Hypoplastic Left Heart Syndrome Group Research Articles

Abstract 4123926: Suprasomatic Serial Growth of Right Heart Structures in Fetuses with Hypoplastic Left Heart Syndrome Demonstrated by Fetal Echocardiography

Background: In hypoplastic left heart syndrome (HLHS), the single right ventricle (RV) accounts for the entire cardiac stroke volume. This physiology may produce elevated transpulmonary flow velocities and dilation of the right heart structures. Little data exists regarding normal right heart dimensions and transpulmonary velocities in relation to somatic growth in these fetuses. We sought to assess serial changes in the size of right heart structures and pulmonary valve (PV) velocities in fetuses with HLHS and compare findings to fetuses with normal cardiac anatomy. Methods: A retrospective cohort study of fetuses with HLHS or normal cardiac anatomy confirmed by fetal echocardiogram between 1/1/13 – 12/31/22 was performed, excluding multiple gestation pregnancies. Fetal echocardiograms were assessed by an independent reviewer who obtained RV, PV and tricuspid valve annulus dimensions, and PV flow velocities. Nomograms were created for both HLHS and normal cohorts. The association between gestational age and PV velocity, PV annulus, RV diameter and tricuspid valve annulus was assessed and compared between groups using linear mixed models. Results: There were 290 total fetal echocardiograms for 177 patients with HLHS compared against 408 normal fetuses. [MG1] PV velocities were higher for patients with HLHS compared to normal cardiac anatomy throughout gestation (p < 0.001). In addition, the PV velocity increased more rapidly with gestational age for the HLHS (+0.02 m/s/week) group compared to those with normal cardiac anatomy (+0.01 m/s/week) (p=0.019) (Figure 1). Similarly, the RV dimension grew more rapidly with gestational age for those with HLHS (+3.2% cm/week) compared to those with normal cardiac anatomy (+2.5% cm/week) (p<0.001) (Figure 2). Lastly, the tricuspid valve annulus grew more rapidly with gestational age for patients with HLHS (+2.6% cm/week) compared to those with normal cardiac anatomy (+2.3% cm/week) (p=0.010) (Figure 3). While the PV annulus size increased with gestational age, there was not a significant difference in growth between the two groups (p=0.119). Conclusions: In fetuses with HLHS, the PV velocity, RV size and tricuspid valve size increase at a rate greater than normal somatic growth. These nomograms help identify expected RV size, tricuspid valve size and PV velocities for fetuses with HLHS and any who may deviate from the norm.

Bioinformatic Multi-Strategy Profiling of Congenital Heart Defects for Molecular Mechanism Recognition

Congenital heart defects (CHDs) rank among the most common birth defects, presenting diverse phenotypes. Genetic and environmental factors are critical in molding the process of cardiogenesis. However, these factors’ interactions are not fully comprehended. Hence, this study aimed to identify and characterize differentially expressed genes involved in CHD development through bioinformatics pipelines. We analyzed experimental datasets available in genomic databases, using transcriptome, gene enrichment, and systems biology strategies. Network analysis based on genetic and phenotypic ontologies revealed that EP300, CALM3, and EGFR genes facilitate rapid information flow, while NOTCH1, TNNI3, and SMAD4 genes are significant mediators within the network. Differential gene expression (DGE) analysis identified 2513 genes across three study types, (1) Tetralogy of Fallot (ToF); (2) Hypoplastic Left Heart Syndrome (HLHS); and (3) Trisomy 21/CHD, with LYVE1, PLA2G2A, and SDR42E1 genes found in three of the six studies. Interaction networks between genes from ontology searches and the DGE analysis were evaluated, revealing interactions in ToF and HLHS groups, but none in Trisomy 21/CHD. Through enrichment analysis, we identified immune response and energy generation as some of the relevant ontologies. This integrative approach revealed genes not previously associated with CHD, along with their interactions and underlying biological processes.

