The reliability of pacemaker electrode-leads.

Extensive experience has been obtained with Medtronic pacemakers, in Glasgow where over 400 patients have received their primary implant. In this review, which covers a period of seven and a half years ending December 31, 1973, the technical reliability of electrode-leads is considered in terms of failed implant lifetimes and incomplete implant lifetimes. Too few myocardial electrode-leads have been used to reach firm conclusions about its reliability, but the incidence of failures with the endocardial bipolar electrode-lead (Type 5818) has so far been small and it is evidently more reliable than its predecessor (Type 5816). More time must elapse, however, before it can be claimed with confidence that the present design of bipolar catheter will match the theoretical implant lifetimes of generators with the long-life power sources. Insulation failures are usually of no immediate clinical significance whereas any broken conductor is hazardous. The use of multistranded conductors is therefore advocated. All pacemakers should be retrieved after the deaths of patients.