Abstract 17192: Characterization and Localization of Focal Atrial Tachycardia in Adult Congenital Heart Disease

Abstract

Introduction: Patients with adult congenital heart disease (ACHD) often develop atrial arrhythmias, including focal atrial tachycardia (FAT). In non-ACHD patients, algorithms using surface ECG P-wave morphology are helpful to predict FAT location to assist in planning targeted ablation procedures, but similar algorithms have not been fully developed for ACHD patients with complex anatomy, including prior surgical correction and other anatomic differences. Methods: In this single-center retrospective cohort study, 29 patients with ACHD who underwent catheter ablation for FAT were included. FAT P-waves from 12-lead electrocardiograms obtained in clinic or the electrophysiology laboratory were classified as 1) positive, 2) negative, 3) isoelectric, or 4) biphasic. FAT ablation sites identified by electroanatomic mapping were grouped by region: right atrium (RA), paraseptal (PS), and left atrium (LA). Accuracy of P-wave classification criteria to predict FAT region were determined. Results: Thirty FATs were assessed in 29 patients (mean age 47 +/- 16 yrs, female 55%). RA FAT sites: crista terminalis (14), Fontan baffle (3) non-septal tricuspid annulus (1). PS FAT sites: PS tricuspid annulus (2), coronary sinus ostium (3), foramen ovale (1). LA FAT sites: mitral annulus (2), right superior pulmonary vein (1), left atrial appendage (3). Based on previously reported P-wave morphology localization criteria in normal hearts, sensitivities and specificities were analyzed in these ACHD patients and are shown in the Table. Additional algorithms were also tested. We determined that a biphasic (+/-) or negative P-wave in lead V1 was associated with a 100% specificity for the RA compared to PS or LA. Conclusions: P-wave morphology may be useful in predicting atrial location of FAT in ACHD patients. Similar to patients with normal hearts, lead V1 P-wave morphology in ACHD patients provides the most useful information for localizing FAT with a high degree of specificity.