Hypoplastic Left Heart Syndrome Variants Research Articles

Abstract 18288: Mice Harboring a Novel De Novo Missense RBFOX2 Variant Display Abnormal Heart Development

Hypoplastic Left Heart Syndrome (HLHS) is a complex form of congenital heart disease, characterized by severe underdevelopment of the left ventricle, stenosis or atresia of the mitral and aortic valves, and hypoplasia of the ascending aorta and aortic arch. Despite advances in surgical and palliative strategies leading to improved neonatal survival outcomes, HLHS is still associated with early mortality and long-term morbidity. Elucidation of HLHS etiology is compounded by its complex inheritance mechanism and heterogenous genetic landscape, with studies indicating a multigenic etiology. We performed exome sequencing on a parent-offspring trio in which the proband was affected with HLHS and identified a novel de novo missense variant in the gene, RBFOX2, that was bioinformatically predicted to be pathogenic. RBFOX2 belongs to a family of RNA-binding proteins that is broadly expressed in all tissues and regulates splicing and transcription of many targets, including those involved in heart development. In order to determine the in vivo pathogenicity of the RBFOX2 variant, we generated a knock-in mouse model harboring orthologous missense RBFOX2 variant using CRISPR/Cas9 technology. RBFOX2 KI/KI mice were found to be embryonic lethal. Morphological analysis revealed 100% of homozygous mutants exhibit gross developmental defects. Normal Mendelian ratios are found at E9.5 but homozygous mutants display severe growth retardation from E9.5 to E11.5. Histologic analysis demonstrated underdevelopment of the ventricular chambers starting at E9.5. Overall, these mutant mice, harboring a clinically relevant human HLHS variant in RBFOX2 , display highly penetrant hypoplastic hearts with significant growth retardation. The use of this new murine model will pave the way for better cellular and molecular characterization of the deficits in RBFOX2 function that contribute to HLHS.

New approach in stage 1 surgery for hypoplastic left heart syndrome: preliminary outcomes.

We present the short-term results of an alternative method in stage 1 surgery for hypoplastic left heart syndrome. Data of 16 consecutive patients who were treated with the novel method in our clinic between February 2019 and March 2021 were analysed retrospectively. Preoperative data and postoperative follow-up were recorded. Of the 16 operated patients, 12 were diagnosed with hypoplastic left heart syndrome, while four were diagnosed with hypoplastic left heart syndrome variants. Seven patients died during early postoperative period. One patient died at home waiting stage 2 surgery. Three patient underwent stage 2 surgery. Pulmonary artery reconstruction was performed in one patient due to left pulmonary artery distortion. We believe that our method can be an effective alternative in the surgery of hypoplastic left heart syndrome and its variants. It is hoped that with increasing number of studies and more experience better outcome will be achieved.

Noonan syndrome associated with hypoplastic left heart syndrome.

Noonan syndrome is an inherited disorder caused by alterations in the RAS-MAPK pathway. There have been several identified genotype-phenotype associations made with respect to congenital cardiac lesions and Noonan syndrome variants, but limited data exist regarding single ventricle disease in this population. Here, we report two patients with PTPN11-related Noonan syndrome and hypoplastic left heart syndrome variants.

Abstract 17250: Novel Association Of Left Ventricular Outflow Tract Obstructions With Chromosome 5p Deletions

