Left Ventricular Strain, Arch Angulation, and Velocity-Time Integral Ratio Improve Performance of a Clinical Pathway for Fetal Diagnosis of Neonatal Coarctation of the Aorta.

INTRODUCTION: Neonatal presentation of coarctation of the aorta (CoA) is a potentially life-threatening condition that is difficult to diagnose in fetal life. We therefore sought to validate and compare novel metrics that may add diagnostic value for fetal CoA, including the diastolic to systolic aortic isthmus VTI ratio (VTId:VTIs), ascending aorta to descending aorta angle (AAo-DAo), transverse aorta to descending aorta angle (TAo-DAo), and LV longitudinal strain (LVS), then to evaluate whether these novel metrics improve specificity to identify fetuses at the highest risk for postnatal CoA without compromising sensitivity. METHODS: Retrospective cohort study of fetuses followed a prospective clinical pathway and previously classified as mild, moderate, or high-risk for CoA based on standard fetal echo metrics. Novel metrics were retrospectively measured in a blinded manner. RESULTS: Among fetuses with prenatal concern for CoA, VTId:VTIs, AAo-DAo angle, TAo-DAo angle, and LVS were significantly different between surgical and non-surgical cases (p < 0.01 for all variables). In the subgroup of moderate- and high-risk fetuses, the standard high-risk criteria (flow reversal at the foramen ovale or aortic arch) did not discriminate effectively between surgical and non-surgical cases. VTId:VTIs, AAo-Dao angle, Tao-DAo angle, and LVS all demonstrated greater discrimination than standard high-risk criteria, with specificity of 100% and PPV (positive predictive value) of 78-100%. CONCLUSIONS: The incorporation of novel metrics added diagnostic value to our clinical pathway for fetal CoA with higher specificity than the previous high-risk criteria. The incorporation of these metrics into the evaluation of fetuses at moderate- or high-risk for surgical CoA may improve prenatal counseling, allow for more consistent surgical planning, and ultimately optimize hospital resource allocation.

Current State of Fetal Heart Disease Counseling and Training: Room for Improvement? : Endorsed by the Fetal Heart Society.

We sought to describe the fellowship experiences and current practice habits of pediatric cardiologists who counsel patients with fetal heart disease (FHD) and to identify fellowship experiences related to FHD counseling perceived as valuable by respondents as well as opportunities for improvement. A cross-sectional survey of attending pediatric cardiologists who care for patients with FHD was performed. The respondents' demographics, fellowship experiences related to FHD counseling, reflections on fellowship training, and current practice habits were collected. The Fetal Heart Society endorsed this survey. There were 164 survey responses. 56% of respondents did not have 4th-year subspecialty training in fetal cardiology. Observing and performing FHD counseling were the most commonly used methods of training, with the highest perceived effectiveness. The number of counseling sessions observed and performed correlated moderately with confidence in FHD counseling skills at fellowship graduation. Extracardiac pathology and neurodevelopment were the least frequently addressed topics in fellowship training and in current practice. Fewer than 50% of respondents received formal education and feedback in counseling techniques during fellowship training. A significant proportion of practicing pediatric cardiologists provide FHD counseling with only standard categorical training. This highlights the potential importance of expanding FHD counseling education into categorical fellowship curricula. We suggest increasing opportunities for fellows to perform FHD counseling and receive feedback as this is a valued and beneficial experience during training. A formalized curriculum including extracardiac pathology and neurodevelopment and the use of evidence-based workshops in counseling techniques may address identified gaps in fellowship education.

A Fetal Risk Stratification Pathway for Neonatal Aortic Coarctation Reduces Medical Exposure.

