Echocardiographic image collection and evaluation in infants with CHD: lessons learned from the imaging core lab for the Residual Lesion Score study.

Many factors affect patient outcome after congenital heart surgery, including the complexity of the heart disease, pre-operative status, patient specific factors (prematurity, nutritional status and/or presence of comorbid conditions or genetic syndromes), and post-operative residual lesions. The Residual Lesion Score is a novel tool for assessing whether specific residual cardiac lesions after surgery have a measurable impact on outcome. The goal is to understand which residual lesions can be tolerated and which should be addressed prior to leaving the operating room. The Residual Lesion Score study is a large multicentre prospective study designed to evaluate the association of Residual Lesion Score to outcomes in infants undergoing surgery for CHD. This Pediatric Heart Network and National Heart, Lung, and Blood Institute-funded study prospectively enrolled 1,149 infants undergoing 5 different congenital cardiac surgical repairs at 17 surgical centres. Given the contribution of echocardiographic measurements in assigning the Residual Lesion Score, the Residual Lesion Score study made use of a centralised core lab in addition to site review of all data. The data collection plan was designed with the added goal of collecting image quality information in a way that would permit us to improve our understanding of the reproducibility, variability, and feasibility of the echocardiographic measurements being made. There were significant challenges along the way, including the coordination, de-identification, storage, and interpretation of very large quantities of imaging data. This necessitated the development of new infrastructure and technology, as well as use of novel statistical methods. The study was successfully completed, but the size and complexity of the population being studied and the data being extracted required more technologic and human resources than expected which impacted the length and cost of conducting the study. This paper outlines the process of designing and executing this complex protocol, some of the barriers to implementation and lessons to be considered in the design of future studies.

Reintervention Before Bidirectional Cavopulmonary Shunt and Intermediate Outcomes in Children with Single Ventricle Who Underwent Main Pulmonary Artery Banding.

Unplanned reinterventions following pulmonary artery banding (PAB) in single ventricle patients are common before stage 2 palliation (S2P) but associated risk factors are unknown. We hypothesized that reintervention is more common when PAB is placed at younger age and with a looser band, reflected by lower PAB pressure gradient. Retrospective single center study of single ventricle patients undergoing PAB between Jan 2000 and Dec 2020. The association with reintervention and successful S2P was modeled using exploratory cause-specific hazard regression. A multivariable model was developed adjusting for clinical and statistically relevant predictors. The cumulative proportion of patients undergoing reintervention were summarized using a competing risk model. 77 patients underwent PAB at median (IQR) 47 (24-66) days and 3.73 (3.2-4.5) kg. Within18 months of PAB, 60 (78%) reached S2P, 9 (12%) died, 1 (1%) transplanted and 7 (9%) were alive without S2P. Within 18 months of PAB 10 (13%) patients underwent reintervention related to pulmonary blood flow modification: PAB adjustment (n = 6) and conversion to Damus-Kaye-Stansel/Blalock-Taussig-Thomas shunt (n = 4). 6/10 (60%) reached S2P following reintervention. A trend toward higher intervention in patients with a genetic syndrome (p-0.06) and weight < 3 kg (p-0.057) at time of PAB was noted. Only genetic syndrome was a risk factor associated with poor outcome (p-0.025). PAB has a reasonable outcome in SV patients with unobstructed systemic and pulmonary blood flow, but with a high reintervention rate. Only a quarter of patients with genetic syndromes reach S2P and further study is required to explore the benefits from an alternative palliative strategy.

Modified Warden Procedure for Partial Anomalous Pulmonary Venous Drainage to Promote Growth.

Extreme forms of partially anomalous pulmonary venous drainage with high entrance of the pulmonary veins into the superior caval vein can be challenging to correct without obstructing both systemic and pulmonary venous pathways. We report an unusual morphologic subform of this malformation and a surgical technique to address its specific anatomic peculiarities while maintaining growth potential of the venous pathways. We highlight that even such complex reconstructions can be performed minimally invasively.

