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Background: The clinical applicability and reliability of three-dimensional (3D) speckle-tracking echocardiography has not been well studied in pediatric patients. The aim of this study was to compare two-dimensional (2D) echocardiography and 3DE real-time full-volume-derived strain and rotation indices in healthy children and patients with dilated cardiomyopathy (DCM)., Methods: Children with either normal function or DCM were prospectively recruited in an outpatient setting, and deformation indices, including circumferential, radial, and longitudinal strain and torsion, were measured by 2D and 3D echocardiography. Control subjects were compared with patients using the Mann-Whitney U test, correlations between 2D and 3D measurements were analyzed using Spearman correlation analysis, and reproducibility analyses are reported using intraclass correlation coefficients and coefficient of variations., Results: The study cohort consisted of 15 patients (47%) with DCM and 17 control subjects (53%). The median age of the cohort was 13.4 years (range, 5.7-19.3 years). By both 2D and 3D analysis, magnitudes of global longitudinal (P = .01), circumferential (P = .007), and radial (P = .004) strain were significantly lower in patients with DCM in comparison with control subjects. Using receiver operating characteristic curves, lower values of absolute circumferential (area under the curve = 0.95, P < .0001) and longitudinal (area under the curve = 0.93, P < .0001) strain were associated with left ventricular dysfunction. No difference was noted in torsion between control subjects and patients. Three-dimensional analysis was superior to 2D analysis in terms of intraobserver, interobserver, and test-retest reliability., Conclusions: Left ventricular deformation shows significant changes while torsion is preserved in outpatients with DCM compared with control subjects. Three-dimensional global strain can discriminate subtle left ventricular dysfunction and has better reproducibility in comparison with 2D echocardiography. High-resolution 3D imaging is a useful clinical assessment tool for cardiac performance and may overcome some of the limitations of 2D analysis., (Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

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.

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.

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.

Background: The assessment of left ventricular (LV) systolic function using conventional echocardiographic measures is problematic in the setting of mitral regurgitation (MR) given that altered loading conditions can mask underlying ventricular dysfunction. The purpose of this study was to characterize LV function and deformation before and after effective mitral valve repair or replacement to determine echocardiographic measures associated with early postoperative myocardial dysfunction., Methods: Baseline LV function was assessed retrospectively by conventional echocardiography and speckle-tracking strain analysis pre- and postoperatively in patients diagnosed with MR between January 2000 and March 2013, excluding patients with less than mild to moderate MR preoperatively, left-sided obstructive lesions, large septal defects, or more than mild MR postoperatively., Results: Forty-six pediatric patients were evaluated (average age, 8.2 ± 6.4 years). Thirteen patients had normal preoperative ejection fractions but significant postoperative dysfunction (defined as an ejection fraction < 50%). Compared with the 33 patients with normal postoperative function, age (11.5 ± 7.1 vs 7.3 ± 5.7 years, P = .04), global circumferential strain (-13.2 ± 5.6% vs -17.1 ± 4.6%, P = .02), and global circumferential strain rate (-0.94 ± 0.40 vs -1.36 ± 0.42 sec(-1), P = .004) were found to be statistically different. Using receiver operating characteristic curves, an older preoperative age (area under the curve, 0.67; P = .03), lower global circumferential strain magnitude (area under the curve, 0.74; P = .007), and lower global circumferential strain rate magnitude (area under the curve, 0.80; P = .0004) were determined to be factors associated with early postoperative LV dysfunction after surgical repair of MR., Conclusions: Strain measurements may be useful as part of the echocardiographic assessment of patients with MR and can guide timing for surgical repair in the pediatric population., (Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

In tetralogy of Fallot with absent pulmonary valve, pulmonary stenosis and regurgitation results in significant pulmonary artery dilatation. Branch pulmonary artery dilatation often compresses the tracheobronchial tree, causing fluid trapping in fetal life and air trapping and/or atelectasis after birth. Prenatal diagnosis predicts poor prognosis, which depends on the degree of respiratory insufficiency from airway compromise and lung parenchymal disease after birth. Fetal magnetic resonance imaging (MRI) has been useful in evaluating the effects of congenital lung lesions on lung development and indicating severity of pulmonary hypoplasia. This report is the first demonstrating the utility of fetal MRI in tetralogy of Fallot/absent pulmonary valve patients, which predicted postnatal pulmonary artery size and visualized airway compression and lung parenchymal lesions. The distribution of lobar fluid trapping on fetal MRI correlated with air trapping on postnatal computed tomography angiogram., (© 2013 Wiley Periodicals, Inc.)

Advances in fetal cardiac imaging have resulted in changes in the practice of fetal cardiology, and in improved neonatal outcomes for these patients. As the anatomic diagnostic accuracy of fetal cardiology has improved, cardiologists have sought new challenges in fetal imaging, and with new emphasis on improved front line detection, treatment/intervention during fetal life, and assessment of fetal ventricular function and cardiovascular performance. The evolution of noninvasive assessment of fetal cardiac function is related to technologic advances in ultrasound imaging. This article reviews conventional methods of the assessment of cardiac function, as well as some promising directions for future evaluation with emphasis on future applications of 3D echocardiography and 3D speckle tracking echocardiography.

