189-06: Rapid 3D Reconstruction of the Left Atrium using a Novel Non-Contact Ultrasound Array Catheter in Patients Undergoing Left Atrial Ablation

Introduction: Electroanatomic 3D mapping systems that employ registration of segmented CT (sCT) images are effective in rendering the LA and PV anatomy veins but require substantial technical skill by the operator. We tested the accuracy of ultrasound (U/S) chamber reconstruction using a basket catheter system able to both rapidly image and globally map the LA. Methods: The AcQMap system (Acutus Medical Inc) employs a basket catheter [25 mm dia, 48 U/S transducers (m-mode), 48 electrodes] that acquires 100,000+ endocardial U/S points/min. The operator maneuvers/rotates the catheter in the LA. Algorithms filter and decimate the point set into a 3D surface with a mesh density comparable to sCT. The 3D LA anatomy is reconstructed from these U/S point sets. Results: In 16 pts undergoing LA ablation (age 62.7 ± 8.4 yrs; 75% male; LA 43.7 ± 6.5 mm; rhythm AF-12/AFL-2/both-2; prior ablation in 7), 3D AcQMaps were compared to pre-procedure sCTs. The absolute median distance between AcQMap and sCT surfaces was 1.86 mm ± 2.62. Mean U/S acquisition time was 7.4 ± 3.5 min for the full cohort; a 14% reduction (6.2 ± 2.3 min) occurred in the last 7 subjects. Conclusions: Real-time U/S-based 3D LA reconstruction was facile, rapid and the 3D anatomy compared favorably in quality to sCT. While algorithmic refinements are likely to further improve the quality of the 3D LA-PV anatomy, the current reconstruction provides discernable PV ostia and anatomic landmarks required for ablation guidance.