High impedance alert with safety switching: An unreported hazard of hybrid pacing systems.

Several Boston Scientific pacemaker models have a known issue with intermittent oversensing of the minute ventilation sensor when paired with non-Boston Scientific leads. Several of our patients with these hybrid systems have had transient out of range impedances and oversensing after safety switching which we suspected may be related. A retrospective analysis of 395 patients who had pacemakers implanted between 2015-2017 found that transient out of range impedances with safety switching was present in 9% of Boston Scientific pacemakers paired with Abbott or Medtronic leads compared with 0% in other device-lead combinations (P = 0.