Organisation of paediatric echocardiography laboratories and governance of echocardiography services and training in Europe: current status, disparities, and potential solutions. A survey from the Association for European Paediatric and Congenital Cardiology (AEPC) imaging working group.

BACKGROUND: There is limited data on the organisation of paediatric echocardiography laboratories in Europe. METHODS: A structured and approved questionnaire was circulated across all 95 Association for European Paediatric and Congenital Cardiology affiliated centres. The aims were to evaluate: (1) facilities in paediatric echocardiography laboratories across Europe, (2) accredited laboratories, (3) medical/paramedical staff employed, (4) time for echocardiographic studies and reporting, and (5) training, teaching, quality improvement, and research programs. RESULTS: Respondents from forty-three centres (45%) in 22 countries completed the survey. Thirty-six centres (84%) have a dedicated paediatric echocardiography laboratory, only five (12%) of which reported they were European Association of Cardiovascular Imaging accredited. The median number of echocardiography rooms was three (range 1-12), and echocardiography machines was four (range 1-12). Only half of all the centres have dedicated imaging physiologists and/or nursing staff, while the majority (79%) have specialist imaging cardiologist(s). The median (range) duration of time for a new examination was 45 (20-60) minutes, and for repeat examination was 20 (5-30) minutes. More than half of respondents (58%) have dedicated time for reporting. An organised training program was present in most centres (78%), 44% undertake quality assurance, and 79% perform research. Guidelines for performing echocardiography were available in 32 centres (74%). CONCLUSION: Facilities, staffing levels, study times, standards in teaching/training, and quality assurance vary widely across paediatric echocardiography laboratories in Europe. Greater support and investment to facilitate improvements in staffing levels, equipment, and governance would potentially improve European paediatric echocardiography laboratories.

Leg-focused high-weight resistance training improves ventricular stroke volume, exercise capacity and strength in young patients with a Fontan circulation.

AIMS: Effective therapy to improve exercise capacity in Fontan patients is lacking. Leg-focused high-weight resistance training might augment the peripheral muscle pump and thereby improve exercise capacity. METHODS AND RESULTS: This randomized semi-cross-over controlled trial investigated the effects of a 12-week leg-focused high-weight resistance training plus high-protein diet, on (sub)maximal exercise capacity, cardiac function (assessed with cardiovascular magnetic resonance), muscle strength, and quality of life in paediatric Fontan patients. Twenty-eight paediatric Fontan patients were included, 27 patients, (median age 12.9 [10.5-15.7]), and successfully completed the programme. Peak oxygen uptake (PeakVO2) at baseline was reduced [33.3 mL/kg/min (27.1-37.4), 73% (62-79) of predicted]. After training PeakVO2/kg and Peak workload improved significantly with +6.2 mL/kg/min (95%CI: 3.4-9.0) (+18%) P < 0.001 and +22 Watts (95%CI: 12-32) (+18%) P < 0.001, respectively, compared to the control period. Indexed single ventricle stroke volume increased significantly [43 mL/beat/m2 (40-49) vs. 46 (41-53), P = 0.014], as did inferior vena cava flow [21 mL/beat/m2 (18-24) vs. 23 (20-28), P = 0.015], while superior vena cava flow remained unchanged. The strength of all measured leg-muscles increased significantly compared to the control period. Self-reported quality of life improved on the physical functioning and change in health domains of the child health questionnaire, parent-reported quality of life improved the bodily pain, general health perception, and change in health domains compared to the control period. CONCLUSION: In a relatively large group of 27 older Fontan children, 12-weeks of leg-focused high-weight resistance training improved exercise capacity, stroke volume, (sub)maximal exercise capacity, muscle strength, and domains of quality of life. REGISTRATION: International Clinical Trials: Trial NL8181.

Is leg-focused high-weight resistance training an effective therapy to improve reduced exercise capacity in patients with a Fontan circulation? Key Finding: Twelve weeks of leg-focused high-weight resistance training in children with a Fontan circulation improved exercise capacity, single ventricular stroke volume, (sub)maximal exercise capacity, muscle strength, and physical domains of quality of life. Take-home Message: Leg-focused high-weight resistance training results in improved exercise capacity, cardiac function, and quality of life patients with a Fontan circulation. Patients with a Fontan circulation should be motivated to perform lower limb strengthening exercises.