Prospective Assessment of Coronary Artery Flows Before and After Cardiopulmonary Bypass in Children With a Spectrum of Congenital Heart Disease.

Background: Normative data for the effect of cardiopulmonary bypass (CPB) on coronary artery Doppler velocities by transesophageal echocardiography in paediatric patients with congenital heart disease (CHD) are lacking. The objective of the study was to prospectively examine the effects of CPB on coronary artery flow patterns by transesophageal echocardiography before and after CPB in children with CHD. Methods: All cases undergoing CHD surgery at the Hospital for Sick Children, Toronto, were eligible. The excluded cases included Norwood operation, heart transplantation, or weight <2.5 kg. Coronary Dopplers and coronary flow reserve (CFR) for the right coronary artery (RCA) and left anterior descending (LAD) were obtained. Multivariable analyses using linear regression models were performed, adjusted for age and cross-clamp time. Results: From May 2017 to June 2018, 69 children (median age at surgery: 0.7 years, interquartile range [IQR]: 0.4-3.7 years; median weight: 7.4 kg, IQR: 5.8-13.3 kg) were included. They were grouped into shunt lesions (N = 26), obstructive lesions (N = 26), transposition of the great arteries (N = 5), and single ventricle (N = 12). N = 39 (57%) were primary repairs, and 56 (81%) had 1 CPB run. For RCA and LAD peak velocities, there was an increase from pre- to post-CPB in RCA peak 39 cm/s (IQR: 30-54 cm/s) to 65 cm/s (IQR: 47-81 cm/s), P < 0.001, mean CFR 1.52 (IQR: 1.25-1.81), and LAD peak 49 cm/s (IQR: 39-60 cm/s) to 70 cm/s (IQR: 52-90 cm/s), P < 0.001, mean CFR 1.48 (IQR: 1.14-1.77). Conclusions: Coronary flow velocities increase from pre- to post-CPB in congenital heart lesions. CFR is consistent across all lesions but is relatively low compared with the adult population.

Contexte: On ne dispose pas de données normatives sur les effets de la dérivation cardiopulmonaire (DCP) sur le débit coronarien mesuré au moyen d'une échocardiographie transœsophagienne Doppler chez des enfants présentant une cardiopathie congénitale. L'objectif de l'étude était d'examiner de manière prospective les effets de la DCP sur le débit coronarien avant et après l'intervention chez des enfants présentant une cardiopathie congénitale. Méthodologie: Tous les enfants ayant subi une intervention chirurgicale pour une cardiopathie congénitale à l'Hospital for Sick Children de Toronto étaient admissibles à l'étude, à l'exception de ceux ayant subi une intervention de Norwood ou une transplantation cardiaque, de même que les enfants pesant moins de 2,5 kg. Les résultats du test Doppler et la réserve coronarienne pour l'artère coronaire droite (ACD) et la branche antérieure de l'artère coronaire gauche (ACG) ont été obtenus. Des analyses multivariées ont été réalisées au moyen de modèles de régression linéaire, avec correction en fonction de l'âge et du temps de clampage total. Résultats: Entre mai 2017 et juin 2018, 69 enfants (âge médian au moment de la chirurgie : 0,7 an, intervalle interquartile (IIQ) : 0,4-3,7 ans; poids médian : 7,4 kg, IIQ : 5,8-13,3 kg) ont été inclus dans l'étude. Les sujets ont été répartis en quatre groupes : shunts (n = 26), lésions obstructives (n = 26), permutation des gros vaisseaux (n = 5) et ventricule unique (n = 12). Chez 39 sujets (57 %), il s'agissait d'une réparation primitive, et 56 enfants (81 %) avaient déjà subi une DCP. Les vitesses maximales dans l'ACD et dans la branche antérieure de l'ACG ont augmenté après la DCP, passant de 39 cm/s (IIQ : 30-54 cm/s) à 65 cm/s (IIQ : 47-81 cm/s), p < 0,001; réserve coronarienne moyenne : 1,52 (IIQ : 1,25-1,81) pour l'ACD, et de 49 cm/s (IIQ : 39-60 cm/s) à 70 cm/s (IIQ : 52-90 cm/s), p < 0,001; réserve coronarienne moyenne : 1,48 (IIQ : 1,14-1,77) pour la branche antérieure de l'ACG. Conclusions: Le débit coronarien augmente après une DCP dans les cas de lésions cardiaques congénitales. La réserve coronarienne est constante dans tous les types de lésions, mais elle est relativement faible comparativement à celle de la population adulte.

