Longitudinal Follow-Up of Children With HLHS and Association Between Norwood Shunt Type and Long-Term Outcomes: The SVR III Study.

OBJECTIVE: In the SVR trial (Single Ventricle Reconstruction), newborns with hypoplastic left heart syndrome were randomly assigned to receive a modified Blalock-Taussig-Thomas shunt (mBTTS) or a right ventricle-to-pulmonary artery shunt (RVPAS) at Norwood operation. Transplant-free survival was superior in the RVPAS group at 1 year, but no longer differed by treatment group at 6 years; both treatment groups had accumulated important morbidities. In the third follow-up of this cohort (SVRIII [Long-Term Outcomes of Children With Hypoplastic Left Heart Syndrome and the Impact of Norwood Shunt Type]), we measured longitudinal outcomes and their risk factors through 12 years of age. METHODS: Annual medical history was collected through record review and telephone interviews. Cardiac magnetic resonance imaging (CMR), echocardiogram, and cycle ergometry cardiopulmonary exercise tests were performed at 10 through 14 years of age among participants with Fontan physiology. Differences in transplant-free survival and complication rates (eg, arrhythmias or protein-losing enteropathy) were identified through 12 years of age. The primary study outcome was right ventricular ejection fraction (RVEF) by CMR, and primary analyses were according to shunt type received. Multivariable linear and Cox regression models were created for RVEF by CMR and post-Fontan transplant-free survival. RESULTS: Among 549 participants enrolled in SVR, 237 of 313 (76%; 60.7% male) transplant-free survivors (mBTTS, 105 of 147; RVPAS, 129 of 161; both, 3 of 5) participated in SVRIII. RVEF by CMR was similar in the shunt groups (RVPAS, 51±9.6 [n=90], and mBTTS, 52±7.4 [n=75]; P=0.43). The RVPAS and mBTTS groups did not differ in transplant-free survival by 12 years of age (163 of 277 [59%] versus 144 of 267 [54%], respectively; P=0.11), percentage predicted peak Vo2 for age and sex (74±18% [n=91] versus 72±18% [n=84]; P=0.71), or percentage predicted work rate for size and sex (65±20% versus 64±19%; P=0.65). The RVPAS versus mBTTS group had a higher cumulative incidence of protein-losing enteropathy (5% versus 2%; P=0.04) and of catheter interventions (14 versus 10 per 100 patient-years; P=0.01), but had similar rates of other complications. CONCLUSIONS: By 12 years after the Norwood operation, shunt type has minimal association with RVEF, peak Vo2, complication rates, and transplant-free survival. RVEF is preserved among the subgroup of survivors who underwent CMR assessment. Low transplant-free survival, poor exercise performance, and accruing morbidities highlight the need for innovative strategies to improve long-term outcomes in patients with hypoplastic left heart syndrome. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT0245531.

Intranasal dexmedetomidine for transthoracic echocardiography in infants with shunt-dependent single ventricle heart disease.

OBJECTIVES: We investigated the efficacy and complication profile of intranasal dexmedetomidine for transthoracic echocardiography sedation in patients with single ventricle physiology and shunt-dependent pulmonary blood flow during the high-risk interstage period. METHODS: A single-centre, retrospective review identified interstage infants who received dexmedetomidine for echocardiography sedation. Baseline and procedural vitals were reported. Significant adverse events related to sedation were defined as an escalation in care or need for any additional/increased inotropic support to maintain pre-procedural haemodynamics. Minor adverse events were defined as changes from baseline haemodynamics that resolved without intervention. To assess whether sedation was adequate, echocardiogram reports were reviewed for completeness. RESULTS: From September to December 2020, five interstage patients (age 29-69 days) were sedated with 3 mcg/kg intranasal dexmedetomidine. The median sedation onset time and duration time was 24 minutes (range 12-43 minutes) and 60 minutes (range 33-60 minutes), respectively. Sedation was deemed adequate in all patients as complete echocardiograms were accomplished without a rescue dose. When compared to baseline, three (60%) patients had a >10% reduction in heart rate, one (20%) patient had a >10% reduction in oxygen saturations, and one (20%) patient had a >30% decrease in blood pressure. Amongst all patients, no significant complications occurred and haemodynamic changes from baseline did not result in need for intervention or interruption of study. CONCLUSIONS: Intranasal dexmedetomidine may be a reasonable option for echocardiography sedation in infants with shunt-dependent single ventricle heart disease, and further investigation is warranted to ensure efficacy and safety in an outpatient setting.

