Abstract 20203: Electrophysiologic Features and Ablation of Junctional Tachycardia
Introduction: Junctional tachycardias (JTs) originate from different foci within or close to the atrioventricular (AV) junction and can exit to the atrium from various extensions of the AV node. Catheter ablation can be challenging because of this variability, rarity of JTs, and risk of complete heart block (CHB). We reviewed our series of JT ablations to evaluate their electrophysiological properties and outcomes.
Methods: We retrospectively identified 15 consecutive JT ablations (4 males; age range 5-77 years) at Mayo Clinic Rochester since 2006, and reviewed the electronic medical record and the stored electrograms. Origin of JT was determined by the successful site of ablation (radiofrequency or cryoablation) as His bundle (HB, n=4), slow pathway region (SP, n=8), or fast pathway/non-coronary cusp region (FP, n=3).
Results: Fifteen patients (mean age 35±19 years; 6 with structural heart disease; 7 with prior ablation failure) underwent ablation for JT (cycle length range 240-760, median 402 ms). Retrograde atrial activation was seen in 13 of 15 JTs (intermittently in 7). Among 4 patients with HB-JT, 3 had demonstrable distal to proximal His activation, and 2 of 4 developed CHB with ablation, while 1 had subsequent recurrence. Among 8 SP-JT, earliest atrial activation was at SP in 4, FP in 1, and not mapped in 3. Among 3 FP-JT, earliest atrial activation was in FP in 2 and SP in 1. Over median follow-up of 35 months (range 1-88), 1 FP-JT and 2 SP-JT had recurrences requiring antiarrhythmic drugs.
CONCLUSIONS: JT ablation had long term success in 12 of 15 patients, while 2 of 15 developed CHB. HB-JT could be predicted by distal to proximal His activation and ablation of HB-JT had high risk of developing CHB. SP-JT and FP-JT can exit to the atrium using the SP or FP extensions of the AV node irrespective of the site of origin. Sequential ablation targeting the SPs and non-coronary cusp with radiofrequency energy followed by FP region with cryoablation can be successful with lesser risk of CHB.
Author Disclosures: E. Ebrille: None. S. Nanda: None. A. Noheria: None. S.J. Asirvatham: Honoraria; Modest; Abiomed, Atricure, Biotronik, Biosense Webster, Boston Scientific, Medtronic, Spectranetics, St. Jude, Sanofi-Aventis, Wolters Kluwer, Elsevier. Ownership Interest; Modest; Aegis, ATP, Nevro, Sanovas, Sorin Medical.
- © 2014 by American Heart Association, Inc.