HIGH ATRIAL-PACING IMPEDANCE - EFFICIENT OR WASTEFUL - A COMPARISON OF AN ACTIVE AND A PASSIVE FIXATION LEAD

We compared the stimulation characteristics of two atrial fixation lea ds: the CPI model 4269 (n = 45) and Cordis-Telectronics model 327-752 (n = 42). The CPI lead uses an active fixation method, whereas the Cor dis-Telectronics lead is fixated passively. impedance and threshold we re measured at implant and during 12 months of follow-up. P wave sensi ng was good with both types of leads. Follow-up of these 87 leads show ed that both the impedance and threshold increased with the active lea ds, but not with the passive fixation leads. in the active fixation gr oup, regardless of the high atrial pacing impedance, 93% could still b e programmed to 2.5 V-0.6 msec (with a 2:1 threshold safety margin). i t is concluded that the high chronic pacing impedance of the active fi xation leads will be beneficial on current drain if no major increase in pacing threshold occurs simultaneously.