Speckle-Tracking Echocardiographic Measures of Right Ventricular Diastolic Function Correlate with Reference Standard Measures Before and After Preload Alteration in Children.

The accuracy of echocardiographic measures of right ventricular (RV) diastolic function has been sparsely studied. Our objective was to evaluate the correlation between echocardiographic and reference standard measures of RV diastolic function derived from micromanometer pressure analysis before and after preload alteration in children. Echocardiograms and micromanometer pressure analyses were prospectively performed before and after fluid bolus in children undergoing right heart catheterization. The isovolumic relaxation time constant (τ) and end-diastolic pressure (EDP) were measured. Conventional and speckle-tracking echocardiographic (STE) parameters of RV systolic and diastolic function were assessed. Normal saline bolus was given to increase RV EDP by 20 %. Twenty-eight studies were performed in 22 patients with congenital heart disease or postheart transplantation. Mean age was 8.7 ± 6.1 years. RV longitudinal early diastolic strain rate (EDSR) correlated with τ before (r = 0.57, p = 0.001) and after fluid bolus (r = 0.48, p = 0.008). No conventional echocardiographic measures correlated with τ both before and after fluid bolus. Multiple regression analysis revealed RV EDSR and LV circumferential EDSR as independent predictors of RV τ. There were no independent predictors of EDP. RV EDSR appears to correlate with the reference standard measure of early active ventricular relaxation in children at baseline and after changes in preload. Conventional echocardiographic measures of diastolic function were not predictive of diastolic function after preload alteration. Future studies should assess the prognostic significance of STE measures of diastolic function in this population.

Impact of Variability in Echocardiographic Interpretation on Assessment of Adequacy of Repair Following Congenital Heart Surgery: A Pilot Study.

Technical Performance Score (TPS) is based largely on the presence and magnitude of residual lesions on postoperative echocardiograms; this score correlates with outcomes following repair of congenital heart defects. We evaluated reader variability for echocardiographic components of TPS for complete repair of tetralogy of Fallot (TOF) and arterial switch operation (ASO) in two centers and measured its effect on TPS. Postoperative echocardiograms were evaluated in 67 children (39 TOF and 28 ASO). Two readers (one per center) interpreted each echocardiogram. Reader variability in image quality assessments and measurements was compared using weighted kappa (κ), percent agreement, and intra-class correlation. TPS class (1 optimal-no residua, 2 adequate-minor residua, 3 inadequate-major residua) was assigned for each echocardiographic review by an independent investigator. The effect of reader interpretation variability on TPS classification was measured. There was strong agreement for TPS between the two readers (κ = 0.88). The readers were concordant for TPS classes for 57 children (85%) and discordant for classes 2 (minor residua) versus 3 (major residua) in six (9%). Coronary arteries and branch pulmonary arteries were frequently suboptimally visualized. Although inter-reader agreement for TPS was strong, inter-reader variation in echocardiographic interpretations had a small, but important effect on TPS for TOF and ASO, particularly for the distinction between minor and major residua. Further studies of generalizability and reproducibility of TPS and refinement of scoring modules may be needed before it can be used as a tool to assess pediatric cardiac surgical performance and outcomes.

Echocardiography of coarctation of the aorta, aortic arch hypoplasia, and arch interruption: strategies for evaluation of the aortic arch.

Aim Echocardiography is the modality of choice for the diagnosis and serial follow-up of aortic arch pathology. In this article, we review the types of obstruction of the aortic arch, various classification schemes of coarctation of the aorta and interrupted aortic arch, methodology for optimal echocardiographic imaging of the aortic arch, and key echocardiographic measurements for accurate diagnosis of obstruction and hypoplasia of the aortic arch. Finally, we will discuss the limitations of echocardiography in optimal imaging of the aortic arch and the use of other non-invasive imaging modalities such as CT or MRI to provide additional information in these cases. BACKGROUND: Coarctation of the aorta is the more common lesion of the two, with an estimated incidence of four in every 10,000 live births in the United States of America. Interrupted aortic arch is rarer, with an incidence of 19 per one million live births. 1 There is a spectrum of pathology of obstruction of the aortic arch, ranging from coarctation of the aorta with and without hypoplasia of the arch to interrupted aortic arch. Both these lesions are frequently encountered in congenital cardiology practice, and will be discussed in the remainder of this article. Obstruction of the aortic arch in the setting of hypoplastic left heart structures or atresia of the aortic valve is beyond the scope of this review and will not be discussed further.

