Image integration using NavX fusion: Initial experience and validation

BackgroundThree-dimensional virtual anatomic navigation is increasingly used during mapping and ablation of complex arrhythmias. NavX Fusion software aims to mold the virtual anatomy to the patient’s computed tomography (CT) image; however, the accuracy and clinical usefulness of this system have not been reported.ObjectiveThe purpose of this study was to assess the accuracy and describe the initial experience of CT image integration using NavX Fusion for atrial fibrillation ablation.MethodsThis study consisted of 55 consecutive patients undergoing atrial fibrillation ablation using NavX Fusion navigation. Left atrial NavX geometries were compared to a corresponding CT for geometric match. Geometric match, expressed as the difference in millimeters between CT and NavX geometry, was calculated for the original geometry (GEO-1), field scaled and primary fused geometry (GEO-2), and final secondary fused geometry (GEO-3). Navigational accuracy was assessed by moving the catheter to 10 discrete anatomic sites and determining the distance between the catheter tip and the closest GEO-2, GEO-3, and CT surface. Fusion integration time and procedural and fluoroscopic durations were recorded to assess clinical usefulness.ResultsGEO-1, GEO-2 and GEO-3 were associated with CT–GEO errors of 6.6 ± 2.8 mm, 4.1 ± 0.7 mm, 1.9 ± 0.4 mm, respectively. Navigational accuracy was not significantly different for GEO-2, GEO-3, and CT at 3.4 ± 1.6 mm to any surface. A significant (P ≤.001) inverse curvilinear relationship was present between case number and the time required for image integration (r2 = 0.35) and the fluoroscopic time normalized for procedural duration (r2 = 0.18).ConclusionImage integration using the NavX Fusion software is highly accurate and is associated with a progressive reduction in fluoroscopic time relative to procedural duration.