2024 SIAC guidelines on cardiorespiratory rehabilitation in pediatric patients with congenital heart disease.

The 2024 Interamerican Society of Cardiology (SIAC) guidelines on cardiorespiratory rehabilitation (CRR) in pediatric patients with congenital heart disease aim to gather and evaluate all relevant evidence available on the topic to unify criteria and promote the implementation of CRR programs in this population in Latin America and other parts of the world. Currently, there is no unified CRR model for the pediatric population. Consequently, our goal was to create these CRR guidelines adapted to the characteristics of congenital heart disease and the physiology of this population, as well as to the realities of Latin America. These guidelines are designed to serve as a support for health care workers involved in the care of this patient group who wish to implement a CRR program in their workplace. The guidelines include an easily reproducible program model that can be implemented in any center. The members of this Task Force were selected by the SIAC on behalf of health care workers dedicated to the care of pediatric patients with congenital heart disease. To draft the document, the selected experts performed a thorough review of the published evidence.

Textile-based Wearable to Monitor Heart Activity in Paediatric Population: A Pilot Study.

Background: Cardiac monitoring for children with heart disease still employs common clinical techniques that require visits to hospital either in an ambulatory or inpatient setting. Frequent cardiac monitoring, such as heart rate monitoring, can limit children's physical activity and quality of life. The main objective of this study is to evaluate the performance of a textile-based device (SKIIN) in measuring heart rate (HR) in different tasks: lying down, sitting, standing, exercising, and cooling down. Methods: Twenty participants including healthy children and children with heart disease were included in this study. The difference between the HRs recorded by the SKIIN was compared with a reference electrocardiogram collection by normalized root mean squared error. Participants completed a questionnaire on their experience wearing the textile device with additional parental feedback on the textile device collected. Results: Participants had the median age of 14 years (range: 10-17 years), with body mass index 23.1 ± 3.8 kg/m2 and body surface area 1.70 ± 0.25 m2. The HR recorded by SKIIN and reference system significantly changes between tasks (P < 0.001), while not significantly different from each other (P > 0.05). The normalized root mean squared error was 3.8% ± 3.0% and 3.6% ± 3.7% for healthy and the heart disease groups, respectively. All participants found the textile device non-irritating and easy to wear. Conclusions: This study provides proof of concept that HR can be robustly and conveniently monitored by smart textiles, with similar accuracy to standard-of-care devices.

Contexte: Encore aujourd'hui, la surveillance cardiaque chez les enfants atteints de cardiopathie repose sur des techniques cliniques courantes qui doivent être réalisées à l'hôpital, en soins ambulatoires ou en contexte d'hospitalisation. Chez les enfants, la surveillance cardiaque répétée, comme c'est le cas pour la fréquence cardiaque (FC), peut limiter leurs activités physiques et leur qualité de vie. La présente étude évalue principalement la performance d'un dispositif textile (SKIIN) dans la mesure de la FC pendant différentes tâches : en position couchée, en position assise, en position debout, pendant l'activité physique et pendant le retour au calme. Méthodologie: Vingt participants, y compris des enfants en santé et des enfants présentant une cardiopathie, ont été inclus dans l'étude. La différence entre la FC enregistrée par le dispositif SKIIN et la FC mesurée par une électrocardiographie (ECG) de référence a été comparée à l'aide de la racine de l'erreur quadratique moyenne normalisée (REQMN). Les participants ont rempli un questionnaire sur leur expérience avec le dispositif textile, et les commentaires des parents sur ce dispositif ont été recueillis. Résultats: Les participants avaient un âge médian de 14 ans [10-17 ans], un indice de masse corporelle de 23,1 ± 3,8 kg/m2 et une surface corporelle de 1,70 ± 0,25 m2. La FC enregistrée par le système SKIIN et le système de référence variait significativement d'une tâche à l'autre (p < 0,001), mais il n'y avait pas de différence significative entre les deux systèmes (p > 0,05). La REQMN était de 3,8 ± 3,0 % pour le groupe en santé et de 3,6 ± 3,7 % pour le groupe présentant une cardiopathie. Tous les participants ont trouvé que le dispositif textile ne causait pas d'irritation et qu'il était facile à porter. Conclusions: Cette étude démontre que les textiles intelligents permettent de surveiller la FC de façon fiable et pratique, avec une exactitude semblable à celle des dispositifs de référence.

