Efficacy of Propafenone for Treating Idiopathic Premature Ventricular Contractions in Children

Background. Premature ventricular contractions (PVCs) are a common heart rhythm disorder in children, often following a benign course. However, in rare cases, antiarrhythmic therapy is required for managing this arrhythmia. Limited data is available regarding the effectiveness of such therapy specifically in children. Objective. To evaluate the efficacy and safety of propafenone administration in children with idiopathic PVCs. Methods. The study enrolled 33 children aged 11.1 ± 4.8 years (29 days — 17 years) with idiopathic PVCs. Propafenone dose was titrated from initial (5–7 mg/kg/day) to effective (no more than 15 mg/kg/day) dose under clinical and electrocardiographic control to monitor for proarrhythmias and other side effects. An increase in PQ interval duration and a widening of the QRS complex no more than 25% compared to baseline was considered acceptable. Results. The incidence of PVCs before propafenone administration was 36.3 ± 10.1 (22.0–60.6) thousands/day or 33.2 ± 8.4% (20.5–50.0). Complex forms of PVCs were observed in 25 (75.8%) children: 25 (75.8%) had frequent paired PVCs, 6 (18.2%) had polymorphic PVCs, 20 (60.6%) had short runs of ventricular tachycardia (VT), and 19 (27.6%) had a combination of various forms of PVCs. The starting dose of propafenone was 5.6 ± 2.2 mg/kg/day with subsequent increases to 10 ± 0.8 mg/kg/day. Propafenone was employed as the initial therapy in 23 (69.7%) children and as a second line therapy in 10 (30.3%) children, following the ineffectiveness or adverse effects of beta-adrenoblockers. The duration of propafenone therapy was 95.8 ± 62.8 days. Propafenone was effective in 25 (75.8%) children. The average reduction in the number of PVCs during therapy was 71.7 ± 32.6% (13.0–100.0) during therapy. One (3%) child developed proarrhythmia — sustained VT and 1 (3%) child had gastrointestinal side effects. Conclusion. Propafenone is an effective antiarrhythmic drug in children with idiopathic PVCs, including patients with poor response to beta-adrenoblockers. Arrhythmogenic and extracardiac side effects are possible during propafenone therapy, which require clinical and electrocardiographic observation in the process of selecting an effective dose of the drug.