Ventricular function and biomarkers in relation to repair and pulmonary valve replacement for tetralogy of Fallot.

OBJECTIVE: Cardiac surgery may cause temporarily impaired ventricular performance and myocardial injury. We aim to characterise the response to perioperative injury for patients undergoing repair or pulmonary valve replacement (PVR) for tetralogy of Fallot (ToF). METHODS: We enrolled children undergoing ToF repair or PVR from four tertiary centres in a prospective observational study. Assessment-including blood sampling and speckle tracking echocardiography-occurred before surgery (T1), at the first follow-up (T2) and 1 year after the procedures (T3). Ninety-two serum biomarkers were expressed as principal components to reduce multiple statistical testing. RNA Sequencing was performed on right ventricular (RV) outflow tract samples. RESULTS: We included 45 patients with ToF repair aged 4.3 (3.4 - 6.5) months and 16 patients with PVR aged 10.4 (7.8 - 12.7) years. Ventricular function following ToF repair showed a fall-and-rise pattern for left ventricular global longitudinal strain (GLS) (-18±4 to -13±4 to -20±2, p < 0.001 for each comparison) and RV GLS (-19±5 to -14±4 to 20±4, p < 0.002 for each comparison). This pattern was not seen for patients undergoing PVR. Serum biomarkers were expressed as three principal components. These phenotypes are related to: (1) surgery type, (2) uncorrected ToF and (3) early postoperative status. Principal component 3 scores were increased at T2. This increase was higher for ToF repair than PVR. The transcriptomes of RV outflow tract tissue are related to patients' sex, rather than ToF-related phenotypes in a subset of the study population. CONCLUSIONS: The response to perioperative injury following ToF repair and PVR is characterised by specific functional and immunological responses. However, we did not identify factors relating to (dis)advantageous recovery from perioperative injury. TRIAL REGISTRATION NUMBER: Netherlands Trial Register: NL5129.

Functional Echocardiographic and Serum Biomarker Changes Following Surgical and Percutaneous Atrial Septal Defect Closure in Children.

Background Ventricular performance is temporarily reduced following surgical atrial septal defect closure. Cardiopulmonary bypass and changes in loading conditions are considered important factors, but this phenomenon is incompletely understood. We aim to characterize biventricular performance following surgical and percutaneous atrial septal defect closure and to relate biomarkers to ventricular performance following intervention. Methods and Results In this multicenter prospective study, children scheduled for surgical or percutaneous atrial septal defect closure were included. Subjects were assessed preoperatively, in the second week postintervention (at 2-weeks follow-up), and 1-year postintervention (1-year follow-up). At each time point, an echocardiographic study and a panel of biomarkers were obtained. Sixty-three patients (median age, 4.1 [interquartile range, 3.1-6.1] years) were included. Forty-three patients underwent surgery. At 2-weeks follow-up, right ventricular global longitudinal strain was decreased for the surgical, but not the percutaneous, group (-17.6±4.1 versus -27.1±3.4; P<0.001). A smaller decrease was noted for left ventricular global longitudinal strain at 2-weeks follow-up for the surgical group (surgical versus percutaneous, -18.6±3.2 versus -20.2±2.4; P=0.040). At 1-year follow-up, left ventricular performance returned to baseline, whereas right ventricular performance improved, but did not reach preintervention levels. Eight biomarkers relating to cardiovascular and immunological processes differed across study time points. Of these biomarkers, only NT-proBNP (N-terminal pro-B-type natriuretic peptide) correlated with less favorable left ventricular global longitudinal strain at 2-weeks follow-up. Conclusions Right, and to a lesser degree left, ventricular performance was reduced early after surgical atrial septal defect closure. Right ventricular performance at 1-year follow-up remained below baseline levels. Several biomarkers showed a pattern over time similar to ventricular performance. These biomarkers may provide insight into the processes that affect ventricular function. Registration URL: https://www.trialregister.nl/; Unique identifier: NL5129.

Associations between blood biomarkers, cardiac function and adverse outcome in a young tetralogy of Fallot cohort.

