Population-based review of tetralogy of Fallot with absent pulmonary valve: is prenatal diagnosis really associated with a poor prognosis?

OBJECTIVES: Tetralogy of Fallot with absent pulmonary valve syndrome (TETAPV) is reported in obstetric literature to have an extremely poor prognosis. We sought to determine the clinical outcome associated with TETAPV and whether prenatal diagnosis confers a poor prognosis. METHODS: All cases of TETAPV diagnosed in British Columbia between 1980 and 2009 were reviewed and grouped according to time of diagnosis, either prenatal or postnatal. The groups were compared with respect to mortality, respiratory problems, number of interventions and functional capacity at last follow-up. RESULTS: Eight and 11 patients were included in the prenatally and postnatally diagnosed groups, with overall long-term survival of 71% and 82%, respectively. There was no significant difference in mortality, frequency of preoperative intubation, number of interventions or functional capacity between groups. CONCLUSION: From a population-based retrospective analysis of TETAPV cases identified over three decades it is concluded that the prognosis for TETAPV is better than that previously reported in the obstetric literature. This information should be used to guide prenatal counseling.

Endothelial dysfunction and compromised eNOS/Akt signaling in the thoracic aorta during the progression of Marfan syndrome.

BACKGROUND AND PURPOSE: Aortic complications account for the major mortality in Marfan syndrome (MFS), a connective tissue disorder caused by mutations in FBN1 encoding fibrillin-1. We hypothesized that MFS impaired endothelial function and nitric oxide (NO) production in the aorta. EXPERIMENTAL APPROACH: Mice (at 3, 6, 9 and 12 months of age) heterozygous for the Fbn1 allele encoding a cysteine substitution (Fbn1 (C1039G/+), Marfan mice, n=75), the most common class of mutation in MFS, were compared with age-matched control littermates (n=75). Thoracic and abdominal aortas from the two groups were studied. KEY RESULTS: Isometric force measurements revealed that relaxation to ACh (but not to sodium nitroprusside) was diminished in the phenylephrine-precontracted Marfan thoracic aorta at 6 months of age (pEC(50)=6.12+/-0.22; maximal response, E(max)=52.7+/-6.8%; control: pEC(50)=7.34+/-0.19; E(max)=84.8+/-2.2%). At one year, both inhibition of NO production with N(omega)-nitro-L-arginine methyl ester, or denudation of endothelium increased the phenylephrine-stimulated contraction in the control thoracic aorta by 35%, but had no effect in the Marfan aorta, indicating a loss of basal NO production in the Marfan vessel. From 6 months, a reduced phosphorylation of endothelial NOS (eNOS)(Ser1177) and Akt(Thr308) detected by Western blotting was observed in the Marfan thoracic aorta, which was accompanied by decreased levels of cGMP. Expressions of Akt and eNOS in the abdominal aorta were not different between the two groups. CONCLUSIONS AND IMPLICATIONS: MFS impairs endothelial function and signaling of NO production in the thoracic aorta, suggesting the importance of NO in the age-related progression of thoracic aortic manifestations.

Diagnosis of fetal ductus arteriosus aneurysm: importance of the three-vessel view.

OBJECTIVE: To present four cases of ductus arteriosus aneurysm (DAA) detected by fetal echocardiography and highlight the value of the three-vessel view in the diagnosis of DAA. METHODS: In addition to the standard fetal echocardiographic views, we examined the three-vessel view in four cases of DAA. The three-vessel view was achieved by sliding the transducer cranially from the four-chamber plane toward the fetal upper mediastinum to demonstrate cross-sections of the main pulmonary artery, the ascending aorta and superior vena cava arranged in a straight line from the left anterior to the right posterior aspect of the mediastinum. DAA was diagnosed when there was a tortuous ductus arteriosus with a dilation that protruded leftward of the aortic arch. CASE SERIES: In the first case, an insulin-dependent diabetic woman underwent fetal ultrasound examination at 36 weeks' gestation showing right-to-left cardiac disproportion and bidirectional flow in the aorta and main pulmonary artery (PA). The three-vessel view showed a dilated ductus arteriosus (DA) which was stenosed at its distal end. In the second case, a woman had fetal ultrasound scans at 38 and 39 weeks' gestation for suspected intrauterine growth restriction and oligohydramnios. The scans identified an abnormal aortic arch and the three-vessel view showed an elongated vascular structure at the distal end of the PA, which was the DAA. In the third case, a woman with a high-risk obstetric history had multiple scans showing an abnormal PA to aorta relationship, with an apparent 'kink' in the PA. The three-vessel view clarified that this was the DAA. In the fourth case, a woman was scanned because of a 3-kg weight gain in 1 week. The fetal ultrasound scan showed moderate polyhydramnios with normal fetal growth and normal intracardiac anatomy and flow, and the three-vessel view demonstrated a large DA. In each of these cases, the DAA appeared to have occurred in isolation with non-specific clinical findings. CONCLUSION: We advocate the use of the three-vessel view, in conjunction with the standard echocardiography views currently employed, to assist in the diagnosis of DAA.

