Abstract 18351: Reentrant Atrial Tachycardia in Congenital Heart Disease Patients, Role of a Crista Leak
Introduction: Atrial tachycardias (AT) occur commonly in adult patients with congenital heart disease (CHD). Common mechanisms include macroreentry utilizing the cavo-tricuspid isthmus or atriotomy scars, and focal tachycardias (FAT). Increasingly we have observed macroreentry around the crista terminalis utilizing slow, transverse conduction through the crista terminalis which we have termed “crista leak” (AF-CtL).
Methods: We performed a single center retrospective chart review of patients >18 years with postoperative CHD undergoing ablation (RFA) for AT between May 2011 to September 2015. 60 patients underwent ablation of 120 ATs in 73 procedures. Among these 13 patients displayed AF-CtL.
Results: RFA was acutely effective for 117/120 ATs (71/73 cases) and in 13/13 AF-CtL. Median age of the 13 patients with AF-CtL was 37.5 years (19.9-59.8). Congenital lesions included tetralogy of Fallot (2), congenitally corrected transposition (1), double outlet right ventricle (2, one s/p single ventricle repair), VSD/Coarctation of the aorta (1), pulmonary atresia/VSD (1), and ASD (6). 12/13 patients had additional RA scar due to atriotomy or previous ablations. 11/13 had up 4 to additional ATs (median 2), including 4 with additional FAT. Though, 3D-activation mapping suggested a focal origin, entrainment with concealed fusion was achieved along both sides of the crista terminals during AT, confirming the mechanism. In all patients, a broad, low amplitude EGM was recorded at the site of the “crista leak,” often comprising more than 30% of the tachycardia CL. AF-CtL often terminated with a single lesion (total lesions delivered were <10 in all patients, median 5). Differential pacing post-ablation confirmed elimination of conduction through the “crista leak.”
Conclusion: In this single center cohort of CHD patients with AT, macroreentry around the crista terminalis with transverse slow conduction through the crista was common and could be mistaken for FAT. Recognition of this mechanism can improve the efficacy of RFA and help avoid injury to the SA node and phrenic nerve.
Author Disclosures: A. Dalal: None. P. Kannankeril: None. A. Radbill: None. F. Fish: None.
- © 2016 by American Heart Association, Inc.