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Pacing system malfunction: Evaluation and management

David L Hayes, MD
Section Editor
Mark S Link, MD
Deputy Editor
Brian C Downey, MD, FACC


Periodic evaluations of an implanted pacemaker are required to maintain optimal programming and to identify any system problem that should be corrected. Common pacing system problems of single and dual chamber pacemakers and the methods of evaluation and therapy will be reviewed here. The malfunctions discussed will be limited to those that are manifest on an ECG rhythm strip.

Complications not related to pacing system malfunction — Other complications not related to pacing are presented separately. These include infections, venous thrombosis and emboli, pacemaker syndrome, tricuspid regurgitation, and specific problems associated with dual-chamber pacemakers. (See "Infections involving cardiac implantable electronic devices" and "Cardiac implantable electronic devices: Long-term complications", section on 'Tricuspid regurgitation' and "Dual chamber pacing system malfunction: Evaluation and management".)


The incidence of pacing system malfunction is difficult to determine due to inconsistent definitions and the lack of any comprehensive reporting mechanism or registry [1,2]. Overall, device hardware is highly reliable [3]. In terms of comparative reliability, there is a higher incidence of complications of leads compared with pulse generators. In terms of lead malfunction, more complex ICD leads have a higher incidence of failure than simpler pacemaker leads. As a result of a series of lead malfunctions, a policy was published by Heart Rhythm Society with lead performance guidelines [4].


The pacing system is comprised of the pulse generator (picture 1), also called the pacemaker, and the lead or leads which connect the pulse generator to the heart.

The phrase "pacing system malfunction" includes problems that might arise from any of the components of the system. Inappropriately programmed pacemaker parameters, although they do not represent abnormal pacing system function, may be suboptimal for the patient. The normal characteristics and unique timing systems and algorithms of a given pacemaker are also an issue, as they may be interpreted as a malfunction by a clinician who is not familiar with the specific pulse generator. Recording system artifacts must always be considered in the differential diagnosis of a pacing system malfunction.

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Literature review current through: Nov 2017. | This topic last updated: Jul 06, 2016.
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