Uso de la ivrabadina para el tratamiento de la taquicardia ectópica de la unión congénita / Use of ivabradine for the treatment of congenital junctional ectopic tachycardia

Resumen La taquicardia ectópica de la unión en su variante congénita es una taquiarritmia pediátrica poco frecuente, que por su naturaleza incesante y su refractariedad a los agentes farmacológicos tradicio nales lleva asociada una alta morbimortalidad. Se presentan los casos clínicos de dos pacientes pediátricos con diagnóstico de taquicardia ectópica de la unión congénita, que mostraron respuesta inadecuada a las alternativas de tratamiento habituales y que, en consecuencia, desarrollaron miocardiopatía dilatada y disfunción ventricular secundaria a la taquicardia sostenida. En ambos se utilizó ivabradina como alternativa farmacológica innovadora pare el control de ésta con excelente respuesta clínica.

Abstract The congenial form of junctional ectopic tachycardia is a rare variant of pediatric tachyarrhythmia that due to its incessant nature and its refractoriness to the traditionally used antiarrhythmic agents has a high morbimortality The clinical cases of two patients with a diagnosis of congenital junctional ectopic tachycardia with inadequate response to the regular pharmacological options, who developed dilated cardiomyopathy and ventricular dysfunc tion secondary to sustained tachycardia, are presented. In both ivrabadine, a new innovative option was used with excellent clinical response.

[Use of ivabradine for the treatment of congenital junctional ectopic tachycardia]. / Uso de la ivrabadina para el tratamiento de la taquicardia ectópica de la unión congénita.

The congenial form of junctional ectopic tachycardia is a rare variant of pediatric tachyarrhythmia that due to its incessant nature and its refractoriness to the traditionally used antiarrhythmic agents has a high morbimortality The clinical cases of two patients with a diagnosis of congenital junctional ectopic tachycardia with inadequate response to the regular pharmacological options, who developed dilated cardiomyopathy and ventricular dysfunction secondary to sustained tachycardia, are presented. In both ivrabadine, a new innovative option was used with excellent clinical response.

La taquicardia ectópica de la unión en su variante congénita es una taquiarritmia pediátrica poco frecuente, que por su naturaleza incesante y su refractariedad a los agentes farmacológicos tradicionales lleva asociada una alta morbimortalidad. Se presentan los casos clínicos de dos pacientes pediátricos con diagnóstico de taquicardia ectópica de la unión congénita, que mostraron respuesta inadecuada a las alternativas de tratamiento habituales y que, en consecuencia, desarrollaron miocardiopatía dilatada y disfunción ventricular secundaria a la taquicardia sostenida. En ambos se utilizó ivabradina como alternativa farmacológica innovadora pare el control de ésta con excelente respuesta clínica.

Características electrocardiográficas de vías fascículo-ventriculares en pediatría: estudio comparativo con las vías accesorias anteroseptalesderechas / Electrocardiographic characteristics of fasciculo-ventricular accessory pathways in children: A comparative study with right anteroseptal accessory pathways

Resumen Objetivos: Las vías accesorias (VAc) fascículo-ventriculares (FV) tienen una localización anatómica similar a las VAcanteroseptales derechas (ASD) y comparten características electrocardiográficas. El objetivo es comparar características electrocardiográficas de las VAC FV con las de las ASD en pediatría. Métodos: Se incluyeron pacientes con preexcitación manifiesta sometidos a estudio electrofisiológico. Las VAc FV se definieron por un intervalo HV ≤ 32ms y un alargamiento del AH sin modificación del HV, del grado o patrón de preexcitación ventricular durante la estimulación auricular. Tres observadores independientes y ciegos analizaron los ECG en cada grupo. Resultados: De 288 pacientes, 15 (5.2%) presentaban VAC FV y 14 VAC ASD (4.9%). El intervalo PR fue más largo en las VAc FV que en las ASD (113 ± 21 vs. 86 ± 13 ms respectivamente; p = < 0.001) y la duración del QRS fue menor (95 ± 12 vs. 137 ± 24 ms respectivamente; p = < 0.001). El ECG de las VAc FV presentó una deflexión rápida de baja amplitud previa al inicio del QRS en 13 de 15 pacientes (87%) y en 2 con VAc AV ASD (14%); (p = 0.003). Conclusiones: El intervalo PR fue más largo y el complejo QRS más angosto en la VAC FV respecto de las ASD. La presencia de una deflexión rápida de baja amplitud previa al inicio del QRS permitiría diferenciarlas de las aurículo-ventriculares ASD de manera no invasiva.

