The morphology and mechanism of obstruction to the pulmonary venous pathway in patients following either Mustard or Senning repair of complete transposition was assessed using transoesophageal echocardiography. Seven patients underwent catheterization and complete transoesophageal study in both transverse and longitudinal planes, followed by balloon dilation of the obstructed venous pathway in five of seven under transoesophageal echocardiography guidance. A complete scan of both systemic and venous pathway was obtained in all patients. Four patients with a Mustard repair were found to have a ‘tubular’ baffle, with stenosis resulting from a discrete wedge of tissue arising from the atrial free wall in association with fibrous adhesions to the baffle. In the three patients with a Senning repair the intra-atrial baffle showed a characteristic ‘peaked’ appearance, with stenosis of the venous pathway stenosis related directly to con tracture of the patch used to augment the atrial free wall. The mechanism of obstruction appears to be inherent to the different surgical techniques. Indwelling transoesophageal echocardiography provided immediate haemodynamic and morphologic assessment of the efficacy of dilation of the obstructed venous pathway.

Atrioventricular septal defect with common valvar orifice and tetralogy of Fallot is a rare combination of congenital cardiac anomalies. Approaches to this lesion have tended to emphasize either staged repair or complete repair beyond infancy. Between July 1992 and August 1997, nine patients underwent repair of complete atrioventricular septal defect with tetralogy of Fallot. One patient, aged 9.6 years at the time of repair, had previously undergone construction of a modified Blalock-Taussig shunt. Primary complete repair was performed in the other 8 patients at ages ranging from 2.5 to 16 months (median 4.6 months), and all but one were infants. All patients had a Rastelli type C defect, a single ventricular septal defect with inlet and outlet components, and malalignment of the muscular outlet septum with subpul-monary stenosis. A single patch technique, with closure of the zone of apposition (‘cleft’) in the left atrioventricular valve, was used in all eight patients undergoing primary repair, while a double patch was employed in the previously palliated older patient. In all cases of repair using a single patch, the anterosu-perior bridging leaflet was divided obliquely to the right, following the malaligned outlet septum, in order to avoid subaortic obstruction. Repair of the right ventricular outflow tract included infundibular myectomy in eight, pulmonary valvotomy in four, infundibular or transannular patching in three and one, respectively, and reconstruction with a valved allograft conduit in two patients. There was no early mortality or significant morbidity. At a median follow-up of 45 months, there had been one death related to non-cardiac causes and no reinterventions. Left atrioventricular valvar regurgitation was moderate or mild in two patients, and right atrioventricular valvar regurgitation was mild in one patient. No patient had more than mild pulmonary regurgitation or a gradient across the right ventricular outflow tract in excess of 18 mm Hg. Our results demonstrate that primary repair of atrioventricular septal defect with tetralogy of Fallot can be performed with excellent early and mid-term results in young infants. Although it has been suggested that a technique utilizing oblique division of the anterosuperior bridging leaflet may lead to high rates of atrioventricular valvar regurgitation, medium-term atrioventricular valvar function in the present cohort of patients has been excellent.

Malta is a small island with minimal changes in its population, making it an ideal location for epidemiological and historical studies dealing with congenital heart malformations. Ventricular septal defect was studied retrospectively from 1930 to 1994. A sharp and significant decline in age at diagnosis was found, predating echocardiography. All defects are now diagnosed by echocardiography, which has resulted in an increased prevalence of this lesion as seen at birth, particularly of minor defects. The prevalence of ventricular septal defect from 1990 to 1994 was 3.85/1000 live births, with 3.O3/1OOO not needing surgery and 0.83/1000 requiring operative intervention. Half the defects closed spontaneously. The majority of ventricular septal defects overall, and those spontaneously closing, were muscular defects. The overall prevalence at birth was significantly higher than that reported in recent studies using similar methodologies, implying that the reported rate is more likely to be the true prevalence at birth of clinically detectable defects.

To determine whether a newly synthesized oral analog of prostacyclin, called beraprost sodium, could cause pulmonary vasodilation, we studied its hemodynamic effect on pulmonary hypertension of children, comparing it to other vasodilatory agents, such as nitric oxide and tolazoline. We studied 20 children (mean age 24 months) having pulmonary hypertension secondary to congenital heart disease. A single oral dose of beraprost sodium resulted in an appreciable reduction of pulmonary vascular resistance (mean 34%), which was comparable to that induced by inhalation of nitric oxide and intravenous delivery of tolazoline (mean 41% and 31%, respectively). The results suggest that beraprost sodium may serve as a novel and safe vasodilator for the screening of pulmonary vasoreactivity, as well as the treatment of pulmonary hypertension in children.