The Role of Cardiopulmonary Testing to Risk Stratify Tetralogy of Fallot Patients.

Neonatal repair has completely changed the clinical history of patients with tetralogy of Fallot (ToF); however, these patients carry a significant risk of severe arrhythmias and sudden cardiac death in the long term. The exact mechanism for late sudden cardiac death is multifactorial and still not well defined, and the risk stratification for primary prophylaxis in these patients remains challenging. Cardiopulmonary exercise testing (CPET) is a well-established and safe method to assess cardiopulmonary function in children and adults with congenital heart disease. Several parameters obtained with CPET have been identified as potential prognostic of major adverse cardiovascular events in congenital heart disease. CPET is routinely used to assess functional capacity also in patients with ToF, and there is some evidence showing its usefulness in predicting the cardiac adverse events in patients with repaired ToF. Current guidelines recognize the importance of CPET in the evaluation and management of patients with ToF, but there is no clear consensus on which the CPET parameter or level of exercise intolerance, as measured by CPET, is truly predictive of an increased risk of arrhythmia and major adverse cardiovascular events in this population. Therefore, the aim of this narrative review is to describe the current evidence on the potential use of CPET in the risk stratification of patients with repaired ToF.

La chirurgie réparatrice néonatale a complètement changé le parcours clinique des patients nés avec une tétralogie de Fallot (TF). Ces patients demeurent toutefois exposés à un risque important d'arythmie sévère et de mort cardiaque subite (MCS) à long terme. Le mécanisme causal exact de la MCS tardive est multifactoriel et demeure mal défini, ce qui complique la stratification du risque pour le traitement préventif primaire chez ces patients. L'épreuve d'effort cardiorespiratoire (EECR) est une méthode sécuritaire et bien établie pour évaluer la fonction cardiopulmonaire des enfants et des adultes atteints de cardiopathie congénitale (CC). Plusieurs paramètres obtenus lors d'une EECR ont été décrits comme des marqueurs pronostiques potentiels d'événements cardiovasculaires indésirables majeurs (ECIM) en contexte de CC. L'EECR est couramment utilisée pour évaluer la capacité fonctionnelle des patients atteints de TF et des données probantes démontrent son utilité pour prédire les manifestations cardiaques défavorables chez les patients opérés d'une TF. Les lignes directrices en vigueur conviennent de l'importance de l'EECR dans l'évaluation et la prise en charge des patients opérés d'une TF, mais il n'existe aucun consensus clair sur le paramètre ou le seuil d'intolérance à l'effort mesuré par l'EECR qui possède une réelle valeur prédictive d'un risque élevé d'arythmie et d'ECIM dans cette population. L'objectif de la présente synthèse narrative est de décrire les données probantes actuelles sur l'utilisation potentielle de l'EECR dans la stratification du risque chez les patients opérés d'une TF.

Non-invasive MR imaging techniques for measuring femoral arterial flow in a pediatric and adolescent cohort.

Magnetic Resonance Imaging (MRI) is well-suited for imaging peripheral blood flow due to its non-invasive nature and excellent spatial resolution. Although MRI is routinely used in adults to assess physiological changes in chronic diseases, there are currently no MRI-based data quantifying arterial flow in pediatric or adolescent populations during exercise. Therefore the current research sought to document femoral arterial blood flow at rest and following exercise in a pediatric-adolescent population using phase contrast MRI, and to present test-retest reliability data for this method. Ten healthy children and adolescents (4 male; mean age 14.8 ± 2.4 years) completed bloodwork and resting and exercise MRI. Baseline images consisted of PC-MRI of the femoral artery at rest and following a 5 × 30 s of in-magnet exercise. To evaluate test-retest reliability, five participants returned for repeat testing. All participants successfully completed exercise testing in the MRI. Baseline flow demonstrated excellent reliability (ICC = 0.93, p = 0.006), and peak exercise and delta rest-peak flow demonstrated good reliability (peak exercise ICC = 0.89, p = 0.002, delta rest-peak ICC = 0.87, p = 0.003) between-visits. All three flow measurements demonstrated excellent reliability when assessed with coefficients of variance (CV's) (rest: CV = 6.2%; peak exercise: CV = 7.3%; delta rest-peak: CV = 7.1%). The mean bias was small for femoral arterial flow. There was no significant mean bias between femoral artery flow visits 1 and 2 at peak exercise. There were no correlations between age or height and any of the flow measurements. There were no significant differences between male and female participants for any of the flow measurements. The current study determined that peripheral arterial blood flow in children and adolescents can be evaluated using non-invasive phase contrast MRI. The MRI-based techniques that were used in the current study for measuring arterial flow in pediatric and adolescent patients demonstrated acceptable test-retest reliability both at rest and immediately post-exercise.