BACKGROUND: To determine the potential prognostic value and clinical correlations of blood biomarkers in a cohort of patients with Tetralogy of Fallot (TOF). METHODS: In the setting of multicenter prospective research studies TOF patients underwent blood sampling, cardiopulmonary exercise testing and low-dose dobutamine stress cardiac magnetic resonance (CMR) imaging. In the blood sample NT-proBNP, GDF-15, Galectin-3, ST-2, DLK-1, FABP4, IGFBP-1, IGFBP-7, MMP-2, and vWF were assessed. During subsequent follow-up, patients were evaluated for reaching the study endpoint (cardiac death, arrhythmia-related hospitalization or cardioversion/ablation, VO2 max ≤65% of predicted). Regression analysis was used to explore the correlation between blood biomarkers (corrected for age and gender) and other clinical parameters. The potential predictive value of blood biomarkers and events were assessed with Kaplan-Meier analysis and Cox proportional hazard analysis. RESULTS: We included 137 Fallot patients, median age 19.2 (interquartile range: 14.6-25.7) years, median age at TOF-repair 0.9 (0.5-1.9) years. After a median follow-up of 8.7 (6.3-10.7) years, 20 (14.6%) patients reached the composite endpoint. In a multivariable cox-regression analysis corrected for age at study baseline, elevated IGFBP-7 and MMP-2 levels were associated with the composite endpoint. We also noted a correlation between DLK-1 and relative change in right ventricular end systolic volume during dobutamine stress CMR (ß = -0.27, p = 0.010), a correlation between FABP4 and Max VO2 (ß = -0.41, p ≤0.001 and between MMP-2 and tricuspid valve E/A ratio (ß = -0.15, p = 0.037). CONCLUSIONS: IGFBP-7, MMP-2 and DLK-1 levels are related to cardiac function and long-term outcome in TOF patients.

Associations Between Blood Biomarkers, Cardiac Function, and Adverse Outcome in a Young Fontan Cohort.

Background Patients who have undergone the Fontan procedure are at high risk of circulatory failure. In an exploratory analysis we aimed to determine the prognostic value of blood biomarkers in a young cohort who have undergone the Fontan procedure. Methods and Results In multicenter prospective studies patients who have undergone the Fontan procedure underwent blood sampling, cardiopulmonary exercise testing, and stress cardiac magnetic resonance imaging. Several biomarkers including NT-proBNP (N-terminal pro-B-type natriuretic peptide), GDF-15 (growth differentiation factor 15), Gal-3 (galectin-3), ST2 (suppression of tumorigenicity 2), DLK-1 (protein delta homolog 1), FABP-4 (fatty acid-binding protein 4), IGFBP-1 (insulin-like growth factor-binding protein 1), IGFBP-7, MMP-2 (matrix metalloproteinase 2), and vWF (von Willebrand factor) were assessed in blood at 9.6 (7.1-12.1) years after Fontan completion. After this baseline study measurement, follow-up information was collected on the incidence of adverse cardiac events, including cardiac death, out of hospital cardiac arrest, heart transplantation (listing), cardiac reintervention (severe events), hospitalization, and cardioversion/ablation for arrhythmias was collected and the relation with blood biomarkers was assessed by Cox proportional hazard analyses. The correlation between biomarkers and other clinical parameters was evaluated. We included 133 patients who have undergone the Fontan procedure, median age 13.2 (25th, 75th percentile 10.4-15.9) years, median age at Fontan 3.2 (2.5-3.9) years. After a median follow-up of 6.2 (4.9-6.9) years, 36 (27.1%) patients experienced an event of whom 13 (9.8%) had a severe event. NT-proBNP was associated with (all) events during follow-up and remained predictive after correction for age, sex, and dominant ventricle (hazard ratio, 1.89; CI, 1.32-2.68). The severe event-free survival was better in patients with low levels of GDF-15 (P=0.005) and vWF (P=0.008) and high levels of DLK-1 (P=0.041). There was a positive correlation (ß=0.33, P=0.003) between DLK-1 and stress cardiac magnetic resonance imaging functional reserve. Conclusions NT-proBNP, GDF-15, vWF, DLK-1, ST-2 FABP-4, and IGFBP-7 levels relate to long-term outcome in young patients who have undergone the Fontan procedure.

