Abstract 16255: Unraveling the Complex Interplay: Atrial Flutter in a Patient With Prior Double Outlet Right Ventricular Repair

Abstract

Introduction: Double Outlet Right Ventricle (DORV) is a rare complex congenital heart disease (CHD) in which both the great arteries arise predominantly or entirely from the right ventricle. It is one of the rare CHD lesions with a prevalence of about 0.9%. These patients have complex anatomy, which increases their risk of recurrent arrhythmias. We present a challenging case of Atrial Flutter (AFL) in a patient with DORV. Case: A 31-year-old male with a history of DORV repair presented with palpitations and chest pain for 2 days. His heart rate (HR) was 240 bpm. EKG showed AFL with variable block [Figure 1]. Labs were unremarkable. The patient remained in AFL with HR above 120 bpm despite receiving diltiazem and adenosine. Considering his underlying complex anatomy, ablation was deferred, and the patient was cardioverted to sinus rhythm [Figure 1]. A loop monitor was placed and was started on flecainide with outpatient follow-up at a higher centre. Discussion: Infundibulotomy, removal of obstructive muscle bundles, and a patch to widen the passageway from the right ventricle to the pulmonary arteries are all steps in DORV repair. These surgeries result in scar tissue, an akinetic right ventricular outflow tract, and pulmonary valve insufficiency. Reentrant tachycardias may form due to surgical scars. In DORV patients, Atrial tachyarrhythmias have undesirable outcomes resulting in congestive heart failure, stroke, and mortality. Antiarrhythmics and cardioversion are the cornerstones of managing AFL in patients with DORV due to increased failure rates of catheter ablation. Conclusion: This case illustrates persistent atrial arrhythmias more likely due to DORV repair, resulting in cardiac remodeling. The abnormal anatomy makes localization of irritated ectopic foci and ablations ineffective and difficult.