Myocardial contractility in premature neonates with and without patent ductus arteriosus.

Controversy exists as to whether a hemodynamically significant left-to-right shunt due to a patent ductus arteriosus (PDA) affects ventricular contractility. Load-dependent indices such as ejection fraction and shortening fraction have traditionally been used to assess contractility, but the relationship between the rate-corrected velocity of fiber shortening (MVCFc) and wall stress may be more suitable, as it is a preload-independent, afterload-adjusted method of assessing ventricular contractility. Age-related differences have been established for these variables in normal adults and children and it has been recommended for use in the premature neonate. The study was performed to assess left ventricular contractility in premature neonates with a significant left-to-right shunt due to a PDA. Using echocardiography, we measured the relationship of MVCFc to stress at peak systole (SPS) in two groups of premature infants. Group 1 consisted of 15 controls (680-1495 g, 25-32 weeks' gestation), and Group 2 of 15 neonates with hemodynamically significant PDA (840-1635 g, 26-33 weeks' gestation). In both groups, MVCFc was linearly and inversely related to SPS ( p < 0.001). The regression equations were as follows: Group 1, MVCFc = -0.0153SPS + 1.70 ( R(2) = 0.68); and Group 2, MVCF = - 0.019SPS + 1.89 ( R(2) = 0.76). There was no significant difference in the relationship between the two groups, but their slopes were significantly steeper and had a higher Y-intercept than the relationship we previously reported for older children. This preliminary study establishes the normal MVCFc/SPS relationship in the premature neonate (25-33 weeks' gestation) and suggests that premature infants function at a higher resting contractile state than older children. A hemodynamically significant PDA has no effect on contractility. These data will be useful in assessing left ventricular contractility in premature neonates with other types of ventricular loading and noncardiac stress.

Balloon angioplasty of right ventricular outflow tract conduits.

Palliation of complex congenital heart disease, requiring reconstruction of the right ventricular outflow tract (RVOT), is standard practice. Survival of the homograft is a limiting factor. We examined the role of balloon angioplasty (BAP) in prolonging conduit life. Twelve patients underwent 15 BAP procedures between February 1989 and October 1997. The median age at conduit insertion was 28 months with detection of a significant echo gradient 42 months later. Calcification of homografts, with attendant obstruction and valve dysfunction, was present in all patients. BAP was performed within 1 month of echocardiography and reduced the gradient from a median of 57 to 38 mmHg (p < 0.0005). Echocardiographic follow-up showed persistent gradients (median 68 mmHg) and 11/12 patients went on to conduit replacement after BAP. Only one patient had replacement deferred as a result of BAP. Complications requiring intervention occurred in 20% of the procedures and included bleeding and an unusual balloon fracture. Although BAP can reduce the pressure gradient across the RVOT conduit, the effect is transient and the delay of surgery is not due to improved hemodynamic function. Approximately 10% of cases will benefit from BAP alone, but given the high rate of complications, we do not recommend this procedure as a means of prolonging conduit life.

Postpericardiotomy syndrome: no evidence for a viral etiology.