Severe Acute Respiratory Syndrome Coronavirus 2 Placental Infection and Inflammation Leading to Fetal Distress and Neonatal Multi-Organ Failure in an Asymptomatic Woman.

BACKGROUND: In general, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy is not considered to be an increased risk for severe maternal outcomes but has been associated with an increased risk for fetal distress. Maternal-fetal transmission of SARS-CoV-2 was initially deemed uncertain; however, recently a few cases of vertical transmission have been reported. The intrauterine mechanisms, besides direct vertical transmission, leading to the perinatal adverse outcomes are not well understood. METHODS: Multiple maternal, placental, and neonatal swabs were collected for the detection of SARS-CoV-2 using real-time quantitative polymerase chain reaction (RT-qPCR). Serology of immunoglobulins against SARS-CoV-2 was tested in maternal, umbilical cord, and neonatal blood. Placental examination included immunohistochemical investigation against SARS-CoV-2 antigen expression, with SARS-CoV-2 ribonucleic acid (RNA) in situ hybridization and transmission electron microscopy. RESULTS: RT-qPCRs of the oropharynx, maternal blood, vagina, placenta, and urine were all positive over a period of 6 days, while breast milk, feces, and all neonatal samples tested negative. Placental findings showed the presence of SARS-CoV-2 particles with generalized inflammation characterized by histiocytic intervillositis with diffuse perivillous fibrin depositions with damage to the syncytiotrophoblasts. CONCLUSIONS: Placental infection by SARS-CoV-2 leads to fibrin depositions hampering fetal-maternal gas exchange with resulting fetal distress necessitating a premature emergency cesarean section. Postpartum, the neonate showed a fetal or pediatric inflammatory multisystem-like syndrome with coronary artery ectasia temporarily associated with SARS-CoV-2 for which admittance and care on the neonatal intensive care unit (NICU) were required, despite being negative for SARS-CoV-2. This highlights the need for awareness of adverse fetal and neonatal outcomes during the current coronavirus disease 2019 pandemic, especially considering that the majority of pregnant women appear asymptomatic.

Long-term follow-up after transatrial-transpulmonary repair of tetralogy of Fallot: influence of timing on outcome.

OBJECTIVES: Our goal was to report the long-term serial follow-up after transatrial-transpulmonary repair of tetralogy of Fallot (TOF) and to describe the influence of the timing of the repair on outcome. METHODS: We included all patients with TOF who had undergone transatrial-transpulmonary repair between 1970 and 2012. Records were reviewed for patient demographics, operative details and events during the follow-up period (death, pulmonary valve replacement, cardiac reinterventions and hospitalization/intervention for arrhythmias). In patients with elective early primary repair of TOF after 1990, a subanalysis of the optimal timing of TOF repair was performed. RESULTS: A total of 453 patients were included (63% male patients; 65% had transannular patch); 261 patients underwent primary elective repair after 1990. The median age at TOF repair was 0.7 years (25th-75th percentile 0.3-1.3) and decreased from 1.7 to 0.4 years from before 1990 to after 2000, respectively (P < 0.001). The median follow-up duration after TOF repair was 16.8 years (9.6-24.7). Events developed in 182 (40%) patients. In multivariable analysis, early repair of TOF (<6 months) [hazard ratio (HR) 3.06; P < 0.001] and complications after TOF repair (HR 2.18; P = 0.006) were found to be predictive for an event. In a subanalysis of the primary repair of TOF after 1990, the patients (n = 125) with elective early repair (<6 months) experienced significantly worse event-free survival compared to patients who had elective repair later (n = 136). In multivariable analysis, early repair (HR 3.00; P = 0.001) and postoperative complications (HR 2.12; P = 0.010) were associated with events in electively repaired patients with TOF. CONCLUSIONS: Transatrial-transpulmonary repair of TOF before the age of 6 months may be associated with more events during the long-term follow-up period.

A case report on endarteritis in a child with coarctation of aorta.

