Junctional Ectopic Tachycardia Localization and Procedural Approach using Cryoablation

BACKGROUND: Idiopathic junctional ectopic tachycardia (JET) may still be difficult to control with antiarrhythmic therapy. Transcatheter ablation can be challenging and may be associated with a high risk of unintended atrioventricular block. The objective of this manuscript is to report the procedural technique, the location of the successful ablation, and the procedural characteristics while utilizing 3D mapping for cryoablation of JET. METHODS: A retrospective analysis was performed on all patients who had undergone cryothermal ablation for the treatment of JET at a single center. Patient, arrhythmia, and procedural information and long-term outcomes were evaluated. RESULTS: Thirteen patients with JET were treated by cryothermal ablation. The JET arrhythmia burden varied greatly, generally with inadequate control on medications. Left ventricular dilation was present in three patients, and one patient had dilated cardiomyopathy. The median age at the time of procedure was 13 years, with median weight of 54.1 kg. The ectopic focus was ablated in 11/13 patients within the lower 2/3 of the triangle of Koch (TOK) with cryotherapy. Ablations, which were not successful, low in the TOK were associated with substantially longer procedures, and had a higher risk of recurrence. There was late resolution of the arrhythmia in two of three acutely unsuccessful ablations. There were no complications. CONCLUSION: In the majority of patients JET can be safely ablated with the use of cryotherapy. Foci not identified in the lower 2/3 of the TOK are associated with longer procedures, more lesions, and decreased chance for long-term success.