Case Presentation: Patient 1: Female infant diagnosed with Cri du Chat Syndrome (CdCS) (Fig. 1A), hypoplastic left heart syndrome variant (Fig. 1 B), duodenal atresia (Fig. 1 E, F), IUGR. Chromosomal microarray (CMA) showed a 4.3 Mb deletion at 5p15.33 (Fig. 1A) and a 32.2 Mb duplication of 5q32. Dysmorphisms including hypertelorism, low set ears, and micrognathia were noted. Echocardiogram showed a hypoplastic left ventricle, mitral valve dysplasia (Fig. 1B), dysplastic aortic valve (Fig. 1C), interrupted aortic arch (Fig. 1D). Patient 2: Male infant prenatally diagnosed with aortic valve stenosis, aortic arch hypoplasia (Fig. 1H, I), and IUGR. Multiple dysmorphic features including microcephaly, hypertelorism, down slanting palpebral fissures, and abnormal distal extremities. CMA revealed a large deletion at 5p13.33-p13.2 (Fig 1G). He underwent aortic valvuloplasty complicated by development of a posterior left ventricular wall pseudoaneurysm (Fig. 1J). He later underwent arch reconstruction. At 2 months of age, he was diagnosed with obstructive jaundice requiring a biliary drain (Fig.1K, L). He had been gaining weight and height steadily (Fig.1M, N). We identified 5 more patients with 5p deletions and left outflow tract obstructions (LVOTO) from the Cytogenomics of Cardiovascular Malformations Consortium (Table 1). Discussion: CdCS is the most common 5p deletion syndrome and is associated with mild congenital heart defects in 15-30% of individuals. There is no reported association between LVOTO and 5p deletions. These 7 patients did not all share the same deletions and had high mortality. Further studies are needed to better understand possible genetic etiologies.

Norwood With Obstructed Total Anomalous Pulmonary Venous Connection and Tracheoesophageal Fistula Repair: Operating Room Delivery

A baby boy with prenatally diagnosed hypoplastic left heart syndrome variant with obstructed veins was born in the operating room (OR) and underwent emergent Norwood operation and repair of obstructed infra-diaphragmatic total anomalous pulmonary venous connection. Post-operatively, esophageal atresia with tracheoesophageal fistula was identified and repaired on day of life 11. The patient is thriving at 22 months of age. (Level of Difficulty: Advanced.)

In-hospital interstage improves interstage survival after the Norwood stage 1 operation.

The interstage mortality rate after a Norwood stage 1 operation remains 12-20% in current series. In-hospital interstage facilitates escalation of care, possibly improving outcome. A retrospective study was designed for hypoplastic left heart syndrome (HLHS) and HLHS variants, offering an in-hospital stay after the Norwood operation until the completion of stage 2. Daily and weekly examinations were conducted systematically, including two-dimensional and speckle-tracking echocardiography. Primary end points included aggregate survival until the completion of stage 2 and interstage freedom from escalation of care. Moreover, we calculated the sensitivity and specificity of speckle-tracking echocardiographic myocardial deformation in predicting death/transplant after the Norwood procedure. Between 2015 and 2019, 33 neonates with HLHS (24) or HLHS variants (9) underwent Norwood stage 1 (31) or hybrid palliation followed by a comprehensive stage 2 operation (2). Stage 1 Norwood-Sano was preferred in 18 (54.5%) neonates; the classic Norwood with Blalock-Taussig shunt was performed in 13 (39.4%) neonates. The Norwood stage 1 30-day mortality rate was 6.2%. The in-hospital interstage strategy was implemented after Norwood stage 1 with a 3.4% interstage mortality rate. The aggregate Norwood stage 1 and interstage Kaplan-Meier survival rate was 90.6 ± 5.2%. Escalation of care was necessary for 5 (17.2%) patients at 2.5 ± 1.2 months during the interstage for compromising atrial arrhythmias (2), Sano-shunt stenosis (1) and pneumonia requiring a high-frequency oscillator (2); there were no deaths. A bidirectional Glenn (25) or a comprehensive-Norwood stage 2 (2) was completed in 27 patients at 4.7 ± 1.2 months with a 92.6% survival rate. The overall Kaplan-Meier survival rate is 80.9 ± 7.0% at 4.3 years (mean 25.3 ± 15.7 months). An 8.7% Δ longitudinal strain 30 days after Norwood stage 1 had 100% sensitivity and 81% specificity for death/transplant. In-hospital interstage facilitates escalation of care, which seems efficacious in reducing interstage Norwood deaths. A significant reduction of longitudinal strain after Norwood stage 1 is a strong predictor of poor outcome.

Interstage management of pulmonary blood flow after the Norwood procedure with right ventricle-to-pulmonary artery conduit.

