All study tips
General·2026-03-16

Pacemakers and AICDs: Managing Intraoperative EMI

Electromagnetic interference and the 'magnet' logic. Don't let your patient's device be their undoing.

The Device Dilemma: Man vs. Machine

You’ve probably seen the confusion when a surgeon asks "Do we need a magnet?" The reality is, the magnet's behavior is device-specific and mode-specific. For the boards, you must have a clear algorithm.

The Cliff: The "Asynchronous" Trap

While a magnet often puts a pacemaker into an asynchronous mode (VOO/DOO), it usually disables the tachy-therapy (shocks) on an AICD without changing the pacing. "For major surgery with significiant EMI risk above the umbilicus, I will have the AICD's antitachycardia therapy disabled and have external pacing/defibrillation pads placed on the patient."

The Pivot: The "Bipolar" Surgeon

The best way to manage EMI is to minimize it at the source. "I will request that the surgeon use bipolar cautery or short, low-voltage bursts of monopolar cautery at a distance from the device."

Conclusion: Safe Integration

Understand the difference between "pacer dependent" and not. Practice defending your device management plan in the Oral Boards Bot to avoid being tripped up by "Wait, what does the magnet do to *this* one?"