[Physical activity in patients with repaired and unrepaired congenital heart diseases. Task Force for exercise prescription in patients with congenital heart disease of the Italian Society of Pediatric Cardiology and Congenital Heart Disease]. / L'attività fisica nei soggetti con cardiopatia congenita in storia naturale ed operata. Task Force sull'attività fisica nel cardiopatico congenito della Società Italiana di Cardiologia Pediatrica e delle Cardiopatie Congenite.

Regular physical activity is essential for physical health and mental wellbeing in children and teenagers. However, patients with congenital heart disease are often restricted from being physically active due to parental overprotection and lack of physical activity promotion or exercise prescription from their physicians. A comprehensive medical evaluation is crucial for the development of personalized exercise programs for these patients. The aim of this review is to provide physicians with a practical guide on how to promote physical activity and prescribe exercise for patients with congenital heart disease with or without surgical correction.

Congenital central hypoventilation syndrome and ventilatory responses during cardiopulmonary exercise testing.

BACKGROUND: Previous studies have shown evidence of hypoxemia and hypercapnia during cardiopulmonary exercise test (CPET) evaluation in children with congenital central hypoventilation syndrome (CCHS). However, there are no longitudinal studies which compared CPET findings to polysomnogram (PSG) or PHOX2B mutation, to date. OBJECTIVES: To describe the longitudinal CPET findings in a cohort of children with CCHS and correlate the findings to the PSG results. METHODS: This retrospective study was conducted in children with CCHS followed in the Long-term Ventilation Program at SickKids, Toronto, Canada between September, 2013 and January, 2020. CCHS genetic mutation, age of diagnosis, ventilatory support, family history, disease associations of CCHS, CPETs, and PSG parameters were recorded and analyzed. RESULTS: A total of nine patients with CCHS (46 CPETs and 46 PSGs) were enrolled. Four (44.4%) children had polyalanine repeat mutations. The mean (SD) age at the time of diagnosis and duration of ventilatory usage were 3.2 ± 3.4 years and 11.5 ± 2.8 years, respectively. All abnormal CPETs had hypercapnia in at least 1 phase of the exercise test. Hypercapnia (12/46; 26.1%) at peak of exercise was the most common abnormality. None of the children experienced an oxygen desaturation below 90%. End-tidal CO2 (PetCO2 ) at rest and at peak exercise in the CPETs were significantly correlated with PSG TcCO2 while PetCO2 at anaerobic threshold was correlated with CO2 in pre-PSG capillary blood gas. CONCLUSION: Nocturnal hypoventilation may impact the CPET results in CCHS children. Serial CPETs should be considered standard clinical care for all CCHS children.

Sleep-disordered breathing, respiratory patterns during wakefulness and functional capacity in pediatric patients with rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation syndrome.