Coarctation of aorta(CoA), complicated by endarteritis in a children is very rare. Here we present a case of endarteritis in an unoperated CoA in a four year old boy. CoA had been diagnosed in the referring hospital, yet the diagnosis of endocarditis distal to CoA, was made in the tertiary center using modified transthoracic echo windows or focused views. After six weeks of intravenous antibiotic treatment, a coarctectomy and end-to-end anastomosis was performed and he recovered clinically well. This case report concludes that echocardiography remains as the standard diagnostic method for identifying intracardiac manifestations of infective endocarditis/endarteritis. Last but foremost, it delineates the importance of modified transthoracic echo windows or focused views in identifying the unusual position of endocarditis.

Reference values for two-dimensional myocardial strain echocardiography of the left ventricle in healthy children.

BACKGROUND: Myocardial deformation by speckle tracking echocardiography provides additional information on left ventricular function. Values of myocardial deformation (strain and strain rate) depend on the type of ultrasound machine and software that is used. Normative values for QLAB (Philips) are scarce, especially for children. It is important to evaluate the influence of age and body size on myocardial deformation parameters, since anthropometrics strongly influence many standard echocardiographic parameters. The aim of this study was to provide comprehensive normal values for myocardial deformation of the left ventricle using a Philips platform and to evaluate the association with anthropometric and standard echocardiographic parameters. METHODS: Healthy children between 1 and 18 years of age were prospectively examined using a standard echocardiographic protocol. Short-axis and apical four-chamber, two-chamber, and three-chamber views were used to measure peak systolic circumferential and longitudinal strain and systolic and early diastolic strain rate of the left ventricle using dedicated software. RESULTS: A total of 103 children were included with a mean age of 10.8 and inter-quartile range 7.3-14.3 years. Global circumferential strain values (±SD) were -24.2±3.5% at basal, -25.8±3.5% at papillary muscle, and -31.9±6.2% at apex levels. Global left ventricular longitudinal strain values were -20.6±2.6% in apical four-chamber view, -20.9±2.7% in apical two-chamber, and -21.0 ±2.7% in apical three-chamber. Age was associated with longitudinal strain, longitudinal systolic and early diastolic strain rate, but not with circumferential strain. CONCLUSIONS: Normal values for left ventricular deformation parameters in children are obtained using a Philips platform. Age partly explains normal variation of strain and strain rate.

Right ventricular function in infants with bronchopulmonary dysplasia and pulmonary hypertension: a pilot study.

Premature birth and bronchopulmonary dysplasia (BPD) are risk factors for the development of echocardiographic signs of pulmonary hypertension (PH) and are associated with changes in cardiac structure and function. It is unclear whether this association persists beyond early infancy. The aims of this study are to prospectively investigate the prevalence of PH in children with severe BPD and to investigate the effect of BPD and PH on myocardial structure and function at six months corrected age. Preterm infants (gestational age ≤ 32 weeks) with severe BPD were included. Echocardiography was used to define PH and to measure speckle tracking derived longitudinal and circumferential strain of the left ventricle (LV) and right ventricle (RV). Sixty-nine infants with a median (interquartile range [IQR]) gestational age of 25.6 (24.9-26.4) weeks and a median birthweight of 770 (645-945) gram were included. Eight (12%) infants had signs of PH at six months corrected age. RV fractional area change was lower in infants with severe BPD and PH at six months compared to infants without PH (35% ± 9% vs. 43% ± 9%, P = 0.03). RV mean longitudinal systolic strain was lower in infants with severe BPD and PH compared to infants without PH (17.6% [-19.5%/-16.1%] vs. -20.9% [-25.9%/-17.9%], P = 0.04). RV size and LV longitudinal and circumferential strain in children with BPD with or without PH were similar. Signs of PH were found in 12% of infants with severe BPD at six months corrected age and the presence of PH is associated with reduced RV systolic function.

Cardiac outcome in classic infantile Pompe disease after 13 years of treatment with recombinant human acid alpha-glucosidase.

