An epicardial screw lead for stimulation/defibrillation implantable by a guide-catheter inserted into the pericardial space is described. The lead is a monodiameter lead with a helical anchoring screw extending axially of the lead body. The guide-catheter (24) has a pre-shaped tube having, in the absence of stress, a first bend (26) for supporting the lead body on the outer wall of the pericardial space (38), and a second bend (28) for orienting the end of the guide-catheter tube in the direction of the outer wall of the myocardium (34) and keeping the axis of the anchoring screw (14) in that same direction during a combined movement of screwing and insertion of the lead head.
