Elliot A. Shinebourne

Relationship Between Type of Outflow Tract Repair and Postoperative Right Ventricular Diastolic Physiology in Tetralogy of Fallot Implications for Long-term Outcome

BACKGROUNDnRestrictive right ventricular (RV) physiology can be present early and late after tetralogy of Fallot repair. It is associated with a complicated early postoperative course but is favorable late after repair because it is associated with less pulmonary regurgitation, better exercise tolerance, and less QRS prolongation and symptomatic ventricular arrhythmias. It is not known, however, whether in the current surgical era, this physiology is present in tetralogy of Fallot patients at mid-term follow-up and whether it is related to the type of RV outflow tract repair. Finally, the impact of this physiology on the early evolution of QRS prolongation has not been examined previously. In this study we attempted to address these issues in a cohort of recently operated patients.nnnMETHODS AND RESULTSnNinety-five patients were studied 4.3 years after repair by Doppler echocardiography, serial electrocardiograms, and chest radiographs. Restrictive RV physiology defined by the presence of antegrade pulmonary artery flow in late diastole was present in 38% of the patients. It was more common in patients with transannular patch (TAP) repair compared with non-TAP repair (50% versus 21%, P < .05). QRS duration at follow-up was 121.2 +/- 17.6 and 132.6 +/- 11.8 ms in restrictive and nonrestrictive patients with TAP repair, respectively (P < .02).nnnCONCLUSIONSnRestrictive RV physiology has been identified at mid-term follow-up in a contemporary surgical series. It is associated with less QRS prolongation, regardless of the technique used for outflow tract repair, and may be associated with fewer long-term complications. Nonrestrictive physiology is associated with the most marked QRS prolongation. This subgroup is most at risk from the late deleterious consequences of chronic pulmonary regurgitation.

Criss-Cross Atrioventricular Relationships Producing Paradoxical Atrioventricular Concordance or Discordance Their Significance to Nomenclature of Congenital Heart Disease

Two cases are described in which the systemic and pulmonary blood streams cross at atrioventricular level. One was examined pathologically, the other was diagnosed at cardiac catheterization by angiography. Both possessed situs solitus, but in one heart the right atrium was connected to a morphologic right ventricle on the left, whereas in the other it was connected to a left-sided morphologic left ventricle. In both cases transposition of the great arteries was present. The cases have been interpreted as representing rotation of embryonic d- and l-bulboventricular loops following septation.In attempting to describe these heart difficulties in terminology were encountered which were partially overcome by combining the concepts of concordant and discordant atrioventricular relationships with those of transposition and malposition. However, to give an accurate interpretation of the hearts, it proved necessary to include a term indicating rotation of the bulboventricular loop following septation. Thus the hearts were described as situs solitus, discordant (d-rotated) loop with d-transposition, and situs solitus, concordant (l-rotated) loop with l-transposition.

Sequential segmental analysis in complex fetal cardiac abnormalities: a logical approach to diagnosis

Cardiac abnormalities are common. A wide spectrum of lesions can be encountered in the child and fetus. Complex abnormalities are over-represented in prenatal series as these may be more readily recognized during routine anatomical surveys. While the diagnosis of ‘simple’ defects such as pulmonary stenosis or an isolated ventricular septal defect in an otherwise normally connected heart is usually considered straightforward, the description and understanding of the infinite variety of ‘complex’ cardiac abnormalities may be perceived as a difficult task. It need not be so. Sequential segmental analysis offers a step-by-step approach to describing the cardiac anatomy in different malformations and leads to a thorough appreciation of its pathophysiology. This approach was developed and disseminated in the late 1970s and early 1980s1–3 and is based on the concept that all heart malformations can be readily analyzed with reference to three basic segments4–6. ‘Complex’ congenital heart anomalies become simple when approached in a logical fashion. Knowledge of cardiac embryogenesis is unnecessary to describe the anatomy of the heart after 8 weeks’ gestation. All hearts, normal or malformed, are made up of three segments: atria, ventricles and great arteries (Figure 1). In sequential segmental analysis, the cardiac segments (i.e. the morphologically right and left atria, the morphologically right and left ventricles and the great arteries) are identified separately based on their most consistent anatomical features, not their spatial orientation. The atria are separated from the ventricles at the level of the fibrous tissue plane of the valves at the atrioventricular (AV) junction. The ventriculoarterial junction is marked by the attachment of the arterial valves to the ventricular mass. Atrial situs is established first by determining the position of each atrium in relation to each other within the chest and the AV and ventriculo-arterial connections ascertained. Atria Arterial trunks