Prognostic utility of echocardiographically derived left ventricular strain in assessing neonatal enteroviral myocarditis outcome.

BACKGROUND: Neonatal enteroviral myocarditis is a rare but potentially fatal illness. We sought to identify echocardiographic markers at diagnosis that could help risk-stratify infants for poor outcome and to characterise late sequelae. METHODS: We reviewed data for infants <30 days of age diagnosed with enteroviral myocarditis between 1999 and 2019 at Children's Wisconsin. Echo measures were collected retrospectively from the initial neonatal study including left ventricular ejection fraction, shortening fraction, diastolic and systolic dimensions, and peak global circumferential and longitudinal strain. RESULTS: Fourteen neonates were diagnosed at an average age of 11 days. All had abnormal left ventricular ejection fraction (mean 38%; range 22-53%) at diagnosis. Three infants died, and one required transplantation during initial hospital. The 10 transplant-free survivors had significantly better global circumferential strain and global longitudinal strain at the initial echo compared to the 4 who died or needed transplant (global circumferential strain -13.2% versus -6.8%, p = 0.005; global longitudinal strain -8.8% versus -4.7%, p = 0.016). All other measures of left ventricular systolic function/dimensions were similar between the two groups. Follow-up data were available for 8/10 survivors; 5/8 had a persistently abnormal echo at an average interval of 8.3 years. 4/8 developed a left ventricular aneurysm that was consistently localised to the posterior basal wall. CONCLUSIONS: Neonatal enteroviral myocarditis carries a high risk of early mortality and late morbidity. Echo-derived left ventricular strain measures have utility in risk stratifying infants with enteroviral myocarditis. Most survivors continue to have late dysfunction necessitating cardiology surveillance and medical therapy.

Conal Septal Hypoplasia in Tetralogy of Fallot-Impact on Clinical Course, Treatment Strategies, and Outcomes After Surgical Intervention.

We sought to characterize the clinical course and outcomes of intervention for Tetralogy of Fallot (TOF) with associated conal septal hypoplasia (CSH) compared to those with identifiable conal septum on initial newborn echocardiogram. We performed a retrospective, 1:2 case-control study of children with TOF anatomy, 33 with CSH and 66 with typical TOF, who underwent surgical repair from 1991-2019 at Children's Wisconsin. Data on echocardiographic anatomic features, systemic oxygen saturations, medical therapies, admissions, palliative interventions, operative strategies, and long-term follow-up were compared. The CSH group had fewer hypercyanotic spells (6% vs 42%, p < 0.001), beta-blockers prescribed (12% vs 41%, p = 0.005), and hospital admissions for cyanosis (12% vs 44%; p = 0.001) prior to any intervention. Of 14 who required palliative intervention, 8 had balloon pulmonary valvuloplasty (BPV) (7 from the CSH group and 1 from the control group), and 6 had systemic-to-pulmonary artery shunts (all from the control group). Definitive repair was performed at a significantly older age in the CSH group (10.2 ± 10 vs 5.6 ± 5.9 months, p = 0.011), with less subpulmonary muscle resection (57.6% in vs 92.4%, p < 0.001) and higher use of a transannular patch (84.8% vs 65.2%, p = 0.040). The average time to surgical reintervention was similar in both groups (9.7 ± 5.9 vs 8.6 ± 6.4 years in controls). We conclude that infants with TOF and CSH have a milder preoperative clinical course with fewer hypercyanotic spells or need for medical therapy. They also respond well to palliative BPV and can safely undergo later definitive repair compared to typical TOF with a well-developed conal septum.