OBJECTIVE: To test the hypothesis that a fetal stratification pathway will effectively discriminate between infants at different levels of risk for surgical coarctation and reduce unnecessary medicalization. STUDY DESIGN: We performed a pre-post nonrandomized study in which we prospectively assigned fetuses with prenatal concern for coarctation to 1 of 3 risk categories and implemented a clinical pathway for postnatal management. Postnatal clinical outcomes were compared with those in a historical control group that were not triaged based on the pathway. RESULTS: The study cohort comprised 109 fetuses, including 57 treated along the fetal coarctation pathway and 52 historical controls. Among mild-risk fetuses, 3% underwent surgical coarctation repair (0% of those without additional heart defects), compared with 27% of moderate-risk and 63% of high-risk fetuses. The combined fetal aortic, mitral, and isthmus z-score best discriminated which infants underwent surgery (area under the curve = 0.78; 95% CI, 0.66-0.91). Compared with historical controls, infants triaged according to the fetal coarctation pathway had fewer delivery location changes (76% vs 55%; P = .025) and less umbilical venous catheter placement (74% vs 51%; P = .046). Trends toward shorter intensive care unit stay, hospital stay, and time to enteral feeding did not reach statistical significance. CONCLUSIONS: A stratified risk-assignment pathway effectively identifies a group of fetuses with a low rate of surgical coarctation and reduces unnecessary medicalization in infants who do not undergo aortic surgery. Incorporation of novel measurements or imaging techniques may improve the specificity of high-risk criteria.

Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome.

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC ≤ 35% and TAPSE Z-score ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Comprehensive Echocardiographic Assessment of Ventricular Function and Pulmonary Pressure in the Neonatal Omphalocele Population.

OBJECTIVE: Pulmonary hypertension (PH) has been described in the neonatal omphalocele population. This study was aimed to describe cardiac function and PH severity using echocardiography in newborns with giant omphalocele (GO) and with non-GO and determine if right ventricular (RV) dysfunction is associated with mortality. STUDY DESIGN: Retrospective, single-center analysis of first echocardiography among neonatal omphalocele patients born between 2004 and 2017 was conducted. Multivariate logistic and univariate Cox's regression was constructed to measure hazard ratio (HR) for death outcome. RESULTS: There were 32 newborns, of whom 18 were GO and 7 died. GO had increased systolic pulmonary arterial to systolic systemic blood pressure ratio (97% [isosystemic] vs. 73% [three-fourths systemic] p = 0.03). RV performance parameters (tricuspid annular plane excursion, HR = 0.40; fractional area change, HR = 0.90; and RV peak global longitudinal strain, HR = 1.39) were associated with mortality. These RV performance parameters remained associated in a multiple logistic regression accounting for gestational age and GO status. The overall population had abnormal eccentricity index and pulmonary artery acceleration time to RV ejection time ratio, two markers of PH. CONCLUSION: Patients with omphalocele have increased pulmonary pressure, with GO being worse than non-GO. RV dysfunction at initial echocardiography was significantly associated with mortality.

Maternal Hyperoxygenation Testing in Fetuses with Hypoplastic Left-Heart Syndrome: Association with Postnatal Atrial Septal Restriction.

INTRODUCTION: In fetuses with hypoplastic left-heart syndrome (HLHS), maternal hyperoxygenation (MHO) may aid risk stratification. We hypothesized that pulmonary vein (Pvein) velocity time integral (VTI) change with MHO would more reliably identify neonates who undergo emergent atrial septoplasty (EAS) than changes in pulmonary arterial pulsatility index (PA PI). METHODS: Fetuses with HLHS who underwent MHO testing at our institution between 2014 and 2019 were identified. Data were reviewed in a blinded, retrospective manner. Pvein VTI ratio (prograde:retrograde) was calculated. The primary outcome was neonatal EAS. RESULTS: Twenty-seven HLHS fetuses underwent MHO, and 5 (19%) underwent EAS. Without MHO, a Pvein VTI ratio <3 conferred 60% sensitivity and 100% specificity for EAS. With MHO, a Pvein VTI ratio <6.5 conferred 100% sensitivity and specificity. For an intermediate group of fetuses with a baseline Pvein VTI ratio 3-7, the ratio decrease with MHO conferred 100% sensitivity and specificity. Compared to the Pvein VTI ratio, PA PI was less accurate in identifying EAS neonates. DISCUSSION/CONCLUSION: Addition of MHO appears to improve the diagnostic ability of the Pvein VTI ratio to identify HLHS fetuses who undergo EAS. The Pvein VTI ratio change may more accurately identify fetuses who undergo EAS than change in PA PI and has less interobserver variability.

