Abstract 9023: Post-Operative Ectopic Atrial Tachycardia in Congenital Heart Disease

Abstract

Introduction: Ectopic atrial tachycardia (EAT) is relatively common in infants following surgery for congenital heart disease (CHD). There is limited data regarding this arrhythmia. Hypothesis: Operative factors, including CHD diagnosis, can identify risk factors for post-operative EAT. Methods: This was a retrospective analysis of patients undergoing CHD surgery in the first year of life between January 2007 and July 2020. Patients and surgeries with EAT were compared to those without EAT. Results: Out of 5,792 infant CHD surgeries, 129 (2.2%) developed postoperative EAT. The onset of EAT occurred at a median of 9 days (IQR 5-14 days) after CHD surgery. Compared to controls, the EAT cohort was younger (median 7 vs 85 days, p <0.01) and had lower weight (3.3 vs 4.3 kg, p <0.01) with no gender difference. EAT occurred following 24/265 (9%) total anomalous pulmonary venous connection (TAPVC) repairs (relative risk of 4.7, p<0.001), 22/351 (6%) arterial switch operations (RR 3.2, p<0.001), 6/90 (7%) interrupted arch repair (RR 3.1, p=0.004), and 23/460 (5%) Norwood operations (RR 2.5, p<0.001). EAT patients had longer cardiopulmonary bypass (median 64 vs 58 min, p=0.008) and deep hypothermic circulatory arrest times (15 vs 0 min, p<0.001) but no statistically significant difference in cross clamp times (25 vs 31 min). Antiarrhythmics were given to 109 patients (84%), but treated patients were more likely to be identified for study inclusion potentially biasing this percent-treated value. Propranolol (60%), amiodarone (22%), and flecainide (4%) were the most frequently used antiarrhythmics during hospitalization. On discharge, 60% of EAT patients were on antiarrhythmics, most commonly propranolol (55%), amiodarone (4%), and flecainide (4%). Although 15 patients did not survive to hospital discharge, EAT was not directly implicated in any deaths. Conclusions: In this study of a large cohort of postoperative EAT patients, the arrhythmia occurred in 2.2% of cases with a median onset of 9 days after surgery. TAPVC repair carried the highest risk of postoperative EAT, followed by arterial switch, interrupted aortic arch repair, and Norwood operations. Patients with EAT were younger, smaller, and had longer bypass and circulatory arrest times than controls.