Introduction: Three-dimensional (3D) navigation systems are widely used for pulmonary vein antrum isolation (PVAI). To circumvent left atrial (LA) mapping, 3D CT reconstructions of the LA can be superimposed directly (CT overlay) on the fluoroscopy image to guide ablation catheters and to mark ablation sites.
Methods and results: Sixty-eight patients (pts) with symptomatic AF refractory to medical therapy were randomly assigned to CT overlay (group 1, n = 38) or CartoMerge (group 2, n = 30). In group 1 registration of the CT image was performed with contrast injections in 2 orthogonal projections. In group 2, visualization of all pulmonary vein (PV) ostia was done by PV angiography, followed by merging of the CT image and the Carto shell. We compared procedural success, procedure time, fluoroscopy time and radiation burden, measured as dose area product (DAP). Baseline characteristics were comparable in both groups. Procedural success, defined as disappearance of PV potentials in all PVs, was achieved in 37/38 (97%) of group 1 patients and 27/30 (90%) patients in group 2 (P = NS). Total procedure time was significantly shorter in group 1 compared to group 2 (129 +/- 34 vs 181 +/- 30 min, P < 0.0001). Although fluoroscopy time tended to be longer in the CT overlay group (47 +/- 16 vs 40 +/- 13 min, P = 0.06), proper use of diaphragmation resulted in comparable radiation values for both groups (DAP 53 +/- 27 vs 56 +/- 35 Gy cm(2), P = 0.76).
Conclusions: CT overlay for PV isolation is feasible and may, in comparison to conventional LA navigation systems, shorten procedural time without increases in radiation burden.