OBJECTIVE: To characterize the clinical presentation of sleep-disordered breathing and respiratory patterns at rest and during a 6-min walk test (6MWT) in children with rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome. METHODS: Retrospective study of children with ROHHAD who had a diagnostic baseline polysomnography, daytime cardiorespiratory monitoring at rest and a 6MWT. Polysomnography data were also compared with body mass index-, age-, and sex-matched controls. RESULTS: Of the eight children with ROHHAD, all eight (100%) had obstructive sleep apnea (OSA) and 2/8 (25%) had nocturnal hypoventilation (NH) on their baseline polysomnography. Comparing the ROHHAD group to the control group, there were no significant differences in the median (interquartile range [IQR]) obstructive apnea-hypopnea index (11.1 [4.3-58.4] vs. 14.4 [10.3-23.3] events/h, respectively; p = .78). However, children with ROHHAD showed a significantly higher desaturation index compared to the control group (37.9 [13.7-59.8] vs. 14.7 [4.3-27.6] events/h; p = .05). While awake at rest, some children with ROHHAD experienced significant desaturations associated with central pauses. During the 6MWT, no significant desaturations were observed, but two children showed moderate functional limitation. CONCLUSIONS: Among children with ROHHAD, respiratory instability may be demonstrated by a significant number and severity of oxygen desaturations during sleep in the presence of OSA, with or without NH, and oxygen desaturations with central pauses at rest during wakefulness. Interestingly, during daily activities that require submaximal effort, children may not experience oxygen desaturations. Early recognition of respiratory abnormalities and targeted therapeutic interventions are important to limit associated morbidity and mortality in ROHHAD.

Non-invasive imaging techniques to assess myocardial perfusion.

INTRODUCTION: Coronary artery disease affecting myocardial perfusion continues to be the leading cause of cardiovascular morbidity and mortality worldwide. While invasive evaluation based on coronary angiography and flow measurements still is considered the reference technique for assessing myocardial perfusion, technological evolutions in noninvasive imaging techniques resulted in them playing a more important role in assessing myocardial perfusion influencing therapeutic decision-making and prognostication. AREAS COVERED: Different imaging modalities are used to evaluate coronary perfusion, including echocardiography, coronary computerized tomography scan, magnetic resonance imaging, and nuclear myocardial perfusion imaging. Through a combination of different techniques, it is possible to describe coronary artery anatomy and the diameter of the epicardial vessels but more recently also of the coronary microcirculation. Quantification of myocardial perfusion is feasible both at baseline and during pharmacological or physiological stress. EXPERT OPINION: The objective of this state-of-the-art paper is to review the recent evolutions in imaging methods to estimate myocardial perfusion and to discuss the diagnostic strengths and limitations of the different techniques. The new ultrasound technologies and the hybrid approaches seem to be the future is these fields.

Physical Activity Promotion in Pediatric Congenital Heart Disease: Are We Running Late?

Low levels of habitual physical activity in children and adolescents with congenital heart disease (CHD) leads to various negative health outcomes, yet review of the literature indicates that many physicians, caregivers, and patients restrict physical activity owing to safety concerns. There is no evidence supporting absolute restriction of physical activity in pediatric patients with CHD; in fact, physically active lifestyles are as important for pediatric patients living with CHD as for the general population. To encourage long-term maintenance of physically active lifestyles, physical activity counselling and exercise prescription should be started early in childhood and be a core component of every patient encounter. Physical activity counselling should include clear messaging from physicians about recommended physical activities-not just restrictions-and a personalised written exercise prescription for the patient and family. Regular follow-up is essential to ensure adherence to recommendations, monitor patient responses to the increased physical activity level, and long-term surveillance. This review discusses the importance of a physically active lifestyle in children and adolescents with and without surgically repaired CHD and hypertrophic cardiomyopathy, excluding those with electrical abnormalities and channelopathies. It outlines gaps in knowledge regarding best practices for physical activity promotion in these patient populations, and provides recommendations on how to include physical activity promotion and exercise prescription in clinical practice based on existing literature. An important role for clinicians is identified, because the type of messaging they provide regarding physical activity will have a major impact on patients' and families' decisions to adopt an active lifestyle.

Left ventricular remodelling in long-term survivors after the arterial switch operation for transposition of the great arteries.

