The Direct Lead Parameters Measurements on Implanted Ventricular Leads in the Patients With Pulse Generator Replacement

We undertook this study to measure the direct lead parameters of implanted ventricular leads in the patents with pulse generator replacement.26 patients with third degree atrioventricular block in 14 and sick sinus syndrome in 12, 15 male and 11 female, mean age 63.9±13.6 years, were involved.Direct lead parameters of implanted ventricular leads that had been implanted for 114.2±27.4 (58～179) months were detected using a pacing system analyzer during pulse generator replacement.Results showed the chronic pacing threshold of leads during pulse generator replacement were higher than initial pacing threshold (1.60±0.75 V vs 0.59±0.27 V, P0.0001).Chronic pacing threshold of leads during pulse generator replacement were increased by 198.1%±141.1%(20%～567%), with mean increased value of 1.0±0.7(0.1～3.0) V.Chronic lead impedances were 558.5±136.3 Ω during pulse generator replacement. Postoperatively, 22 old leads were continued to perform the pacing function and were followed up for 48.7±30.6 months (6～96 months).Leads malfunction occured in 2 cases of the 22 old leads in 12 months or 24 months after replacement operation, respectively.It is concluded that most direct lead parameters on implanted ventricular leads for near 10 years are within normal ranges, and are considered to continue performing pacing function.Follow up should be taken regularly for those patients.[Chinese Journal of Cardiac Pacing and Electrophysiology,2000,14(2):107～109] Cardiac pacing,permanent Ventricle pacing lead Lead parameters measurements,direct