Unsatisfying results in long-term atrial pacing with a bipolar active fixation atrial lead.

A high dislodgment rate during long-term atrial pacing using the unipolar sickle-shaped active fixation lead was recently reported; therefore, the long-term results of atrial pacing in 118 consecutive patients with the bipolar sickle-shaped active fixation lead (Biotronik FH60-BP) were evaluated. Between January 1989 and September 1993, 87 leads (74%) were inserted for dual chamber pacing and 31 leads (26%) for atrial pacing only. At the time of implantation, the bipolar atrial electrogram had a mean voltage of 4.4 +/- 1.6 mV, whereas the acute atrial threshold was 0.72 +/- 0.38 V and 1.46 +/- 0.67 mA at 0.5-msec pulse duration and mean resistance 506 +/- 79 omega. Early lead dislodgment (< 1 month after implantation) occurred in 9 patients (7.6%). During a mean follow-up of 21.8 months (median 20.9 months), late dislodgment (> 1 month after implantation) occurred in 6 patients (5.1%) after a mean interval of 7.9 months (range 3-14 months). Due to the unacceptably high late dislodgment rate, which to date remains unexplained, new implants of this lead are not recommended.