BACKGROUND: Postpericardiotomy syndrome has been considered a disorder induced by viral infection. This conclusion is based on serologic criterions, but these may be unreliable following either cardiopulmonary bypass or transfusion therapy. Previous studies have not verified the proposed etiology either by isolation of viruses, or by detection of their genome. We sought, therefore, to clarify the role, if any, of viruses in this syndrome. METHODS AND RESULTS: We studied prospectively 149 children aged from 6 months to 16 years who were undergoing open heart surgery. Blood samples were collected from all prior to operation, and again 7 to 10 days post-operatively, and 47 were sampled at the time of development of symptoms of pericardial involvement. Serums were analyzed for the presence of IgM and IgG antibodies to cytomegalovirus, herpes simplex virus, and Epstein-Barr virus. The polymerase chain reaction was used for amplification when assessing the genome of the enteroviruses. Cultures for viruses were established on samples of stool, urine, and throat swabs collected 7 days post-operatively, and at the time of postpericardial symptoms. Pericardial fluid obtained from 5 patients with the syndrome was cultured for viruses, and tested for enterovirus genome. On the basis of clinical and echocardiographic findings, 34 children were determined to have definite evidence of the syndrome, 13 were considered to have possible evidence, and the results from these patients were compared to those from patients with no pericardial symptoms, the latter being matched for age and transfusion status. We isolated viruses from one or more sites in five patients with definite evidence (16%), from one (9%) of those with possible evidence, and from seven (19%) of the controls. All serums and pericardial samples were negative for enterovirus genome. IgM antibodies were found in only 5 patients, three with symptoms of pericardial involvement and two without. Rates of seroconversion to IgG for the viruses were lower in the patients with symptoms of pericardial involvement compared to controls, but were strongly influenced by transfusion status. CONCLUSION: Our study has provided no evidence to support a viral etiology for the postpericardiotomy syndrome.

Echocardiography and pulmonary function testing in childhood onset systemic lupus erythematosus.

The aim of this paper was to investigate the frequency of echocardiography (ECHO) and pulmonary function test (PFT) abnormalities in childhood onset systemic lupus erythematosus (SLE), and to determine the relationship of these abnormalities to disease activity. The charts of 50 patients with childhood onset SLE attending a pediatric rheumatology clinic were reviewed for ECHO and PFT studies. The frequency and description of ECHO and PFT abnormalities were documented. Possible associations of PFT and ECHO abnormalities with clinical cardiopulmonary disease, radiographic findings, and measures of lupus disease activity were evaluated. Forty patients (80%) had at least one ECHO study. Twenty-seven (68%) had an abnormal initial study. Nine of 14 patients with an initial abnormal ECHO had normal findings on repeated study. Three abnormalities were considered moderately severe. Thirty-three patients (66%) had at least one PFT performed. Sixteen (48%) were abnormal initially. Four of these 'abnormal' studies were repeated and the abnormalities persisted. Nine patients (27%) were considered to have a severe abnormality. Thirty-one children (62%) had both studies performed. An initial abnormal ECHO and abnormal PFT was found in 10 (32%) of these children. No relationship between ECHO or PFT abnormality and any measure of disease activity (physician's global assessment, anti DNA, C3 or ESR) could be found. Occult cardiac and pulmonary disease as demonstrated by ECHO or PFT occurs frequently in childhood onset SLE. If we wish to understand the natural history of these abnormal heart and lung findings, it will be necessary to do serial testing with ECHO and PFTs in this population.

Interrupted right aortic arch and origin of the left pulmonary artery from the aorta in DiGeorge syndrome.

We describe a neonate with DiGeorge syndrome undergoing diagnosis and successful repair of interrupted right aortic arch and origin of the left pulmonary artery from the aorta. We discuss a link between this lesion and persistence of a left fifth arch.

Coil occlusion of the patent ductus arteriosus: lessons learned.

PURPOSE: To review the clinical outcomes of catheter-directed coil occlusion (coil occlusion) of persistently patent ductus arteriosus (PDA) at a pediatric tertiary care hospital. METHODS: A retrospective review of all patients referred to the Cardiac Catheterization Laboratory for coil occlusion at our institution was performed. Twenty-one consecutive patients (12 female) underwent coil occlusion and follow-up between May 1995 and December 1997. We undertook PDA occlusion if: (a) the PDA narrowed to less than 4 mm on echocardiogram and (b) the minimum body weight was approximately 10 kg. Standard right and retrograde left heart catheterization was performed, followed by coil occlusion. Color-flow mapping (CFM) was used intra-procedurally to confirm occlusion of the PDA with a follow-up study several weeks later. RESULTS: The median age and weight of the patients were 33 months and 13.2 kg, respectively. Fourteen patients received one coil, with six requiring a second coil and one requiring multiple coils. Initial follow-up was at a median of 2.4 months. At latest follow-up, 2 patients still have persistent flow at the ductal level. The coils were deployed without complication or embolization. CONCLUSIONS: A review of our first 21 cases demonstrated three important lessons: (1) the maximum diameter of the PDA suitable for coil occlusion is approximately 3 mm; (2) CFM must show complete obliteration of flow in the catheterization lab in order to ensure occlusion of the PDA at follow-up; and (3) the Jackson detachable system allows for precise placement of the coil, often within another coil.