Patients With Hypoplastic Left Heart Syndrome Have a Shorter Superior Vena Cava

BackgroundThe primary treatment for hypoplastic left heart syndrome (HLHS) is the Fontan pathway, which entails performing the Glenn procedure. We hypothesized that the superior vena cava in patients with HLHS was short. As the length of the superior vena cava influences the Glenn procedure, we compared its length between patients with HLHS and those with other congenital heart diseases. MethodsPatients with HLHS or its variant, patients with ventricular septal defects (VSD), and patients with pulmonary atresia with intact ventricular septum (PA/IVS)—including critical pulmonary stenosis—were enrolled in this study. The effective superior vena cava ratio (ESCVR), which is defined as the inferior border of the left brachiocephalic vein to the superior surface of the right pulmonary artery/height, was measured. ResultsThe median ESVCR of the HLHS, VSD, and PA/IVS patients was 12.54 mm/m, 17.96 mm/m, and 18.46 mm/m, respectively. ESVCR of the HLHS group was significantly smaller than that of the other groups (P = .0013 vs VSD group, P = .0002 vs PA/IVS group). ConclusionsPatients with HLHS have a relatively short superior vena cava, which may complicate the Glenn procedure.

The outcomes of Fontan operation in patients with hypoplastic left heart syndrome (HLHS) versus other forms of univentricular heart

Abstract Background Single ventricle physiology is a rare condition but is highly represented in clinical practice due to a high prevalence of late complications and comorbidities. The Fontan operation has undergone considerable modification over the past 5 decades and is now in a superior hydrodynamic form. Purpose The purpose was to identify the potential differences in outcomes of Fontan operation between patients with hypoplastic left heart syndrome (HLHS) and with other indications to this treatment. Methods and results The study comprised 74 patients (20±6 years) after the Fontan operation (26 females) divided based on the indication to this operation as a group with HLHS (19 patients) and the group without HLHS (54 patients). Patients with HLHS had significantly more often had a fenestration between the systemic venous return and the pulmonary venous atrium (89% vs 41%; p=0.001) which was closed in further observation in 89% in HLHS versus 39% in patients without HLHS, p=0.001. Regarding complications after Fontan operation, in HLHS group more often narrowings of pulmonary arteries requiring stenting occurred (74% vs 13%; p=0.001) and Fontan-associated liver disease (37% vs 9%, p=0.05). There were no differences in stenting of the lateral tunnel connection, fistulas, enteropathy, rhythm disturbances, peacemaker implantation, vascular complications, strokes between groups. HLHS patients more often were treated with antiplatelet drugs (26% vs 0, p=0.001), spironolactone (63% vs 23%, p=0.01) and angiotensin-converting-enzyme inhibitors (89% vs 44%, p=0.01). Conclusions HLHS patients have worse outcomes of Fontan operation. This group of patients more often needs fenestrations and regular controls towards pulmonary arteries narrowings and Fontan-associated liver disease. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Polish Mother's Memorial Hospital - Research Institute

Near-Term Cerebroplacental Doppler, Heart Morphology, and Neonatal Biometry in Hypoplastic Left Heart Syndrome.

To analyze near-term cerebroplacental Doppler, heart morphology, and neonatal biometry in isolated hypoplastic left heart syndrome (HLHS) relative to healthy controls. This retrospective study included 55 fetuses with HLHS (29 with mitral valve stenosis [MS]/aortic valve atresia [AA], 14 with MS/aortic valve stenosis, and 12 with mitral valve atresia [MA]/[AA]) diagnosed prenatally between 2010 and 2019 at 2 referral centers and 101 healthy controls. Ultrasound assessment included umbilical artery (UA), middle cerebral artery (MCA) pulsatility index (PI), and cerebroplacental ratio (CPR), with neonatal weight, length, head circumference (HC), Apgar score, and UA pH measured at birth. In total, 32.7% of HLHS fetuses had abnormal MCA-PI and UA-PI, and 38.2% had CPRs below the fifth percentile before birth. All tested Doppler parameters differed from those of the healthy controls (P ≤ .01). Birth weight and length were comparable between HLHS and control fetuses, whereas birth HCs were smaller in the HLHS group than in the control group (P=.018). In both groups, increased UA-PI correlated with lower birth weight, but only HLHS fetuses with UA-PI > the 95th percentile had a lower median HC at birth than those with normal UA-PI (P=.045). The median UA-PI percentile was higher in fetuses with MA than in fetuses with MS (P=.015). The ascending aortic diameter correlated with birth weight (P=.036) and birth length (P=.039). Abnormal cerebroplacental hemodynamics are evident in a high percentage of near-term fetuses with HLHS, and increased placental resistance may contribute to birth weight and HC. Moreover, heart morphology may impact placental circulation and neonatal biometry.

