Objectives:
This study aimed to evaluate the efficacy and long-term clinical outcomes of fully CMR-guided radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) in a large-scale cohort of patients with isthmus-dependent right atrial flutter.
Background:
Electrophysiological cardiovascular magnetic resonance (EPCMR) interventions have recently transitioned into clinical practice, but data on long-term success and recurrence rates are currently lacking. Methods and Results: A total of 142 consecutive patients with isthmus-dependent right atrial flutter underwent CMR-guided RF ablation using real-time active catheter tracking. This approach enabled precise 3D navigation within segmented cardiac cavities integrated with patient-specific multiplanar reformatted geometries. EPCMR procedure duration was 51±30 min (range, 11‒154 min) independent of anatomical variations. Acute procedural success, defined as the achievement of complete bidirectional isthmus block, occurred in 138 patients (97%). Recurrence of atrial flutter was documented in 8 patients during a mean follow-up period of 20 months. Cumulative recurrence-free survival rate at 1-year follow-up was 97%. Predictors of atrial flutter recurrence included age, procedure duration, number of ablation points, and maximum conduction time difference; however, only the maximum conduction time difference remained a significant independent predictor on binary logistic regression analysis (p=0.022).
Conclusions:
Fully CMR-guided radiofrequency ablation represents a robust approach for isthmus-dependent atrial flutter, delivering high procedural success rates and sustained clinical durability across diverse anatomical variants.