Impact of Udenafil on Echocardiographic Indices of Single Ventricle Size and Function in FUEL Study Participants.

BACKGROUND: The FUEL trial (Fontan Udenafil Exercise Longitudinal) demonstrated statistical improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle function in this cohort has not been studied. METHODS: The 400 enrolled participants were randomized 1:1 to udenafil or placebo. Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline indices of single ventricle systolic, diastolic and global function, atrioventricular valve regurgitation, and mean Fontan fenestration gradient in the udenafil cohort versus placebo, controlling for ventricular morphology (left ventricle versus right ventricle/other) and baseline value. RESULTS: The udenafil participants (n=191) had significantly improved between baseline and 26 weeks visits compared to placebo participants (n=195) in myocardial performance index (P=0.03, adjusted mean difference [SE] of changes between groups -0.03[0.01]), atrioventricular valve inflow peak E (P=0.009, 3.95 [1.50]), and A velocities (P=0.034, 3.46 [1.62]), and annular Doppler tissue imaging-derived peak e' velocity (P=0.008, 0.60[0.23]). There were no significant differences in change in single ventricle size, systolic function, atrioventricular valve regurgitation severity, or mean fenestration gradient. Participants with a dominant left ventricle had significantly more favorable baseline values of indices of single ventricle size and function (lower volumes and areas, E/e' ratio, systolic:diastolic time and atrioventricular valve regurgitation, and higher annular s' and e' velocity). CONCLUSIONS: FUEL participants who received udenafil demonstrated a statistically significant improvement in some global and diastolic echo indices. Although small, the changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular compliance, which may help explain improved exercise performance in that cohort. REGISTRATION: URL: https://clinicaltrials.gov; Unique Identifier: NCT02741115.

Is native aortic valvuloplasty at time of Norwood operation in infants with hypoplastic left heart syndrome and aortic stenosis safe?

In hypoplastic left heart syndrome, the size and function of the left ventricle vary and are dependent on the patency of the aortic valve. A patent native aortic valve, permitting left ventricular ejection, can augment cardiac output. We performed a retrospective chart review of patients with hypoplastic left heart syndrome and a stenotic aortic valve who underwent native aortic valvuloplasty at the time of Norwood and found that none of the eight patients identified had clinically significant aortic insufficiency. This case series suggests that surgical aortic valvuloplasty at Norwood is associated with aortic valve patency/augmented systemic cardiac output without the development of clinically significant aortic regurgitation at intermediate follow-up in a limited cohort.

Intranasal dexmedetomidine: the ideal drug for sedation in the pediatric echo lab?

BACKGROUND: Intranasal dexmedetomidine is an attractive option for procedural sedation in pediatrics due to ease of administration and its relatively short half-life. This study sought to compare the safety and efficacy of intranasal dexmedetomidine to a historical cohort of pediatric patients sedated using chloral hydrate in a pediatric echo lab. METHODS: Chart review was performed to compare patients sedated between September, 2017 and October, 2019 using chloral hydrate and intranasal dexmedetomidine. Vital signs, time to sedation, duration of sedation, need for second dose of medication, rate of failed sedation, and impact on vital signs were compared between groups. Subgroup analysis was performed for those with complex and cyanotic heart disease. RESULTS: Chloral hydrate was used in 356 patients and intranasal dexmedetomidine in 376. Patient age, complexity of heart disease, and duration of sedation were similar. Rates of failed sedation were very low and similar. Average heart rate and minimum heart rate were lower for those receiving intranasal dexmedetomidine than chloral hydrate. Impact on vital signs was similar for those with complex and cyanotic heart disease. No adverse events occurred in either group. CONCLUSIONS: Sedation with intranasal dexmedetomidine is comparable to chloral hydrate in regards to safety and efficacy for children requiring echocardiography. Consistent with the mechanism of action, patients receiving intranasal dexmedetomidine have a lower heart rate without morbidity.