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.

The Impact of the Left Ventricle on Right Ventricular Function and Clinical Outcomes in Infants with Single-Right Ventricle Anomalies up to 14 Months of Age.

BACKGROUND: Children with single-right ventricle anomalies such as hypoplastic left heart syndrome (HLHS) have left ventricles of variable size and function. The impact of the left ventricle on the performance of the right ventricle and on survival remains unclear. The aim of this study was to identify whether left ventricular (LV) size and function influence right ventricular (RV) function and clinical outcome after staged palliation for single-right ventricle anomalies. METHODS: In the Single Ventricle Reconstruction trial, echocardiography-derived measures of LV size and function were compared with measures of RV systolic and diastolic function, tricuspid regurgitation, and outcomes (death and/or heart transplantation) at baseline (preoperatively), early after Norwood palliation, before stage 2 palliation, and at 14 months of age. RESULTS: Of the 522 subjects who met the study inclusion criteria, 381 (73%) had measurable left ventricles. The HLHS subtype of aortic atresia/mitral atresia was significantly less likely to have a measurable left ventricle (41%) compared with the other HLHS subtypes: aortic stenosis/mitral stenosis (100%), aortic atresia/mitral stenosis (96%), and those without HLHS (83%). RV end-diastolic and end-systolic volumes were significantly larger, while diastolic indices suggested better diastolic properties in those subjects with no left ventricles compared with those with measurable left ventricles. However, RV ejection fraction was not different on the basis of LV size and function after staged palliation. Moreover, there was no difference in transplantation-free survival to Norwood discharge, through the interstage period, or at 14 months of age between those subjects who had measurable left ventricles compared with those who did not. CONCLUSIONS: LV size varies by anatomic subtype in infants with single-right ventricle anomalies. Although indices of RV size and diastolic function were influenced by the presence of a left ventricle, there was no difference in RV systolic function or transplantation-free survival on the basis of LV measures.

Dynamic Myocardial Response to Exercise in Childhood Cancer Survivors Treated with Anthracyclines.

BACKGROUND: Anthracycline cardiotoxicity can cause significant long-term morbidity in childhood cancer survivors (CCS), but many CCS do not manifest clinical symptoms until adulthood. The aims of this study were to characterize the dynamic myocardial response to exercise of CCS at long-term follow-up by combining semisupine bicycle exercise stress echocardiography with myocardial imaging techniques and to establish whether semisupine bicycle exercise stress echocardiography could identify CCS with abnormal exercise response. METHODS: This was a single-center prospective cross-sectional study. One hundred CCS and 51 control subjects underwent semisupine bicycle exercise stress echocardiography. Color Doppler tissue imaging peak systolic (s') and diastolic (e') velocities, myocardial acceleration during isovolumic contraction, and longitudinal strain were measured at rest and at incremental heart rates in the left ventricular (LV) lateral wall, basal septum, and right ventricle. The relationship with increasing heart rate was evaluated for each parameter by plotting the values against heart rate at each stage of exercise. Kernel density estimate was used to establish the normality of the individual CCS exercise responses. RESULTS: At rest, no significant differences were found for LV lateral wall, right ventricular (RV), and basal septal systolic and diastolic velocities between CCS and control subjects. Only septal e' was lower in CCS. LV longitudinal strain was similar between groups, while RV longitudinal strain was lower in CCS. At peak exercise, LV lateral wall, RV, and septal s' were not different between groups, while e' were significantly lower in CCS. LV lateral wall and septal isovolumic acceleration were also reduced in CCS. LV longitudinal strain was different between groups, while RV longitudinal strain was similar. The dynamic response of Doppler tissue imaging velocities, isovolumic acceleration, and strain was similar between CCS and control subjects. Kernel density estimate analysis confirmed that most CCS responses were within the normal range. CONCLUSIONS: At 10-year follow-up, anthracycline-treated CCS with normal baseline ejection fractions have LV and RV systolic and diastolic myocardial exercise response comparable with that of control subjects. Minor differences were observed between CCS and control subjects at rest and at peak exercise, but the dynamic response is within the normal range.