In fetuses with congenital lung masses, decreased ventricular and atrioventricular valve dimensions are associated with lesion size and clinical outcome.

INTRODUCTION: The clinical importance of mass effect from congenital lung masses on the fetal heart is unknown. We aimed to report cardiac measurements in fetuses with congenital lung masses and to correlate lung mass severity/size with cardiac dimensions and clinical outcomes. METHODS: Cases were identified from our institutional database between 2009 and 2016. We recorded atrioventricular valve (AVVz) annulus dimensions and ventricular widths (VWz) converted into z scores, ratio of aortic to total cardiac output (AoCO), lesion side, and congenital pulmonary airway malformation volume ratio (CVR). Respiratory intervention (RI) was defined as intubation, extracorporeal membrane oxygenation (ECMO), or use of surgical intervention prior to discharge. RESULTS: Fifty-two fetuses comprised the study cohort. Mean AVVz and VWz were below expected for gestational age. CVR correlated with ipsilateral AVVz (RS = -.59, P < .001) and ipsilateral VWz (-0.59, P < .001). Lower AVVz and AoCO and higher CVR were associated with RI. No patient had significant structural heart disease identified postnatally. CONCLUSION: In fetuses with left-sided lung masses, ipsilateral cardiac structures tend to be smaller, but in our cohort, there were no patients with structural heart disease. However, smaller left-sided structures may contribute to the need for RI that affects a portion of these fetuses.

Physician Barriers and Facilitators for Screening for Congenital Heart Disease With Routine Obstetric Ultrasound: A National United States Survey.

OBJECTIVES: Prenatal detection of congenital heart disease with obstetric screening remains at less than 50% in most population studies, far from what is thought to be achievable. We sought to identify barriers/facilitators for screening from the perspective of interpreting physicians and to understand how these barriers/facilitators may be associated with interpretation of screening images. METHODS: Our mixed-methods studies included 4 focus groups in centers across the United States with obstetric, maternal-fetal medicine, and radiology providers who interpreted obstetric ultrasound studies. Themes around barriers/facilitators for fetal heart screening were coded from transcripts. A national Web-based survey was then conducted, which quantitatively measured reported barriers/facilitators and measured physicians' ability to interpret fetal heart-screening images. Multivariable generalized linear random-effect models assessed the association between barriers/facilitators and the accuracy of image interpretation at the image level. RESULTS: Three main themes were identified in the focus groups: intrinsic barriers (ie, comfort with screening), external barriers (ie, lack of feedback), and organizational barriers (ie, study volumes). Among 190 physician respondents, 104 interpreted ultrasound studies. Perceptions of barriers varied by practice setting, with nontertiary providers having lower self-efficacy and perceived usefulness of cardiac screening. Facilitators associated with the odds of accurate interpretation of screening images were knowledge (odds ratio, 2.54; P = .002) and the volume of scans per week (odds ratio, 1.01 for every additional scan; P = .04). CONCLUSIONS: Some of the main barriers to cardiac screening identified and prioritized by physicians across the United States were knowledge of screening and minimal volumes of scans. Targeting these barriers will aid in improving prenatal detection of congenital heart disease.

Cerebrovascular blood flow in patients with tetralogy of fallot: prediction for early surgical intervention.

OBJECTIVES: Children with tetralogy of Fallot (TOF) require initial intervention at varying times reflecting a spectrum of obstruction to pulmonary blood flow. In utero, fetal patients with right sided obstructive lesions demonstrate increased middle cerebral artery (MCA) pulsatility index (PI). We sought to determine whether MCA flow patterns are associated with the degree of pulmonary obstruction and the consequential need for early surgical intervention (ESI). METHODS: We performed a multi-center retrospective study evaluating patients with a prenatal diagnosis of TOF. All echocardiographic fetal studies performed from 16 weeks' gestational age through delivery were reviewed between 2001 and 2015 with subsequent postnatal medical chart review. RESULTS: 82 patients met inclusion criteria. Patients who ultimately required ESI (n=30) demonstrated an increased MCA PI z-score (-0.68 vs -1.32, p=0.02) compared to those who did not (n=52). An elevated MCA PI in patients with TOF was associated with ESI after 24 weeks' gestational age (-0.36 vs -1.22, p=0.02). CONCLUSIONS: Fetal patients with TOF demonstrate altered MCA flow that correlates with need for ESI. This effect is blunted earlier in gestation which may reflect cerebral autoregulation. MCA PI may be a beneficial tool in helping determine perinatal management and counseling for patients with TOF.