Computational Assessment of Hemodynamic Significance in Patients With Intramural Anomalous Aortic Origin of the Coronary Artery Using Virtually Derived Fractional Flow Reserve and Downstream Microvascular Resistance.

Anomalous aortic origin of a coronary artery (AAOCA) is the second most common cause of sudden cardiac death in young athletes. One of the hypothesized mechanisms of ischemia in these patients is the lateral compression of the anomalous artery with an intramural or interarterial course. The presence of a narrowing in the anomalous artery will cause physiologic changes in downstream resistance that should be included for computational assessment of possible clinical ramifications. In this study, we created different compression levels, i.e., proximal narrowing, in the intramural course of a representative patient model and calculated hyperemic stenosis resistance (HSR) as well as virtual fractional flow reserve (vFFR). Models also included the effect of the distal hyperemic microvascular resistance (HMR) on vFFR. Our results agreed with similar FFR studies indicating that FFR is increased with increasing HMR and that different compression levels could have similar FFR depending on the HMR. For example, vFFR at HSR: 1.0-1.3 and HMR: 2.30 mmHg/cm/s is 0.68 and close to vFFR at HSR: 0.6-0.7 and HMR: 1.6 mmHg/cm/s, which is 0.7. The current findings suggest that functional assessment of anomalous coronary arteries through FFR should consider the vascular resistance distal to the narrowing in addition to the impact of a proximal narrowing and provides computational approaches for implementation of these important considerations.

Pediatric Heart Network Echocardiographic Z Scores: Comparison with Other Published Models.

BACKGROUND: Different methods have resulted in variable Z scores for echocardiographic measurements. Using the measurements from 3,215 healthy North American children in the Pediatric Heart Network (PHN) echocardiographic Z score database, the authors compared the PHN model with previously published Z score models. METHODS: Z scores were derived for cardiovascular measurements using four models (PHN, Boston, Italy, and Detroit). Model comparisons were performed by evaluating (1) overlaid graphs of measurement versus body surface area with curves at Z = -2, 0, and +2; (2) scatterplots of PHN versus other Z scores with correlation coefficients; (3) Bland-Altman plots of PHN versus other Z scores; and (4) comparison of median Z scores for each model. RESULTS: For most measurements, PHN Z score curves were similar to Boston and Italian curves but diverged from Detroit curves at high body surface areas. Correlation coefficients were high when comparing the PHN model with the others, highest with Boston (mean, 0.99) and lowest with Detroit (mean, 0.90). Scatterplots suggested systematic differences despite high correlations. Bland-Altman plots also revealed poor agreement at both extremes of size and a systematic bias for most when comparing PHN against Italian and Detroit Z scores. There were statistically significant differences when comparing median Z scores between the PHN and other models. CONCLUSIONS: Z scores from the multicenter PHN model correlated well with previous single-center models, especially the Boston model, which also had a large sample size and similar methodology. The Detroit Z scores diverged from the PHN Z scores at high body surface area, possibly because there were more subjects in this category in the PHN database. Despite excellent correlation, significant differences in Z scores between the PHN model and others were seen for many measurements. This is important when comparing publications using different models and for clinical care, particularly when Z score thresholds are used to guide diagnosis and management.

Patient-Specific Numerical Analysis of Coronary Flow in Children With Intramural Anomalous Aortic Origin of Coronary Arteries.