Acute renal failure following cardiopulmonary bypass in children: results of treatment

Following open heart surgery using cardiopulmonary bypass, 18 (4%) of 441 operated children required treatment with peritoneal dialysis for acute renal failure or refractory oliguria. Nine recovered renal function (50%) and 5 (28%) survived. Only 2 died from renal causes. Despite both adequate symptomatic treatment of renal failure and few complications of dialysis itself, the prognosis remains poor, even with early treatment, but an aggressive approach is justified because some survivors can be expected.

Exercise ability after Mustard's operation.

Twenty children who were well six to 12 years after undergoing Mustards operation for transposition of the great arteries were studied. Each child performed a graded maximal treadmill test with measurements of gas exchange and oxygen saturation, and had electrocardiography carried out. Nineteen were also catheterised, and oxygen consumption was measured so that pulmonary and systemic flow could be calculated. Compared with 20 age and size matched controls, seven of the patients had normal exercise tolerance (as judged by a maximal oxygen consumption of greater than 40 ml/kg/min), 10 showed a moderate reduction (30-39 ml/kg/min), and three were more seriously limited. None of the patients with normal exercise tolerance had obstruction of venous return but six of those with mild impairment of exercise ability had partial or complete obstruction of one or both of the vena cavas. More severe limitation was associated with pulmonary vascular disease and fixed ventricular outflow tract obstruction. Formal exercise testing of apparently well children who have undergone Mustards operation identifies those with haemodynamic abnormalities that may require intervention.

Fatal persistent pulmonary hypertension presenting late in the neonatal period.

Two cases of fatal idiopathic persistent pulmonary hypertension presented late in the neonatal period. Lungs were examined histologically by light and electron microscopy, and immunocytochemical studies were used to identify nerves. There was extension of medial smooth muscle distally along the arterial pathway so that most precapillary arteries had completely muscular walls, which in some cases completely obliterated the vessel lumen. Enlarged endothelial cells also contributed to the reduction in the size of the lumen. Nerve fibres accompanying muscular arteries were found in the alveolar region, more distal than is normal. The predominant neuropeptide was the vasoconstrictor tyrosine. Possible aetiological factors in persistent pulmonary hypertension of the newborn are increased muscularity of the peripheral pulmonary arteries antenatally, an increase in the number of vasoconstrictor nerves, or an imbalance in the production of leukotrienes and prostacyclins in the perinatal period.

Prenatal identification of the pulmonary arterial supply in tetralogy of Fallot with pulmonary atresia.

OBJECTIVEnTo define the patterns of flow of blood to the lungs in fetuses with tetralogy of Fallot and pulmonary atresia.nnnBACKGROUNDnIn this condition, supply of blood to the lungs is provided via an arterial duct or systemic-to-pulmonary collateral arteries, or very rarely through other conduits such as coronary arterial fistulas or an aortopulmonary window. The intrapericardial pulmonary arteries vary in size, and may be absent. These variables influence the prognosis and management.nnnMETHODSnWe carried out a retrospective review of cases from a tertiary service for fetal cardiology, identifying all cases of tetralogy of Fallot with pulmonary atresia diagnosed antenatally between January, 1997, and April, 2006. We established pre- and postnatal outcomes, and compared the prenatal diagnosis with postnatal or autopsy findings.nnnRESULTSnOf 6587 fetuses scanned during this period, 11 were diagnosed as having tetralogy of Fallot with pulmonary atresia and no other cardiac defect. In 5, arterial flow to the lungs was via an arterial duct, and in the other 6, the main identified source of flow was systemic-to-pulmonary collateral arteries. Of the latter 6 pregnancies, 4 were terminated, along with 3 of the 5 with ductal supply. The presence of systemic-to-pulmonary collateral arteries was confirmed at postmortem examination in 3 instances, and in the two delivered neonates, in neither of whom was an infusion of prostaglandin commenced.nnnCONCLUSIONnThe patterns of pulmonary flow can be identified prenatally in the setting of tetralogy with pulmonary atresia. Supply through systemic-to-pulmonary collateral arteries impacts on counselling, introducing uncertainty regarding postnatal surgical management.