Outcome of fetuses diagnosed with atrioventricular septal defect.

OBJECTIVE: To quantify the association of prenatally diagnosed atrioventricular septal defect with Down syndrome and to evaluate its impact on obstetric and neonatal outcomes. METHODS: Charts of 42 cases of atrioventricular septal defect diagnosed by fetal echocardiography from July 1985 to July 1997 were reviewed for prenatal history and outcome data (pregnancy outcome, pathologic confirmation, postnatal echocardiographic findings, and neonatal outcome). Statistical analysis was done using Fisher exact test and odds ratios. RESULTS: The mean gestational age at diagnosis was 26 weeks. Four cases could not be confirmed antenatally on repeat echocardiograms and were excluded. Reasons for referral of the remaining 38 fetuses included an abnormal four-chamber view in 76%. Twenty-two fetuses (58%) had abnormal karyotypes: 19 trisomy 21, one trisomy 18, one trisomy 13, and one mosaicism. The cardiac lesions were isolated in 20 fetuses (53%). After excluding cases of termination, ten of 12 fetuses (83%) with Down syndrome survived, compared with seven of 13 (54%) with normal karyotypes (P = .125). The odds of trisomy 21 were 16 times higher (95% confidence interval 3.0, 85.3) in fetuses with isolated cardiac lesions compared with those with associated cardiac anomalies. CONCLUSION: Prenatal diagnosis of atrioventricular septal defect was associated with a 58% risk of aneuploidy (mainly trisomy 21). Down syndrome fetuses with this cardiac anomaly appeared to have a better survival rate than fetuses with normal karyotypes. Our sample did not have enough power to show a statistically significant difference. When an isolated atrioventricular septal defect was diagnosed prenatally, the odds of trisomy 21 were significantly higher than when other associated cardiac lesions were diagnosed. This information should be considered in prenatal counseling for atrioventricular septal defect.

Vascular abnormalities in Adams-Oliver syndrome: cause or effect?

We describe a young girl diagnosed with the Adams-Oliver syndrome (AOS) associated with double outlet right ventricle, portal hypertension, and pulmonary hypertension. We hypothesize that a congenital vascular abnormality is the underlying pathogenesis and that the cutaneous defects characteristically seen in AOS represent the most common manifestation of this. We suggest that AOS should not merely be considered a syndrome consisting of aplasia cutis congenita and terminal transverse limb defects but rather a constellation of clinical findings resulting from an early embryonic vascular abnormality.

Kawasaki disease in the older child.

OBJECTIVES: To determine the prevalence of Kawasaki disease in older children and to evaluate its clinical presentation, time to diagnosis, and outcome in comparison with younger patients with the disease. METHODOLOGY: A retrospective analysis of all patients discharged with a diagnosis of Kawasaki disease at a pediatric tertiary care hospital over a 12-year period. RESULTS: A total of 133 patients were included in this study; 7.5% were 9 years of age or older at the time of illness. Patients were grouped by age: infants included children age 1 to 8 years of age and children 9 years of age or older. Older children had a higher frequency of abnormal cardiovascular physical examination (50%) versus children (6%) and infants (10%). The older age group and the infants had a higher prevalence of coronary artery abnormalities and poor left ventricular function than did the 1- to 8-year-olds. Eighty percent of the older children had coronary arteries that were either dilated or aneurysmal, and 30% demonstrated left ventricular dysfunction on initial echocardiography. The number of days to diagnosis after meeting the diagnostic criteria was 5.8 +/- 2.3 for infants, 5.2 +/- 1.5 for older children, and 1.9 +/- 0.3 for children. Older children had a complicated course of Kawasaki disease compared with younger patients. CONCLUSION: We found a higher prevalence of older children with Kawasaki disease at our center than has previously been reported. Older patients, as well as infants, had a higher rate of coronary artery abnormalities than did the children between 1 and 8 years of age. Older age at the time of illness or a delay in treatment may be important factors in determining cardiac involvement in Kawasaki disease.

Differences in dose scheduling as a factor in the etiology of anthracycline-induced cardiotoxicity in Ewing sarcoma patients.