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. 183 mL/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.

Fetal Echocardiographic Parameters and Surgical Outcomes in Congenital Left-Sided Cardiac Lesions.

This study aimed to evaluate fetal echocardiographic parameters associated with neonatal intervention and single-ventricle palliation (SVP) in fetuses with suspected left-sided cardiac lesions. Initial fetal echocardiograms (1/2002-1/2017) were interpreted by the contemporary fetal cardiologist as coarctation of the aorta (COA), left heart hypoplasia (LHH), hypoplastic left heart syndrome (HLHS), mitral valve hypoplasia (MVH) ± stenosis, and aortic valve hypoplasia ± stenosis (AS). The cohort comprised 68 fetuses with suspected left-sided cardiac lesions (COA n = 15, LHH n = 9, HLHS n = 39, MVH n = 1, and AS n = 4). Smaller left ventricular (LV) length Z score, aortic valve Z score, ascending aorta Z score, and aorta/pulmonary artery ratio; left-to-right shunting at the foramen ovale; and retrograde flow in the aortic arch were associated with the need for neonatal intervention (p = 0.005-0.04). Smaller mitral valve (MV) Z score, LV length Z score, aortic valve Z score, ascending aorta Z score, aorta/pulmonary artery ratio, and LV ejection fraction, as well as higher tricuspid valve-to-MV (TV/MV) ratio, right ventricular-to-LV (RV/LV) length ratio, left-to-right shunting at the foramen ovale, abnormal pulmonary vein Doppler, absence of prograde aortic flow, and retrograde flow in the aortic arch were associated with SVP (p < 0.001-0.008). The strongest independent variable associated with SVP was RV/LV length ratio (stepwise logistical regression, p = 0.03); an RV/LV length ratio > 1.28 was associated with SVP with a sensitivity of 76% and specificity of 96% (AUC 0.90, p < 0.001). A fetal RV/LV length ratio of > 1.28 may be a useful threshold for identifying fetuses requiring SVP.

Utility of screening echocardiogram after endomyocardial biopsy for identification of cardiac perforation or tricuspid valve injury.

Per protocol, our institution obtains echocardiograms immediately after each EMB to rule out procedural complication. We sought to determine the incidence of echocardiogram-detected cardiac perforation and TV injury and to evaluate the utility of routine screening echocardiogram after each EMB in the current era. At a single center, 99% (1917/1942) EMB performed in 162 patients were immediately followed by an echocardiogram per protocol. There were five newly diagnosed pericardial effusions, and only one required pericardiocentesis. In the three echocardiograms demonstrating new flail TV, only one patient underwent surgical repair 2 months later. This study demonstrates the very low incidence of significant hemopericardium and TV injury after EMB in pediatric heart transplant recipients and argues against the utility of post-EMB echocardiograms to screen solely for procedural complications.

Diminished Cardiac Performance and Left Ventricular Dimensions in Neonates with Congenital Diaphragmatic Hernia.