We describe 4 patients in whom the pulmonary veins were compressed between the descend ing aorta and the atrial part of the heart in consequence of an abnormal distribution of the pulmonary blood flow after the Fontan procedure.

The Maltese populartion constitutes an ideal location for epidemiological and historical studies dealing with congenital hearr malformations. Pulmonary stenosis was studied retrospectively from 1943 to 1994. A sharp, significant decline in age at diagnosis was found, which predates the introduction of echocardiography. All defects are now diagnosed by echocardiography, which has resulted in an increased prevalence at birth of this lesion, patticularly of pulmonary stenosis not requiring intervention. The prevalence at birth of pulmonary stenosis from 1990 to 1994 was 1.65/1000 live births (95% CL: 1.21–2.24), with 1.11/1000 mild lesions (95% CI: 0.76–1.62) and 0.54/1000 lesions requiring intervention (95% CI: 0.31–0.92). The prevalence at birth overal was significantly higher than that reported in recent studies with similar methodologies due to the higher pickup of milder variants of pulmonary stenosis by echocardiography.Significantly more pulmonary more pulmonary stenosis was found in females than in males.

Although patients undergoing surgery with the Fontan procedure or its modifications are increasingly recognised to be at risk for thromboembolism, further knowledge is needed to minimise this complication and its sequels. To address this issue, we reviewed 100 patients operated with the Fontan procedure, the bidirectional Glenn anastomosis and/or the total cavopulmonary connection to describe our incidence and clinical characteristics of postoperative formation of thrombus. Symptomatic thrombosis or cerebrovascular accidents were found in 5 patients. Asymptomatic thrombus were found in another 5 patients. Three patients had venous thrombi. In 6 patients the thrombosis was found on the arterial side. In all these cases, the thrombus was located in the stump of the divided pulmonary trunk. In 3 of these patients, sudden onset of hemiparesis preceded the diagnosis of the thrombus while the remaining 3 patients were asymptomatic. In 3 cases, the formation of thrombus in the stump of the divided pulmonary trunk occurred after a bidirectional Glenn anastomosis. One patient developed severe neurological symptoms 2 months after a total cavopulmonary connection. No thrombus was found, but the patient had a small right-to-left shunt and embolization could not be excluded. The incidence of thrombosis after Fontan-type surgery in this study is 10%. Although not all episodes of thrombosis are symptomatic, there is a significant risk of severe sequels due to embolization to the pulmonary or cerebral circulations. The stump of the divided pulmonary trunk is one of the main sites for intracardiac formation of thrombus, even after a bidirectional Glenn anastomosis.

Isolation of the subclavian artery is an unusual anomaly in which the subclavian artery arises not from the aortic arch but from a pulmonary artery via an arterial duct. Such isolation most often occurs with a right aortic arch, and in lesions frequently associated with a right arc, such as tetralogy of Fallot. Since1994, we have undertaken surgery in four young infants with isolated subclavian arteries and unusual associated anomalies, including one with atrioventricular septal defect and common valvar orifice, two with interruption of a left aortic arch and one with interruption of a right aortic arch. In both patients with interrupted left arch, the isolated subclavian artery was diagnosed preperatively by echocardiography. We emphasize the significant issues.

Between January 1985 and April 1994, 42 children aged between 7 and 14 years (mean 11.3 years) underwent repair of severely incompetent rheumatic mitral valves with no accompanying mitral stenosis. In 19 patients the tricuspid valve was severely incompetent, while 8 patients had severe aortic incompetence. Overall, the repair incorporated shortening of elongated tendinous cords and insertion of a Duran or Carpentier prosthetic ring. The repair was the sole procedure in 15 patients, whilst 19 patients also had a De Vega tricuspid valvar annuloplasty and 8 had repair or replacement of the aortic valve. There were no hospital deaths. Postoperative transthoracic echocardiographic studies revealed trivial residual mitral valvar regurgitation in 6 patients, mild regurgitation in 18, moderate in 15, and regurgitation severe enough to warrant replacement of the mitral valve in 3 patients. The mean follow-up period was 37 months (maximum 120 months, minimum 1 month). 0139 patients followed-up, 28 attended for more than 5 years. Of these, 7 underwent replacement of the mitral valve for severe regurgitation within 4 years of the repair. Severe mitral regurgitation in 3 patients was controlled by medical therapy. One was eventu ally lost to follow-up, and one patient died of causes unrelated to surgery. The remaining 16 patients had absent to moderate mitral valvar regurgitation. These results contrast with 10 repairs of congenital mitral incompetence, where no patients required re-operation in the immediate 5 years period of follow-up. Every effort should be made in children with rheumatic mitral incompetence to preserve the natural valve by con servative repair, despite the fact that repair of the incompetent rheumatic mitral valve is not so durable as repair of congenitally incompetent valves.