Clinical observation suggested a high prevalence of cardiac morbidity and mortality in children with Ewing sarcoma (ES) treated at B.C.'s Children's Hospital. We therefore compared 30 patients treated for Ewing sarcoma between 1978 and 1991 with 26 soft tissue sarcoma (STS) patients treated with similar chemotherapy over the same period of time. All patients were evaluated for cardiac function using echocardiography. Shortening fraction (SF) and left ventricular mass index (Massl) were compared before and after treatment. The role of chest irradiation, dose concentration (DC) of adriamycin (AD), total mean doses of AD, cyclophosphamide (CY) and actinomycin (AC) were analysed. SF for patients with ES and STS postchemotherapy was significantly lower (P < .001 and P = 0.0004, respectively) than pretreatment values. Postchemotherapy SF for ES was lower than STS (P = 0.0097). Massl for each group did not change significantly. Six of the ES patients had postchemotherapy SF of < 0.20, with three in congestive failure, two cardiac deaths and one heart transplant. One additional ES patient had sick sinus syndrome and needed a pacemaker. Among the STS patients only one had SF < .20 and none were symptomatic. There were no significant differences in the mean AD, CY and AC doses for ES versus STS. The difference in the DC of AD for ES (mean 744) compared to STS (mean = 362) was significant (P = < 0.001). Regression analysis indicated a trend for decreasing SF with increasing DC (P = 0.017). Chest irradiation did not appear to increase the likelihood of cardiotoxicity. ES patients had a higher prevalence of cardiac dysfunction compared to STS. Studies are required to evaluate the importance of the components of DC, i.e., size of the individual dose and frequency of administration of AD, and to look at other possible factors in the causation of cardiomyopathy in ES.

Effectiveness of primary level antenatal screening for severe congenital heart disease: a population-based assessment.

The four-chamber view of the fetal heart has been advocated as an effective antenatal screen for severe forms of congenital heart disease (CHD). To evaluate the sensitivity of this test at a primary care level, a retrospective review was undertaken for the period 1988 to 1992 of ultrasonograms of fetuses referred for fetal echocardiography, mothers of neonates referred for cardiac assessment, and perinatal deaths attributed to CHD. The study centers serve a population base of 3.5 million persons. Sixty-nine cases of severe forms of CHD were reviewed. The diagnoses were chosen because all show abnormal findings on four-chamber view: 38 hypoplastic left heart syndrome, 13 pulmonary atresia with intact ventricular septum, and 17 variants of univentricular heart. The cases involved a total of 94 scans. These were reviewed by diagnosis and stratified by gestational age and year of scanning. No diagnosis was made at a gestational age younger than 16 weeks. From 16 weeks to term, overall sensitivity was 40% (32/80 scans); sensitivity improved with advanced gestational age (34% to 48% at 16 to 24 and > 24 weeks' gestation, respectively). There was no longitudinal evidence of a learning curve. Reasons for this low sensitivity are related to unfamiliarity with CHD, low incidence in small populations, and inadequate evaluation of the fetal heart. These problems can be resolved with continued training and direction from a major center.

Short- and long-term variability of echocardiographic stress-velocity indexes of cardiac function in a pediatric population.

This study determined the short- and long-term variability of stress-velocity relationships at end systole and peak systole. A prospective study during the short term (0 to 15 and 0 to 30 minutes) and long term (0 to 1 and 0 to 12 months) was performed calculating variability by the limits of agreement method. The study was performed in a tertiary-care pediatric echocardiographic laboratory. Twenty-five normal children underwent repeat testing as described. Standard blood pressure, carotid pulse tracing, and M-echocardiography of the left ventricle was performed at the intervals described. The rate-corrected mean velocity of fiber shortening (MVCFC), echocardiographic stress at end systole (SES), and echocardiographic stress at peak systole (SPS) were calculated for all recordings. The slopes of MVCFC-SES and MVCFC-SPS were determined by regression and plotted. With these slopes, the second and third stress values were normalized to the first stress value for the short and long term. The differences in normalized MVCFC and MVCFC (delta MVCFC) for 15 to 0 minutes, 30 to 0 months, 1 to 0 month, and 12 to 1 month were obtained for both SES and SPS, and 95% limits of agreement were estimated. The mean delta MVCFC for SES and SPS for the short and long term were not different from 0 or each other, indicating no bias. The 95% limits of agreement of delta MVCFCs (i.e., variability for SES at 15 to 0 minutes, 30 to 0 minutes, 1 to 0 month, and 12 to 0 month) were +/- 0.18, +/- 0.24, +/- 0.34, and +/- 0.27, respectively, and for SPS +/- 0.18, +/- 0.24, +/- 0.33, and +/- 0.28. Variability showed an increasing trend with time but was significant only from 15 to 0 minutes and 1 to 0 month (p = 0.006). This study has established short- and long-term variability in the stress-velocity relationship that is essential for monitoring acute and chronic changes in ventricular contractility in an individual patient.

