Sixteen failures in a single model of bipolar polyurethane-insulated ventricular pacing lead: a 44-month experience.

During a 44-month period, 105 Medtronic model 6972-58 polyurethane-insulated, bipolar ventricular pacing leads were implanted, of which 16 failed clinically at a mean of 20.5 months post-implant. Pacing dysfunction presented as either intermittent or complete loss of sensing and/or capture and, rarely, oversensing . Thirteen of the 16 patients were asymptomatic, and problems were detected in 11 instances during routine telephonic surveillance. At the time of lead replacement, low or widely fluctuating lead resistance values and high current drain were uniformly observed. The single lead capable of total extraction revealed rupture of both internal and external insulation. A brief summary of the currently much-discussed "polyurethane controversy" is presented, and the issue of patient management is discussed.