INTRODUCTION: Newborns with congenital diaphragmatic hernia (CDH) have varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH), and there is limited evidence that cardiac dysfunction is present. We sought to study early neonatal biventricular function and performance in these patients by reviewing early post-natal echocardiography (ECHO) measurements and comparing them to normal term newborns. METHODS: Retrospective case-control study reviewing clinical and ECHO data on term newborns with CDH and normal controls born between 2009 and 2016. Patients were excluded if major anomalies, genetic syndromes, or no ECHO available. PH was assessed by ductal shunting and tricuspid regurgitant jet velocity. Speckle-tracking echocardiography was used to assess myocardial deformation using velocity vector imaging. RESULTS: Forty-four patients with CDH and 18 age-matched controls were analyzed. Pulmonary pressures were significantly higher in the CDH cohort (systolic pulmonary arterial pressure to systolic blood pressure of 103 ± 13 vs. 78 ± 29%, p = 0.0001). CDH patients had decreased RV fractional area change (FAC - 28.6 ± 11.1 vs. 36.2 ± 9.6%, p = 0.02), tricuspid annular plane of systolic excursion (TAPSE-5.6 ± 1.6 vs. 8.6 ± 1.6 mm, p = 0.0001), and RV outflow tract stroke distance (8.6 ± 2.7 vs. 14.0 ± 4.5 cm, p = 0.0001) compared with controls. The left ventricular (LV) ejection fraction was similar in both groups, but CDH patients had a decreased LV end-diastolic volume by Simpson's rule (2.7 ± 1.0 vs. 5.0 ± 1.8 mL, p = 0.0001) and LVOT stroke distance (9.7 ± 3.4 vs. 12.6 ± 3.6 cm, p = 0.004). Biventricular global longitudinal strain (GLS) was markedly decreased in the CDH population compared to controls (RV-GLS: - 9.0 ± 5.3 vs. - 19.5 ± 1.4%, p = 0.0001; LV GLS: - 13.2 ± 5.8 vs. - 20.8 ± 3.5%, p = 0.0001). CONCLUSION: CDH newborns have evidence of biventricular dysfunction and decreased cardiac output. Abnormal function may be a factor in the non-response to pulmonary arterial vasodilators in CDH patients. A two-pronged management strategy aimed at improving cardiac function, as well as reducing pulmonary artery pressure in CDH newborns, may be warranted.

Impact of Fetal Somatic Growth on Pulmonary Valve Annulus Z-Scores During Gestation and Through Birth in Patients with Tetralogy of Fallot.

Previous studies have suggested reduced pulmonary valve annulus (PVA) growth and progression of pulmonary outflow obstruction in fetuses with tetralogy of Fallot (TOF). The goals of this study were to (1) investigate the trajectory of PVA growth in utero, and (2) compare two methods of z-score determination for fetal and postnatal PVA size by echocardiography in order to improve prenatal counseling for patients with TOF. Fetal echocardiograms (FE) at a single institution with a diagnosis of TOF between 8/2008 and 12/2015 were retrospectively reviewed. Patients included had at least 2 FEs and 1 immediate postnatal echocardiogram (TTE). Fetal and postnatal demographic, clinical, and echocardiographic data were collected. Fetal body surface area (BSA) was calculated by estimating fetal weight and height; z-scores were determined based on fetal gestational age (GA) and BSA for both FEs and TTEs. Fetal PVA z-scores by GA or BSA were then compared to postnatal PVA z-scores by BSA. Twenty-two patients with 44 FEs and 22 TTEs were included. GA at the first FE was 23 weeks ± 3.4 and 32 weeks ± 3.1 at the second FE. There was no difference in PVA z-scores (by BSA) between the first and second FE (p = 0.34), but a decrease in PVA z-scores (by BSA) between the second FE and TTE (- 1.6 ± 0.5 vs. - 2.0 ± 0.7; p = 0.01). Repeat comparison with fetal PVA z-scores indexed to GA revealed no difference in z-scores between the first and second FE, but an increase in PVA z-scores between the second FE (by GA) and TTE (by BSA) (- 4.1 ± 1.0 vs. - 2.0 ± 0.7; p < 0.0001). The rate of PVA growth between the two FEs (23 µm/day ± 9.8) and between the second FE and TTE (28 µm/day ± 42) remained comparable (p = 0.57); however, the rate of BSA increase was greater in later gestation (9 cm2/day ± 3 vs. 20 cm2/day ± 11; p = 0.001). In patients with TOF, the rate of PVA growth appears to remain consistent through gestation; however, somatic growth rate increases in late gestation. Fetal PVA z-scores indexed to GA are thus inaccurate in predicting postnatal PVA z-scores typically indexed to BSA. This observation should be considered during prenatal consultation and delivery planning.

