Clinical surveillance of an active fixation, bipolar, polyurethane insulated pacing lead, Part I: The atrial lead.

Since 1989, 168 Telectronics model 330-801 active fixation, polyurethane insulated atrial leads (Accufix) have been implanted at the Mayo Clinic. There were four (2.4%) acute lead related complications, (i.e., perforation, microdislodgment, and pericarditis). Over a median follow-up time of 7.6 months (up to 2.7 years), there were 14 (8.3%) chronic complications, including 1 instance (0.6%) of definite lead failure. Most of these complications were early (within the first month) and transient. Four patients (2.4%) required reoperation for chronic complications. During follow-up, 23% of the examined patients had high pacing thresholds, most at about 3 months after implantation, necessitating high-output programming. The exact mechanism and natural history of this phenomenon should be further investigated.