2.2 Preparation of the lead and determination of the implant site.
Preparation of the stylet-driven lead (Solia S60, Biotronik, SE & Co, KG, Berlin, Germany) and determination of the implant site were performed as previously described.[7–9] In summary, the stylet was fully advanced to the tip of the pacing lead and maintained in this position until the end of the implant procedure. Turning the CP 10 times clockwise exposed the helix. Further torque on the inner coil was subsequently delivered by applying 10 additional clockwise rotations on the CP by using the stylet insertion tool. Finally, without loosing the built-up tension (without unwinding of the CP), the stylet insertion tool was pushed over the silicon part adjacent to the CP to maintain the build-up torque onto the outer lead body. Thereafter, the sheath with pacing lead was positioned in the right atrium. The His bundle region was delineated using the pacing lead unipolar electrograms for mapping, and its localization on fluoroscopic image was set as a reference. Next, starting from the right ventricle, the sheath and pacing lead were positioned according to the nine-partition method in the right anterior oblique view.[9] A counterclockwise rotation was performed to direct the sheath towards the RV septum. A left anterior oblique view was used to confirm a perpendicular position to the septum. From that position, and after unipolar pacing demonstrated a ”W” QRS pattern in V1 with a vertical inferior lead vector and a discordant pattern in aVR and aVL, the implantation of the lead was started.