We describe 4 cases of congenitally corrected transposition associated with atrioventricular septal defect, diagnosed by echocardiography and angiocardiography. Two had usual atrial arrangement and two had mirror imaged atrial arrangement. All cases were associated with subpulmonary valvar stenosis. All patients presented with cyanosis and were in sinus rhythm. Atrioventricular septal defect with common atrioventricular junction was easily diagnosed on the basis of a common atrioventricular valve permitting interatrial and interventricular communications. All patients had balanced right and left ventricles. The echocardiographic recognition of the ventricles was based on the presence of the moderator band within the morphologically right ventricle, the characteristics of the apical septal trabeculations, and the shape of the ventricles. Angiocardiographic recognition of the ventricles was achieved on the basis of right and left ven-triculography.

In one case with usual atrial arrangement, we recorded two His bundle potentials, one anteriorly and another posteriorly. Atrial stimulation revealed blocked atrioventricular conduction at the level of the pos terior bundle, and normal atrioventricular conduction through the anterior bundle. In both cases with atrial mirror-imagery, only a posterior His bundle potential was found, with normal atrioventricular conduction revealed by atrial stimulation

The clinical course with this combination depends on the other lesions present in addition to the common atrioventricular valve. Our electrophysiological studies show that the conduction system in presence of a common atrioventricular valve is as expected for congenitally corrected transposition with two atrioventric ular valves.

Severe protein losing enteropathy occurred in 3 of our 128 patients undergoing the Fontan procedure in the period of 1982 to 1994. The complication occurred 4, 4.5 and 5 years after the procedure, respectively. One patient had double inlet left ventricle while the other two had tricuspid atresia. All had initially undergone an atrio-pulmonary connection, and the duration of the enteropathy was 12, 13,5 and 15 months. All patients were in functional class IV of the New York Heart Association. The presence of protein losing enteropathy was confirmed by determining levels of fecal alfa-1 antitrypsin, enteric clearance of 51 Cromo labeled albumin, and endoscopy with histopathological study of the small bowel.

They underwent further surgery to convert the atrio-pulmonary to a cavo-pulmonary anastomosis which excluded all the hepatic veins. A bovine pericardial baffle was sutured in the inferior caval vein so as to leave the hepatic venous flow draining to the right atrium and thence through an atrial septal defect to the left atrium and systemic circulation. The inferior caval venous flow was directed through an intra-atrial tunnel to the right pulmonary artery, and the superior caval vein was anastomosed to the superior aspect of the right pulmonary artery, thus completing the total cavo-pulmonary anastomosis with exclusion of the portal venous flow.

Postoperatively, there was total regression of the clinical and laboratory findings. All patients are now in functional class I or II of the New York Heart Association. They have mild to moderate cyanosis up to three and a half years from the reoperation. We recommend the technique as an alternative for patients with severe protein losing enteropathy occurring after the Fontan procedure.

Cognitive, functional, educational achievement and behavioural measures were employed to assess neurobehavioral status in 57 of 60 participants who were initially enrolled in the Baltimore–Washington Infant Study, and who survived surgical correction of complete transposition (concordant atrioventricular and discordant ventriculo-arterial connections). Charts were reviewed to investigate the relationship between birth variables, surgical strategy and developmental outcomes. Higher preoperative weight was associated with better outcomes on the Stanford–Biner Short-term Memory subtest, while lower preoperative oxygen tension was associated with better outcomes on the Abstract/Visual Reasoning subtest and a test of Visual–Motor Integration. Longer total bypass time was associated with poor outcomes on the Short-term Memory subtests. Higher average flow rates during cooling and rewarming were associated with higher scores in the test of short term memory but poorer outcomes on a test for visual motor integration. Longer cooling times were associated with higher scores on the test for Visual–Motor Integration. Patients suffering seizures scored lower on the Stanford–Biner Composite, as well as in their tests of achievement. The data indicate that non-verbal. skills may be particularly sensitive to variations in surgical strategies employed to correct complete transposition. Overt neurological events, such as seizures, were related to global deficits in intellectual functioning. Prospective studies evaluating systemic variations in surgical procedures and attempts to prevent and manage perioperative neurological events are important for further investigation of neurodevelopmental outcomes in children surviving surgical correction.

