EFFICACY AND PROARRHYTHMIA OF ORAL SOTALOL IN PEDIATRIC-PATIENTS

Objectives. This study sought to assess the efficacy of oral sotalol f or various arrhythmias in pediatric patients and to evaluate the incid ence of proarrhythmia and systemic side effects. Background. Sotalol i s a beta-adrenergic blocking agent with additional class III antiarrhy thmic properties. Experience in pediatric patients is limited. Data co ncerning the incidence of proarrhythmia in children are lacking. Metho ds. Seventy-one pediatric patients (mean age 7.3 years) with various s upraventricular and ventricular tachyarrhythmias were treated with ora l sotalol. All the patients were admitted to the hospital for initiati on of sotalol therapy. Antiarrhythmic and proarrhythmic effects of sot alol were assessed by daily surface electrocardiograms (ECGs) during t he in-hospital phase and by serial Holter monitoring. Results. Sotalol was either completely (27 [66%] of 41 patients) or partially effectiv e (11 [27%] of 41) in 38 (93%) of 41 patients with supraventricular re entrant tachycardias. In patients with atrial flutter predominantly af ter operation for congenital heart disease, sotalol was effective in 8 4% of patients (completely in 9 of 19 and partially in 7 of 19). Ventr icular tachycardia was completely (3 of 11) or partially (4 of 11) con trolled in 61% of children. Proarrhythmia occurred in seven patients ( 10%) and consisted of symptomatic bradycardia from sinoatrial block an d high grade atrioventricular (AV) block, respectively, in two childre n; asymptomatic high grade AV block in one; torsade de pointes in one; and relevant increased ventricular ectopic activity in three. Proarrh ythmia required drug discontinuation in four patients. Mean duration o f treatment for all patients was 18 months (range 1 to 40). Conclusion s. Sotalol was an effective antiarrhythmic drug for a wide range of pe diatric tachyarrhythmias. The considerable number of patients with pro arrhythmic effects indicates the need for initiation of treatment on a n inpatient basis and close monitoring by serial Holter electrocardiog raphy.