Apparent Pacemaker Failure Caused by Activation of Ventricular Threshold Test by a Magnetic Instrument Mat During General Anaesthesia

Abstract

A patient with a permanent pacemaker underwent radical neck dissection. After induction of anaesthesia, a magnetic surgical instrument mat was placed over the patient's chest. This caused the pacemaker to go into a threshold test which included a 2.5-s period of asystole. Surgery had to be abandoned temporarily. We suggest that magnetic instrument mats should not be used with pacemaker patients; not all pacemakers are converted to a fixed magnetic rate by application of a magnet. The anaesthetist should check to see if the patient has a pacemaker with a threshold test and, if possible, this should be rendered inactive.

Asystole during pacemaker magnet application

“…Two previous reports have described magnet use resulting in loss of ventricular capture. One case was in the setting of an obsolete pacemaker model's antiquated method of threshold testing that was activated by a magnet and a second case was associated with intermittent loss of capture due to an inadequately programmed output in a pacemaker that was not interrogated for >1 year before surgery . A summary of other possibilities is provided in Table .…”

Practice Advisory for the Perioperative Management of Patients with Cardiac Implantable Electronic Devices: Pacemakers and Implantable Cardioverter-Defibrillators

“…Although no controlled trials of the clinical impact of performing a focused preoperative evaluation for CIED patients were found, case reports suggest that incomplete preoperative examination of patients with CIEDs may lead to adverse outcomes (e.g., inhibited CIED function and asystole) (Category B3 evidence). 1,2 The majority of consultants, ASA members, and HRS members agree that the above four preoperative evaluation activities should be conducted. ** Advisory for Preoperative Evaluation.…”

Assessment and management of patients with pacemakers and implantable cardioverter defibrillators

“…In such circumstances, clinical events such as hypotension, bradycardia, asystole, and ventricular tachyarrhythmias may occur. There are numerous case reports of such occurrences (22)(23)(24)(25)(26)(27)(28)(29), and review articles and book chapters have analyzed the issue (7,(17)(18)(19). Recently, as a result of a joint effort by the American College of Cardiology and American Heart Association, formal guidelines were published on the perioperative care of pacemaker patients (30).…”