Patients with Fontan circulation have abnormal aortic wave propagation patterns: A wave intensity analysis study

BackgroundElevated systemic afterload in patients with Fontan circulation may lead to impaired single ventricular function. Wave intensity analysis (WIA) enables evaluation of compression and expansion waves traveling through vasculature. We aimed to investigate the unfavorable wave propagation causing excessive afterload may be an important contributor to the overall single ventricle function and to the limited functional capacity in this patient population. MethodsPatients with hypoplastic left heart syndrome (HLHS) (n = 25), single left ventricle (SLV) (n = 24), and normal controls (n = 10) underwent phase-contrast MRI based WIA analysis evaluated in the ascending aorta. Forward compression wave (FCW) representing dP/dt, backward compression wave (BCW) reflecting vascular stiffness, and forward decompression wave (FDW) representing LV relaxation were recorded and indexed to each other. ResultsFCW was lowest in HLHS patients (1098 mm5/s), and higher in the SLV group (1457 mm5/s), and controls (6457 mm5/s) (P < 0.001). BCW/FCW was increased in HLHS (0.22) and SLV (0.14) groups compared to controls (0.08) (P = 0.003). Peak VO2 correlated with FCW (R = 0.50, P = 0.015), stroke volume (R = 0.72, P < 0.001), and cardiac output (R = 0.44, P = 0.034). ConclusionsPatients with HLHS and SLV have unfavorable aortic WIA patterns with increased BCW/FCW ratio indicating increased systemic afterload due to retrograde compression waves. Reduced FCW and systolic MRI indices correlated with peak VO2 suggesting that abnormal systolic wave propagation may play a role in exercise intolerance for Fontan patients.

Fetal Umbilical Arterial Pulsatility Correlates With 2-Year Growth and Neurodevelopmental Outcomes in Congenital Heart Disease

BackgroundChildren with congenital heart disease (CHD) are at risk of adverse long-term neurodevelopmental outcomes, believed to be, in part, secondary to prenatal insults. Placental pathology and altered fetal middle cerebral arterial (MCA) flow suggestive of brain sparing have been documented in fetal CHD. In the present study we investigated the relationship between MCA and umbilical arterial (UA) flow patterns in fetal transposition of the great arteries (d-TGA) and hypoplastic left heart syndrome (HLHS) and growth and 2-year neurodevelopmental outcomes. MethodsWe included children with d-TGA and HLHS who had third-trimester fetal echocardiograms between 2004 and 2014, at which time umbilical artery (UA) and MCA pulsatility indices (PIs) were measured, and who underwent 2-year growth and neurodevelopmental assessments. ResultsWe identified 24 children with d-TGA and 36 with HLHS. Mean age at fetal echocardiography was 33.8 ± 3.5 weeks. At 2-year follow-up, head circumference z score (standard deviation [SD]) was –0.09 (1.07) and 0.17 (1.7) for the d-TGA and HLHS groups, respectively. Bayley III mean (SD) cognitive, language, and motor scores were 97.7 (10.8), 94.7 (13.4), and 98.6 (8.6) for the d-TGA group and 90.3 (13.9), 87.2 (17.5), and 85.3 (16.2) for the HLHS group. On multivariate linear regression analysis, UA-PI was associated (effect sizes [95% CI]) with length (–1.45 [–2.7, –0.17], P = 0.027), weight (–1.46 [–2.6 to –0.30], P = 0.015) and cognitive scores (–14.86 [–29.95 to 0.23], P = 0.05) at 2 years of age. MCA PI showed no statistically significant correlation. ConclusionsIn fetal d-TGA and HLHS, a higher UA-PI in the third trimester, suggestive of placental insufficiency—but not MCA-PI—is associated with worse 2-year growth and neurodevelopment.

Expression of connexin-43 in the cardiac muscle of children diagnosed with hypoplastic left heart syndrome: a Western blot and confocal laser scanning microscopy study.

