To implant a lead system for an implantable cardiac stimulation device, a guide wire is slidably introduced into a longitudinally extending internal passage of an elongated stylet. In turn, the combined stylet and guide wire are slidably introduced into the longitudinally extending lumen of an elongated tubular lead body of flexible resilient insulative material having a thrusting region near its distal end. With the distal end of the stylet in engagement with the thrusting region of the lead, the stylet together with the lead and guide wire are advanced until the lead should encounter a tortuous turn in the vasculature of the body. At this point, the guide wire is advanced through the stylet and into the vasculature until the distal end of the guide wire arrives at a chosen location. The stylet then re-continues its advance together with the lead until the lead reaches the desired implant location.