Coronary artery Doppler patterns are associated with clinical outcomes post-arterial switch operation for transposition of the great arteries.

Aims: Transposition of the great arteries (TGA) is generally repaired using the arterial switch operation (ASO) involving coronary transfer. The objective of this prospective study was to determine whether specific coronary Doppler patterns intra-operatively predicted adverse early myocardial events. Methods and results: Patients < 3 months old with TGA undergoing the ASO were eligible. All patients (when feasible) underwent an intra-operative transoesophageal echo (TEE) plus an epicardial echo and had pre-op, early post-op, pre-discharge and follow-up functional echocardiograms. The primary endpoint was a composite myocardial ischaemic event (any of: post-operative ST changes, ventricular tachycardia, need for extracorporeal membrane oxygenation (ECMO). Associations of coronary Doppler flow patterns with outcomes were modelled with logistic regression models. From May 2009 to December 2012, 40 patients (29 male, birth weight 3.29 ± 0.58 kg) were recruited. n = 32 had TEE + epicardial, four TEE only, four epicardial only. Seven (18%) patients had an adverse myocardial event (five ST changes, two ventricular tachycardia (one also ECMO). There was one death. n = 3 had a coronary artery (CA) revision post-operatively, and three had re-operation for non-CA causes. By TEE, flow reversal in the left coronary artery was associated with the composite endpoint [Odds Ratio (OR) 31.5, P = 0.004], and for chest open > 3 days (OR 6.67, P = 0.0537). Coronary Doppler flow patterns were similar by TEE and epicardial echo. The tissue Doppler parameters showed an early post-op decrease (P < 0.001 for all measures), with full recovery at follow-up in 31/37 cases. Conclusion: Intra-operative evaluation of coronary artery flow patterns should be considered for patients undergoing the ASO.

Contemporary Outcomes and Factors Associated With Mortality After a Fetal or Neonatal Diagnosis of Ebstein Anomaly and Tricuspid Valve Disease.

BACKGROUND: Ebstein anomaly (EA) and tricuspid valve dysplasia (TVD) are rare anomalies and data on outcomes after a fetal or neonatal EA/TVD diagnosis are conflicting. METHODS: To examine the outcome and identify markers predictive of mortality, we reviewed our single-centre experience from 2000-2014. Variables were analyzed separately for cases diagnosed in utero without pregnancy termination and for all live-born patients. RESULTS: Of 47 fetal cases, 8 (17%) died in utero and 10 (21%) as neonates. Independent predictors associated with fetal demise included severe tricuspid regurgitation with a Doppler gradient < 40 mm Hg (odds ratio, 1.22 per mm Hg deduction; P = 0.003) and pulmonary regurgitation (odds ratio, 11.4; P = 0.03) at the baseline examination. A novel prognostic score (range, 0-10) combining the severity of 5 echocardiographic findings was independently associated with overall mortality (hazard ratio [HR], 1.39 per point increase; P = 0.01). Survival rates of 66 live births at 1 month, 1 year, and 5 years were 86%, 82%, and 80% respectively, and 75%, 60%, and 55% remained free from surgery at the same points in time. Factors associated with postnatal death in multivariate analysis included a younger gestational age at birth (HR per week, 1.59; P < 0.001), tricuspid annulus diameter (HR per z-score increase, 1.76; P = 0.004), and no pulmonary forward flow (HR, 4.63; P = 0.03). CONCLUSIONS: Our experience with fetal and neonatal EA/TVD shows better survival rates than previously reported. Mortality after a fetal diagnosis was significantly associated with hemodynamic changes indicative of a circular shunt, including pulmonary and tricuspid regurgitation severe enough to cause diastolic umbilical arterial flow reversal.