A tunnel from the left sinus of Valsalva to the right atrium

We describe an individualised approach in the rare situation of a tunnel between the left aortic sinus of Valsalva and the junction of the superior caval vein with the right atrium. It is necessary, in this rare anomaly, to identify the origin of the left coronary artery prior to intervention.

Do asymptomatic school children have normal haemodynamics 6–13 years after Mustard's operation?

Twenty asymptomatic school children who had undergone Mustards operation for simple complete transposition (concordant atrioventricular and discordant ventriculo-arterial connexions) were catheterised electively 6-13 years later. The studies were carried out under general anaesthesia in air and in 100% O2. Oxygen consumption was measured and end-tidal gases were monitored using respiratory mass spectrometry. There was significant left ventricular outflow tract obstruction in 2 patients. Cardiac output in air was normal in 15 and decreased in 5 patients. The pulmonary vascular resistance was normal in 18 of 19 cases, but grossly elevated in one patient. Baffle dysfunction was present in 11 patients: 10 with important gradients between the venous pathways and the systemic venous atrium, and 5 with a leak identified either by a left-to-right shunt or by the course of the catheter. Balloon dilatation was attempted in the inferior caval venous channel in 6 and in the superior caval venous channel in 2. Mean gradient before the dilatation fell after the procedure. No pulmonary venous obstruction was identified. Even in this group of children selected as asymptomatic, approximately half had a detectable haemodynamic abnormality.

OP04.09: Pulmonary blood supply in pulmonary atresia with ventricular septal defect: prenatal identification of systemic to pulmonary collateral arteries

Objective: To describe the antenatal findings of systemic to pulmonary collateral arteries (SPCA) in the setting of pulmonary atresia (PA) and ventricular septal defect (VSD) and the impact upon pregnancy management. Methods: Retrospective review of cases in tertiary fetal cardiology centre. All prenatally diagnosed cases of PA with VSD that presented between January 1997 and December 2004 were identified using hospital databases. Findings from prenatal echocardiography were compared to postnatal data, or autopsy findings in cases where pregnancy was terminated. Results: Of 4949 fetuses 29 (0.6%) had PA, 8 with an intact ventricular septum and 21 with a large VSD. Among those with a VSD, 8 had ‘tetralogy type’ anatomy with anterior deviation of the outlet septum and an overriding aorta: in 4 of these cases pulmonary blood supply was retrograde through the arterial duct and in 4 SPCA from the descending aorta were identified. In 3 of the 4 with SPCA despite absence of the arterial duct, central pulmonary arteries were identified. Pregnancy was continued in 2 cases while 2 underwent termination. In three cases the presence of SPCA was confirmed by cardiac catheterisation, post-mortem examination or postnatal echocardiography. Pregnancy was terminated in the fourth case and no post-mortem was performed. In the 2 live births we did not commence on prostaglandin E infusion. In one case, severe pulmonary stenosis rather than atresia was shown post-natally. In the remaining 13 cases with a VSD, PA was part of more complex anomalies and pulmonary blood supply was via the arterial duct in all. Conclusion: SPCA can be accurately identified prenatally with and without central pulmonary arteries. This allows precise description of pulmonary blood supply in the fetus with PA and VSD, thus helping prenatal counselling, pregnancy management and management of the newborn.