Transluminal balloon dilation of resected coarcted segments of thoracic aorta: histological study and clinical implications

The effect of experimental balloon dilation on seven excised specimens of classic coarctation was assessed histologically. Widening of the lumen was achieved in all specimens by tears in the vessel wall. The tears extended through the intima in one specimen and through both intimal and medial layers in six specimens. In view of the extent of wall damage, we postulate that there would be serious long-term complications following balloon dilation for the treatment of native coarctation.

Conjoined twins, right atrial isomerism, and sequential segmental analysis

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.

The pathology of balloon pulmonary valvoplasty

The pulmonary valve was examined following balloon dilation of pulmonary valve stenosis in six children. Stenosis was due to commissural fusion in two. In these patients, cineangiography showed that the valve was slightly thickened and "domed" during systole. Balloon valvoplasty produced complete separation of fused commissures in one and partial separation in the other. Commissural splitting is likely to be the most common mechanism of relief of pulmonary stenosis by balloon dilation. Incomplete separation could account for the partial reduction of the gradient in most children treated with this technique. Four children had pulmonary valve dysplasia. Balloon valvoplasty did not produce haemodynamic improvement or morphological changes that were identifiable at the time of surgical correction. Tearing of pulmonary valve tissue and avulsion of pulmonary cusps were not seen in this series.

Pulmonary atresia with hypoplastic left ventricle

We report a case with concordant atrioventricular connexion in association with pulmonary atresia and origin of the aorta from the right ventricle. The left ventricle was hypoplastic and the ventricular septum intact.

The ventricular septal defect in complete transposition of the great arteries: pathologic anatomy in 57 cases with emphasis on subaortic, subpulmonary, and aortic arch obstruction

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.

Zinc in multiple sclerosis. II: Correlation with disease activity and elevated plasma membrane-bound zinc in erythrocytes from patients with multiple sclerosis

Previous studies have shown that zinc levels in erythrocytes are significantly elevated in patients with multiple sclerosis (MS). To examine the correlation between erythrocyte Zn levels and disease activity, we measured erythrocyte Zn levels longitudinally. Levels were dramatically decreased during a clinically documented exacerbation of MS. To determine the localization of increased Zn levels in MS erythrocytes, we employed standard techniques for the isolation of nonhemoglobin erythrocyte membrane ghosts. Patients with MS had three times more Zn in ghost material than did controls. Chloroform-methanol extraction in erythrocyte ghosts followed by determination of Zn levels indicated that most of the membrane-bound Zn was associated with the lipid-soluble fraction. Non-lipid-associated Zn and total membrane protein concentration were similar in MS and control samples. Results suggest that mechanisms which govern cellular availability, compartmentalization of Zn, or the binding of Zn to cell surface membranes may be altered in patients with MS, and that these mechanisms vary with disease activity.

Coronary arteries in complete transposition: the significance of the sinus node artery

Hearts from 29 children with complete transposition were examined postmortem to analyze the pattern of the coronary arteries and the origin of the sinus node artery. Four patterns of origin and distribution of the coronary arteries were found. In all, the coronary arteries arose from one or both of the facing sinuses, which were termed sinus 1 and sinus 2. The patterns were left coronary artery from sinus 1 and right coronary artery from sinus 2; anterior descending artery from sinus 1 and right coronary artery and circumflex artery from sinus 2; left coronary and right coronary from sinus 2; and circumflex artery from sinus 2 and right coronary artery from sinus 1. This study highlights the patterns of the coronary arteries in complete transposition and categorizes the variability using a simple classification. It also emphasizes the surgical significance of variations in distribution of the sinus node artery.

Anatomy of congenital complete heart block and relation to maternal anti-Ro antibodies

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.

Diagnosis and significance of atrial isomerism

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.

Absent aortic valve leaflets

A newborn with difficulty in feeding and with tachypnoea was admitted to the hospital. During the following days his condition deteriorated and he died at the age of 8 days. At autopsy we found an unusual association of hypoplastic left heart syndrome and absence of the aortic leaflets.

The surgical anatomy of the left ventricular outflow tract in atrioventricular septal defect

The left ventricular (LV) outflow tract (OT) in atrioventricular (AV) septal defect is an important structure that paradoxically is hardly ever seen by a surgeon. The LVOT is prone to develop obstruction following surgical procedures, such as left AV valve replacement, that seemingly do not affect the LVOT itself. We examined 15 hearts with AV septal defects and noted the anatomical boundaries of the LVOT. Additionally, the LVOT was examined microscopically, and it was sectioned to replicate echocardiographic images. A sham operation was performed to show the extent of the proposed resection for AV valve replacement. The mean length of this area was 91.8 +/- 35.5% (range, 28.6 to 167.0%) of the diameter of the ascending aorta in our specimens of the Rastelli A variety. The mean diameter of the LVOT was 68.2 +/- 13.5% (range, 42.9 to 100.0%) of the diameter of the ascending aorta. The posterior wall of the OT can either be resected or widened. Resection seems to be opportune at AV valve replacement, whereas widening could be performed when the OT is intrinsically stenotic. When one fully appreciates the concept of a five-leaflet common valve, it is clear that the length of the OT depends on the extent of adherence between the superior bridging leaflet and the septal crest. In hearts that have two separate AV valve orifices, the OT is fully developed; there is no potential for interventricular shunting ("ostium primum defect"), because the superior bridging leaflet is always tightly adherent to the septal crest. AV valve replacement in these cases is especially hazardous.(ABSTRACT TRUNCATED AT 250 WORDS)