Effect of hydration status on atrial and ventricular volumes and function in healthy adult volunteers.

BACKGROUND: Assessment of cardiac chamber volumes is a fundamental part of cardiac magnetic resonance (CMR) imaging. While the effects of inter- and intraobserver variability have been studied and have a recognized effect on the comparability of serial cardiac MR imaging studies, the effect of differences in hydration status has not been evaluated. OBJECTIVE: To evaluate the effects of volume administration on cardiac chamber volumes. MATERIALS AND METHODS: Thirteen healthy adults underwent a baseline cardiac MR to evaluate cardiac chamber volumes after an overnight fast. They were then given two saline boluses of 10 ml/kg of body weight and the cardiac MR was repeated immediately after each bolus. RESULTS: From the baseline scan to the final scan there was a significant increase in all four cardiac chamber end-diastolic volumes. Right atrial volumes increased 8.0%, from 61.1 to 66.0 ml/m2 (P<0.001), and left atrial volumes increased 10.0%, from 50.0 to 55.0 ml/m2 (P<0.001). Right ventricular volumes increased 6.0%, from 91.1 to 96.5 ml/m2 (P<0.001), and left ventricular volumes increased 3.2%, from 87.0 to 89.8 ml/m2 (P<0.001). CONCLUSION: Hydration status has a significant effect on the end-diastolic volumes of all cardiac chambers assessed by cardiac MR. Thus, hydration represents a "variable" that should be taken into account when assessing cardiac chamber volumes, especially when performing serial imaging studies in a patient.

Impact of Norwood versus hybrid palliation on cardiac size and function in hypoplastic left heart syndrome.

OBJECTIVE: The hybrid approach for hypoplastic left heart syndrome (HLHS) could theoretically result in better preservation of right ventricular (RV) function then the Norwood procedure. The aim of this study was to compare echocardiographic indices of RV size and function in patients after Norwood and hybrid throughout all stages of palliation. METHODS: 76 HLHS patients (42 Norwood, 34 hybrid) were retrospectively studied. Echocardiography was obtained before stage I, before and after stage II, and before and after Fontan. Median follow-up was 4.9 years (range 1.1-8.5). RESULTS: Baseline characteristics before stage I were similar. Hybrid patients demonstrated a significant decrease in RV fractional area change (FAC) between baseline and pre-stage II (36±9% vs 27±6%; p<0.01); Norwood patients remained stable (32±10% vs 32±7%; p=0.21). At pre-stage II, moderate/severe tricuspid valve (TV) regurgitation was found in nine Norwood (33%) and four hybrid (18%) patients (p=0.19). After stage II, the difference in FAC became insignificant (29±7% vs 25±8%, p=0.08) and moderate/severe TV regurgitation (TR) was found in 13 Norwood (48%) and four hybrid patients (19%) (p=0.18). At pre-Fontan, RV FAC was similar after Norwood and hybrid (34±5% vs 33±6%, p=0.69), which remained unchanged after Fontan. After Fontan, one Norwood and one hybrid patient had moderate TR. RV and TV size were similar for both groups at each time point. CONCLUSIONS: Patients after Norwood and hybrid procedures had equivalent indices of RV size, and systolic and diastolic function throughout all stages of palliation. Small differences in individual RV and TV indices are likely to be explained by differences in physiology or surgical timing rather than by intrinsic differences in myocardial and valve function.

Longitudinal assessment of right ventricular myocardial strain in relation to transplant-free survival in children with idiopathic pulmonary hypertension.