Children with functionally single ventricle in the setting of visceral heterotaxy (isomerism) may present a surgical challenge at the time of Fontan completion because of anomalies of systemic and pulmonary venous drainage. We have used an extracardiac conduit in this population to direct inferior caval venous blood to the pulmonary arteries.

Over the past five years, nine children with heterotaxy and a functionally single ventricle underwent correction by placement of an extracardiac synthetic (Gore-Tex) conduit. All patients had previously undergone a bidirectional Glenn procedure. Age and weight at the time of insertion of the extracardiac conduit were 26±15 months, and 11±2 kilograms, respectively.

To evaluate left ventricular diastolic filling in infants with ventricular septal defect, which has yet to be documented, we measured various Doppler echocardiographic indexes from transmitral flow in the following groups: 10 infants with ventricular septal defect without pulmonary hypertension; 10 infants with ventricular septal defect with pulmonary hypertension; and 9 normal infants to serve as controls. The peak A, total velocity time integral, E area, and A area in patients without pulmonary hypertension were all significantly larger than those in controls. The peak ratio E/A, and 1/3 filling fraction, in patients without pulmonary hypertension were significantly lower than in controls. The peak A, A area, and deceleration time in patients with pulmonary hypertension were significantly larger than in patients without pulmonary hypertension and controls. The peak E/A, area E/A, and 1/3 filling fraction in patients with pulmonary hypertension were significantly lower than in those without pulmonary hypertension and controls. The index of left ventricular mass, as well as the index of end-diastolic left ventricular wall thickness, correlated strongly with peak A, A area, and deceleration time. The ratio between the systolic pulmonary and systemic pressures correlated strongly with peak A, A area, peak E/A, area EtA, and 1/3 filling fraction.

These results demonstrated that the patterns of left ventricular filling in infants with ventricular septal defect were different from those in normal infants, and suggested that the abnormal patterns may indicate the insufficiency of adaptation of left ventricle (increase of left ventricular compliance) for volume overload in the presence of a ventricular septal defect..

Between 1983 and 1995, 546 Blalock-Taussig shunt procedures were performed in 472 patients: 128 (23.0%) were classical shunts, 90 of them on the same side as to the aortic arch, and 418 (77.0%) were modified shunts, 182 on the same side of the arch. At the time of surgery, 78 patients were aged below one week, 270 from one week to 12 months, and 198 patients were over one year of age. The mean pre-operative arterial saturation (71.7%±16.5%) was significantly increased to 83%±17.9% imme-diately after the procedure (p=0.017). The overall hospital mortality rate was 2.9% (16/546), with rates of 2.3% (3/128) for the classical, and 3.1% (13/418) for the modified shunts (p= not significant). The rate was significantly higher, however, for classical shunts when the pulmonary arterial diameter was less than 4 mm (15.4% versus zero; p=0.047), though this relationship was reversed for modified shunts (zero versus 3.6%; p=0.338). Early mortality was significantly influenced by the age at surgery, 5/78 (6.4%) in patients aged below 1 week, 3.7% between 1 week and 1 year, and 0.5% over 1 year (p=0.019). Early mortality was also significantly increased in patients weighing 3kg or less, 8/156 (5.1%), versus 3/303 (1.0%), p=0.037. Overall, 51 shunts failed (9–3%), 10 early and 41 late. Early failure was significantly increased in patients weighing 3kg or less, 8/156 (5.1%) versus 3/303 (1.0%), p=0.016. The overall early failure rate was 1.4% (3/215) when heparin was administered intra-operatively and for 48 hours postoperatively, in contrast to an early failure rate of 3.4% (7/203) when heparin was not used (p = 0.294). Overall rates of failure during follow-up were 9.1% (17/188) in heparinized patients versus!3.6% (24/177), (p=0.173) in non-heparinized patients. Failure of classical shunts was 10.2% (13/128), compared with 6.7% (28/418) for modified shunts (p=0.195). Failure was more common overall if the pulmonary arterial diameter was less than 4 mm, 14.7% (9/61), as opposed to 8.7% (26/300) when the diameter was 4 mm or greater, (p=0.144). Administration of aspirin during follow-up after the modified shunt procedure reduced failure from 11 % (18/163) to 6.7% (10/150), p=0.176. Classical or modified Blalock-Taussig shunts, either on the same side or opposite to the aortic arch, can be performed on patients of any age with minimum postoperative complications and low operative mortality. The use of intra- and post-operative heparin appears to reduce the overall rate of failure, and the administration of aspirin during follow-up appears to reduce failure of modified Blalock-Taussig shunts.

