Abstract 11574: Ventricular Arrhythmia Ablation Lesions in Children and Adolescents: Acute Magnetic Resonance Imaging With Outcome Correlation

Abstract

Introduction: Catheter ablation for arrhythmias is not always 100% effective when using current techniques. Failure of ablation may be secondary to inadequate lesion development. Peri-procedural visualization of ablation lesions may identify inadequate lesions or gaps to guide further ablation and reduce risk of arrhythmia recurrence. Methods: This pilot feasibility study assessed acute post-procedure ablation lesions by MRI, and correlated these findings with clinical outcomes. Six patients who underwent ventricular tachycardia ablation were transferred immediately post-ablation to a 1.5T MRI scanner for imaging. Late gadolinium enhancement (LGE) imaging was performed using a novel motion-corrected, phase sensitive inversion recovery sequence while free breathing. Immediate and short term arrhythmia recurrences were assessed. Results: Patient characteristics include median age 14.5 yrs (11 - 17 yrs), median weight 59 kg (43 - 81kg), normal cardiac anatomy (n = 4), anomalous coronary artery post repair (n = 1), and cardiac rhabdomyomas (n = 1). All patients underwent radiofrequency catheter ablation of ventricular arrhythmia with acute procedural success. LGE was identified at the reported ablation site in 5/6 patients, and not seen in 1 patient. The 5 patients with identifiable lesions were arrhythmia- and symptom-free at follow-up, ranging 1-6 months. The 1 patient in whom a lesion could not be identified had recurrence of frequent premature ventricular contractions within 2 hours post-procedure, confirmed on Holter monitoring 1 month later. Conclusions: Ventricular ablation lesion visibility by MRI in the acute post-procedure setting is feasible, and lesions identifiable with MRI may correlate with clinical outcomes. MRI identification of gaps or inadequate lesions may provide the unique temporal opportunity for additional ablation therapy to decrease arrhythmia recurrence.