Hypoplastic left heart syndrome consists of several structural abnormalities in the left side of the heart and may be associated with a hereditary genetic cause, possibly related to the connexin gene GJA1; however, only a few studies have investigated it. The present study aimed to analyse the expression of connexin-43 in the cardiac muscle of hypoplastic left heart syndrome children by Western blot method and confocal laser scanning microscopy. For that, tissue samples were taken during corrective surgery to treat heart defects. Patients of control group (8) presented any type of heart defect not related to hypoplastic left heart syndrome, connexin-43, or its gene and those of hypoplastic left heart syndrome group (9) presented this disease singly, without any other associated congenital diseases. By means of confocal laser scanning microscopy, it was noticed no connexin-43 qualitative differences in positioning and location pattern between both groups. From Western blot analysis, the connexin-43 expression did not show a statistically significant difference (p = 0.0571) as well. Within the limits of this study, it is suggested that cardiomyocytes of hypoplastic left heart syndrome children are similar in connexin-43 location, distribution, and structural and conformational patterns to those of children with heart defects not related to this protein and its genes.

Cerebral blood flow dynamic in foetuses with hypoplastic left heart syndrome: Incremental value of the first segment of the anterior cerebral artery over the middle cerebral artery?

To investigate the blood flow Doppler parameters of the anterior cerebral artery (ACA) in foetuses with hypoplastic left heart syndrome (HLHS). Doppler parameters (peak systolic velocity [PSV], end-diastolic velocity [EDV], time-averaged maximum velocity [TAMXV] and pulsatility index [PI]) and biometric parameters were measured in two anatomical segments of the ACA (S1 and S2) and in the middle cerebral artery (MCA) in 35 HLHS foetuses and 73 gestational age-matched normal foetuses. Correlations between the cerebral artery PIs and head circumference (HC) were assessed. Both EDV and TAMXV of the ACA and MCA in the HLHS group were significantly higher than in the normal group (P < .05). The PI of the ACA and MCA in the HLHS group were significantly lower than in the normal group (P < .05). ACAS1PI and ACAS2PI in the HLHS foetuses with retrograde blood flow in the aortic isthmus (AoI) were significantly lower than those of HLHS foetuses without retrograde blood flow in the AoI (P < .05). ACAS2PI was significantly lower than ACAS1PI in the HLHS foetuses with retrograde blood flow in the AoI (P = .047). The abnormal rates of ACAS1 and ACAS2 were significantly higher than that of the MCA (P < .05) in the HLHS group. The HC and biparietal diameter were significantly lower in the HLHS group than in the control group (P < .05). HC was correlated with the PIs of ACAS1, ACAS2 and the MCA in the HLHS group (P < .05). A redistribution of foetal cerebral blood flow appeared in HLHS, and the measurement of ACA PI might provide early information on brain hypoxia.

Prenatally diagnosed foramen ovale restriction in fetuses with hypoplastic left heart syndrome may be a predictor of longer hospitalization, but not of a need for an urgent rashkind procedure.

This prospective study aimed to assess the effectiveness of foramen ovale examination in classifying prenatal hypoplastic left heart syndrome (HLHS) in accordance with the new classification groupings for congenital heart defects. The analysis included 145 fetuses with HLHS, diagnosed and monitored between 2008 and 2015 in Prenatal Cardiology Department at Polish Mother's Memorial Hospital Research Institute in Lodz. The main criteria for classifying our study population into three sub-groups was was the presence of a foramen ovale restriction, which we diagnosed by evaluating the diameter and blood flow through the foramen ovale. Of the total group, 73.8% (n = 107) were classified as severe planned, 24.1% (n = 35) as severe urgent, and 2.1% (n = 3) as the severest group. Comparing the severe planned and the severe urgent HLHS groups showed: gestational age of delivery 38 vs 38 weeks respectively (p = 0.45); cesarean delivery 62% vs 79.2% (p = 0.15); neonatal birth weight 3110 g vs 2985 g (p = 0.2); Apgar score 9 vs 9 points; survival rate 65.8% vs 61.9% (p = 0.8); and hospitalization 38 vs 46.5 days (p = 0.059). Prenatal qualification for the group of severe urgent HLHS was characterized by 100% sensitivity, 80.6% specificity and a low posi- tive predictive value of 9.5%. 1. Prenatal qualification into the group of severe urgent CHD based on the features of foramen ovale was characterized by high sensitivity, a satisfying specificity and a low positive predictive value. 2. Prenatally diagnosed foramen ovale restriction may be a predictor of longer hospitalization, but not of a need for an urgent Rashkind procedure. 3. New classifications of CHDs allowed clinicians to determine prognoses and to plan optimal multi-specialized care which resulted in similar outcomes between the severe planned and severe urgent HLHS groups.