BACKGROUND: Cardiac failure is the main cause of death in untreated classic infantile Pompe disease, an inheritable metabolic myopathy characterized by progressive hypertrophic cardiomyopathy. Since the introduction of enzyme replacement therapy (ERT), survival has increased significantly due to reduced cardiac hypertrophy and improved cardiac function. However, little is known about ERT's long-term effects on the heart. METHODS: Fourteen patients were included in this prospective study. Cardiac dimensions, function, conduction and rhythm disturbances were evaluated at baseline and at regular intervals thereafter. RESULTS: Treatment duration ranged from 1.1 to 13.9 years (median 4.8 years). At baseline, all patients had increased left ventricular mass index (LVMI) (median LVMI 226 g/m2, range 98 to 599 g/m2, Z-score median 7, range 2.4-12.4). During the first four weeks, LVMI continued to increase in six patients. Normalization of LVMI was observed in 13 patients (median 30 weeks; range 3 to 660 weeks). After clinical deterioration, LVMI increased again slightly in one patient. At baseline, PR interval was shortened in all patients; it normalized in only three. A delta-wave pattern on ECG was seen in six patients and resulted in documented periods of supraventricular tachycardias (SVTs) in three patients, two of whom required medication and/or ablation. One patient had severe bradycardia (35 beats/min). CONCLUSION: This study shows that ERT significantly reduced LVMI, and sustained this effect over a period of 13.9 years. The risk for rhythm disturbances remains. Regular cardiac evaluations should be continued, also after initially good response to ERT.

Normal myocardial strain values using 2D speckle tracking echocardiography in healthy adults aged 20 to 72 years.

AIMS: Evaluation of left ventricular (LV) myocardial deformation by speckle tracking echocardiography (STE) is useful for clinical and research purposes. However, strain measurements depend on the used software. Normative data for QLAB 10 (Philips) are scarce. Additionally, little is known about the influence of anthropometric factors. We aimed to establish normal adult STE-derived strain and strain rate values and to evaluate associations with anthropometrics. METHODS: One hundred fifty-five healthy subjects aged 20 to 72 years (≥28 subjects per decile) were prospectively gathered and examined with electrocardiography and two-dimensional echocardiography. With STE, we assessed peak systolic LV global longitudinal strain (GLS), segmental longitudinal strain, and strain rate from the three standard apical views. RESULTS: We included 147 healthy subjects (age 44.6±13.7 years, 50% female, GLS -20.8±2.0%). Men had significantly lower GLS than women (-20.1±1.8% vs -21.5±2.0%, P<.001). GLS was significantly lower in subjects with age above 55 years (P=.029), higher blood pressure (P<.001), higher body surface area (BSA, P<.001), larger LV end-systolic and end-diastolic volumes (both P<.001), lower LV ejection fraction (P<.001), and some indices of diastolic function. After multivariable regression analysis, the correlation with systolic blood pressure, E-wave, and LV end-systolic volume remained significant. The systolic strain rates of most segments correlated with BSA. CONCLUSIONS: Our study resulted in normative LV GLS values assessed with QLAB 10. Male sex, higher BSA, and higher blood pressure negatively influence GLS. Therefore, these factors should be taken into account for strain interpretation in clinical practice.

Regional ventricular performance and exercise training in children and young adults after repair of tetralogy of Fallot: randomized controlled pilot study.

BACKGROUND: Public-health guidelines recommend patients with congenital heart disease to exercise. Studies have shown that patients with congenital heart disease can improve physical exercise capacity. The effect of training on regional ventricular performance has hardly been studied. We performed a pilot study to assess whether an exercise training program would result in adverse changes of regional ventricular performance in patients with corrected tetralogy of Fallot. METHODS AND RESULTS: Multicenter prospective randomized controlled pilot study in patients with tetralogy of Fallot aged 10 to 25 years. A 12-week standardized aerobic dynamic exercise training program (3 one-hour sessions per week) was used. Pre- and post-training cardiopulmonary exercise tests, MRI, and echocardiography, including tissue-Doppler imaging, were performed. Patients were randomized to the exercise group (n=28) or control group (n=20). One patient in the exercise group dropped out. Change in tissue-Doppler imaging parameters was similar in the exercise group and control group (change in right ventricle free wall peak velocity E' exercise group, 0.8±2.6 cm/s; control group, 0.9±4.1; peak velocity A' exercise group, 0.4±2.4 m/s; control group 4.6±18.1 cm/s). CONCLUSIONS: This randomized controlled pilot study provides preliminary data suggesting that regional ventricular performance is well maintained during 3-month aerobic dynamic exercise training in children and young adults with repaired tetralogy of Fallot. This information might help patients adhere to current public-health guidelines. CLINICAL TRIAL REGISTRATION: URL: http//:www.trialregister.nl. Unique identifier: NTR2731.