Our goal was to assess the efficacy of managing pulmonary blood flow from the Norwood procedure with a right ventricle-to-pulmonary artery (RV-PA) conduit until stage 2 palliation (S2P). Among 48 consecutive patients undergoing the Norwood procedure between 2008 and 2018, 40 (83.3%) patients who survived to discharge were included in this study. The primary diagnosis was hypoplastic left heart syndrome in 28 (70%) patients and hypoplastic left heart syndrome variant in 12 (30%) patients. All patients received bilateral pulmonary artery banding. The median age and weight at the time of the Norwood procedure were 41 (25th-75th percentiles: 27-89) days and 3.2 (2.7-3.9) kg, respectively. In keeping with institutional strategy, S2P was undertaken when body weight exceeded 5.0 kg, and normal gross motor development was confirmed. The RV-PA conduit was clipped in 28 (70%) patients during the perioperative period of the Norwood procedure, then partial unclipping was performed in 8 (20%) patients and full unclipping was performed in 20 (50%) patients. Before S2P, the median pulmonary-to-systemic blood flow ratio was 1.0 (0.7-1.3). The median age and weight at the time of S2P were 10.7 (9.0-12.9) months and 6.3 (5.5-7.1) kg, respectively. The survival rate 5 years after Norwood discharge was 85.3%. Pre-S2P pulmonary-to-systemic blood flow ratio was linearly correlated with greater interstage changes in systemic atrioventricular valve regurgitation (R2 = 0.223, P = 0.004). Interstage management of pulmonary blood flow by RV-PA conduit clipping and gradual unclipping provided good interstage outcomes. The median pulmonary-to-systemic blood flow ratio could be controlled to 1.0 at pre-S2P catheter examination.

1233 Can speckle tracking echocardiography predict outcome in hypoplastic left heart syndrome patients?

Abstract Funding Acknowledgements EACVI Training Grant Introduction Children with Hypoplastic Left Heart Syndrome (HLHS) have a high mortality (up to 95%) and morbidity. Systemic right ventricle (RV) dysfunction plays a key-role in their outcome. Purpose The aim of this study is to evaluate the accuracy of speckle-tracking echocardiographic (STE) assessment of RV deformation and 2D standard echo parameters in predicting death and need for heart transplantation (HT) in HLHS patients. Methods 31 patients with diagnosis of HLHS successfully completed Norwood (n = 29) or comprehensive Norwood stage II (n = 2) at our Institution between 2015 and 2019. Survival at 6 months was 90.32%, survival at 18 months was 85.72%. We studied 29 HLHS patients (17 male). Patients with HLHS variant (n = 2) were excluded. All the studied patients underwent in-hospital interstage stay. Serial echocardiographic assessment was performed in all the included patients (baseline, one month after Norwood, three months after Norwood, one week before bidirectional cavopulmonary anastomosis [BCPA] and two months after BCPA). From the apical view we measured: tricuspid annulus peak systolic excursion (TAPSE), fractional area change (FAC), longitudinal strain (LS) and strain rate (LSR). Results After a mean follow-up of 1.83 ± 1.16 years, 8 out of 29 of the included patients met the composite endpoint of death/HT. At pre-Norwood assessment, there was no statistical difference in echo measurements between survivors and patients who reached the endpoint. In death/HT group TAPSE and LS declined already at one-month after Norwood procedure evaluation. At one-month evaluation, a TAPSE ≤ 5 mm had a good sensitivity for death/HT (85.71%) and a moderate specificity (66.67%), with an area under the curve of 0.789. Always at one-month evaluation, a Δ LS ([{baseline LS – one-month post Norwood LS}/ baseline LS] *100) of 8.7% showed a 100% sensitivity and good specificity (80.95%) for death/HT, with an area under the curve of 0.888. Multivariate analysis showed that one-month-after-Norwood Δ LS was the best predictor of worse outcome (p = 0.02). Conclusions HLHS patients with Δ LS of > 8.7% at one-month after Norwood procedure had a high likelihood of death or HT. These data encourage the routine use of LS to monitor cardiac function in HLHS patients. Abstract 1233 Figure. HLHS LS and trend of TAPSE and LS.

The effect of right ventricular function on survival and morbidity following stage 2 palliation: An analysis of the single ventricle reconstruction trial public data set.