The Effect of Multidisciplinary Approach on the Birth Rate of Fetuses with Prenatally Diagnosed Congenital Heart Disease.

BackgroundThis study aimed to determine the effect of a multidisciplinary approach on the birth rate of fetuses with prenatally diagnosed congenital heart diseases (CHDs).MethodsAmong the fetuses of 724 gravidas who underwent fetal echocardiography in Samsung Medical Center from January 2013 to June 2017, 463 fetuses with normal cardiac structure, arrhythmia or simple left-to-right shunt were excluded, and the remaining 261 were included in the study. The subjects were subdivided into groups based on whether they were consulted multidisciplinarily, that is, consulted simultaneously by pediatric cardiologists, obstetricians and pediatric cardiac surgeons or not. They were also categorized based on the initial fetal echocardiogram results.ResultsAmong the fetuses in the multidisciplinary group, 64.5% of the fetuses were given birth to, and the proportion was not different from that in the non-multidisciplinary group (68.6%, P = 0.48). The delivery rate in the multidisciplinary consultation group were 69.2% in the transposition of the great arteries group, 63.6% in the tetralogy of Fallot group, 68.8% in the pulmonary atresia or interrupted aortic arch group, 62.5% in the coarctation of aorta group, 60.0% in the atrioventricular septal defect group, 70.0% in the functional single ventricle group, and 55.6% in the hypoplastic left heart syndrome group; there were no significant differences between the 10 echocardiogram groups. However, when the subjects were categorized into Fontan repair group and biventricular repair group, the Fontan repair group showed a significant increase in the likelihood of delivery when a multidisciplinary approach was taken (P = 0.035).ConclusionWhen a fetus was diagnosed with a CHD where Fontan repair should be considered, a multidisciplinary approach resulted in increased possibility of delivery.

Immediate Postnatal Ventricular Performance Is Associated with Mortality in Hypoplastic Left Heart Syndrome.

Right ventricular (RV) function as assessed by deformation has been evaluated prenatally and after palliation in hypoplastic left heart syndrome (HLHS). However, limited data exist about the immediate postnatal cardiac adaptation and RV function in HLHS. We compared echocardiographic measures of cardiac performance in HLHS versus controls in their first week of life. As a secondary objective, we evaluated if markers at the first echocardiogram were associated with mid- and long-term outcomes. Clinical and echocardiographic data of patients with HLHS between 2013 and 2016 were reviewed. The study population was matched with controls whose echocardiograms were obtained due to murmur or rule out coarctation. Speckle-tracking echocardiography was used to assess deformation. Thirty-four patients with HLHS and 28 controls were analyzed. Age at echocardiogram was similar between HLHS and controls. The RV of HLHS was compared to both RV and left ventricle (LV) of controls. HLHS deformation parameters [RV peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR)] and tricuspid annular plane systolic excursion (TAPSE) were decreased compared to RV of controls. The LV-fractional area change, peak GLS, GLSR, circumferential strain, and strain rate of controls were higher than the RV of HLHS. Calculated cardiac output (CO) was higher in the HLHS group (592 vs. 183mL/kg/min, p = 0.0001) but similar to the combined LV and RV output of controls. Later mortality or cardiac transplantation was associated with the RV CO and RV stroke distance at initial echocardiogram. Cox proportional hazard regression determined that restriction at atrial septum, decreased initial RV stroke distance and decreased TAPSE had a higher risk of death or cardiac transplantation. TAPSE and RV stroke distance by velocity time integral had adequate inter-reader variability by Bland-Altman plot and Pearson's correlation. Our study found that the HLHS RV deformation is decreased in the early postnatal period when compared to both LV and RV of controls, but deformation was not associated with mid- and long-term outcomes. Later mortality or cardiac transplantation was associated with decreased initial stroke distance and cardiac output. Early evaluation of patients with HLHS should include an assessment of stroke distance and future research should evaluate its implication in management strategies.