BACKGROUND: Right ventricular (RV) function is an important determinant of mortality in patients with idiopathic pulmonary arterial hypertension (iPAH). The aim of this study was to serially evaluate global and regional RV two-dimensional strain and their relation to transplantation-free survival in children with iPAH. METHODS: RV regional and global longitudinal strain was retrospectively assessed in children with iPAH. Serial echocardiograms at 3 to 6 months from presentation and then at yearly intervals were analyzed. Results were compared with those from controls and between iPAH survivors (group 1) and those who died or needed transplantation (group 2). Survival stratified by RV global longitudinal strain at presentation was analyzed. RESULTS: Seventeen patients with iPAH (mean age, 8.4 ± 4.8 years; seven male patients), of whom 11 were alive (group 1) and six had died or undergone transplantation (group 2), and 17 age-matched controls were studied. The median follow-up period was 1.5 years (range, 0.04-7.8 years). RV global longitudinal strain was significantly reduced in patients with iPAH compared with controls (-13.5 ± 5.9% vs -24.4 ± 3.9%, P < .001) and in group 2 compared with group 1 at presentation (-9 ± 2.8% vs -16 ± 5.7%, P < .05) and throughout follow-up. During follow-up, RV global and regional longitudinal strain worsened in group 2, especially in RV apical segments (-6.3 ± 5% vs -1.9 ± 1.6% at presentation compared with the last echocardiographic assessment in group 2, P < .05), but was unchanged in group 1. RV global longitudinal strain > -14% predicted transplantation-free survival with 100% sensitivity and 54.5% specificity. CONCLUSIONS: RV strain imaging may be useful for serial follow-up and prognostication in children with iPAH.

Evaluation of knowledge-based reconstruction for magnetic resonance volumetry of the right ventricle in tetralogy of Fallot.

BACKGROUND: Cardiac magnetic resonance using the Simpson method is the gold standard for right ventricular volumetry. However, this method is time-consuming and not without sources of error. Knowledge-based reconstruction is a novel post-processing approach that reconstructs the right ventricular endocardial shape based on anatomical landmarks and a database of various right ventricular configurations. OBJECTIVE: To assess the feasibility, accuracy and labor intensity of knowledge-based reconstruction in repaired tetralogy of Fallot (TOF). MATERIALS AND METHODS: The short-axis cine cardiac MR datasets of 35 children and young adults (mean age 14.4 ± 2.5 years) after TOF repair were studied using both knowledge-based reconstruction and the Simpson method. Intraobserver, interobserver and inter-method variability were assessed using Bland-Altman analyses. RESULTS: Knowledge-based reconstruction was feasible and highly accurate as compared to the Simpson method. Intra- and inter-method variability for knowledge-based reconstruction measurements showed good agreement. Volumetric assessment using knowledge-based reconstruction was faster when compared with the Simpson method (10.9 ± 2.0 vs. 7.1 ± 2.4 min, P < 0.001). CONCLUSION: In patients with repaired tetralogy of Fallot, knowledge-based reconstruction is a feasible, accurate and reproducible method for measuring right ventricular volumes and ejection fraction. The post-processing time of right ventricular volumetry using knowledge-based reconstruction was significantly shorter when compared with the routine Simpson method.

Determinants and clinical significance of flow via the fenestration in the Fontan pathway: a multimodality study.

BACKGROUND: The use of a fenestration in the Fontan pathway remains controversial, partly because its hemodynamic effects and clinical consequences are insufficiently understood. The objective of this study was to quantify the magnitude of fenestration flow and to characterize its hemodynamic consequences after an intermediate interval after surgery. METHODS: Twenty three patients with a fenestrated extracardiac conduit prospectively underwent investigation by cardiac magnetic resonance (CMR), echocardiography, and invasive manometry under the same general anesthetic 12 ± 4 months after Fontan surgery. Fenestration flow was determined using phase contrast CMR by subtracting flow in the Fontan pathway above the fenestration from Fontan flow below the fenestration. RESULTS: Fenestration flow constituted a mean of 31 ± 12% (range 8-50%) of ventricular preload. It was associated with a lower Qp/Qs (r = -0.64, p=0.001) and oxygen saturation (r = -0.74, p<0.0001). Fenestration flow volume was correlated with pulmonary vascular resistance (r = 0.45, p = 0.04) and markers of ventricular diastolic function (early diastolic strain rate r = 0.57, p = 0.008 and ventricular untwist rate r = 0.54, p = 0.02). In 14 patients (61%) all of the net inferior vena cava flow and part of the superior vena cava flow were diverted into the systemic atrium and did not reach the lungs. CONCLUSIONS: Fenestration flow can be measured accurately with CMR. In two-thirds of the patients not only all of the inferior vena cava flow, but also some of the superior vena cava flow is diverted through the fenestration. Fenestration flow is driven by a balance between pulmonary vascular resistance and early diastolic ventricular function.