Limited information is known on how right ventricular function affects outcomes after stage 2 palliation. We evaluated the impact of different right ventricular indices prior to stage 2 palliation on morbidity and mortality. Retrospective study design. Pediatric Heart Network Single Ventricle Reconstruction Trial Public Data Set. Any variant of stage 1 palliation and all anatomic hypoplastic left heart syndrome variants in the trial were evaluated. Echocardiograms prior to stage 2 palliation were analyzed and compared between those who failed and those who survived. None. Mortality was defined as death, listed for transplant, or transplanted after stage 2 palliation. Morbidity was evaluated as hospital length of stay and duration of intubation. A total of 283 patients met criteria for analysis. Of those, only 18 patients failed stage 2. Right ventricular fractional area change was less in those who failed (30% vs 34%, P=.039) and right ventricular indexed end-diastolic volume and end-systolic volume were larger in those who failed (142.74 mL/ BSA1.3 vs 111.29 mL/BSA1.3 , P=.023, 88.45 mL/ BSA1.3 vs 62.75 mL/ BSA1.3 , P=.025, respectively). Larger right ventricular indexed end-diastolic and systolic volumes were associated with failure (OR 1.17 [1.01-1.35] P=.021, OR 1.25 [1.03-1.52] P=.021, respectively). Every 10% increase in RV ejection fraction had a 63% decrease in length of stay and a 68% decrease in duration of intubation (P=.014, and P=.039, respectively). Patients with decreased right ventricular fractional area change and larger right ventricular indexed end-diastolic and systolic volumes were more likely to fail stage 2 palliation. Those with preserved right ventricular function had a shorter hospital length of stay and duration of intubation. Echocardiographic measurements of right ventricular indices during the interstage period can be utilized to determine the prognosis following stage 2 palliation.

Cerebrovascular response to maternal hyperoxygenation in fetuses with hypoplastic left heart syndrome depends on gestational age and baseline cerebrovascular resistance.

Compared with normal fetuses, fetuses with hypoplastic left heart syndrome (HLHS) have smaller brain volumes and are at higher risk of brain injury, possibly due to diminished cerebral blood flow and oxygen content. By increasing cerebral oxygen delivery, maternal hyperoxygenation (MH) might improve brain development and reduce the risk of brain injury in these fetuses. This study investigated whether gestational age and baseline cerebrovascular resistance affect the response to MH in fetuses with HLHS. The study population comprised 43 fetuses with HLHS or HLHS variant referred for fetal echocardiography between January 2004 and September 2008. Middle cerebral artery (MCA) pulsatility index (PI), a surrogate measure of cerebrovascular resistance, was assessed between 20 and 41 weeks' gestation at baseline in room air (RA) and after 10 min of MH. Z-scores of MCA-PI were generated. A mixed-effects model was used to determine whether change in MCA-PI depends upon gestational age and baseline MCA-PI. In RA and following MH, MCA-PI demonstrated a curvilinear relationship with gestational age in fetuses with HLHS, peaking at around 28 weeks and then falling more steeply near term. MCA-PI Z-score declined in a linear manner, such that it was 1.4 SD below that in normal fetuses at 38 weeks. Increase in MCA-PI Z-score after MH was first seen at ≥ 28 weeks. A baseline MCA-PI Z-score ≤ -0.96 was predictive of an increase in cerebrovascular resistance in response to MH. In fetuses with HLHS, MCA-PI first increases in response to MH at ≥ 28 weeks' gestation. A baseline MCA-PI Z-score ≤ -0.96 predicts an increase in cerebrovascular resistance in response to MH. These results may have implications for clinical trials utilizing MH as a neuroprotective agent. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Hemodynamic parameters predict adverse outcomes following biventricular conversion with single-ventricle palliation takedown

