Dipole charge density mapping demonstrates superiority in catheter ablation of post-surgical atrial tachycardias

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Atrial tachycardia (AT) frequently occurs after cardiac surgery or surgical ablation procedures. The novel dipole charge density-based mapping system (AcQMap) provides global chamber mapping and can detect multiple slow conduction zones and re-entry isthmuses; therefore, it has a potential added value in post-surgical AT ablation. We aimed to test the hypothesis that AcQMap guided catheter ablation (CA) procedures are safe, feasible, and may provide improved outcome compared to conventional sequential 3D mapping (CARTO) based CA. METHODS: Consecutive patients undergoing CA for post-surgical ATs guided by the AcQMap or the CARTO system were enrolled. Procedural safety characterized by procedural complications, and efficiency characterized by procedure duration, fluoroscopy use, radiofrequency (RF) application and duration, were analyzed. Acute success, one-year outcome as freedom from AT and atrial fibrillation were assessed. RESULTS: A total of 40 patients (mean age 58.2±13.0 years, 42.5% female), underwent CA of AT using the AcQMap (n=20) and CARTO mapping system (n=20). No differences were found in procedural complication (AcQMap 3 vs. CARTO 2 patients, p=0.63). There were no differences in procedure duration (188.1 vs. 153.8 minutes, p=0.08), fluoroscopy dose (165.0 IQR 121.0-254.0 vs. 107.0 IQR 28.8-284.0 mGy, p=0.16), RF application number (30.0 IQR 18.8-63.5 vs. 25.5 IQR 10.5-44.3, p=0.20) or duration (1397.0 IQR 690.5-1869.8 vs. 1238.0 IQR 499.0-2074.8 s, p=0.47). Acute success was 95.0% in AcQMap group and 80.0% in CARTO group (p=0.15). A total number of 70 ATs were mapped in 40 patients (35 in the AcQMap group and 35 in the CARTO group, average 1.6 ± 0.7). Four patients had focal ATs, 26 patients had macro re-entrant ATs, and 9 patients had ATs with both mechanisms. In one patient AT was not mappable with the CARTO system, empiric ablation was performed. There were no differences in AT mechanism between the patient groups (p=0.53). Cumulative AT recurrence rates were lower in AcQMap group compared to CARTO group (18.8% vs. 52.6%, p=0.01). Freedom from all arrhythmias was 75.0% in the AcQMap and 36.8% in the CARTO group (p < 0.01). CONCLUSIONS: The AcQMap system is safe and feasible. Our data suggest that patients treated with AcQMap-guided CA developed fewer AT recurrences as compared to CARTO-guided procedures. [Figure: see text]