In chronic aortic insufficiency (AI), left-ventricular (LV) dysfunction must be detected early to allow timely surgery. Strain and strain rate have been used for this purpose in adults, but the value of this method in pediatric AI has not been established. Forty patients with moderate to severe AI were included in this retrospective study. LV function was assessed by strain analysis and conventional echocardiography both before and after surgery. Of the 32 patients with preserved preoperative ejection fraction (EF; >50 %), 8 had postoperative dysfunction (<50 %). Mean conventional indices of global LV systolic performance for the entire cohort of patients with AI were predominantly in the normal range before surgery. Preoperative values for LV global longitudinal strain (GLS) and strain rate (GLSr) were normal. After surgery, there was a significant decrease in shortening and EF. There was a significant decrease from preoperative to postoperative values for both GLS (-16.07 ± 3.82 vs. -11.06 ± 3.88; p < 0.0001) and GLSr (-0.89 ± 0.24 vs. -0.72 ± 0.27; p = 0.0021). A preoperative GLS of -15.3 (AUC = 0.83, CI = 0.69-0.98, p < 0.0001) and a GLSr of -0.79/s (AUC = 0.86, CI = 0.73-0.98, p < 0.0001) were determined to be predictors of early postoperative dysfunction after surgical repair of moderate to severe AI. A preoperative GLS value of ≤-15.3 and GLSr value of -0.79/s or less are predictors of postoperative ventricular dysfunction, which is defined by EF <50 %. GLS and GLSr value determination may be useful as part of the echocardiographic assessment AI and may help determine the optimal timing of surgery in pediatric patient with at least moderate AI.

Multiple echocardiographic techniques have been utilized to quantify systolic function. The shortening and ejection fraction remain the most commonly used and accepted methods. However, these measures are affected by altered loading conditions, and are not applicable when ventricular geometry differs from the prolate ellipsoid typical of a left ventricle. Mitral valve annular acceleration during isovolumic contraction (IVA) has been proposed as a load independent index of left ventricular contractility. However, published values for IVA demonstrating normal function vary. In addition, the value of IVA which may discern impaired systolic function has not been established. The purpose of this study is to determine a threshold IVA value for abnormal left ventricular function in the pediatric population. Structurally/functionally normal control (n = 90) and dilated cardiomyopathy (study = 64) patients were compared for differences in left ventricular: wall stress (WS), velocity of circumferential fiber shortening (VCFc), ejection fraction (EF), ejection force, and pulsed wave-derived medial and lateral wall IVA. No difference in body surface area (p = 0.61) or gender (p = 0.53) was noted. Left ventricular ejection fraction, ejection force, VCFc, and IVA were significantly lower and WS was significantly higher in the study group (p < 0.01). The medial IVA was 1.71 ± 0.89 m/s(2) for an EF <40%, 1.74 ± 0.70 m/s(2) for an EF = 40-50%, 2.46 ± 0.89 m/s(2) for an EF >50%. The lateral IVA was 1.81 ± 1.03 m/s(2) for an EF <40%, 2.07 ± 0.78 m/s(2) for an EF = 40-50%, 2.54 ± 0.99 m/s(2) for an EF >50%. ROC analysis demonstrated a medial IVA of 1.97 m/s(2) as the cut-off for predicting an EF <50% with a 77% sensitivity of and specificity of 66% (AUC = 0.75, CI = 0.67-0.83, p < 0.01). ROC analysis demonstrated a lateral IVA of 2.31 m/s(2) as the cut-off for predicting an EF <50% with a 73% sensitivity of and specificity of 63% (AUC = 0.72, CI = 0.63-0.82, p < 0.01). IVA lateral of 1.93 m/s(2) or less was associated with heart transplant and death. ICC analysis demonstrated some interobserver variability in IVA measurement (0.57-0.65). The normal IVA of the medial and lateral mitral valve annulus measure over 1.97 m/s(2) and 2.31 m/s(2), respectively; values less than this cut-off are associated with EF <50%. Despite some problems with reproducibility IVA remains a promising method of screening for diminished ventricular contractility in the setting of abnormal geometry.

Patients with 1-ventricle (1V) physiology may be at risk for peripheral arterial dysfunction at a young age. To determine whether infants and young children with 1V physiology and hypoxemia have peripheral arterial dysfunction before undergoing the Fontan operation, we measured (1) flow-mediated vasodilation (FMD) in the brachial artery, (2) serum levels of vasoactive mediators endothelin-1 (ET-1) and metabolites of nitric oxide, and (3) arterial stiffness with pulse-wave velocity (PWV) in the aorta. Eighteen patients with 1V physiology before the Fontan procedure and hypoxemia and 19 patients with normoxemia and 2-ventricle (2V) physiology were studied. Measurements were collected during cardiac catheterization. FMD in the brachial artery was the diameter gain after 4.5 minutes of forearm occlusion measured with high-resolution ultrasound and edge-detection software. Nitric oxide and ET-1 levels were measured in venous blood. PWV between the left carotid and femoral arteries was measured using pulse Doppler ultrasound. FMD was lower (2.4 +/- 3.7% vs 11.3 +/- 6%, p <0.0005) and ET-1 levels were higher (35.5 +/- 11.3% vs 24.1 +/- 9.7%, p = 0.003) in subjects with 1V physiology versus those with 2V physiology, respectively. There were no differences in nitric oxide levels or PWV. In conclusion, infants and young children with 1V physiology and hypoxemia have blunted FMD and higher ET-1 levels before undergoing the Fontan operation compared with normoxemic subjects with 2V physiology. A further understanding of pathophysiologic mechanisms underlying peripheral arterial dysfunction, including the roles of hypoxemia, low cardiac index, and ET-1, may lead to targeted therapies and improve the long-term survival of patients with 1V physiology.