ObjectivePatients with a borderline left ventricular hypoplasia in the hypoplastic left heart syndrome variant or an unbalanced atrioventricular canal who undergo initial single-ventricle palliation may be candidates for biventricular (BiV) conversion following left ventricle (LV) recruitment procedures. We investigated associations among preoperative parameters and postoperative outcomes in patients undergoing BiV conversion. MethodsWe performed a retrospective review of patients who underwent BiV conversion to determine variables associated with clinical outcomes. Predictor variables included cardiac diagnosis, age and weight, LV dimension, LV end diastolic volume, LV mass, preoperative LV end diastolic pressure (LVEDP), and preoperative left atrial pressure. Primary outcome was a composite of death, heart transplant, or BiV takedown. ResultsOf 51 patients, 11 experienced primary outcome (22%). Patients with hypoplastic left heart syndrome variant were more likely to experience primary outcome than those with an unbalanced atrioventricular canal (30% vs 6%; P = .03). Receiver operating characteristic analysis demonstrated that preoperative LVEDP had good predictive accuracy in classifying patients with and without the primary outcome (area under the curve, 0.757; 95% confidence interval, 0.594-0.919; P = .012). The Youden J-index indicated a cutoff of LVEDP ≥ 13 mm Hg as optimal for predicting the primary outcome. Multivariable Cox regression demonstrated that LVEDP ≥ 13 mm Hg (adjusted hazard ratio, 4.00; P = .037) and postoperative right ventricle pressure > 3/4 (adjusted hazard ratio, 21.75; P < .001) were significantly associated with primary outcome, independent of age, weight, and diagnosis. ConclusionsElevated preoperative LVEDP is a risk factor for suboptimal postoperative hemodynamic parameters and adverse outcome following BiV conversion from single-ventricle palliation.

A Common Variant of Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) includes a group of closely related anomalies characterized by severe hypoplasia of the left-sided structures of the heart including rudimentary left ventricle, combinations of mitral and aortic valve stenosis, or atresia with diminutive ascending aorta and aortic arch. Here, the case of a 10-day-old male baby with a variant of HLHS is being reported.

Off-Pump Atrial Septectomy for Infants With Restrictive Atrial Septal Defect

The management of some subsets of patients with an unsuccessful balloon atrial septostomy (BAS) and poor general condition is typically challenging. Our novel technique involves off-pump atrial septectomy using laparoscopic forceps guided by intraoperative direct pericardial echocardiography. The technique was first used in a case of tricuspid atresia in a patient in preshock and was then used in 2 more patients with hypoplastic left heart syndrome (HLHS) (age, 10-116 days; body weight, 2.4-3.7 kg). There were no operative complications of embolism or bleeding in our series. Our off-pump atrial septectomy technique is an effective approach in specific cases.

Expectations and limitations after bilateral pulmonary artery banding.

Bilateral pulmonary artery banding (bil-PAB) has been developed as a part of a hybrid procedure for hypoplastic left heart syndrome (HLHS). We use this procedure for palliation of complex congenital heart disease, particularly in patients with arch anomaly. We reviewed our experience with bil-PAB. Sixty-six consecutive cases between 2003 and 2014 were reviewed retrospectively. Fifty-one patients (77%) had single ventricle physiology (HLHS: 37, HLHS variant: 13, others: 1). Twelve patients had biventricular physiology [5 interrupted aortic arch with ventricular septal defect (VSD); 4 coarctation of the aorta with VSD; 2 truncus arteriosus; 1 other]. In 3 patients, it was difficult to determine if the physiology was single ventricle or biventricle due to borderline left ventricle size. Age and body weight at the time of operation were 4.3 ± 3.4 days and 2.7 ± 0.5 kg, respectively. Overall hospital mortality was 11% (7/66). Of the 42 patients from 2010, only 1 with multiple anomalies died between bil-PAB and the second-stage operation. Thirteen patients (20%) required reoperation of bil-PAB. The mean waiting time for the next operation was 44.3 ± 42.8 days. The body weight at the second-stage operation was 3.2 ± 0.8 kg. Seven (11%) patients developed patent ductus arteriosus obstruction during the waiting period. Twenty-four patients were 2.5 kg or less; 20 patients in this group progressed to the second-stage operation and of these 19 gained body weight. Forty-two patients were above 2.5 kg, but of these only 23 patients gained body weight. Ten patients underwent bil-PAB because of shock and 8 of these recovered from shock. In 2 borderline cases, the patients underwent the Norwood procedure and 1 patient had arch repair and VSD closure. Bil-PAB could be applied to a wide variety of complex diseases. Our mortality rates with bil-PAB improved significantly post-2010. Good indications for bil-PAB were shock and situations where it was unclear whether the physiology was single ventricle or biventricular. Body weight gain was difficult to predict, but patients weighing less than 2.5 kg could be expected to gain body weight after the procedure.