Acute changes in myocardial systolic function in preterm infants undergoing patent ductus arteriosus ligation: a tissue Doppler and myocardial deformation study.

BACKGROUND: Ligation of a patent ductus arteriosus (PDA) in preterm infants causes profound hemodynamic changes that can result in low cardiac output syndrome and hypotension. The effect of PDA ligation on left ventricular myocardial function has not been studied using tissue Doppler and myocardial deformation imaging, mainly because of the limited validation of these methods in preterm infants. The primary objective of the present study was to determine the feasibility and reliability (intraobserver and interobserver variability) of tissue Doppler and myocardial deformation imaging for evaluating myocardial function in preterm infants undergoing surgical PDA ligation. Additionally, we sought to study the immediate effect of surgical ligation on the left ventricular tissue Doppler and strain measurements in the first 24 hours after surgery. METHODS: Echocardiography was performed in 19 preterm infants before, 1 hour after, and 18 hours after PDA ligation born at 24-29 weeks of gestation. The tissue Doppler velocities of the lateral tricuspid and lateral and septal mitral valve annuli were obtained. The global and regional longitudinal peak systolic strain values were determined using two-dimensional speckle tracking echocardiography. The results of the three measurement points were compared using repeated measures analysis of variance. The intra- and interobserver variability was assessed using the intraclass correlation coefficient and Bland-Altman analysis. RESULTS: The median gestational age was 25.0 weeks (interquartile range 24.9-25.9) and the birth weight was 750 g (interquartile range 600-810). For the global longitudinal strain, the intraobserver intraclass correlation coefficient was 0.92 (95% CI, 0.78-0.97, P < .001), and the interobserver intraclass correlation coefficient was 0.93 (95% CI, 0.66-0.98, P < .001). Bland-Altman analysis showed no significant bias between the two observers, with good agreement. The systolic and diastolic tissue Doppler velocities of the mitral valve decreased significantly immediately after ligation and remained significantly lower than the preoperative levels at 18 hours. Also, the global longitudinal strain values significantly decreased 1 hour after the procedure (global longitudinal strain before -19.7% ± -3.8% vs -11.5% ± -3.5%; P = .001) but had significantly improved 18 hours after the procedure (-15.1% ± -2.9%, P = .01). CONCLUSIONS: The present study has shown the feasibility and reliability of using tissue Doppler and strain imaging in premature infants with a hemodynamically significant PDA. Significant changes in myocardial function were observed immediately after PDA ligation, suggesting important changes in myocardial performance immediately after ductal ligation.

Aortopulmonary collateral flow volume affects early postoperative outcome after Fontan completion: a multimodality study.

