First clinical experience using a novel high-resolution electroanatomical mapping system for left atrial ablation procedures

Background: The Rhythmia mapping system was recently launched and allows for rapid ultra-high-resolution electroanatomical mapping. We evaluated the feasibility, acute efficacy and safety of this novel system for ablation of atrial fibrillation (AF) and left atrial (LA) tachycardia (AT). Methods and results: A total of 35 consecutive patients (age 64.3 ± 8.6 years, LA diameter 44.4 ± 5.8 mm) underwent catheter ablation for AF and/or AT. All procedures were performed using Rhythmia in conjunction with the Orion mini-basket catheter. Pulmonary vein isolation (PVI) and linear lesions were performed applying radiofrequency (RF) energy. PVI was confirmed by presence of entrance and exit block using the mini-basket catheter. In addition, pacing maneuvers assessed bidirectional conduction block across linear lesions. Procedure duration was 110.3 ± 33 min, fast acquisition mapping (FAM) time was 19 ± 9 min. A mean number of 10165 ± 5904 mapping points were acquired during the initial map and 6379 ± 3191 for a remap. A total number of 31 ± 15 RF applications were delivered within 45 ± 22 min. Total fluoroscopy time was 21 ± 5, 5 ± 2 min were used for FAM. We observed a significant learning curve for mapping duration (p = 0.01). Complications included pericardial tamponade (n = 1), transient air embolism in the right coronary artery (n = 1), and mild groin hematoma (n = 2). Conclusions: The present study is the largest to describe experience of LA ablation procedures using Rhythmia. PVI was achieved in all patients. Applying this ultra high-resolution electroanatomical mapping system under routine conditions leads to a high level of confidence. More data will be mandatory before final conclusions can be drawn.