Abstract Objectives: Fasciculo-ventricular (FV) accessory pathways (AP's) and right anteroseptal (RAS) AP's share similar anatomic locations and electrocardiographic characteristics. The objective of this article is to compare these features in children. Methods: All patients with manifest pre-excitation who underwent an electrophysiological study were included. Fasciculo-ventricular AP's were defined by the presence of an HV inter- val ≤ 32 ms and a prolongation of the AH without changes in the HV interval, or the level of pre-excitation during atrial pacing. Three independent and blind observers analysed the ECG's in both groups. Results: Out of 288 patients, 15 (5.2%) had FV AP's and 14 (4.9%) right AS AP's. The PR interval was longer in FV AP's than in RAS (113 ± 21 vs 86 ± 13 ms respectively; P < .001) and the QRS was narrower (95 ± 12 vs 137 ± 24 ms respectively; P < .001). The ECG in patients with FV AP's showed a rapid low amplitude deflection at the begining of the QRS in 13 out of 15 patients (87%) and in 2 (14%) the RAS AP group (P = .003). Conclusions: The PR interval was longer and the QRS complex was narrower in patients with FV AP's. The presence of a rapid low amplitude deflection at the beginning of the QRS complex would allow to differentiate them from RAS AP's non-invasively.

[Electrocardiographic characteristics of fasciculo-ventricular accessory pathways in children: A comparative study with right anteroseptal accessory pathways]. / Características electrocardiográficas de vías fascículo-ventriculares en pediatría: estudio comparativo con las vías accesorias anteroseptales derechas.

OBJECTIVES: Fasciculo-ventricular (FV) accessory pathways (AP's) and right anteroseptal (RAS) AP's share similar anatomic locations and electrocardiographic characteristics. The objective of this article is to compare these features in children. METHODS: All patients with manifest pre-excitation who underwent an electrophysiological study were included. Fasciculo-ventricular AP's were defined by the presence of an HV interval≤32ms and a prolongation of the AH without changes in the HV interval, or the level of pre-excitation during atrial pacing. Three independent and blind observers analysed the ECG's in both groups. RESULTS: Out of 288 patients, 15 (5.2%) had FV AP's and 14 (4.9%) right AS AP's. The PR interval was longer in FV AP's than in RAS (113±21 vs 86±13ms respectively; P<.001) and the QRS was narrower (95±12 vs 137±24ms respectively; P<.001). The ECG in patients with FV AP's showed a rapid low amplitude deflection at the begining of the QRS in 13 out of 15 patients (87%) and in 2 (14%) the RAS AP group (P=.003). CONCLUSIONS: The PR interval was longer and the QRS complex was narrower in patients with FV AP's. The presence of a rapid low amplitude deflection at the beginning of the QRS complex would allow to differentiate them from RAS AP's non-invasively.

Sinus node dysfunction associated with lithium therapy in a child.

Lithium salts have been used extensively in both adults and children during the last 30 years, for the treatment of a variety of psychiatric conditions, including bipolar disorder The cardiac side effects of lithium in adult patients have been well described. However, to the best of our knowledge, there are no reports of lithium-induced cardiac side effects in pediatric patients. We describe the case of a 9-year-old boy who developed cardiac toxicity while receiving long-term lithium therapy.