Changes in speckle tracking echocardiography measures of ventricular function after percutaneous implantation of the Edwards SAPIEN transcatheter heart valve in the pulmonary position.

BACKGROUND: Patients with free pulmonary regurgitation or mixed pulmonary stenosis and regurgitation and severely dilated right ventricles (RV) show little improvement in ventricular function after pulmonary valve replacement when assessed by traditional echocardiographic markers. We evaluated changes in right and left ventricular (LV) function using speckle tracking echocardiography in patients after SAPIEN transcatheter pulmonary valve (TPV) placement. METHODS: Echocardiograms were evaluated at baseline, discharge, 1 and 6 months after TPV placement in 24 patients from 4 centers. Speckle tracking measures of function included peak longitudinal strain, strain rate, and early diastolic strain rate. RV fractional area change, tricuspid annular plane systolic excursion, and left ventricular LV ejection fraction were assessed. Routine Doppler and tissue Doppler velocities were measured. RESULTS: At baseline, all patients demonstrated moderate to severe pulmonary regurgitation; this improved following TPV placement. No significant changes were detected in conventional measures of RV or LV function at 6 months. RV longitudinal strain (-16.9% vs. -19.6%, P < 0.01), strain rate (-0.87 s(-1) vs. -1.16 s(-1) , P = 0.01), and LV longitudinal strain (-16.2% vs. -18.2%, P = 0.01) improved between baseline and 6 month follow-up. RV early diastolic strain rate, LV longitudinal strain rate and early diastolic strain rate showed no change. CONCLUSION: Improvements in RV longitudinal strain, strain rate, and LV longitudinal strain are seen at 6 months post-TPV. Diastolic function does not appear to change at 6 months. Speckle tracking echocardiography may be more sensitive than traditional measures in detecting changes in systolic function after TPV implantation.

Does initial shunt type for the Norwood procedure affect echocardiographic measures of cardiac size and function during infancy?: the Single Vventricle Reconstruction trial.

BACKGROUND: The Pediatric Heart Network trial comparing outcomes in 549 infants with single right ventricle undergoing a Norwood procedure randomized to modified Blalock-Taussig shunt or right ventricle-pulmonary artery shunt (RVPAS) found better 1-year transplant-free survival in those who received RVPAS. We sought to compare the impact of shunt type on echocardiographic indices of cardiac size and function up to 14 months of age. METHODS AND RESULTS: A core laboratory measured indices of cardiac size and function from protocol exams: early after Norwood procedure (age 22.5 ± 13.4 days), before stage II procedure (age 4.8 ± 1.8 months), and at 14 months (age 14.3 ± 1.2 months). Mean right ventricular ejection fraction was <50% at all intervals for both groups and was higher in the RVPAS group after Norwood procedure (49 ± 7% versus 44 ± 8%; P<0.001) but was similar by 14 months. Tricuspid and neoaortic regurgitation, diastolic function, and pulmonary artery and arch dimensions were similar in the 2 groups at all intervals. Neoaortic annulus area (4.2 ± 1.2 versus 4.9 ± 1.2 cm(2)/m(2)), systolic ejection times (214.0 ± 29.4 versus 231.3 ± 28.6 ms), neoaortic flow (6.2 ± 2.4 versus 9.4 ± 3.4 L/min per square meter), and peak arch velocity (1.9 ± 0.7 versus 2.2 ± 0.7 m/s) were lower at both interstage examinations in the RVPAS compared with the modified Blalock-Taussig shunt group (P<0.001 for all), but all were similar at 14 months. CONCLUSIONS: Indices of cardiac size and function after the Norwood procedure are similar for modified Blalock-Taussig shunt and RVPAS by 14 months of age. Interstage differences between shunt types can likely be explained by the physiology created when the shunts are in place rather than by intrinsic differences in cardiac function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Three-dimensional echocardiography in congenital heart disease.

