Myocardial function, mechanics and work by echocardiography in adolescents with severe obesity.

Introduction: Obesity and its metabolic complications can impact the heart's structure and function in childhood, although demonstrating this impact has been challenging. New echocardiographic parameters such as left atrial strain (LAε) and left ventricular strain (LVε), as well as myocardial work (MW), could reveal subclinical alterations in cardiac function. Objective: The aim is to evaluate the feasibility of these parameters in adolescents with severe obesity and explore their associations with body fat, metabolic comorbidities, and physical capacity. Methods: This is a cross-sectional study in adolescents with obesity who underwent echocardiography with analysis of LAε, LVε and MW using speckle tracking. Feasibility and association with anthropometry, body fat percentage, comorbidities and cardiopulmonary test were analyzed. Results: Twenty adolescents were recruited, 13 (65%) were males, median age 14.2 (interquartile range: 12.9-14.9) years old. The median Z-score for BMI (zBMI) was +3.03 (2.87-3.14), 14 (70%) had severe obesity (zBMI ≥+3), 12 (60%) body fat ≥95th percentile, 9 (45%) high blood pressure (HBP) and 8 (40%) metabolic syndrome. The analysis of the echocardiographic parameters was feasible in 95% (LAε) and 100% (LVε and MW). LVε was lower in adolescents with vs. without metabolic syndrome: 17.8% (17.5-19.3%) vs. 19.3% (18.3-20.3%), P = 0.046; and with vs. without HBP 17.8% (17.5-18.6%) vs. 19.7% (18.4-20.3%), P = 0.02. Those with body fat ≥95th percentile had lower LAε and MW parameters, without association with cardiopulmonary test. Conclusion: Echocardiographic evaluation of LAε, LVε and MW is feasible in adolescents with severe obesity. A higher proportion of body fat and the presence of comorbidities are associated with alterations in these new echocardiographic functional parameters suggesting myocardial impact of higher metabolic compromise.

Insulin resistance parameters in children born very preterm and adequate for gestational age.

BACKGROUND: Preterm neonates are at risk for metabolic syndrome later in life. Whether prematurity constitutes an independent risk factor for the development of cardiovascular disease and metabolic syndrome remains controversial. OBJECTIVE: To compare anthropometric measures, cardiometabolic risk factors and insulin resistance variables between children who were born very preterm (VPT, <32 gestational weeks) and at term (Term, >37 gestational weeks) and adequate for gestational age (AGA). METHODS: We designed a cross-sectional cohort study, recruiting 120 children (5.0-8.5 years old) from the preterm clinic at Red de Salud UC-Christus and Complejo Asistencial Dr. Sótero del Río, and term children from the community. We excluded children born small for gestational age, based on INTERGROWTH21. Anthropometrics data were classified using WHO reference standards. The homeostasis model assessment insulin resistance (HOMA-IR) index, quantitative insulin sensitivity check index (QUICKI), triglyceride-to-HDL-C ratio (TG/HDL-C) and Pediatric Score Index for Metabolic Syndrome (PsiMS) were calculated. RESULTS: VPT children born AGA had lower HDL cholesterol levels (p = .019) and a higher PsiMS score than those born at term (p = .043). We observed a higher percentage of children with HDL cholesterol ≤40 mg/dl (13.0% vs. 2.3%, p = .026) and BP ≥90th percentile among the VPT children than among the Term children (26.0% vs. 11.6%, p = .031). CONCLUSIONS: At school age, blood pressure was higher, and HDL-C was lower among VPT children born AGA, suggesting a potential metabolic risk; therefore, it is essential to follow this group throughout their lives.

Urinary sodium-to-potassium ratio and plasma renin and aldosterone concentrations in normotensive children: implications for the interpretation of results.

OBJECTIVES: To identify associations among the plasma renin concentration (PRC), plasma aldosterone and urinary sodium (Na)/potassium (K) ratio, and to integrate these variables into a nomogram with the aim of estimating the expected versus observed aldosterone concentration. METHODS: We studied 40 healthy normotensive children (5-8 years old, 57.5% girls) who were born at term and were adequate for their gestational age. Following overnight fasting, the PRC and plasma aldosterone in blood samples were measured, and the Na/K ratio was calculated from a simultaneously obtained urinary spot sample. A mathematical function was defined with these three variables, and a nomogram was built that would return the expected aldosterone concentration from the obtained plasma renin and urinary Na/K ratio values. RESULTS: The PRC (B =  5.9, P < 0.001) and urinary Na/K ratio (B = -98.1, P = 0.003) were significant independent predictors of plasma aldosterone. The correlation between the observed plasma aldosterone and the expected plasma aldosterone, as obtained from the nomogram, was r = 0.88, P < 0.001. The average difference between the observed and expected plasma aldosterone was -0.89, with a standard deviation of ±30%. CONCLUSION: The strong correlation between the urinary Na/K ratio, from urine samples taken at the same as the blood samples, and plasma renin and aldosterone concentrations allowed us to build a nomogram to predict aldosterone levels. This approach may be useful for evaluating the renin-angiotensin-aldosterone system (RAAS) in pediatric patients with hypertension and RAAS dysfunction.