Aims: The objective of this study was to quantify imaging markers of myocardial fibrosis and assess myocardial function in long-term transposition of the great arteries survivors after the arterial switch operation (ASO). Methods and results: Paediatric ASO patients were prospectively studied by cardiac magnetic resonance imaging, including first-pass myocardial perfusion, late gadolinium enhancement, and T1 relaxometry, as well as echocardiography for left ventricular (LV) systolic and diastolic function including strain analysis, with comparison to healthy controls. Thirty ASO patients (mean age 15.4 ± 2.9 years vs. 14.1 ± 2.6 years in 28 controls, P = 0.04) were included. Patients had normal LV ejection fraction (EF) (57 ± 5% vs. 59 ± 5%, P = 0.07), but end-diastolic and end-systolic volumes were increased (104 ± 20 mL/m2 vs. 89 ± 10 mL/m2, P < 0.01 and 46 ± 13 mL/m2 vs. 36 ± 7 mL/m2, P < 0.01, respectively). Longitudinal strain at two-, three-, and four-chamber levels of the LV were lower in ASO patients (-19.0 ± 2.6% vs. -20.9 ± 2.3%, P = 0.006, -17.7 ± 2.0% vs. -19.1 ± 2.4%, P = 0.02, and -18.9 ± 1.9% vs. -20.1 ± 1.7%, P = 0.01, respectively), while circumferential strain was higher at all short-axis levels (-24.6 ± 2.3% vs. -19.3 ± 1.6%, P < 0.001 at the mid-ventricular level). LV native T1 times were higher in ASO patients (1042 ± 27 ms vs. 1011 ± 27 ms, P < 0.01) and correlated with LV mass/volume ratio (R = 0.60, P < 0.001). Myocardial scarring or myocardial perfusion defects were not observed in our cohort. Conclusion: Children and adolescents after ASO have normal LV systolic function, in line with their overall good clinical health. At a myocardial level however, imaging markers of diffuse myocardial fibrosis are elevated, along with an altered LV contraction pattern. Whether these abnormalities will progress into future clinically significant dysfunction and whether they are harbingers of adverse outcomes remains to be studied.

Ventricular Torsion in Young Patients With Single-Ventricle Anatomy.

BACKGROUND: In normal left ventricles, clockwise basal rotation and counterclockwise apical rotation result in systolic torsion. Torsion is important for contractile efficiency and may be especially important in single-ventricle (SV) physiology. However, little is known about torsion in patients with SVs. The aim of this study was to measure torsion in SVs and to determine its relationship with other measures of ventricular function. The hypothesis was that torsion would be decreased in all SVs, most significantly in single right ventricles, and that it would correlate with other measures of ventricular function. METHODS: A prospective cross-sectional study was performed in 61 patients with SVs undergoing pre- or post-Fontan cardiac catheterization and 30 matched control subjects. Echocardiography, catheterization, and cardiac magnetic resonance imaging were performed under the same anesthetic. Torsion and strain were measured using speckle-tracking echocardiography. Intracardiac pressures, pulmonary vascular resistance, and cardiac magnetic resonance imaging-derived ventricular volume and ejection fraction were measured. RESULTS: Thirty-five patients were left ventricular dominant, 15 were right ventricular dominant, 10 were codominant, and one had indeterminate morphology. Thirty-seven patients were pre-Fontan and 24 were post-Fontan. Patients with SVs had similar overall torsion as control subjects (median, 1.7°/cm vs 1.65°/cm; P = NS); however, they had decreased or reversed basal rotation (-0.32°/cm vs -0.93°/cm, P < .0001) and increased apical rotation (1.45°/cm vs 1.06°/cm, P = .0065). There were no differences on the basis of ventricular dominance or palliative stage. Torsion did not significantly correlate with other echocardiographic, catheter-based, or cardiac magnetic resonance imaging measures of cardiac function. CONCLUSIONS: Single left and right ventricles exhibit preserved torsion, mainly because of preserved or increased apical rotation. Possible mechanisms of torsion in single right ventricles include myofiber remodeling and altered ventricular-ventricular interactions. Understanding myocardial deformation in SVs will improve the ability to interpret ventricular function in this precarious population.

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

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

The role of echocardiography in Kawasaki disease.