Complex intracardiac anatomy and spatial relationships are inherent to congenital heart defects (CHDs). Recognition of the limitations of two-dimensional echocardiography has stimulated clinical interest in three-dimensional imaging. The current review examines contemporary studies in the following areas where three-dimensional echocardiography has provided additive value in CHD: (1) visualization of morphology, (2) quantitation of chamber sizes and ventricular function, and (3) image-guided interventions.

Universal screening for extracardiac abnormalities in neonates with congenital heart disease.

Extracardiac or genetic abnormalities (EGA) represent a factor in the morbidity of patients with congenital heart disease. We evaluated the way neonates with CHD are screened at our institution and determined the yield for the screening tests. We reviewed the charts of 223 neonates with structural CHD. Subjects were categorized into 6 groups: univentricular, left-sided obstructive lesions, right-sided obstructive lesions, septal defects, conotruncal defects (CTD), and other. We reviewed which patients underwent cranial ultrasonogram (CUS), abdominal ultrasonogram (AUS), and/or genetic studies (GS) as well as their results. There was a high prevalence of EGA in each group by CUS (32% to 42%), AUS (32% to 69%), and GS (10% to 60%). There was considerable variability in the proportion within each group that underwent screening tests, and the consistency of screening often was not congruent with the likelihood of abnormal results. Approximately 50% of our patients had >/=1 EGA identified, resulting in a cost-yield ratio of $4,508/patient with EGA. Screening for EGA at our institution is not uniform and is often at odds with the prevalence of such patients. Given the high prevalence of EGA, we advocate for a universal screening program for neonates with CHD using cranial/abdominal ultrasonography and genetic testing.

Longitudinal measures of deformation are associated with a composite measure of contractility derived from pressure-volume loop analysis in children.

Aims: The relationship between echocardiographic measures of left ventricular (LV) systolic function and reference-standard measures have not been assessed in children. The objective of this study was to assess the validity of echocardiographic indices of LV systolic function via direct comparison to a novel composite measure of contractility derived from pressure-volume loop (PVL) analysis. Methods and results: Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. A composite invasive composite contractility index (ICCI) was developed using data reduction strategies to combine four measures of contractility derived from PVL analysis. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Conventional and speckle-tracking echocardiographic measures of systolic function were measured. Of 24 patients, 18 patients were heart transplant recipients, 6 patients had a small patent ductus arteriosus or small coronary fistula. Mean age was 9.1 ± 5.6 years. Upon multivariable regression, longitudinal strain was associated with ICCI (ß = -0.54, P = 0.02) while controlling for indices of preload, afterload, heart rate, and LV mass under baseline conditions. Ejection fraction and shortening fraction were associated with LV mass and load indices, but not contractility. Conclusion: Speckle-tracking derived longitudinal strain is associated ICCI in children with normal loading conditions. Longitudinal measures of deformation appear to accurately assess LV contractility in children.

Echocardiographic Detection of Increased Ventricular Diastolic Stiffness in Pediatric Heart Transplant Recipients: A Pilot Study.

BACKGROUND: Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients. METHODS: Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, ß, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional speckle-tracking. Ventricular volumes were measured using three-dimensional echocardiography. The novel echocardiographic estimates of ventricular stiffness included E:e'/end-diastolic volume (EDV) and E:early diastolic strain rate/EDV. RESULTS: Of 24 children, 18 were heart transplant recipients. Six control patients had hemodynamically insignificant patent ductus arteriosus or coronary fistula. The mean age was 9.1 ± 5.6 years. Median end-diastolic pressure was 9 mm Hg (interquartile range, 8-13 mm Hg). Lateral E:e'/EDV (r = 0.59, P < .01), septal E:e'/EDV (r = 0.57, P < .01), and (E:circumferential early diastolic strain rate)/EDV (r = 0.54, P < .01) correlated with ß. Lateral E:e'/EDV displayed a C statistic of 0.93 in detecting patients with abnormal LV stiffness (ß > 0.015 mL-1). A lateral E:e'/EDV of >0.15 mL-1 had 89% sensitivity and 93% specificity in detecting an abnormal ß. CONCLUSIONS: Echocardiographic estimates of ventricular stiffness may be accurate compared with the gold standard in pediatric heart transplant recipients. The clinical usefulness of these noninvasive measures in assessing LV stiffness merits further study in children.