Perioperative Cerebral Oxygenation Metabolism in Neonates with Hypoplastic Left Heart Syndrome or Transposition of the Great Arteries.

Optimizing oxygen delivery to the brain is one of the main goals in children with congenital heart defects after surgery. It has been shown that cerebral oxygen saturation (cSO2) is depressed within the first day after neonatal cardiopulmonary bypass surgery. However, peri-operative cerebral oxygen metabolism has not yet been assessed in previous studies. The aim of this study was to describe the peri-operative changes in cerebral oxygen metabolism in neonates with congenital heart defects following cardiopulmonary bypass surgery. Prospective observational cohort study. PICU of a tertiary referral center. Fourteen neonates with hypoplastic left heart syndrome (HLHS) undergoing Norwood procedure and 14 neonates with transposition of great arteries (TGA) undergoing arterial switch operation (ASO) were enrolled. Pediatric heart surgery. We measured non-invasively regional cSO2 and microperfusion (rcFlow) using tissue spectrometry and laser Doppler flowmetry before and after surgery. Cerebral fractional tissue oxygen extraction (cFTOE), the arterio-cerebral difference in oxygen content (acDO2) and approximated cerebral metabolic rate of oxygen (aCMRO2) were calculated. According to the postsurgical hemodynamics, arterial saturation (aSO2) normalized immediately after surgery in the TGA group, whereas HLHS patients still were cyanotic. cSO2 significantly increased in TGA group over 48h after ASO (p = 0.004) and was significantly higher compared to HLHS group after Norwood procedure. cFTOE as a risk marker for brain injury was elevated before surgery (TGA group 0.37 ± 0.10, HLHS group 0.42 ± 0.12) and showed a slight decrease after ASO (p = 0.35) but significantly decreased in patients after Norwood procedure (p = 0.02). Preo-peratively, acDO2 was significantly higher in patients with HLHS compared to patients with TGA (7.7 ± 2.5 vs. 5.2 ± 1.6ml/dl, p = 0.005), but normalized in the posto-perative course. Before surgery, the aCMRO2 was slightly higher in the HLHS group (5.1 ± 1.5 vs. 3.9 ± 2.5 AU, p = 0.14), but significantly decreased after Norwood procedure (- 1.6 AU, p = 0.009). There was no difference in rcFlow between both groups and between the points in time prior and after surgery. Neonates undergoing cardiac surgery suffer from peri-operative changes in hemodynamics and cerebral hypoxemic stress. The cerebral oxygen metabolism seems to be more affected in cyanotic children with functionally univentricular hearts compared to post-operative acyanotic patients. Additional stress factors must be avoided to achieve the best possible neurological outcome.

Prediction of Periventricular Leukomalacia in Neonates after Cardiac Surgery Using Machine Learning Algorithms.

Periventricular leukomalacia (PVL) is brain injury that develops commonly in neonates after cardiac surgery. Earlier identification of patients who are at higher risk for PVL may improve clinicians' ability to optimize care for these challenging patients. The aim of this study was to apply machine learning algorithms and wavelet analysis to vital sign and laboratory data obtained from neonates immediately after cardiac surgery to predict PVL occurrence. We analyzed physiological data of patients with and without hypoplastic left heart syndrome (HLHS) during the first 12h after cardiac surgery. Wavelet transform was applied to extract time-frequency information from the data. We ranked the extracted features to select the most discriminative features, and the support vector machine with radial basis function as a kernel was selected as the classifier. The classifier was optimized via three methods: (1) mutual information, (2) modified mutual information considering the reliability of features, and (3) modified mutual information with reliability index and maximizing set's mutual information. We assessed the accuracy of the classifier at each time point. A total of 71 neonates met the study criteria. The rates of PVL occurrence were 33% for all patients, with 41% in the HLHS group and 25% in the non-HLHS group. The F-score results for HLHS patients and non-HLHS patients were 0.88 and 1.00, respectively. Using maximizing set's mutual information improved the classifier performance in the all patient groups from 0.69 to 0.81. The novel application of a modified mutual information ranking system with the reliability index in a PVL prediction model provided highly accurate identification. This tool is a promising step for improving the care of neonates who are at higher risk for developing PVL following cardiac surgery.

