A body implantable lead and stiffening stylet for imparting rigidity and transmitting torque to the distal end of the lead for enabling the attachment of the lead to an internal body organ. The intravascular lead carries a pin or pins at its proximal end adapted to be connected to a pulse generator and an electrode or electrodes at its distal end adapted to be securely lodged in or permanently attached to a body organ through endothelial tissue. The stiffening stylet is provided for insertion into a lumen in the lead extending from the pin along the length of the conductor to the electrode. The portion of the stylet wire to be inserted in the lumen is of a length somewhat exceeding the corresponding length of the lumen. At the proximal end of the stylet a knob is provided to engage the pin and thereby stretch the lead to effect an increase in its stiffness and torque transmitting ability.