History and Physical Examination
History
Clinical symptoms of pacemaker malfunction are variable and include syncope, dizziness, palpitations, and slow or fast heart rate. Extracardiac stimulation or hiccup may be present. Obtain as much information as possible regarding the pulse generator, leads, and programmed values. Information on time of initial device placement, indication for pacemaker implant, special programming features particular to that model or patient, any recent surgeries, and knowledge of any manufacturer recalls or alerts on pacing systems may provide clues to the underlying malfunction.
Physical examination
Look for the following signs in patients with pacing system malfunction:
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Pocket stimulation
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Erosion of pocket
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Diaphragmatic stimulation
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Cannon A waves during atrioventricular dyssynchrony
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Bradycardia
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Tachycardia
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Hypotension
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Pacemaker Malfunction. Atrial undersensing. The rhythm strip shows an atrial pacing artifact after the intrinsic P wave.
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Pacemaker Malfunction. Ventricular undersensing. The rhythm strip shows ventricular pacing artifacts despite normal underlying ventricular activity.
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Pacemaker Malfunction. Atrial lead dislodgment. The chest radiograph film detail shows a dislodged atrial lead with the tip in the right ventricular cavity.
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Pacemaker Malfunction. Ventricular noncapture. The rhythm strip shows atrial (P wave) sensing followed by a ventricular spike, which failed to capture the ventricle.
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Pacemaker Malfunction. Loss of atrial capture. The rhythm strip shows intermittent loss of atrial capture.
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Pacemaker Malfunction. Pacemaker-mediated tachycardia. The rhythm strip shows ventricular pacing at 110 beats per minute (programmed maximal track rate).
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Pacemaker Malfunction. Termination of pacemaker-mediated tachycardia (PMT). Automatic postventricular atrial refractory period (PVARP) extension terminated the PMT.
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Pacemaker Malfunction. This image shows an artifact due to monitor malfunction or a loose limb lead connection. An abrupt loss of a portion of the QRS complex followed by a flat line can be observed. If R-R intervals are matched, two QRS complexes are missing during the pause. If the artifact is due to a dislodged lead, a pacing artifact with no capture should be observed.
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Pacemaker Malfunction. This is a typical example of ventricular oversensing with inhibition of ventricular pacing. In ventricular noncapture, a ventricular pacing artifact should be present after the third P wave.