Fluoroscopy with contrast in left bundle branch (LBB) pacing. In this left anterior oblique view at 40°, the LBB pacing lead is visible screwed into the interventricular septum. Dotted line: right ventricular surface of the septum. At a depth of > 10 mm, it captured the proximal LBB. Upgrade in a patient with chronic failure of the left ventricular lead implanted via the coronary sinus (CS). RA right atrial lead at the high right atrial septum, RV right ventricular lead at the mid right ventricular septum