a system implantable in the coronary venous system , including a pacing lead with an anchoring screw is disclosed . the system includes a stimulation lead for stimulating a left heart cavity of a patient , and a removable catheter for implanting the lead . the lead has at least one stimulation electrode having an anchoring screw that penetrates into the epicardial tissue of the patient . the catheter tube is a pre - shaped tube with two curvatures in the absence of stress . the two curvatures are inscribed in two separate surfaces for self - orientating the distal end of the catheter tube into the target vein and maintaining the axis of the anchoring screw towards the epicardial wall during the screwing of the lead head .