Echocardiographic evaluation after pediatric heart transplant in Chile: initial application of a functional protocol with global longitudinal strain. / Evaluación ecocardiográfica de pacientes pediátricos post-trasplante cardiaco en Chile: Aplicación inicial de un protocolo funcional con Strain longitudinal global.

INTRODUCTION: The echocardiographic evaluation of patients after heart transplantation is a useful tool. However, it is still necessary to define an optimal follow-up protocol. OBJECTIVE: To describe the results of the application of a functional echocardiographic protocol in patients being followed after pediatric heart transplantation. PATIENTS AND METHOD: Alls patients being followed at our institution after pediatric heart transplantation underwent an echocardiographic examination with a functional protocol that included global longitudinal strain. Contemporaneous endomyocardial biopsy results and hemodynamic data were recorded. RESULTS: 9 patients were evaluated with our echocardiographic functional protocol. Of these patients, only 1 showed systolic left ventricular dysfunction according to classic parameters. However, almost all patients had an abnormal global longitudinal strain. Right ventricular systolic dysfunction was observed in all patients. No epidodes of moderate to severe rejectiom were recorded. No correlation was observed between these parameters and pulmonary artery pressure. CONCLUSIONS: Subclinical biventricular systolic dysfunction was observed in the majority of the patients in this study. No association with rejection episodes or pulmonary hypertension was observed, which may be related to the absence of moderate or severe rejection episodes during the study period, and to the small sample size. Long term follow-up of these patients may better define the clinical relevance of our findings.

Evaluación ecocardiográfica de pacientes pediátricos post-trasplante cardiaco en Chile: Aplicación inicial de un protocolo funcional con Strain longitudinal global / Echocardiographic evaluation after pediatric heart transplant in Chile: initial application of a functional protocol with global longitudinal strain

Resumen: Introducción: La evaluación ecocardiográfica de pacientes post-trasplante cardiaco pediátrico es una herramienta útil. Sin embargo, aún es necesario definir un protocolo óptimo de seguimiento. Obje tivo: Caracterizar los resultados de la aplicación de un protocolo de evaluación ecocardiográfica fun cional en pacientes en control post-trasplante cardiaco pediátrico ortotópico. Pacientes y Método: Posterior al trasplante cardiaco pediátrico se realizó una ecocardiografía con un protocolo funcional que incluyó strain longitudinal global. Se evaluaron además los datos de la biopsia endomiocárdica y del estudio hemodinámico contemporáneos. Resultados: De un total de 9 pacientes sólo 1 presentó disfunción sistólica de ventrículo izquierdo según parámetros clásicos, pero casi la totalidad presentó un strain longitudinal global alterado. No se observaron episodios de rechazo moderado o severo en estos pacientes. Todos los pacientes presentaban disfunción sistólica ventricular derecha. No se ob servó correlación entre estos parámetros y la presión de arteria pulmonar. Conclusiones: Se observó disfunción sistólica biventricular subclínica en la mayoría de los pacientes de esta serie. No hubo aso ciación con episodios de rechazo o con hipertensión pulmonar, lo que podría estar en relación con la ausencia de episodios de rechazo moderado o severo en la biopsia contemporánea y con el reducido tamaño muestral. Sólo el seguimiento a largo plazo de estos pacientes permitirá definir la relevancia clínica de los hallazgos descritos.

Abstract: Introduction: The echocardiographic evaluation of patients after heart transplantation is a useful tool. However, it is still necessary to define an optimal follow-up protocol. Objective: To describe the results of the application of a functional echocardiographic protocol in patients being followed after pediatric heart transplantation. Patients and Method: Alls patients being followed at our institution after pediatric heart transplantation underwent an echocardiographic examination with a functional protocol that included global longitudinal strain. Contemporaneous endomyocardial biopsy results and hemodynamic data were recorded. Results: 9 patients were evaluated with our echocardiographic functional protocol. Of these patients, only 1 showed systolic left ventricular dysfunction according to classic parameters. However, almost all patients had an abnormal global longitudinal strain. Right ventricular systolic dysfunction was observed in all patients. No epidodes of moderate to severe rejectiom were recorded. No correlation was observed between these parameters and pulmonary artery pressure. Conclusions: Subclinical biventricular systolic dysfunction was observed in the majority of the patients in this study. No association with rejection episodes or pulmonary hypertension was observed, which may be related to the absence of moderate or severe rejection episodes during the study period, and to the small sample size. Long term follow-up of these patients may better define the clinical relevance of our findings.

