AIMS Left ventricular (LV) lead implantation is feasible using remote magnetic navigation of a guidewire (Stereotaxis, St Louis, MO, USA). A novel software that performs a three-dimensional (3D) reconstruction of vessels based on two or more angiographic views has been developed recently (CardiOp-B system, Paeion Inc., Haifa, Israel). The objective of this paper is to evaluate: (i) the performance of the 3D reconstruction software which reproduce the anatomy of the coronary sinus (CS) and (ii) the efficacy of remotely navigating a magnetic guidewire within the CS based on this reconstruction. METHODS AND RESULTS In patients undergoing cardiac resynchronization therapy implantation, a 3D reconstruction of the CS was performed using the CardiOp-B system. Accuracy of the reconstruction was evaluated by comparing with the CS angiogram. This reconstruction was imported into the Stereotaxis system. On the basis of the reconstruction, magnetic vectors were automatically selected to navigate within the CS and manually adjusted if required. Feasibility of deploying the guidewire and LV lead into the selected side branch (SB), fluoroscopy time (FT) required for cannulation of the target SB, and total FT were also evaluated. Sixteen patients were included. In one case, the software could not reconstruct the CS. The quality of the reconstruction was graded as good in 13 and poor in 2. In 10 cases, manual adjustments to the traced edges of the CS were required to perform the 3D reconstruction, and in 5, no adjustments were required. In 13 patients, the target SB was engaged on the basis of the automatically selected vectors. In two cases, manual modification of the vector was required. Mean total FT was 23 +/- 14 min and the FT required to cannulate the target SB was 1.7 +/- 1.3 min. CONCLUSION A 3D reconstruction of the CS can be accurately performed using two angiographic views. This reconstruction allows precise magnetic navigation of a guidewire within the CS.