Impact of Hybrid Stage 1 Palliation for Hypoplastic Left Heart Syndrome: Histopathological Findings

The purpose of the study is to analyze the impact of hybrid stage 1 palliation on right ventricular myocardial pathology in hypoplastic left heart syndrome. Sufficient amount of right ventricular biopsies could be obtained from 16 of 32 patients who underwent Norwood operation between 2007 and 2013. Histopathological findings of right ventricle in patients who underwent primary Norwood operation (primary group, n = 5), patients with aortic atresia (HS1P AA group, n = 6) or aortic stenosis (HS1P AS group, n = 5) who underwent staged Norwood palliation following hybrid stage 1 palliation were compared. To eliminate the influence of right ventricular pressure afterload, right ventricular biopsies were obtained from patients with truncus arteriosus communis (TAC group, n = 6) at total correction. The percentage of myocardial fibrosis was significantly higher in both HS1P groups than in TAC group; moreover, it was significantly higher in HS1P AA group than in primary group. Capillary vascular density was significantly lower in all hypoplastic left heart syndrome groups than in TAC group. At the sub-endocardial layer, collagen type I/III ratios were higher in HS1P AA group than in other hypoplastic left heart syndrome groups. The proportions of N-cadherin immunolocalized to myocyte termini were lower in all hypoplastic left heart syndrome groups than in TAC group. Right ventricle in hypoplastic left heart syndrome showed more significant ischemic change and myocardial immaturity than that in truncus arteriosus communis. Hybrid stage 1 palliation for aortic atresia would be a risk factor for further right ventricular myocardial ischemia.

Cerebral Blood Flow Following Hybrid Stage I Palliation in Infants with Hypoplastic Left Heart Syndrome.

Hypoplastic left heart syndrome (HLHS) palliation may result in altered cerebral blood flow with subsequent neurodevelopmental implications. The purpose of the study was to assess blood flow in the middle cerebral artery (MCA) and investigate the relationship with early neurodevelopmental outcomes in infants with HLHS after hybrid stage I. Transcranial Doppler (TCD) was performed to obtain peak systolic, end-diastolic, and mean velocities, as well as pulsatility index of the MCA in infants with HLHS (n = 18) at baseline and at 2, 4, and 6months of age. Developmental assessment was performed at 6months of age. Results of TCD and development were compared to healthy control subjects (n = 6) and normative data. Overall, peak systolic velocity (p = 0.0031), end-diastolic velocity (p < 0.0001), and mean velocity (p < 0.0001) were significantly lower and pulsatility index (p = 0.0011) significantly higher in the HLHS group compared to the control group. A significant increase in change over time was noted for peak systolic velocity (p < 0.0016) and mean velocity (p < 0.0046). There was no significant correlation between TCD variables and development scores. TCD values in 5-6months old infants with HLHS who undergo hybrid stage I palliation had consistently lower blood flow velocities than control infants; however, pulsatility index was slightly higher. No correlation between TCD measurements and measures of cognitive, language, and motor skills were noted.

83 Use of feature tracking to assess systemic right ventricles in congenital heart disease patients with both single and dual ventricular circulations

IntroductionThe management of congenital patient’s frequently utilises cardiac magnetic resonance imaging to assess changes in patients cardiac function. Ventricular function assessment is challenging in this cohort due to complex ventricular...

Ventricular function and ventriculo-arterial coupling after palliation of hypoplastic left heart syndrome: A comparative study with Fontan patients with LV morphology