Staged Left Ventricular Recruitment and Biventricular Conversion for Patients With Borderline Left Heart

A borderline left heart may be present in patients with hypoplastic left heart syndrome or an unbalanced atrioventricular canal defect. Traditionally, such patients have been managed either by high-risk biventricular repair in infancy or during the neonatal period, or by definitive single-ventricle palliation. In this article, we present an approach for staged left ventricular recruitment that promotes gradual rehabilitation of left heart structures and allows delay in the commitment to either a single-ventricle pathway or a biventricular pathway. The rationale, techniques, and early results are described.

Intermediate Results of Hybrid Versus Primary Norwood Operation

In 2007 we began a hybrid program for hypoplastic left heart syndrome (HLHS) variants to potentially improve outcome in high-risk patients. During implementation we offered both hybrid and Norwood approaches to all risk categories. The purpose of this study was to perform a comparative analysis of intermediate survival. Newborns were evaluated jointly for high-risk characteristics, including birth weight less than 2.5 kg, prematurity (especially < 35 weeks), central nervous system abnormalities, multiorgan failure, intact or severely restrictive atrial septum, severe ventricular dysfunction, and severe atrioventricular valve regurgitation. We prefer Norwood for standard risk and hybrid for high risk, but all groups crossed over into all treatment pathways resulting in the following 5 treatment groups: standard risk Norwood; high-risk Norwood; standard risk hybrid ductal stent (HDS); high-risk hybrid DS; and high-risk hybrid prostaglandin E1 (HPGE). We reviewed all consecutive patients from 2007 to 2012, obtained follow-up, and analyzed the results. Sixty-eight newborns presented (median 2.96 kg, 8 days); 29 (43%) were high and 39 (57%) were standard risk. There were 14 stage I hospital deaths strongly associated with risk: 3 of 39 standard (7.7%) and 11 of 29 high (38%, p= 0.002). Stage I discharge mortality was highest for high-risk Norwood and high-risk HPGE groups (p < 0.001). Actuarial survival up to 5 years demonstrated superior survival for Norwood versus hybrid (78.1% vs 56.4%, p= 0.0182). With risk stratification there was suboptimal survival for all 3 high-risk groups (p= 0.003); HDS fared better than HPGE but had higher birth weight (p < 0.001). While a risk-stratified approach for HLHS variant patients with selective use of hybrid palliation resulted in acceptable stage I mortality, the longer term mortality for high-risk patients remains higher than for standard risk regardless of treatment modality. Intrinsic patient risk factors (rather than treatment modality) likely determine long-term outcome in experienced centers. Our current high-risk approach has evolved to HPGE application with Norwood conversion whenever deemed medically possible.

Hypoplastic Left Heart Syndrome and Ventriculocoronary Connections

Hypoplastic left heart syndrome (HLHS) is a critical congenital heart defect. There are variants of HLHS, consisting of permutations of stenosis or atresia of the mitral and aortic valves. A notable phenomenon described in all HLHS subtypes is ventriculocoronary connections (VCCs). The significance of VCCs remains undetermined. Some studies have demonstrated higher mortality associated with VCCs, while others have shown no difference in mortality compared to other HLHS variants. All variants of HLHS are associated with myocardial disarray and endomyocardial fibroelastosis, although recent evidence demonstrates a higher association of those findings with the mitral stenosis–aortic atresia (MS-AA) variant. And VCCs may have a higher incidence in MS-AA as they constitute the only egress of blood from the LV. These associations may play a role in the survival of patients with MS-AA. We present a case of HLHS with MS-AA and significant VCCs. Figure 1 depicts the diminutive LV, no outflow, and opacification of the entire coronary system. Coronary opacification can only be achieved via VCCs, given the aortic valve atresia. Figure 2 demonstrates the severely hypoplastic ascending aorta. The aorta is similar in size to the 3F catheter and the coronaries do not opacify.

