The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy.

AIMS: The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. METHODS AND RESULTS: Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7. CONCLUSION: In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.

[Fetal cardiac tumors]. / Tumores cardíacos fetales.

INTRODUCTION AND OBJECTIVES: Fetal cardiac tumors are rare and have a different histology than in adults: in the fetus, rhabdomyoma is more prevalent, but myxoma has not been described. We report our experience with nine fetuses with prenatally diagnosed primary cardiac tumours. METHODS: This is an observational and descriptive study of fetuses investigated because of the prenatal and echographic diagnosis of heart tumors. RESULTS: There were nine fetuses with thirteen cardiac masses among more than 700 fetal echocardiographic studies performed by pediatric cardiologists. Histology was available in four of them; three rhabdomyomas and once cavernous hemangioma. In one of the cases, the parents elected to interrupt the pregnancy; three patients died in the neonatal period (two as a direct consequence of the tumors and one due to sepsis) and we have no histological information regarding any of the other five fetuses. The subjects who survived beyond the neonatal period are mostly doing well. However, one developed tuberous sclerosis and another developed a hypoplastic left heart syndrome, perhaps due to the massive restriction of flow across the foramen ovale. The tumors in the other cases were well tolerated and hemodynamic or arrhythmic consequences were minimal of absent. No women with risk factors such as tuberous sclerosis were included in our study. CONCLUSIONS: Fetal cardiac tumors are rare and display a different histology. We recommend a conservative approach to treatment.

[High frequency ventilation in the newborn. Study of 27 cases]. / Ventilación de alta frecuencia en el recién nacido. Estudio de 27 casos.

The clinical histories of 27 neonates ventilated with high frequency respirators (Volumetric Diffusive Respirator VDR-2) have been analyzed in order to evaluate the efficiency of this type of ventilation in neonatal pathology. The average gestational age of these patients was 32 +/- 4 weeks. Most of them (70%) presented respiratory distress due to hyaline membrane disease. Of the remaining cases, three (11%) presented with congenital diaphragmatic hernia, two with pulmonary hypertension, two with meconium aspiration syndrome, one with Group B Streptococal sepsis/shock and one with case diaphragmatic agenesia. Between two and six hours after initiation of high frequency ventilation (HFV), pH, paCO2 and pO2 improved significantly in relationship to former values (p < 0.05- p < 0.001), reaching values in the normal range at 6.5 +/- 14 hours regarding pH, 30 +/- 50 hours regarding paCO2 and 6.5 +/- 10 hours regarding paO2. No hemodynamic modification could be attributed to this procedure. The principal complications were ectopic air (62%) and necrotizing tracheobronchitis (TBN) (25%). Bronchopulmonary dysplasia (BDP) was diagnosed in 20% of the cases, ductus (DAP) in 33% of the cases and intracraneal hemorrhage in 25% of the cases. Mortality was 70%. High frequency ventilation is an alternative procedure to conventional ventilation in this group of neonates. It produces an important number of favorable responses, but has complications that can not be overlooked.

PIP: Clinical records of 27 newborns treated with high frequency ventilation in a hospital neonatal service in Madrid were retrospectively studied. High frequency ventilation is a technique with specific indications that has recently been applied in some neonatal pathologies as an alternative to conventional ventilation. The respirators, model 2 Volumetric Diffusive Respirators, were used in 24 of the 27 cases because of failure of conventional ventilation. The 27 newborns weighed an average of 1850 +or- 944 g and ranged from 900 to 4000 g. Their average gestational age was 32 +or- 4 weeks, and the range was 26-42 weeks. 19 had respiratory difficulties stemming from hyaline membrane disease, 3 had congenital diaphragmatic hernias, 2 had pulmonary hypertension, and one each had meconium aspiration syndrome, septic shock from group B streptococcus, and diaphragmatic agenesia. 66% were delivered by cesarean. The pH, paCO2, and paO2 improved significantly between 2 and 6 hours after initiation of HFV treatment. Values in the normal range were reached at 6.5 +or- 14 hours for pH, 30 +or- 50 hours for paCO2, and 6.5 +or- 10 hours for paO2. No hemodynamic modifications were attributed to HFV. The most significant complications were ectopic air (62%) and necrotizing tracheobronchitis (25%). Broncopulmonary dysphasia was diagnosed in 20%, ductus in 33%, and intracraneal hemorrhage in 25%. The case fatality rate was 70%. Ten newborns improved definitively with HFV and proceeded to conventional ventilation. Two later succumbed to other causes. The study showed that HFV can lead to serious complications and should be applied with great prudence despite it great potential benefit.