was seen in 7 hearts from children born to mothers with anti-Ro antibodies. The anticipated area of the atrioventricular node was occupied by fibrous and adipose tissue. The heart from the only child whose maternal serum was anti-Ro negative had nodoventricular discontinuity of the conduction system. This difference in anatomy may have etiologic significance.
Fetal echocardiography can ascertain, at an early stage in pregnancy, recurrences of congenital heart disease (CHD) in mothers with a family history of CHD. In 1,021 mothers referred for this reason, 20 recurrences were found; 17 occurred when there had been 1 previously affected child, and 3 when there had been 2 previously affected children. No recurrences were found in the 41 cases in which a parent had CHD. The overall recurrence rate was 1 in 52 with a previously affected child and 1 in 10 with 2 previously affected children. However, certain forms of CHD recurred much more frequently than others. Aortic valve atresia was associated with a recurrence rate of 1 in 28, coarctation of the aorta at a rate of 1 in 15, complex CHD at a rate of 1 in 11 and truncus arteriosus at 1 in 13. These findings are inconsistent with previous family studies; this may be due to more complete ascertainment, particularly of major lesions, possibly overlooked by postnatal family studies because of fetal loss. Alternatively, the availability of prenatal diagnosis may be producing an increase in family size after major CHD. The results support current doubts on the polygenic theory of inheritance for all forms of CHD.
Fifty-one patients at the Brompton Hospital were identified as having either right or left atrial isomerism by reviewing the records and catheterization, echocardiographic and, in 17 cases, autopsy data. Every study patient had 1 or more of the following conditions: isomeric bronchial anatomy; angiographic or necropsy evidence of atrial anatomy; echocardiographic diagnosis of isomerism; and anomalies of systemic or pulmonary venous connection. Patients with anomalous venous connections all had additional signs of isomerism. Neither right nor left type was predominant in either sex. The heart was in the left chest slightly more often than the right. Abdominal visceral heterotaxy was the most frequent radiographic finding. An ambiguous and biventricular connection was the commonest type of atrioventricular (AV) connection in left isomerism. A common AV valve was the most frequent mode of connection in both forms. Univentricular AV connection, double-outlet right ventricle, pulmonary atresia and discordant ventriculoarterial connection were commoner in right isomerism. Left isomerism is associated with much longer survival, its constellation of associated malformations frequently being less severe and more amenable to corrective surgery. A precise diagnosis must be made during life in order to select the most appropriate treatment.
The sexually dimorphic nucleus of the preoptic area (SDN-POA) has recently been shown to be reduced in cross-sectional area in prenatally stressed male rats. As masculine copulatory behavior is also reduced in prenatally stressed animals, the present study was designed to test a possible relationship between the entire volume of the SDN-POA and masculine sexual activity in both prenatally stressed and control adult male rats. We report here that prenatally stressed adult males have significantly reduced SDN-POA volumes, reduced levels of sexual activity and lower plasma testosterone levels as compared to control animals. Additionally, however, a strong positive relationship was demonstrated between SDN-POA volume and sexual activity in both stressed and control animals. SDN-POA volumes of sexually active animals from stressed and control groups are approximately equal. SDN-POA volumes of sexually non-active animals are also equal and are about two times smaller than those of sexually active animals, either stressed or control. Similar correlations are reported between SDN-POA volume and testosterone level, and between testosterone level and sexual activity. It is concluded that (1) SDN-POA volume is predictive of sexual activity in both stressed and control male rats, (2) there is a relationship between SDN-POA volume and plasma testosterone level, and (3) the SDN-POA likely has multiple roles in the circuitry underlying masculine reproductive processes and hormone regulation.
Left atrioventricular (AV) valve dysfunction is the most frequent major postoperative hemodynamic complication in patients with AV septal defect. The anatomy and function of the left AV valve were investigated in 64 patients with separate valve orifices (ostium primum atrial septal defect) who had survived corrective surgery. M-mode and cross-sectional echocardiograms of the left AV valve were obtained. Doppler flow tracings were obtained at the left AV valve orifice to determine if regurgitation was present. The findings were related to the position of the commissures between the leaflets, the size of the 3 leaflets and the position of the papillary muscles. Left AV valve regurgitation was present in 29 of 51 patients (57%). These patients had a significantly different left AV valve leaflet configuration, characterized by a large mural leaflet and a small inferior bridging leaflet. The size of the superior bridging leaflet is not a determinant factor. Thus, the configuration of the left AV valve in AV septal defect is related to the postoperative functional result. Awareness of the echocardiographic anatomy may influence the surgical approach to this defect.
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We examined the cross-sectional echocardiographic findings of 171 patients with atrioventricular septal defects. The echocardiographic findings were confirmed by angiography, surgery and/or autopsy. The echocardiographic findings determined whether the common atrioventricular junction was guarded by a common valve or separate right and left valves. In addition, we were able to judge whether the bridging leaflets were related to the septal structures so as to permit both interatrial and interventricular communications [127 cases] or whether the interatrial communication ("ostium primum atrial septal defect") [43 cases] or an interventricular communication [1 case] existed in isolation. Defects existing with a common atrioventricular valve could be further classified as having minimal bridging of the antero-superior leaflet (Rastelli Type A [113 cases]); intermediate bridging (Rastelli Type B [3 cases]); or extreme bridging (Rastelli Type C [11 cases]). Of the patients with Down's syndrome, 9 had separate right and left valves while 66 had a common valve, all the latter existing in the setting of minimal bridging of the antero-superior leaflet. In the overall group, there were 9 cases having an unbalanced ventricular mass, 5 with right ventricular dominance and 4 with left dominance. Other associated defects were common. The echocardiographic findings were supplemented by pulsed Doppler examination. Atrioventricular valve insufficiency, when mild, was frequently demonstrated only in the right atrium just above the leaflets of the atrioventricular valve. When there was more severe valve insufficiency the regurgitant jet could be detected for greater distances behind the atrioventricular valve and in either or both atria, but more frequently in the left atrium. As might be anticipated in view of the complexity of the lesion, a combined imaging approach yielded the most accurate results.
The origin and course of the main coronary arteries and the sinus nodal artery are relevant to both intra-atrial and arterial relocation operations for complete transposition (the combination of concordant atrioventricular and discordant ventriculo-arterial connexions). The patterns of the main coronary arteries in 148 hearts with complete transposition have been documented together with the patterns of the sinus nodal artery in 105 of these. The terminology which has been used to describe these arteries has been explained. The findings illustrate the wide variation which exists in the origin and course of all these arteries in complete transposition and indicate areas where they are most at risk.