Impact of childhood obesity on cardiac structure and function.

OPINION STATEMENT: Obesity prevalence is still on the rise worldwide in both adults and children. In adults, obesity is a significant cardiovascular risk factor associated with increased morbidity and mortality. In children and adolescents this is more controversial, but early changes in cardiovascular function have been observed with possible long-term implications. In this review, we focus on the cardiac impact of childhood obesity. Obese children have been shown to have larger left atrial and ventricular dimensions, and increased left ventricular mass compared to normal weight controls. In contrast to the adult population, heart failure and significant ventricular dysfunction with reduced ejection fraction has not been reported in obese children. Several studies suggest the presence of sub-clinical myocardial dysfunction with reduced tissue Doppler velocities and myocardial deformation (strain and strain rate) in obese children. These early myocardial changes are associated with a variety of risk factors, such as systemic hypertension, diabetes, and lipid abnormalities (metabolic syndrome). As the long-term effect of these early changes is uncertain, and only very limited data are available on the effect of weight reduction and lifestyle changes on myocardial functional parameters, no interventional strategies are currently recommended.

Interaction between myocardial and vascular changes in obese children: a pilot study.

BACKGROUND: Changes in vascular and myocardial structure and function have been demonstrated in obese children, but limited data are available on how these changes are related. The aims of this study were to investigate vascular and myocardial changes in obese children with lipid abnormalities and to study the interactions between vascular and myocardial parameters. METHODS: A cross-sectional, prospective observational study was conducted. Twenty-one obese and 27 normal-weight controls aged 14 ± 2 years participated. Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) analysis by color tissue Doppler and speckle-tracking echocardiography. Vascular assessment included carotid intima-media thickness, flow-mediated dilatation, pulse-wave velocity, and other stiffness measures of the aorta and carotid artery, as well as noninvasive estimation of arterial elastance and left ventricular (LV) end-systolic elastance. RESULTS: Obese children compared with controls had lower color tissue Doppler-derived LV systolic radial strain values (45 ± 11% vs 56 ± 12%, P = .002), lower speckle-tracking echocardiography-derived LV systolic longitudinal strain values (-18 ± 2% vs -21 ± 2%, P < .001), and lower speckle-tracking echocardiography-derived LV early diastolic strain rate values (1.7 ± 0.3 vs 2.5 ± 0.4, P < .001). Carotid intima-media thickness was increased, pulse-wave velocity was faster, and arterial distension coefficients were lower in obese children. The ratio of arterial elastance to LV end-systolic elastance (a marker of ventricular-arterial coupling) was lower in obese children than controls (0.73 ± 0.32 vs 0.47 ± 0.15, P = .003). Changes in vascular parameters were correlated with changes in longitudinal myocardial deformation parameters. CONCLUSIONS: Obese children with lipid abnormalities have reduced systolic and diastolic LV deformation characteristics, early vessel wall changes, and increased arterial stiffness. Abnormal ventricular-vascular interaction is suggested by these data and warrants further investigation.

Assessment of myocardial deformation in children using Digital Imaging and Communications in Medicine (DICOM) data and vendor independent speckle tracking software.

BACKGROUND: Analysis of myocardial deformation from data stored in Digital Imaging and Communications in Medicine format using vendor-independent software may be useful for clinical and research purposes but has not been evaluated in children. METHODS: Grayscale images were prospectively acquired on Vivid 7 (GE Healthcare) and iE33 (Philips Medical Systems) ultrasound systems in 49 children. Digital Imaging and Communications in Medicine and raw data were analyzed using vendor-independent software (Cardiac Performance Analysis, Tomtec Imaging Systems) and vendor-specific software (EchoPAC and QLAB) and results compared. In addition, vendor-independent software using images at 30 frames/sec were compared with images at the higher acquisition frame rate. RESULTS: Measurement of short-axis radial and circumferential strain (ε) and apical four-chamber longitudinal ε by vendor-independent software was possible in >92% of the children. Intraobserver and interobserver coefficients of variation for global circumferential and longitudinal ε ranged from 7.1% to 15.3% and for radial ε from 23.9% to 30.2%. Strain values were somewhat higher when using GE images at acquisition frame rates compared with ε values using GE images stored at 30 frames/sec. Strain values obtained by vendor-independent software were comparable with those obtained by vendor-specific software for longitudinal ε and higher for circumferential ε. Radial ε values obtained by vendor-independent software were lower than ε values by EchoPAC and higher than ε values by QLAB. CONCLUSIONS: Vendor-independent software-derived ε is feasible and potentially valuable for measuring myocardial deformation in research and in multicenter studies using images from different ultrasound systems, especially for longitudinal deformation. However, a systematic bias for circumferential ε and a high variability in radial ε measurements remain concerns.