BackgroundConceptually the right ventricle (RV) is less suitable to support the Fontan circulation than the left (LV). After palliation of hypoplastic left heart syndrome (HLHS) involving aortic reconstruction during the Norwood procedure the RV is exposed to abnormal afterload. We studied ventricular function and ventriculo-arterial coupling in HLHS patients (RV) and Fontan patients with single LV morphology that did (LV+N) and did not (LV−N) undergo Norwood-type aortic reconstruction. MethodsEighty patients (55 RV, 8 LV+N, 17 LV− N) were simultaneously studied with the conductance-catheter and echocardiography 4.8 (0.9–22.9)years after Fontan completion. ResultsEjection fraction (EF) was lowest in the HLHS group (RV 60.9±11.0 vs. LV+N 68.4±10.5 vs. LV−N 69.7±8.0, P=0.003) whereas end systolic elastance (Ees), i.e. ventricular contractility, and end diastolic stiffness (Eed) were highest (Ees: RV 3.38±2.2 vs. LV+N 2.3.±13.8 vs. LV−N 1.92±1.37mmHg/ml, P=0.02; Eed: RV 0.59±0.36 vs. LV+N 0.48±0.29 vs. LV−N 0.32±0.17mmHg/ml, P<0.02). Arterial elastance, a measure of afterload, was highest in HLHS patients and correlated positively with Ees and Eed and inversely with EF in the study cohort. Only long axis function analysis suggested superior ventricular function in HLHS patients whereas all other echocardiographic measures did not reveal any group differences. ConclusionVentricular contractility of the RV of HLHS patients is higher than that of the ventricle of Fontan patients with LV morphology. This likely reflects a physiological response to higher arterial elastance resulting from aortic arch reconstruction. Increased arterial elastance negatively impacts diastolic stiffness, which is higher in the systemic RV than LV.

Evaluation of right ventricular function in fetal hypoplastic left heart syndrome by color tissue Doppler imaging.

Postnatal outcome of fetuses with hypoplastic left heart syndrome (HLHS) is determined mainly by right ventricular function. Our study examines whether there are differences in right ventricular function during gestation of fetuses with HLHS compared with healthy fetuses. A prospective study was conducted including 20 fetuses with HLHS and 20 gestational age-matched controls. Peak systolic and diastolic right ventricular free wall velocities were assessed using color tissue Doppler imaging (c-TDI). Subsequently, isovolumic time intervals, ejection time (ET'), E'/A' ratio and tissue Doppler-derived myocardial performance index (MPI') were calculated. Possible changes to c-TDI indices during the course of pregnancy in both the HLHS group and the control group were investigated. Examination of right ventricular function revealed significantly lower E' velocities (13.6 vs 21.0 cm/s; P = 0.017) and E'/A' ratios (0.55 vs 0.76; P = 0.012) and prolonged isovolumic contraction time (ICT') (57.0 vs 45.7 ms; P = 0.008) in the HLHS group compared with healthy fetuses. Furthermore, isovolumic relaxation time and MPI' increased significantly with gestational age in HLHS fetuses but not in controls. Values for systolic and diastolic peak velocities (E', A', S'), ET' and ICT' did not change significantly during gestation in either group. Right ventricular function in HLHS is altered as early as in fetal life, well before palliative surgery is performed. Future research should provide further insight into ventricular remodeling during gestation in cases of HLHS. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Resultados comparativos de cirugía de Fontan en pacientes con y sin hipoplasia de corazón izquierdo

IntroductionDuring the last few years, numerous patients with univentricular heart disease have been treated surgically with total cavopulmonary anastomosis according to a staged surgery protocol in our institution. ObjectiveTo evaluate the perioperative outcomes and survival of patients with hypoplastic left heart syndrome (HLHS) after the Fontan procedure and compare them with other types of univentricular heart disease. Patients and methodA total of 102 patients underwent a Fontan procedure between April 1996 and March 2014, 25 with HLHS (group I), and 77 patients with other types of univentricular heart disease (group II). Groups survival, demographics, hemodinamic studies, morbimortality, mechanical ventilation, surgical drains, post-operative stay, isotopes score, pacemaker use, and requiriment of Fontan takedown were analyzed. ResultsIntraoperative mortality was 4% (n=1) for group I, and 7.8% (n=6) for group II (P=.451). A difference was only found in hospital length of stay (LOS), being 17 days (6-47) for group I and 12 days (5-103) for group II (P=.017). Mean follow-up was 4.24±2.08 years for group I, and 8.7±4.67 for group II. Survival rate at 8 years for both groups was 88%, and 81% at 10 years for group II. ConclusionsThe Fontan procedure had similar mortality, but longer LOS, in patients with HLHS compared to those with another types of single ventricle anatomy. Long term survival was comparable between both groups.