Ventricular Performance is Associated with Need for Extracorporeal Membrane Oxygenation in Newborns with Congenital Diaphragmatic Hernia.

OBJECTIVE: To compare echocardiography (ECHO) findings of patients with congenital diaphragmatic hernia (CDH) who required extracorporeal membrane oxygenation (ECMO) to non-ECMO treated patients. STUDY DESIGN: We reviewed clinical and ECHO data of newborns with CDH born between 2009 and 2016. Exclusions included major anomalies, genetic syndromes, or no ECHO prior to ECMO. Pulmonary hypertension was assessed by ductal shunting and tricuspid regurgitant jet. Speckle tracking echocardiography (STE) assessed function by quantifying deformation. RESULTS: Patients with CDH (15 ECMO and 29 with no ECMO) were analyzed. Most patients had a left CDH (88.6%). Age at ECHO was similar between groups. Outborn status (P = .009) and liver position (P = .009) were associated with need for ECMO. Compared with non-ECMO patients, patients who required ECMO had significantly decreased left and right ventricular function by both conventional and STE measures, as well as decreased right and left ventricular output. The right ventricular eccentricity index was higher in ECMO vs non-ECMO patients (2.2 vs 1.8, P = .02). There was no difference in pulmonary hypertension between CDH groups. CONCLUSIONS: Need for ECMO was associated with decreased left and right ventricular function, as assessed by standard and STE measures. There was no difference in pulmonary hypertension between non ECMO and ECMO patients. Abnormal cardiac function may explain nonresponse to pulmonary vasodilators in patients with CDH. Management strategies to improve cardiac function may reduce the need for ECMO in newborns with CDH.

LVOT-VTI is a Useful Indicator of Low Ventricular Function in Young Patients.

Left ventricular outflow tract velocity time integral (LVOT-VTI), a Doppler-derived measure of stroke distance, is used as a surrogate marker of cardiac function in adults. LVOT-VTI is easily obtained, independent of ventricular geometry and wall motion abnormalities. We investigated the relationship between LVOT-VTI and conventional measures of function in young patients by comparing controls to children with dilated cardiomyopathy (DCM). Sixty-two healthy and 52 DCM patients over 1 year were studied retrospectively. The average pulsed (PW) and continuous wave (CW) LVOT-VTIs from apical views were measured from three cycles. Body surface area (BSA) and Ejection fraction (EF) were obtained. We compared LVOT-VTIs between study and control groups and assessed BSA's impact on LVOT-VTI. The entire cohort was classified into three levels of LV function which were compared. We determined LVOT-VTI cutoff values that indicated an EF <50%. The mean PW-LVOT-VTI in the DCM group was significantly lower than that of the normal group (0.15 vs. 0.18 m; p < 0.0012). The mean CW-LVOT-VTI was significantly lower in DCM (0.20 vs. 0.24 m; p < 0.0001). There was no impact of BSA on LVOT-VTI except when comparing BSA and CW-LVOT-VTI in the normal group. There was a positive relationship between LVOT-VTI and EF for PW (Rs = 0.29, p = 0.0022) and CW (Rs = 0.22, p = 0.0364) and a difference in mean LVOT-VTI between EF groups (p < 0.0001). ROC analysis demonstrated that PW-LVOT-VTI <0.17 m (AUC = 0.73; p < 0.0001) and CW-LVOT-VTI <0.22 m (AUC = 0.76; p < 0.0001) was associated with EF <50%. This study indicates that LVOT-VTI can be a useful alternative measure of LV performance in children over 1 year.

Institution of Veno-arterial Extracorporeal Membrane Oxygenation Does Not Lead to Increased Wall Stress in Patients with Impaired Myocardial Function.

The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06 years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.

Cardioplegia Dose Effect on Immediate Postoperative Alterations in Coronary Artery Flow Velocities After Congenital Cardiac Surgery.

