Antiarrhythmic Treatment Duration and Tachycardia Recurrence in Infants with Supraventricular Tachycardia.

Abstract

We sought to assess the effect of a shorter medication treatment course (up to 4-6months of age) on the recurrence of infantile supraventricular tachycardia (SVT). This was a retrospective review of infants with SVT diagnosed at age 0-12months at Rady Children's Hospital (2010-2017). Infants with structural congenital heart disease, automatic tachycardias, atrial flutter, or lack of follow-up data were excluded. Seventy-four infants met criteria. Median age at diagnosis was 6days (IQR 0-21days); 28.4% presented with fetal tachycardia. Median gestational age was 38.4weeks (IQR 36-40), 30% were preterm. Median age at medication discontinuation was 6.7months (IQR 4.6-9.8). Therapy was stopped at younger age in patients managed by pediatric electrophysiologist (vs. general pediatric cardiologist): 4.9 vs. 8.6months (p = 0.03). Thirty-eight patients (51.4%) were treated for < 6months; 32.4% for 6-12months, and 16.2% for > 12months. SVT recurrence was similar for these groups: 13.2% vs. 16.7%, and 33.3%, respectively, (p = 0.27). Most patients with recurrence required emergency care, though none had significant adverse outcomes. Infants with SVT and structurally normal cardiac anatomy, who remain recurrence free on a single agent, have no increased risk of recurrence with shorter treatment courses of 4-6months, compared to traditional treatment duration of 6-12months.