Purpose: We sought to evaluate the disregarded spatial torsion of the ipsilateral superior and inferior pulmonary veins (PVs).
Methods: Forty-eight consecutive atrial fibrillation patients, with four discrete PVs, were enrolled. The ostium plane of each PV, labeled by three landmarks on the CT image, was identified by three experienced observers respectively. Angle and distance between ostium planes were used to reach a consensus and to select the best ostium plane of each PV. A common ostium plane of the ipsilateral PV was computed using the two geometric centers of each side PVs and the axial center of the two geometric centers. The torsion angle was defined as the absolute difference of the two dihedral angles between the common ostium plane and the best ostium plane of the superior and inferior PVs.
Results: The torsion angle >15° was found in 16 left PVs (16/48) and in nine right PVs (9/48, P = 0.104). Moreover, in two cases (2.1 %), the torsion angle exceeded 30° (one left PV and one right PV). The torsion angle of the left PVs was significantly greater than that of the right PVs (13.65 ± 5.90° vs. 10.61 ± 5.96°, P = 0.014). Furthermore, in 29 paroxysmal AF patients, the spatial torsion of the left side PVs was 13.70 ± 5.18°, which was significant greater than that of the right side PVs (10.69 ± 5.52°, P = 0.037).
Conclusions: There was a significant torsion between the ipsilateral PVs, which should be taken into account when physicians plan their ablation to avoid a single-plane circumferential ablation.