RESUMO
La introducción de la ecografía de alta resolución con Doppler color ha sido el mayor avance en la evaluación del sistema venoso fetal. El diagnóstico prenatal de las anomalías de este sistema son raras y sólo han sido descritos casos aislados. Las implicaciones hemodinámicas de los diferentes patrones de anomalías venosas fetales no se conocen del todo, en parte debido a que el sistema venoso fetal no ha sido estudiado en detalle. La vena umbilical que drena directamente en estructuras cardíacas derechas con ausencia del ductus venoso produce hidropesía fetal y está asociado a mortalidad, anomalías cromósomicas y malformaciones congénitas. Revisamos la literatura y presentamos un segundo caso de ausencia de vena umbilical intrahepática con conexión directa a aurícula derecha, ausencia de ductus venoso y cardiomegalia con predominio de cavidades izquierdas. La evaluación cuidadosa del sistema venoso umbilical y del ductus venoso debe formar parte de la rutina ante un feto con fallo cardíaco, cardiomegalia inexplicada e hidropesía fetal
The introduction of high-resolution ultrasonography with color Doppler offered a breakthrough in the evaluation of the human fetal venous system. Prenatal diagnosis of anomalies of these system are rare, and only anecdotal cases have been described. The hemodynamic implications of different pattern of venous fetal anomalies are probably not well understood because the fetal venous vein systems have not been studied in detail. The umbilical vein wich drains directly into right-sided structures with absent ductus venosus causes hydrops fetalis and its associated with mortality, chromosomal anomalies and congenital malformations. We reviewed the literature and presented the second case of intrahepatic absence of umbilical vein with no evidence of venous ductus and direct connection of the umbilical vein to right atrium with left heart overload. Careful assesment of the umbilical venous system and the ductus venosus should be part of the routine evaluation of fetus with heart failure, unexplained cardiomegaly and fetal hydrops (AU)
Assuntos
Humanos , Feminino , Gravidez , Adulto , Veias Umbilicais/anormalidades , Átrios do Coração/anormalidades , Hidropisia Fetal , Cardiomegalia , Ultrassonografia Pré-Natal/métodosRESUMO
OBJECTIVE: The use of radiofrequency ablation of cardiac arrhythmias in pediatrics requires demonstration that the technique is effective and devoid of significant complications. In this study we present our experience in the ablation of cardiac arrhythmias in children and adolescents. PATIENTS AND METHODS: Between January 1992 and January 1997 we performed a total of 1,543 radiofrequency ablation procedures. Of these, 130 were performed in 117 patients younger than 18 years of age (58 were younger than 14 years old). Indication for ablation was the presence of drug refractory recurrent paroxysmal supraventricular tachycardia in 112 patients and permanent ventricular preexcitation in 5 asymptomatic patients. Final diagnosis in the 112 symptomatic patients was: 4 atrial tachycardias, 21 atrio-ventricular nodal reentrant tachycardias, 53 Wolff-Parkinson-White (WPW) syndromes, 33 orthodromic tachycardias using a concealed accessory pathway and 1 idiopathic left ventricular tachycardia. RESULTS: The initial ablation procedure was effective in 109/117 patients (93%) with a total duration of 90 +/- 31 minutes, using 16 +/- 11 minutes of radioscopy and a median of 4 radiofrequency applications. During follow-up, recurrence occurred in 9 patients (8%). In 7 of them and in 6 of those with an unsuccessful initial procedure, a second effective procedure was performed in 11/13 patients. Finally, radiofrequency ablation was effective in 111/117 patients (95%). We observed a single complication in a 15 year old girl who presented a thrombosis of the right femoral artery requiring balloon recanalization. Comparison of these results with those in the adult population showed no difference in terms of effectiveness, recurrences or complications. CONCLUSIONS: Radiofrequency ablation of cardiac arrhythmias in pediatric and young patients can be safely and effectively done. Results are similar to those obtained in adults suggesting that indications for ablation can also be similar.