Unroofing surgery for anomalous aortic origin of a coronary artery (AAOCA) alters coronary anatomy by opening the intramural segment so that the anomalous coronary orifice arises perpendicularly from appropriate aortic sinus. Computational fluid dynamics modeling (CFD) allows for quantification of hemodynamics linked to morbidity such as wall shear stress (WSS), relative to patient-specific features like the angle of origin (AO). We hypothesize that CFD will reveal abnormal WSS indices in unroofed arteries that are related to AO. Six AAOCA patients (3 left, 3 right) status post unroofing (median = 13.5 years, range 9-17) underwent cardiac magnetic resonance imaging. CFD models were created from pre (n = 2) and postunroofing (n = 6) cardiac magnetic resonance imaging data, for the anomalous and contralateral normally-arising arteries. Downstream vasculature was represented by lumped parameter networks. Time-averaged WSS (TAWSS) and oscillatory shear index (OSI) were quantified relative to AO and measured hemodynamics. TAWSS was elevated along the outer wall of the normally-arising left vs right coronary arteries, as well as along unroofed left vs right coronary arteries (n = 6/group). No significant differences were noted when comparing unroofed and same-sided normally-arising coronaries. TAWSS was reduced after unroofing (eg, 276 ± 28 dyne/cm2 vs 91 ± 15 dyne/cm2; n = 2/group). Models with more acute preoperative AO indicated lower TAWSS at the proximity of ostium. Differences in OSI were not significant. Different flow patterns exist natively between right and left coronary arteries. Unroofing may normalize TAWSS but with variance related to the AO. This study suggests CFD may help stratify risk in AAOCA.

Role of echocardiographic scoring systems in predicting successful biventricular versus univentricular palliation in neonates with critical aortic stenosis.

BACKGROUND: There are several published echo-derived scores to help predict successful biventricular versus univentricular palliation in neonates with critical aortic stenosis. This study aims to determine whether any published scoring system accurately predicted outcomes in these neonates. METHODS: Single centre, retrospective cohort study including neonates who underwent aortic valve intervention (surgical valvotomy or balloon valvuloplasty) with the intention of biventricular circulation. Primary outcome was survival with biventricular circulation at hospital discharge. Data from their initial neonatal echocardiogram were used to compute the following scores - Rhodes, CHSS 1, Discriminant, CHSS 2, and 2 V. RESULTS: Between 01/1999 and 12/2017, 68 neonates underwent aortic valve intervention at a median age of 4 days (range 1-29 days); 35 surgical valvotomy and 33 balloon valvuloplasty. Survival with biventricular circulation was maintained in 60/68 patients at hospital discharge. Of the remaining eight patients, three were converted to univentricular palliation, four died, and one underwent heart transplant prior to discharge. None of the binary score predictions of biventricular versus univentricular (using that score's proposed cut-offs) were significantly associated with the observed outcome in this cohort. A high percentage of those predicted to need univentricular palliation had successful biventricular repair: 89.4% by Rhodes, 79.3% by CHSS 1, 85.2% by Discriminant, and 66.7% by CHSS 2 score. The 2 V best predicted outcome and agreed with the local approach in most cases. CONCLUSION: This study highlights the limitations of and need for alternative scoring systems/cut-offs for consistently accurate echocardiographic prediction of early outcome in neonates with critical aortic stenosis.

Echocardiographic Identification of Pulmonary Artery Flow Reversal: An Indicator of Adverse Outcomes in Single Ventricle Physiology.

Individuals with single ventricle congenital heart disease (CHD) undergo multiple staged surgical palliations. Staged single ventricle palliation with a superior cavopulmonary connection (SCPC) in infancy followed by a Fontan in early childhood relies on passive, unobstructed pulmonary blood flow and normal pulmonary vasculature. We hypothesized that patients with echocardiographic identification of retrograde flow in a branch pulmonary artery (PA) after SCPC or Fontan are at increased risk for adverse outcomes. We conducted a retrospective chart review of patients seen at Children's Wisconsin from 1999 to 2019. Inclusion criteria included a history of single ventricle congenital heart disease and surgical palliation with a superior cavopulmonary connection (SCPC). We created two cohorts based on transthoracic echocardiographic identification of branch PA flow patterns: those with color Doppler-defined pulmonary artery flow reversal (PA reversal cohort) and those with normal anterograde flow (Non-reversal cohort). We identified 21 patients in the PA reversal cohort and 539 patients in the Non-reversal cohort. The PA reversal cohort had increased hospital length of stay after SCPC palliation (p < 0.001) and decreased transplant-free survival (p = 0.032), but there was no difference in overall survival (p = 0.099). There was no difference in hospital length of stay after Fontan (p = 0.17); however, the PA reversal cohort was significantly less likely to progress to Fontan palliation during early childhood (p = 0.005). Echocardiographic color Doppler identification of branch PA flow reversal in patients with single ventricle physiology is a high-risk indicator for adverse short- and long-term outcomes.

