Early Experience with Ivabradine for Focal Atrial Tachycardia in Pediatric Patients with Congenital Heart Disease

Background Ivabradine is a promising anti-arrhythmic therapy for automatic arrhythmias such as inappropriate sinus tachycardia, junctional ectopic tachycardia, and focal atrial tachycardia (AT). However, experience with ivabradine in pediatric patients, especially those with congenital heart disease (CHD) and focal AT, remains limited. We report our findings using ivabradine for focal AT in infants and children with CHD to assess its efficacy and safety. Method A retrospective analysis was conducted on all pediatric patients (<21 years) diagnosed with CHD at Children’s Health of Dallas, who were treated with ivabradine for focal AT. Patient demographics, arrhythmia diagnosis, anti-arrhythmic therapies, and adverse effects were evaluated. A positive response was defined as complete rhythm control within 24 hours of initiation of ivabradine. Results Fifteen patients (median age 7 [1-8] months; 9 males (60%)) were included in this study, including 12 (80%) complex CHD. Fourteen patients (93%) had unifocal AT and one (7%) had multifocal AT. The AT occurred in the early post-operative period in six patients (40%). In two patients (13%) ivabradine was used as monotherapy. Positive response to ivabradine was observed in 12 patients (80%). Adverse events occurred in 7 patients (47%) consisting of bradycardic, which was transient, or resolved upon reducing the ivabradine dosage. Conclusion In infants and children with CHD, ivabradine was efficacious for the treatment of focal AT without major complications. Bradycardia is a frequent adverse event. Therefore, close monitoring may be required during initiation of therapy.