Abnormalities in coronary artery (CA) flow detected by echocardiography are increasingly used to guide clinical decisions in patient management. Increased CA flow has been seen postoperatively in congenital cardiac surgery. This study sought to determine immediate postoperative changes in left anterior descending (LAD) CA flow velocities, and to investigate possible factors associated with these changes. CA flow in the proximal LAD was sampled with pulsed-wave Doppler during trans-esophageal echocardiography imaging in the immediate preoperative and postoperative studies in 46 subjects. The peak velocity, velocity time integral (VTI), VTI corrected for heart rate (VTIc), and VTI rate pressure product (VTIrpp) were determined. The percent change in each measure between the preoperative and postoperative study was calculated and compared to age, body surface area (BSA), cardiopulmonary bypass time, cross-clamp time, and number of cardioplegia (CP) doses. The pH, oxygen saturation, temperature, and hemoglobin concentration (Hb) were compared for those with and without increased flow characteristics. There was an overall increase in LAD flow parameters in subjects who underwent congenital cardiac surgery. There was a significant and positive correlation of percent change in VTI, VTIc, and VTIrrp with number of CP doses and lower Hb. We propose that this phenomenon is likely of multifactorial origin, involving autoregulatory mechanism disturbance. The imaging and measurement of LAD flow velocities are feasible, reliable, and is positively correlated with number of CP doses. Interpretation of postoperative LAD flow velocities should be made in the context of intraoperative events since heart rate, blood pressure, and Hb concentration also influence CA flow parameters.

Assessment of Speckle-Tracking Echocardiography-Derived Global Deformation Parameters During Supine Exercise in Children.

Exercise echocardiography is an underutilized tool in pediatrics with current applications including detecting segmental wall abnormalities, assessing the utility of global ventricular function, and measuring pulmonary hemodynamics. No prior study has applied speckle-tracking echocardiography (STE) during exercise echocardiography in children. The aim of this study was to determine the feasibility of measuring speckle-tracking-derived peak systolic velocities, global longitudinal and circumferential strain, and global strain rates at various phases of exercise. Ninety-seven healthy children underwent cardiopulmonary exercise testing using supine cycle ergometry. The exercise stress test consisted of baseline pulmonary function testing, monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturations while subjects pedaled against a ramp protocol based on body weight. Echocardiographic measurements and specifically speckle-tracking analysis were performed during exercise at baseline, at a heart rate of 160 beats per minute and at 10 min after exercise. Peak systolic velocity, peak systolic strain, and peak systolic strain rate at these three phases were compared in the subjects in which all measurements were accurately obtained. We were able to complete peak velocity, strain, and strain rate measurements in all three exercise phases for 36 out of the 97 subjects tested. There was no significant difference between the feasibility of measuring circumferential versus longitudinal strain (p = 0.25, B-corrected = 0.75). In the 36 subjects studied, the magnitude of circumferential strain values decreased from -18.3 ± 4.8 to -13.7 ± 4.0 % from baseline to HR 160 (p < 0.0001, B-corrected < 0.0001), before returning to -19.6 ± 4.4 % at recovery (p = 0.19 when compared to baseline). Longitudinal strain did not vary significantly from baseline to HR 160 (from -17.7 ± 4.4 to -16.6 ± 4.4 %, p = 0.16); likewise the average recovery strain was no different from those values (-18.4 ± 3.6 %; p = 0.34). Peak circumferential and longitudinal strain rates increased from baseline to HR 160, but neither decreased to baseline levels after 10 min of recovery, which correlated with heart rate variations with exercise. We studied the effects of frame rate on deformation measurements and we observed no difference between measurements taken at lower (<60 frames per second, fps) and higher (≥60 fps) frame rates. This study shows that it is technically difficult to retrospectively measure peak velocities, strain, and strain rate in exercising pediatric subjects with STE. The majority of subjects that were excluded from the study had inadequate echocardiographic images when tachycardic from increased respiratory effort and body movements near peak exercise. Improvements in technique and higher image frame rates could make application of STE to pediatric cardiopulmonary testing more successful in the future.