3-Year Outcomes of the Edwards SAPIEN Transcatheter Heart Valve for Conduit Failure in the Pulmonary Position From the COMPASSION Multicenter Clinical Trial.

OBJECTIVES: This study provides the 3-year follow-up results of the COMPASSION (Congenital Multicenter Trial of Pulmonic Valve Regurgitation Studying the SAPIEN Transcatheter Heart Valve) trial. Patients with moderate to severe pulmonary regurgitation and/or right ventricular outflow tract conduit obstruction were implanted with the SAPIEN transcatheter heart valve (THV). BACKGROUND: Early safety and efficacy of the Edwards SAPIEN THV in the pulmonary position have been established through a multicenter clinical trial. METHODS: Eligible patients were included if body weight was >35 kg and in situ conduit diameter was ≥16 and ≤24 mm. Adverse events were adjudicated by an independent clinical events committee. Three-year clinical and echocardiographic outcomes were evaluated in these patients. RESULTS: Fifty-seven of the 63 eligible patients were accounted for at the 3-year follow-up visit from a total of 69 implantations in 81 enrolled patients. THV implantation was indicated for pulmonary stenosis (7.6%), regurgitation (12.7%), or both (79.7%). Twenty-two patients (27.8%) underwent implantation of 26-mm valves, and 47 patients received 23-mm valves. Functional improvement in New York Heart Association functional class was observed in 93.5% of patients. Mean peak conduit gradient decreased from 37.5 ± 25.4 to 17.8 ± 12.4 mm Hg (p < 0.001), and mean right ventricular systolic pressure decreased from 59.6 ± 17.7 to 42.9 ± 13.4 mm Hg (p < 0.001). Pulmonary regurgitation was mild or less in 91.1% of patients. Freedom from all-cause mortality at 3 years was 98.4%. Freedom from reintervention was 93.7% and from endocarditis was 97.1% at 3 years. There were no observed stent fractures. CONCLUSIONS: Transcatheter pulmonary valve replacement using the Edwards SAPIEN THV demonstrates excellent valve function and clinical outcomes at 3-year follow-up.

Validation of Noninvasive Measures of Left Ventricular Mechanics in Children: A Simultaneous Echocardiographic and Conductance Catheterization Study.

BACKGROUND: The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children. METHODS: Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different methods. These estimates were calculated using a combination of noninvasive blood pressure readings, ventricular volumes derived from three-dimensional echocardiography, and Doppler time intervals. RESULTS: Of 24 patients, 18 patients were heart transplant recipients, and six patients had small patent ductus arteriosus or small coronary fistulae. The mean age was 9.1 ± 5.6 years. The average invasive Ees was 3.04 ± 1.65 mm Hg/mL. Invasive Ees correlated best with echocardiographic Ees by the method of Tanoue (r = 0.85, P < .01), with a mean difference of -0.07 mm Hg/mL (95% limits of agreement, -2.0 to 1.4 mm Hg/mL). CONCLUSIONS: Echocardiographic estimates of Ees correlate well with gold-standard measures obtained via conductance catheters in children with relatively normal loading conditions. The use of these noninvasive measures in accurately assessing left ventricular contractility appears promising and merits further study in children.

Implementation of a Quality Improvement Bundle Improves Echocardiographic Imaging after Congenital Heart Surgery in Children.