Challenges and lessons learned from the Pediatric Heart Network Normal Echocardiogram Database study.

BACKGROUND: The Pediatric Heart Network Normal Echocardiogram Database Study had unanticipated challenges. We sought to describe these challenges and lessons learned to improve the design of future studies. METHODS: Challenges were divided into three categories: enrolment, echocardiographic imaging, and protocol violations. Memoranda, Core Lab reports, and adjudication logs were reviewed. A centre-level questionnaire provided information regarding local processes for data collection. Descriptive statistics were used, and chi-square tests determined differences in imaging quality. RESULTS: For the 19 participating centres, challenges with enrolment included variations in Institutional Review Board definitions of "retrospective" eligibility, overestimation of non-White participants, centre categorisation of Hispanic participants that differed from National Institutes of Health definitions, and exclusion of potential participants due to missing demographic data. Institutional Review Board amendments resolved many of these challenges. There was an unanticipated burden imposed on centres due to high numbers of echocardiograms that were reviewed but failed to meet submission criteria. Additionally, image transfer software malfunctions delayed Core Lab image review and feedback. Between the early and late study periods, the proportion of unacceptable echocardiograms submitted to the Core Lab decreased (14 versus 7%, p < 0.01). Most protocol violations were from eligibility violations and inadvertent protected health information disclosure (overall 2.5%). Adjudication committee reviews led to protocol changes. CONCLUSIONS: Numerous challenges encountered during the Normal Echocardiogram Database Study prolonged study enrolment. The retrospective design and flaws in image transfer software were key impediments to study completion and should be considered when designing future studies collecting echocardiographic images as a primary outcome.

Results of the FUEL Trial.

BACKGROUND: The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking. METHODS: The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide. RESULTS: Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level. CONCLUSIONS: In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

Challenges With Left Ventricular Functional Parameters: The Pediatric Heart Network Normal Echocardiogram Database.

BACKGROUND: The reliability of left ventricular (LV) systolic functional indices calculated from blinded echocardiographic measurements of LV size has not been tested in a large cohort of healthy children. The objective of this study was to estimate interobserver variability in standard measurements of LV size and systolic function in children with normal cardiac anatomy and qualitatively normal function. METHODS: The Pediatric Heart Network Normal Echocardiogram Database collected normal echocardiograms from healthy children ≤18 years old distributed equally by age, gender, and race. A core lab used two-dimensional echocardiograms to measure LV dimensions from which a separate data coordinating center calculated LV volumes and systolic functional indices. To evaluate interobserver variability, two independent expert pediatric echocardiographic observers remeasured LV dimensions on a subset of studies, while blinded to calculated volumes and functional indices. RESULTS: Of 3,215 subjects with measurable images, 552 (17%) had a calculated LV shortening fraction (SF) < 25% and/or LV ejection fraction (EF) < 50%; the subjects were significantly younger and smaller than those with normal values. When the core lab and independent observer measurements were compared, individual LV size parameter intraclass correlation coefficients were high (0.81-0.99), indicating high reproducibility. The intraclass correlation coefficients were lower for SF (0.24) and EF (0.56). Comparing reviewers, 40/56 (71%) of those with an abnormal SF and 36/104 (35%) of those with a normal SF based on core lab measurements were calculated as abnormal from at least one independent observer. In contrast, an abnormal EF was less commonly calculated from the independent observers' repeat measures; only 9/47 (19%) of those with an abnormal EF and 8/113 (7%) of those with a normal EF based on core lab measurements were calculated as abnormal by at least one independent observer. CONCLUSIONS: Although blinded measurements of LV size show good reproducibility in healthy children, subsequently calculated LV functional indices reveal significant variability despite qualitatively normal systolic function. This suggests that, in clinical practice, abnormal SF/EF values may result in repeat measures of LV size to match the subjective assessment of function. Abnormal LV functional indices were more prevalent in younger, smaller children.

