What causes pacemaker failure to output?

Updated: Oct 11, 2019
  • Author: Daniel M Beyerbach, MD, PhD; Chief Editor: Jeffrey N Rottman, MD  more...
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Failure to output occurs when no pacing artifact is present despite an indication to pace. This may be due to battery failure, lead fracture, fractured lead insulation, oversensing (inhibiting pacer output), poor lead connection at the takeoff from the pacer, and "cross-talk" (ie, a phenomenon occurring when atrial output is sensed by a ventricular lead in a dual-chamber pacer).

Management of pacer output complications includes medications to increase the intrinsic heart rate and placement of a temporary pacer. A chest radiograph is warranted to check pacer leads and to evaluate for possible lead fracture, which occurs most commonly at the clavicle or first rib. The patient's pacer identification card should be obtained and his or her electrophysiologist or cardiologist consulted.

Lead impedance (resistance) may also be an indicator of lead malfunction. Very low impedance may signify a fracture of the insulation (ie, the energy is dissipating into the surrounding tissue), whereas infinite (or very high) impedance may signify either complete lead fracture or a lead tip dislodged from the endocardium.

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