Kawasaki disease (KD) is an acute, self-limited vasculitis affecting young children. It can result in coronary artery abnormalities in a significant proportion of patients, especially if the diagnosis is missed or treatment gets delayed. Echocardiography is the imaging modality of choice for detection of coronary artery abnormalities and assessment of myocardial function. It is also useful for characterization and risk stratification of patients with KD. Echocardiography should be performed at the time of diagnosis and then again at 1-2 weeks and 4-6 weeks after treatment, for uncomplicated cases who do not have significant coronary artery involvement. Use of a standardized imaging protocol is necessary to detect and characterize coronary artery abnormalities, including standardization of measurements (Z scores). For patients with evolving abnormalities, more frequent assessment is necessary in order to detect thromboses in aneurysms. Long-term prognosis and management is dependent on both the maximal and current Z scores of aneurysms. Patients with large or giant aneurysms (i.e., Z score ≥ 10) are at the highest risk of both thrombosis and stenosis. Such patients need careful follow-up for subsequent cardiovascular events. Many of them would be candidates for advanced cardiovascular imaging and may require revascularization therapy. Serial echocardiography plays a key role in surveillance. In addition, stress echocardiography has proven useful as a modality to assess for inducible myocardial ischemia. Intravascular ultrasound has been recommended for functional and structural assessment of coronary arteries in children with KD.

Skeletal Muscle Metabolic Dysfunction in Patients With Malignant Hyperthermia Susceptibility.

BACKGROUND: Malignant hyperthermia (MH), a pharmacogenetic disorder of skeletal muscle, presents with a potentially lethal hypermetabolic reaction to certain anesthetics. However, some MH-susceptible patients experience muscle weakness, fatigue, and exercise intolerance in the absence of anesthetic triggers. The objective of this exploratory study was to elucidate the pathophysiology of exercise intolerance in patients tested positive for MH with the caffeine-halothane contracture test. To this end, we used phosphorus magnetic resonance spectroscopy, blood oxygen level-dependent functional magnetic resonance imaging (MRI), and traditional exercise testing to compare skeletal muscle metabolism in MH-positive patients and healthy controls. METHODS: Skeletal muscle metabolism was assessed using phosphorus magnetic resonance spectroscopy and blood oxygen level-dependent functional MRI in 29 MH-positive patients and 20 healthy controls. Traditional measures of physical capacity were employed to measure aerobic capacity, anaerobic capacity, and muscle strength. RESULTS: During 30- and 60-second exercise, MH-positive patients had significantly lower ATP production via the oxidative pathway compared to healthy controls. MH-positive patients also had a longer recovery time with blood oxygen level-dependent functional MRI compared to healthy controls. Exercise testing revealed lower aerobic and anaerobic capacity in MH-positive patients compared to healthy controls. CONCLUSIONS: Results of this exploratory study suggest that MH-positive patients have impaired aerobic metabolism compared to healthy individuals. This could explain the exercise intolerance exhibited in MH-susceptible patient population.

Systolic and Diastolic Myocardial Response to Exercise in a Healthy Pediatric Cohort.

BACKGROUND: The aims of the present study were to evaluate the feasibility and reproducibility of color Doppler tissue imaging (DTI) and two-dimensional speckle-tracking echocardiography during semisupine cycle ergometric stress echocardiography and to establish normal myocardial systolic and diastolic left ventricular (LV) and right ventricular (RV) response to exercise in children. METHODS: This was a single-center prospective study of 62 healthy children (35 girls). The median age was 14 years (range, 8-19 years). A stepwise semisupine cycle ergometric protocol was used. Color DTI peak systolic (s') and peak diastolic (e') velocities and myocardial acceleration during isovolumic contraction were measured in the LV lateral wall, RV free wall, and septum. Early mitral inflow Doppler (E) was measured from the apical four-chamber view, and the ratio of diastolic filling to tissue early diastolic velocity (E/e') was calculated. LV and RV longitudinal strain were measured from four-chamber apical views. LV circumferential strain was derived from the parasternal short-axis view at the midventricular level. The relationship of each parameter with increasing heart rate was evaluated at each stage of exercise. RESULTS: During exercise color DTI, velocities were obtained in 96% of subjects, with isovolumic contraction having the lowest feasibility among DTI measurements (89%). Strain analysis was measurable in 87% of subjects, with LV longitudinal strain measured in 98% of the subjects compared with 93% for circumferential strain. RV longitudinal strain had the lowest feasibility (70%). A linear relationship was observed between heart rate and color DTI velocities, E, E/e', and myocardial longitudinal and circumferential strain. The relationship between isovolumic contraction and heart rate was exponential. CONCLUSIONS: This study provides reference values for systolic and diastolic reserve during exercise in healthy children as measured by color DTI and two-dimensional speckle-tracking echocardiography. These data allow the evaluation of myocardial response in pediatric cardiac disease.

