Skip to Main Content


  • In the United States >500,000 pacemakers are implanted each year, with more than 6 million patients today having a pulse generator device
  • Almost 100% of pacemakers are placed for a specific disease process rather than prophylactically
  • Most patients have concomitant diseases: HTN, CAD, DM, pulmonary disease


  • Symptomatic SA node dysfunction:
    • Bradycardia, pauses
  • Symptomatic AV node dysfunction:
    • Third-degree (complete) heart block
    • Second-degree heart block:
      • With symptomatic bradycardia
      • After AV node resection or following valve surgery
      • Secondary to muscular disease
  • Post-MI heart block (≥Mobitz II)
  • Sick sinus syndrome
  • Long QT syndrome
  • Biventricular pacing for resynchronization in CHF


  • All implanted devises (pacemakers) are contraindicated in MRI suite
  • Possible other causes of interference:
    • Electrocautery (Bovie)
    • RF ablation
    • Lithotripsy
    • Electrolyte/acid–base abnormalities
    • Medications:
      • Succinylcholine (fasciculations can inhibit PM; not an absolute contraindication)
      • Cardiac medications modifying detection or stimulation thresholds (e.g., sotalol, verapamil)
    • Rare: orthopedic saw, telemetric devices, mechanical ventilators


  • Determine type of pacemaker:
    • Manufacturer’s identification card or ID bracelet
  • Obtain EKG, and if needed CXR
  • Determine if patient is pacer dependent:
    • Patient history
    • Postablative procedures
    • Rhythm strip with no spontaneous ventricular activity
  • Determine when PM last interrogated and battery life
  • Have available:
    • External defibrillator/transcutaneous pacer, transvenous pacer
    • Magnet
    • Isoprenaline and/or dopamine
  • Make preparations to have pacemaker company representative available (or other qualified personnel):
    • Interrogation of device in holding area (or in OR if necessary to change device settings only after patient is anesthetized):
      • Turn PM to asynchronous mode (DOO or VOO)
      • Turn off any other option (rate-adaptive, antitachycardia, etc.)
    • If not possible (or if PM inappropriately inhibited by cautery), place magnet over device (must be kept in place for length of procedure); magnets will typically change pacing into asynchronous mode at a preprogrammed rate
  • Minimize electromagnetic interference(s):
    • Place grounding pad away from pacer, and in such a position that the current from the cautery to the pad will not flow through the pacemaker or the heart
    • Use bipolar cautery if possible
    • If monopolar needed, advise surgeon to use short (<1 second) bursts
  • Avoid dysrhythmia-triggering situations:
    • Electrolyte imbalance
    • Ischemia
    • Hypovolemia


  • Intraoperative monitoring:
    • Special attention to EKG (capable of detecting pacer-generated spikes)
  • Applicable alternatives to intrinsic (pacer): external pacer pads, defibrillator, and transvenous pacer
  • Avoid inserting PAC if PM in place <4 weeks (risk of dislodgement)
  • If PM malfunction:
    • Stop any electrical device in use (especially cautery)
    • Evaluate clinical impact
    • If poorly tolerated bradycardia:
      • Apply magnet
      • If ineffective, start isoprenaline/dopamine infusion; use transcutaneous and/or transvenous pacer
    • If cardiac arrest, initiate CPR; use transcutaneous and/or transvenous pacer
    • If tachycardia and DDD pacer, apply magnet; otherwise, treat as appropriate (see chapter 16 on tachyarrhythmias)


  • Reevaluation (by qualified personnel) of pacer
  • Restore preoperative settings
  • Removal of magnet:
    • Pacer should return to normally functioning mode
    • Interrogation of device by qualified personnel and/or admittance for observation until proper function can be determined

Table Graphic Jump Location
Table 18-1 Generic Pacemaker Code (NGB) for All Companies Manufacturing Pulse Generators

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.