Transcatheter neoaortic valve replacement utilizing the melody valve in hypoplastic left heart syndrome

Percutaneous transcatheter pulmonary valve replacement with the Melody Valve is fast becoming an important adjunct in the treatment of older children and adults with failing right ventricular outflow tract conduits. Recently, the Melody Valve has also been successfully implanted in the tricuspid, mitral, and aortic positions, typically within a failing bioprosthetic valve. We present a patient who underwent Fontan palliation for hypoplastic left heart syndrome variant and subsequently developed severe neoaortic regurgitation, which was successfully treated with a transcatheter neoaortic valve replacement. To our knowledge, this is the first successful use of the Melody Valve in the neoaortic position in a patient with single-ventricle physiology. Successful relief of neoaortic valve regurgitation using replacement with a transcatheter valve may allow avoidance of additional surgery, increase functional longevity of single-ventricle palliation, and postpone the need for orthotopic heart transplantation.

Dynamic pulmonary computed tomography angiography: a new standard for evaluation of combined airway and vascular abnormalities in infants

Airway abnormalities are frequently associated with congenital heart disease in infants and children. Respiratory distress in these children frequently requires prolonged respiratory support. Wide-detector dynamic pulmonary computed tomography angiography (DP-CTA) is a non-invasive technique that completely evaluates vascular and airway abnormalities during a single breathe. Our purpose was to evaluate the efficacy of DP-CTA to provide unique actionable information for patient care in newborns and infants with congenital heart disease and persistent respiratory distress. 23 infants with congenital heart disease and persistent respiratory distress underwent DP-CTA. All were intubated at the time of the examinations. The most common cardiac anomalies were tetralogy of Fallot (6) and hypoplastic left heart syndrome variants (5). The most common cardiac surgeries prior to DP-CTA were Norwood (4) and hybrid (3) procedures. The protocol for DP-CTA for intubated infants is four gantry rotations in 1.4 s after intravenous contrast injection. 3D and multiplanar reconstruction with cine loops were created for combined cardiopulmonary imaging. Tracheobronchomalacia was present in 17 children. Lobar bronchomalacia was identified in six children. Branch pulmonary artery stenosis was the most common vascular finding (10 children). Medical management was changed or a surgical procedure performed based on the information resulting from DP-CTA in 16 of the 23 patients (70 %). DP-CTA is non-invasive, fast and provides unique information for the management of infants with congenital heart disease and persistent respiratory distress. DP-CTA is uniquely suited for comprehensive and simultaneous evaluation of airway and vascular abnormalities in infants.

Risk factors for preoperative periventricular leukomalacia in term neonates with hypoplastic left heart syndrome are patient related

Preoperative brain injury is common in neonates with complex congenital heart disease. Increasing evidence suggests a complex interaction of prenatal and postnatal risk factors for development of brain white matter injury, called periventricular leukomalacia (PVL), in neonates with complex congenital heart disease. To date, there remains a limited understanding of the risk factors contributing to preoperative PVL in hypoplastic left heart syndrome (HLHS). Neonates with HLHS or HLHS variants from 3 prospective magnetic resonance imaging studies (2003-2010) were selected for this cohort. Preoperative brain magnetic resonance imaging was performed the morning of the surgery. Stepwise multilogistic regression of patient characteristics, mode of delivery (cesarean section vs vaginal), time of diagnosis (prenatal vs postnatal), HLHS subtypes, brain total maturation score, time to surgery, individual averaged daily preoperative blood gases, and complete blood cell count values was used to determine significant associations. A total of 57 neonates with HLHS were born at 38.7 ± 2.3 weeks; 86% (49/57) had a prenatal diagnosis, with 31% (18/57) delivered by cesarean section. HLHS with aortic atresia (AA) was common in this cohort, 71% (41/57). Preoperative PVL was identified in 19% (11/57). Male patients with AA (P=.004) were at higher risk for PVL. Lower total brain maturation score was also identified as a strong predictor for preoperative PVL (P=.005). In neonates with HLHS, nonmodifiable patient-related factors, including male sex with AA (lackof antegrade blood flow) and lower total brain maturation score, placed neonates at the greatest risk for preoperative white matter injury.