OBJECTIVE: Aortopulmonary collaterals are a frequent phenomenon in patients after bidirectional cavopulmonary connection. The aortopulmonary collateral flow volume can be quantified using cardiac magnetic resonance imaging. However, the significance of aortopulmonary collateral flow for the postoperative outcome after total cavopulmonary connection is unclear and was sought to be determined. METHODS: The data from 33 patients were prospectively studied with cardiac magnetic resonance, echocardiography, and cardiac catheterization before the total cavopulmonary connection operation. The early postoperative outcomes after total cavopulmonary connection completion were recorded. RESULTS: Aortopulmonary collateral flow was 1.59 L/min/m(2) ± 0.65 L/min/m(2) (range, 0.54 L/min/m(2)-3.34 L/min/m(2)), constituting 43% ± 13% (range, 12-87%) of pulmonary blood flow and 35% ± 12% (range, 11-62%) of the cardiac index, resulting in a pulmonary blood flow/systemic blood flow ratio of 1.06 ± 0.17 (range, 0.79-1.55). The aortopulmonary collateral flow correlated with pulmonary blood flow/systemic blood flow ratio (r = 0.69, P < .0001), oxygen saturation (r = 0.42, P = .018), and cardiac index (r = 0.53, P = .002). Of the 36 patients, 24 underwent fenestrated total cavopulmonary connection during the study period. The aortopulmonary collateral flow, relative to the cardiac index, correlated with the duration of hospital stay (r = 0.48, P = .02) and pleural drainage (r = 0.45, P = .03). Patients whose pleural drainage lasted 1 week or less had less aortopulmonary collateral flow before the Fontan operation than those with a longer period until chest tube removal (1.23 L/min/m(2) ± 0.38 L/min/m(2) vs 1.73 L/min/m(2) ± 0.76 L/min/m(2); P = .03). Compared with a contemporary group of total cavopulmonary connection patients with fenestration in their extracardiac conduit who were studied prospectively, with a similar protocol, the bidirectional cavopulmonary connection had a greater amount of aortopulmonary collateral flow (1.59 L/min/m(2) ± 0.65 L/min/m(2) vs 1.30 L/min/m(2) ± 0.57 L/min/m(2), P = .04). CONCLUSIONS: Patients after bidirectional cavopulmonary connection routinely acquire a large amount of aortopulmonary collateral flow. The hemodynamic consequences of aortopulmonary collateral flow translate into adverse outcomes early after total cavopulmonary connection completion.

The impact of additional epicardial imaging to transesophageal echocardiography on intraoperative detection of residual lesions in congenital heart surgery.

OBJECTIVE: Transesophageal echocardiography is the primary intraoperative imaging modality used to evaluate cardiac surgery. Its predecessor, epicardial echocardiography, enables visualization of certain cardiovascular structures that are beyond the visual scope of transesophageal echocardiography. We review the current use of epicardial echocardiography to analyze its contemporary application and benefit. METHODS: A retrospective review of the intraoperative echocardiograms of 1204 children undergoing bypass cardiovascular surgery between January 2007 and December 2009 was performed. The incidence of epicardial echocardiography use, intraoperative revisions, and early reinterventions were analyzed. RESULTS: Epicardial echocardiography was performed in 7.9% of all intraoperative studies: epicardial echocardiography alone (n = 38) and transesophageal echocardiography + epicardial echocardiography (n = 57). Epicardial echocardiography alone was performed in patients with contraindications for transesophageal echocardiography. In the transesophageal echocardiography + epicardial echocardiography group, indications to obtain additional information by epicardial echocardiography were for the assessment of branch pulmonary arteries (40%), coronary arteries (28%), aortic arch/Blalock-Taussig shunt (14%), Glenn/Fontan circuit (9%), pulmonary veins/baffles (7%), and residual ventricular septal defects (1.7%). The overall intraoperative surgical revision incidence was 10.2%, consisting of 21% of the transesophageal echocardiography + epicardial echocardiography group, 5.3% of the epicardial echocardiography alone group (P = .01), and 9.8% of transesophageal echocardiography alone group (P = .02). Intraoperative revisions indicated after epicardial echocardiography were mostly related to extracardiac structures (77%), whereas they were mostly related to intracardiac structures in the transesophageal echocardiography alone group (80.7%) (P = .0002). Early reintervention was indicated mostly for pulmonary artery and Glenn obstructions, the majority (75%) with previously known stenosis or interventions on the pulmonary arteries. CONCLUSIONS: Epicardial echocardiography detects residual intraoperative lesions not visualized by transesophageal echocardiography, most frequently related to pulmonary arteries. Its use, in addition to standard transesophageal echocardiography, may decrease the need for early reintervention.