Impact of Initial Shunt Type on Echocardiographic Indices in Children After Single Right Ventricle Palliations.

Background Heart size and function in children with single right ventricle (RV) anomalies may be influenced by shunt type at the Norwood procedure. We sought to identify shunt-related differences during early childhood after staged surgical palliations using echocardiography. Methods We compared echocardiographic indices of RV, neoaortic, and tricuspid valve size and function at 14 months, pre-Fontan, and 6 years in 241 subjects randomized to a Norwood procedure using either the modified Blalock-Taussig shunt or RV-to-pulmonary-artery shunt. Results At 6 years, the shunt groups did not differ significantly in any measure except for increased indexed neoaortic area in the modified Blalock-Taussig shunt. RV ejection fraction improved between pre-Fontan and 6 years in the RV-to-pulmonary artery shunt group but was stable in the modified Blalock-Taussig shunt group. For the entire cohort, RV diastolic and systolic size and functional indices were improved at 6 years compared with earlier measurements, and indexed tricuspid and neoaortic annular area decreased from 14 months to 6 years. The prevalence of ≥moderate tricuspid and neoaortic regurgitation was uncommon and did not vary by group or time period. Diminished RV ejection fraction at the 14-month study was predictive of late death/transplant; the hazard of late death/transplant when RV ejection fraction was <40% was tripled (hazard ratio, 3.18; 95% CI, 1.41-7.17). Conclusions By 6 years after staged palliation, shunt type has not impacted RV size and function, and RV and valvar size and function show beneficial remodeling. Poor RV systolic function at 14 months predicts worse late survival independent of the initial shunt type. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00115934.

Timing of Fontan Completion in Children with Functionally Univentricular Hearts and Isomerism: The Impact of Age, Weight, and Pre-Fontan Arterial Oxygen Saturation.

Isomerism, or heterotaxy, impacts morbidity and mortality after various stages of univentricular palliation. Timing of Fontan completing in these patients based on preoperative factors has not been investigated previously. The aim of this study was to determine the impact of preoperative factors on various outcomes including length of hospital stay and duration of chest tubes. A cross-sectional study was conducted. Patients with isomerism having undergone Fontan at the Children's Hospital of Wisconsin between 1998 and 2014 were identified. Preoperative, operative, and postoperative data were collected on these patients. Linear regression analysis was conducted to determine preoperative characteristics associated with various postoperative outcomes. Receiver operator curve analysis was also performed to determine the sensitivity and specificity of age and pre-Fontan arterial oxygen saturation in predicting increased length of hospitalization and increased duration of chest tubes. Younger age and lower pre-Fontan arterial oxygen saturation were associated with increased length of hospitalization while younger age, lower pre-Fontan arterial oxygen saturation, interrupted inferior caval vein, and worse pre-Fontan atrioventricular valve regurgitation were associated with increased length of chest tubes. Age, arterial oxygen saturation, pulmonary arteriovenous malformations, interruption of the inferior caval vein, and atrioventricular valve regurgitation should all be taken into consideration when timing Fontan completion in patients with isomerism. Arterial oxygen saturations between 82 and 84% with an approximate age of 3 years appear to be a time at which it is reasonable to consider Fontan in patients with isomerism.