Influence of competitive pulmonary blood flow on the bidirectional superior cavopulmonary shunt. A multi-institutional study.

BACKGROUND: It is common practice to interrupt all alternative sources of pulmonary blood flow ("competitive flow") at the time of a bidirectional superior cavopulmonary anastomosis (BCPA), although the merits of this have not been systematically studied. METHODS AND RESULTS: We reviewed the early and medium-term clinical and hemodynamic findings in 108 consecutive patients 3 weeks to 25 years old (median, 1.9 years) undergoing BCPA at one of three institutions. Preoperatively, pulmonary blood flow was dependent on antegrade ventricular flow (n = 50), systemic-to-pulmonary shunts (n = 33), or mixed sources (n = 25). Postoperatively, competitive sources of pulmonary blood flow were left patent in 43 of 108 patients (40%). There were four early (3.7%) and four late deaths, none related to persistence of competitive flow. After BCPA, patients with competitive flow had significantly higher systemic oxygen saturations at 1 hour (85% versus 79%), 24 hours (84% versus 78%), and at hospital discharge (84% versus 78%) and required a shorter period of artificial ventilation (median, 9 versus 24 hours) and intensive care (median, 2 versus 4 days). Oxygen saturations at late follow-up (median, 2.8 years; range, 1 to 7) did not differ (83% versus 82%). No patient developed pulmonary arteriovenous malformations. CONCLUSIONS: Competitive flow is well tolerated in the short and medium term after BCPA, and early postoperative systemic oxygen saturations are improved. The long-term influence of competitive flow on pulmonary arterial growth, arteriovenous malformation development, and ventricular function warrants investigation.

Role of transesophageal echocardiography in the management of aortic-left ventricular tunnel.

A 10-year-old patient has been followed for 10 years after repair of an aortic-left ventricular tunnel (ALVT) for residual aortic regurgitation and significant recurrent leak through the ALVT. Transesophageal echocardiography (TEE) was done prior to surgery and intraoperatively to (1) clarify the precise anatomy of the ALVT, (2) evaluate the degree of aortic regurgitation, and (3) assess the repair. Delineation of the anatomy of the ALVT and assessment of the residual aortic insufficiency helped with the intraoperative decision-making. We describe the TEE findings of a residual ALVT in this patient and discuss the role of TEE in managing the lesion.

Pulmonary artery banding is not contraindicated in double inlet left ventricle with transposition and aortic arch obstruction.

It has been widely stated that pulmonary artery banding (PAB) is contraindicated in the setting of double inlet left ventricle with transposition of the great vessels (DILV/TGA), especially if aortic arch obstruction is present. We postulated that the poor results for this condition reflect the tendency to leave the band in place long-term without early recognition and relief of subaortic stenosis (SAS). Short-term PAB with early relief of SAS remains an attractive option compared to a neonatal "Norwood" strategy. We reviewed our results applying this approach to 18 consecutive infants presenting since 1980 with DILV/TGA and an obstructive anomaly of the aortic arch (coarctation 16, interruption or atresia 2). Four of the infants (22%) were considered to have important SAS at presentation. One underwent neonatal aortopulmonary connection and died. The remaining 17 patients underwent arch repair with PAB (median age 1.4 weeks; range 2 days-22 weeks) with one early death. The 16 survivors have been followed for 5.6 +/- 3.7 years. All but one ultimately developed SAS. Relief of SAS was performed in 15 patients (median age 8 months) using a proximal aortopulmonary anastomosis. There were two early deaths, and one late death. Thirteen of the 18 patients (72%) are alive and well, and 12 have achieved Fontan repair or bidirectional superior cavopulmonary anastomosis (BCPA) with persistent relief of SAS. Most patients with DILV/TGA and aortic arch obstruction will tolerate temporary PAB with adequate protection of the pulmonary vascular bed. Our current approach (in the absence of severe SAS at presentation) is PAB at the time of arch repair, followed by careful surveillance for, and early relief of, SAS combined with BCPA in infancy.