Left Ventricular Myocardial and Hemodynamic Response to Exercise in Young Patients after Endovascular Stenting for Aortic Coarctation.

BACKGROUND: Endovascular stenting has emerged as a treatment option for children with coarctation of the aortic (CoA), but the impact on left ventricular (LV) function has been poorly documented. The aim of this study was to characterize the LV myocardial and hemodynamic response to exercise in young patients who underwent endovascular stenting for CoA during childhood using semisupine bicycle exercise stress echocardiography. METHODS: This was a single-center prospective cross-sectional study including 30 patients with CoA and 30 age- and gender-matched control subjects who underwent semisupine bicycle exercise stress echocardiography. Color Doppler tissue imaging peak systolic (s') and early diastolic (e') velocities in the LV lateral wall and basal septum, LV myocardial acceleration during isovolumic acceleration were measured at rest and with incremental heart rate (HR). The relationship with increasing HR was evaluated for each parameter by plotting the values at each stage of exercise versus HR. RESULTS: At rest, HR was similar between the two groups. LV ejection fraction and fractional shortening were within the normal range in the CoA group. LV lateral wall and basal septal s' and e' velocities did not differ between the two groups, but isovolumic acceleration values were significantly lower in the CoA group. At peak exercise, HR was similar between the groups, but all Doppler tissue imaging parameters were lower in patients than in control subjects. When assessing the increase of each parameter versus HR, the increase in slope was significantly lower in patients than in control subjects for LV lateral wall Doppler tissue imaging s' and e' velocities, and septal e' velocity, but not for septal s'. The relationship of isovolumic acceleration with HR was significantly reduced in the CoA group. CONCLUSION: The results of this study demonstrate reduced systolic and diastolic myocardial reserve in patients with CoA compared with control subjects. An abnormal myocardial contractile response to exercise was also found, as shown by an abnormal LV force-frequency relationship in patients with stented CoA. The prognostic clinical implications require further study.

Stress echocardiography in paediatric cardiology.

Stress echocardiography is a well-established technique in adult cardiology and is mainly used for assessing regional myocardial function in patients with known or suspected coronary artery disease (CAD). Apart from detecting ischaemia, stress echocardiography has found its place in the assessment of the haemodynamic significance of valve disease, particularly in selected patients with aortic stenosis and mitral regurgitation. Also in the paediatric population, stress imaging is most commonly used for the detection of ischaemia in patients with CADs such as post heart transplantation, Kawasaki Disease, and abnormal origin of coronary arteries. Other paediatric indications include the haemodynamic and myocardial response in patients with different types of congenital heart disease, the early detection of myocardial dysfunction in specific populations such as patients after anthracycline exposure, and the evaluation of pulmonary artery pressures and the right ventricular functional response. Techniques have evolved over time and in different paediatric echocardiographic laboratories, exercise stress echocardiography is replacing dobutamine stress echocardiography in older children. Moreover, integrating tissue Doppler and strain technology with stress imaging allows a more quantitative analysis of regional and global systolic and diastolic function. Current clinical applications mainly include patients after transplant, suspected CAD, and hypertrophic cardiomyopathy.

Left ventricular myocardial response to exercise in children after heart transplant.