Regional dysfunction of the right ventricular outflow tract reduces the accuracy of Doppler tissue imaging assessment of global right ventricular systolic function in patients with repaired tetralogy of Fallot.

BACKGROUND: The influence of regional right ventricular (RV) dysfunction on the accuracy of Doppler tissue imaging (DTI) assessment of global RV function is unknown. The objective of this study was to determine the effect of regional dysfunction of the RV outflow tract (RVOT) on the correlations between RV DTI indices and cardiac magnetic resonance (CMR) measurements of global RV function in patients with repaired tetralogy of Fallot. METHODS: Consecutive patients with repaired tetralogy of Fallot who underwent echocardiography with DTI of the right ventricle and CMR within 4 weeks of each other were retrospectively analyzed. RV DTI measurements were obtained from the lateral wall at the level of the tricuspid valve annulus. CMR measurements included end-diastolic and end-systolic volumes, stroke volume, and ejection fraction (EF) of the entire right ventricle and measured separately for the RV sinus and RVOT segments. RESULTS: The median age of the 51 patients included was 19 years (range, 9.7-71.6 years), and the median interval between echocardiography and CMR was 0 days. The mean RV free wall peak S', isovolumic acceleration, and global, sinus, and RVOT EFs were 8.4 ± 2.0 cm/s, 102 ± 37 cm/s(2), and 46.1 ± 9.8%, 47.9 ± 9.9%, and 33 ± 13.1%, respectively. The correlation between peak S' and global RV EF was weak (r = 0.23) in patients with RVOT dysfunction (RVOT EF <30%) but higher (r = 0.66) in those with RVOT EFs ≥30%. Peak S' ≥8.4 cm/s (area under the receiver operating characteristic curve, 0.77) and isovolumic acceleration ≥95 cm/s(2) (area under the receiver operating characteristic curve, 0.68) best discriminated between patients with global RV EFs >45% and <45%. CONCLUSIONS: In this group of patients with repaired TOF, RV DTI indices showed reasonable correlation with CMR-derived global RV EF, but this correlation was substantially weaker in those with moderate and severe dysfunction of the RVOT. Peak S' <8.4 cm/s and isovolumic acceleration <95cm/s(2) by DTI should prompt an evaluation of RV function by CMR.

Reanimación neonatal / Neonatal resuscitation

La reanimación cardiopulmonar del recién nacido presenta desafíos diferentes a la reanimación del adulto o del niño mayor, especialmente por los dramáticos cambios fisiológicos que ocurren al momento de nacer. En los últimos años se han desarrollado guías universales basadas en evidencia para una adecuada reanimación. El presente artículo es una revisión y resumen de dichas recomendaciones

Atresia pulmonar con septum ventricular intacto: espectro morfológico y diagnóstico prenatal / Pulmonary atresia with ventricular septum intact: morphologic phantom and prenatal diagnosis

We describe the morphologic variability and fetal diagnosis in pulmonary atresi with intact ventricular septum, within a chilean peadiatric cardiovacular center. An uncommon disease, that shows considerable morphologic heterogeneity, and with no local reports about this topic. We studied a consecutive series of 28 cases, in a five year period (1997-2002), at the Luis Calvo Mackenna Cardiovascular center. Morphologic feactures of each case were evaluated by direct review of the echocardiograms, angiocardiograms and from surgical reports. Among 28 infants, atresia was membranous in 82 per cent and muscular in 18 per cent. Right ventricle was bipartite in 30 per cent, unipartite in 6 per cent and tripartite in 64 per cent of cases. Coronary arterial abnormalities were identified in 36 per cent, and right ventricular dependent coronary circulation in 7,1 per cent. Median tricuspid annulus valvar size was -3. Fetal diagnosis was made in six of the 28 cases (21,4). In all of these prenatally diagnosed patients arrengements were made in order for the delivery to be fullfilled near by a cardiovascular center. This study shows data about the morphologic diversity and efforts on early fetal diagnose made in our country, in order asses this uncommon diseases