Clinical evaluation of a sutureless cardiac pacing lead: chronic threshold changes and lead durability

Chronic threshold changes and durability of the Medtronic 6917 sutureless cardiac pacing lead were evaluated in 100 consecutive patients. A bipolar pacing system was established in each patient. Lead failure occurred in 4 patients; all failures resulted from exit block or loss of adequate contact between electrode and myocardium. Electrode fracture or loss of lead insulation was not observed. Fifty patients had replacement of the pulse generator 27.4 +/- 1.8 months after implantation. Long-term stimulation threshold voltage was about 2.5 times greater and current was about 3.5 times greater than values obtained at initial implantation, yet they continued to permit safe and effective cardiac pacing.