BACKGROUND: Data on myocardial response to exercise after pediatric heart transplant (HTx) are limited. In this study we used semi-supine bicycle ergometry (SSCE) stress echocardiography to evaluate left ventricular (LV) systolic and diastolic reserve in pediatric HTx recipients. METHODS: Forty-three HTx patients and 23 controls underwent stepwise SSCE stress echocardiography. Color tissue Doppler imaging (TDI) peak systolic (s') and early diastolic (e') velocities in the LV lateral wall and basal septum, and LV peak global longitudinal and circumferential strain were measured at rest and during different stages of exercise. LV myocardial acceleration during isovolumic contraction (IVA) was measured at incremental heart rates (HRs) to determine the force-frequency relationship (FFR). RESULTS: At rest, compared with controls, HTx patients showed lower TDI velocities in the basal septum (s': 4.7 ± 1.1 vs 5.8 ± 0.8 cm/s, p = 0.002; e': 8.5 ± 2.1 vs 11.3 ± 1.7 cm/s, p < 0.001), whereas in the LV lateral wall only e' was lower (11.2 ± 2.6 vs 13.8 ± 2.3 cm/s, p < 0.001). LV IVA was not different between the groups (p = 0.10). LV peak global longitudinal strain was lower in HTx patients (18 ± 1.9% vs 20 ± 2.2%, p = 0.001), but peak circumferential strain was not different (p = 0.50). At peak, HR was lower in the HTx group (141 ± 12 vs 165 ± 15, p < 0.001), and all systolic and diastolic parameters, except circumferential strain, were lower in HTx recipients. When assessing the increase in TDI and strain values in relation to HR, the slopes were not significantly different between patients and controls. CONCLUSIONS: Despite resting differences in myocardial functional parameters, pediatric HTx recipients have preserved LV diastolic and systolic myocardial reserve in response to exercise.

Structural cardiac disease diagnosed by echocardiography in asymptomatic young male soccer players: implications for pre-participation screening.

PURPOSE: To evaluate the prevalence of structural cardiac lesions using echocardiography in apparently healthy boys referred for pre-participation screening (PPS). SUBJECTS AND METHODS: 3100 male soccer players were evaluated by echocardiography in addition to the standard PPS. RESULTS: In 56 subjects (1.8%), a structural cardiac lesion with potential future complication was detected. Specifically, hypertrophic cardiomyopathy (HCM) was found in two boys; bicuspid aortic valve (BAV) in 24; mitral valve prolapse in 10 and atrial septal defects (ASDs) in 20. Resting physical examination (PE) failed to identify any abnormalities in the majority of the subjects. All the boys presented an uncomplicated echocardiography, except two boys with HCM, one with BAV associated with aortic dilatation and one with a large ASD. CONCLUSION: Asymptomatic young athletes may have a structural cardiac alteration with the potential of present or future haemodynamic and arrhythmic consequences. A majority of mild cardiac lesions are difficult to diagnose or suspect by the current screening based on medical history, PE and ECG. Transthoracic echocardiography significantly improves the diagnostic power of screening in the detection of both mild and serious cardiac conditions in the athletic population.

Mid-term results, and therapeutic management, for patients suffering hypertension after surgical repair of aortic coarctation.

We designed our study to investigate the efficacy of a new therapeutic approach to late onset hypertension in patients after surgical repair of aortic coarctation. Several studies have shown a higher incidence of hypertension during daily activities, and during exercise, in patients after surgical correction of coarctation. To the best of our knowledge, however, no data exists concerning haemodynamics, the response of arterial pressures, and the effects of medications for lowering blood pressure during exercise or during daily activities.We studied 128 patients, aged 15.6 +/- 4.3 years, to determine the response of blood pressure as we administered treatment in the attempt to achieve a normotensive state. We excluded patient with associated cardiac abnormalities, apart from those with bicuspid aortic valves. We evaluated blood pressure at rest in both the right arm and leg to establish presence of any gradient, as well as the blood pressure in the arm during exercise testing, and by 24-hour ambulatory monitoring.Atenolol was prescribed for those with elevated values of blood pressure but with a normal increment of heart rate during exercise. We prescribed Candesartan for those with elevated levels of blood pressure but with reduced increments of heart rate, specifically maximal heart rates of less than 85% of their predicted value. Both drugs were used when one alone was not effective. We found that, in young patients, candesartan provided better control of blood pressure with no side-effects, especially as demonstrated using 24-hour ambulatory monitoring, while atenolol was less effective, with more side-effects. Our experience suggests that both drugs should be used in patients who are non-responsive to monotherapy.