Ostium primum atrioventricular septal defect: an anatomical and surgical review

The results of surgical repair of ostium primum atrioventricular septal defect show continued improvement. This improvement reflects the advances in open-heart surgery in general and, in particular, the better understanding of the anatomy of the conduction tissue and the morphology and function of the left atrioventricular valve. We have corrected this defect in 84 patients over a ten-year period. There were 2 early deaths (2.4%) and 2 late deaths (2.4%). Two patients had problems related to conduction. Our surgical approach has been to place the interatrial baffle in such a way as to avoid the displaced atrioventricular node and thereby leave the coronary sinus in the left atrium. Our approach to repair of the so-called cleft in the left atrioventricular valve (in reality the space between the ventricular components of the bridging leaflets), is based on the unequivocal triple-leaflet morphology of this valve.

Heart block and atrioventricular septal defect

The cardiac conduction system was examined in 2 hearts which had repair of atrioventricular septal defect. The first was from a child known to have had a prolonged P-R interval and the second was from a girl who developed complete heart block before submission to surgery. The atrioventricular conduction axis was histologically discontinuous in the first case, but preserved and surrounded by hemorrhage in the second case. This study draws attention to the inherent vulnerability of the cardiac conduction axis which must also be recognized before surgical intervention.

Congenital heart malformations in the first year of life--a necropsy study

The hearts of 291 babies with congenital heart disease who died before the age of one were examined systematically by sequential segmental analysis to determine the lesions that were present. There was an abnormal connection between the cardiac segments in one third of cases. Patient ductus arteriosus, which is usually a common defect, was not an important finding at necropsy, whereas common arterial trunk (a rare defect) was found in 10%. The clinical and necropsy incidence of complete transposition was similar to that reported in earlier studies. The incidence of some lesions present at necropsy (for example Fallot's tetralogy) has altered over the past 10 years. A decline in the frequency with which a lesion is detected at necropsy may indicate advances in treatment or differences in classification. The presence of additional lesions influences the prognosis and subcategorisation within the major defect groupings gave some insight into the cause of death in many of the cases.

Influence of high dietary iron as ferrous carbonate and ferrous sulfate on iron metabolism in young calves

Twelve intact male Holstein calves averaging 90 kg and 12 wk of age were fed one of three dietary treatments for 28 d. The diets were A) control, B) control plus 1000 ppm iron as ferrous carbonate, and C) control plus 1000 ppm iron as ferrous sulfate monohydrate. Calves were dosed orally on d 15 of the treatment period with 1 mCi of iron-59. Neither source of added iron had a significant effect on weight gains, feed consumption, hemoglobin, packed cell volume, serum total iron, serum total iron-binding capacity, unbound iron-binding capacity, serum copper, tissue copper, fecal dry matter, or a consistent effect on fecal pH. The ferrous carbonate had no significant effect on stable zinc or stable iron in any tissue studied. Calves fed ferrous sulfate had higher average stable iron in most tissues and significantly more in the small intestine. Tissue zinc was lower in spleen and pancreas of ferrous sulfate-fed calves. Both sources of added iron sharply reduced iron-59 in serum, whole blood, and body tissues. The reduction was substantially greater in calves fed the ferrous sulfate iron. Iron in ferrous sulfate had a higher biological availability than that in the ferrous carbonate; however, bioavailability of the ferrous carbonate iron appeared to be substantial and considerably more than that noted in previous studies in which a different source of ferrous carbonate was used. The maximum safe level of dietary iron is materially influenced by the source of iron with a higher tolerance indicated for ferrous carbonated than ferrous sulfate monohydrate.

Morphological observations following "anatomical correction" for abnormal ventriculo-arterial connection

Seven postmortem hearts from children who underwent anatomical correction for complete transposition (6 cases) and double outlet right ventricle (1 case) were examined in order to gain a better understanding of the pathological morphology in relation to the surgical procedure. Associated malformations were ventricular septal defect in all, patient arterial duct in 4 and aortic coarctation in 3. In all hearts the coronary arteries arose from the facing aortic sinuses and were relocated into the facing sinuses of the pulmonary trunk with minimal displacement. The orifices of the coronary arteries were reduced in caliber in one case. The sinus node artery arising from a lateral atrial artery was transected in one case. The Lecompte maneuver was performed in 4 cases and tension on the pulmonary trunk was observed in 2 cases. Potential right ventricular outflow tract obstruction was evident in all (including one in which it had been resected during surgery). The substrates of obstruction were anomalous parietal insertion of the outlet septum (2 cases), anomalous muscular trabeculation (1 case), rightward displacement of the outlet septum (1 case), parietal insertion of the outlet septum (1 case) and restrictive muscular infundibulum (1 case--DORV). In addition, all the complete transposition cases had hypertrophy of the parietal right ventricular wall. This study highlighted the anatomical features which could lead to poor results in the anatomical correction procedure. Some of the potential problems could be avoided by minor modifications to the technique.