We describe three cases of sternal defects of varying severity associated with other congenital anomalies. In the most severe case, both anterior and posterior defects were seen, with near-absence of the sternum and pericardium continuous with a large omphalocele. This resulted in external location of organs usually confined within the thoracic and abdominal cavities. A ventricular septal defect was present, and the arterial duct was absent. The course of the ascending aorta was anomalous. The baby had anencephaly and rachischisis. In the intermediate case, a proximal sternal cleft was associated with shortening of the ster num, and absence of the manubrium. Anterior pericardial and diaphragmatic defects were seen, while a scalp defect and an encephalocele were present on the posterior aspect of the head. This baby had tricuspid atresia. The qremaining case had only an anterior defect with a shortened sternum. A supra-umbilical omphalocele contained a left ventricular diverticulum without interposing pericardium or diaphragm. Ventricular and atrial septal defects were present. The first two cases can be considered as representing fail ure of development of both an anterior and a posterior midline field. The third case, much milder than the other two, represents failure of development of an anterior field.

Despite a good haemodynamic result, many children have amildly decreased arterial oxygen saturation following a total cavopulmonary connection. Our study was performed to determine possible mechanisms of right-to-left shunting in these patients. We performed elective cardiac catheterization in 19 children at a mean interval of 3.6 years following a total cavopulmonary connection. The intrapulmonary right-to-left shunt, the intracardiac right-to-left shunt and the total right-to-left shunt were calculated under mechanical ventilation with 100% oxygen. The intrapulmonary right-to-left shunt was 10.8±3.5% of the pulmonary blood flow, and the total right-to left shunt accounted for 18.9±5.2% of the systemic blood flow. The intracardiac right-to-left shunt in patients with no relevant venovenous collaterals or leaks in the atrial tunnel was calculated at 6.4±3.0% of the systemic blood flow, while the intracardiac right-to-left shunt in patients with relevant collaterials or leaks accounted for 13.0±5.9% of the systemic blood flow. Since intrapulmonary arteriovenous fistulas were not demonstrated angiographically in any of our patients, the intrapulmonary right-to-left shunt is probably due to low ratios of perfusion to ventilation in some pulmonary segments. The intracafdiac right-to-left shunt was due to leaks across the interatrial baffle, collaterals between stystemic and pulmonary veins, and to the coronary sinus draining to the pulmonary venous atrium.

To demonstrate the use of transthoracic contrast echocardiography in the detection of pulmonary arteriovenous fistulas in patients with a previously constructed anastomosis between the superior caval vein and the right pulmonary artery (Glenn shunt), and to examine their prevalence in this special population, we evaluated prospectively all patients followed up in the Grown-Up Congenital Heart Unit subsequent to construction of a classical or bi-directional Glenn shunt. We studied 12 patients, aged from 21 to 38 (mean 28 ± 4.8) years who had had a previous cavopulmonary shunt in place for a period of 4 to 33 years (mean 24±9 years). All were examined with cross-sectional contrast echocardiography, 11 patients had cardiac catheterisation and angiography, and 6 patients had magnetic resonance imaging. Systemic arterial oxygen saturations at rest, and during exercise using the modified Bruce protocol, were measured in all patients. Contrast echocardiography showed evidence of pulmonary arteriovenous fistulas in 7 of the 12 patients, with appearance of echo contrast in the left atrium 1–8 seconds after peripheral venous injection in the arm. Simultaneous appearance of microbubbles in the right atrium revealed a residual communication between the superior caval vein and the right atrium in 2 patients, and presence of collaterals between the superior and inferior caval veins in one. Cardiac catheterisation and angiography showed obvious fistulas in 4 patients, and revealed suggestive findings in 2. In patients deemed to have pulmonary arteriovenous fistulas on contrast echocardiography, arterial oxygen saturations at rest (51–94%, mean 75±15.3%) and on exercise (23–91%, mean 53±24.2%) were significantly lower compared to patients judged to be without fistulas (p<0.005). Pulmonary hypertension in the contralateral lung was more common in patients with fistulas (mean left pulmonary arterial pressure 22–110 mm Hg, p=0.014). In patients with cavopulmonary anastomoses, pulmonary arteriovenous fistulas occur frequently in the long term (10–33, mean 25.7±8 years), and are associated with worsening systemic arterial desaturation. Contrast echocardiography should be included in the regular evaluation of these patients as a simple and sensitive technique for the detection of pulmonary arteriovenous fistulas, particularly with the devel opment of increasing cyanosis.