Myocardial tissue Doppler velocity imaging in children: comparative study between two ultrasound systems.

BACKGROUND: The investigators compared pulsed-wave tissue Doppler (PWTD) and color tissue Doppler (CTD) ventricular tissue velocities obtained using Vivid 7 (GE) and iE33 (Philips) ultrasound systems within a 30-minute time frame and examined interobserver and intraobserver variability. METHODS: Longitudinal PWTD and CTD images were prospectively acquired in 49 children from the base of the right and left ventricular free wall and septum and stored for offline analysis. RESULTS: Intraobserver and interobserver coefficients of variation for PWTD velocities ranged from 4% to 6% and 5% to 10% for GE and from 1% to 10% and 2% to 14% for Philips, respectively. Intraobserver and interobserver coefficients of variation for CTD velocities ranged from 4% to 15% and 6% to 24% for GE and from 6% to 19% and 7% to 25% for Philips, respectively. Mean biases between the two systems for PWTD velocities, expressed as percentage differences, were around 0%, with the narrowest limits of agreement for systolic velocities at the septal annulus and the widest limits of agreement for early diastolic velocities at the lateral tricuspid valve annulus, respectively. Peak CTD-derived velocities were significantly and consistently lower for Philips compared with GE. CONCLUSIONS: Agreement between GE-derived and Philips-derived PWTD velocities was reasonable, whereas CTD-derived velocities differed substantially.

Comparison between different speckle tracking and color tissue Doppler techniques to measure global and regional myocardial deformation in children.

BACKGROUND: Myocardial deformation parameters obtained by speckle-tracking echocardiography (STE) and color Doppler tissue imaging (CDTI) using two different ultrasound systems and three different software packages were compared. METHODS: Apical four-chamber, short-axis grayscale, and color Doppler tissue images were prospectively acquired using Vivid 7 and iE33 ultrasound systems in 34 children and then analyzed using EchoPAC and QLAB (STE) and SPEQLE (CDTI). RESULTS: Measurement of myocardial deformation was feasible for all three modalities. Longitudinal strain (epsilon) measurements showed the lowest intraobserver and interobserver variability (intraobserver and interobserver coefficients of variation, 9% and 8% for EchoPAC, 5% and 6% for QLAB, and 14% and 16% for SPEQLE). In addition, longitudinal epsilon had a small bias and narrow limits of agreement when comparing different techniques. The coefficients of variation of circumferential epsilon by EchoPAC and QLAB were 12% and 11% (intraobserver) and 9% and 13% (interobserver), respectively. Circumferential epsilon by STE had a small systematic bias but relatively narrow limits of agreement. The reproducibility of radial epsilon measurements using STE was low, while CDTI epsilon provided better performance (intraobserver and interobserver coefficients of variation for radial posterior epsilon, 12% and 24% for EchoPAC, 39% and 56% for QLAB, and 12% and 14% for SPEQLE). Radial epsilon was on average 50% lower using QLAB compared with EchoPAC and SPEQLE. Systolic strain rate values obtained by STE were lower compared with CDTI-derived values. The limits of agreement for strain rate values among the three modalities were wide, and intraobserver and interobserver variability was poor for all three modalities. CONCLUSIONS: Some deformation measurements (e.g., longitudinal and circumferential epsilon) are comparable among different ultrasound machines and software packages, whereas others are significantly different (e.g., radial epsilon and strain rate). This study stresses the need for an industry standard for these techniques.