BACKGROUND: Postoperative echocardiography after congenital heart disease surgery is of prognostic importance, but variable image quality is problematic. We implemented a quality improvement bundle comprising of focused imaging protocols, procedural sedation, and sonographer education to improve the rate of optimal imaging (OI). METHODS: Predischarge echocardiograms were evaluated in 116 children (median age, 0.51 years; range, 0.01-5.6 years) from two centers after tetralogy of Fallot repair, arterial switch operation, and bidirectional Glenn and Fontan procedures. OI rates were compared between the centers before and after the implementation of a quality improvement bundle at center 1, with center 2 serving as the comparator. Echocardiographic images were independently scored by a single reader from each center, blinded to center and time period. For each echocardiographic variable, quality score was assigned as 0 (not imaged or suboptimally imaged) or 1 (optimally imaged); structures were classified as intra- or extracardiac. The rate of OI was calculated for each variable as the percentage of patients assigned a score of 1. RESULTS: Intracardiac structures had higher OI than extracardiac structures (81% vs 57%; adjusted odds ratio [OR], 3.47; P < .01). Center 1 improved overall OI from 48% to 73% (OR, 4.44; P < .01), intracardiac OI from 69% to 85% (OR, 3.53; P = .01), and extracardiac OI from 35% to 67% (OR, 5.16; P < .01). There was no temporal difference for center 2. CONCLUSIONS: After congenital heart disease surgery in children, intracardiac structures are imaged more optimally than extracardiac structures. Focused imaging protocols, patient sedation, and sonographer education can improve OI rates.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Function Correlate With Improvement in Exercise Function After Percutaneous Pulmonary Valve Implantation.

BACKGROUND: Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute ventilation [VE]/carbon dioxide production [VCO2] slope), have been shown to be prognostic of mortality in patients who may require TPVI. The aim of this study was to evaluate the correlation between STE measures of RV function and changes in VE/VCO2 after TPVI. METHODS: Speckle-tracking echocardiography and cardiopulmonary exercise testing were performed at baseline and 6 months after TPVI in 24 patients from four centers. Conventional echocardiographic measures of RV function were also assessed. Echocardiographic and exercise stress test results were interpreted by single blinded observers at separate core laboratories. RESULTS: All patients demonstrated relief of pulmonary regurgitation and stenosis after TPVI. Improvements in RV longitudinal strain (-16.9 ± 3.5% vs -19.7 ± 4.3%, P < .01) and strain rate (-0.9 ± 0.4 vs. -1.2 ± 0.4 s(-1), P < .01) were noted. The VE/VCO2 slope improved (32.4 ± 5.7 vs 31.5 ± 8.8, P = .03). No other significant echocardiographic or exercise changes were found. On multivariate regression, the change in VE/VCO2 was independently associated with change in RV longitudinal early diastolic strain rate (P < .001) and tricuspid A velocity (P < .001). Preintervention RV longitudinal strain was found to be a predictor of change in VE/VCO2 after TPVI (r = -0.60, P < .001). CONCLUSIONS: STE measures of RV function appear to hold the potential for use as predictors of improved outcomes in patients requiring TPVI. Future studies should directly assess the prognostic significance of STE measures of RV function in this population.

Implications and limitations of an abnormal fetal echocardiogram.

This study evaluates the accuracy of fetal echocardiograms in terms of anatomic diagnosis and predicted neonatal management over a 7-year period. Although an abnormal fetal echocardiogram is a highly reliable predictor of postnatal structural heart defects, challenges persist in the areas of conotruncal malformations, aortic arch, and pulmonary venous anomalies.

Effectiveness of cardiac surgery in trisomies 13 and 18 (from the Pediatric Cardiac Care Consortium).

Because of severely reduced lifespan in children with trisomies 13 and 18, surgical repair of congenital heart lesions has rarely been offered. With data from a multicenter registry, we report 35 cases of cardiac surgery in infants and children with trisomy 13 or 18 with a 91% hospital survival rate. Those patients without an extended preoperative ventilatory requirement did not require prolonged mechanical ventilation after surgery.

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children.

BACKGROUND: Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children. METHODS: Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician. RESULTS: A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01). CONCLUSIONS: Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.