# AI instructs a nurse to place a magnet over a pacemaker to 'reset' it during asystole, ignoring asynchronous pacing risk

- **ID:** `medical/pacemaker-magnet-response`
- **Domain:** medical
- **Category:** runtime_error
- **Error Code:** `PACEMAKER-MAGNET-ASYSTOLE`
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

Placing a magnet over a pacemaker typically switches it to asynchronous (fixed-rate) pacing mode, which can compete with intrinsic rhythm and cause R-on-T phenomenon leading to ventricular fibrillation. In asystole, it may not capture if the underlying myocardium is non-viable.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Medtronic Adapta DR | active | — | — |
| Boston Scientific Accolade MRI | active | — | — |
| Abbott Assurity MRI | active | — | — |
| Biotronik Evia DR | active | — | — |

## Workarounds

1. **In asystole, do NOT use magnet. Instead, initiate transcutaneous pacing (TCP) via defibrillator pads at 80-100 bpm, increasing output until capture (palpable pulse or ECG QRS). Call for transvenous pacing backup. Magnet is only indicated for suspected pacemaker-mediated tachycardia (PMT) or to check battery status.** (85% success)
   ```
   In asystole, do NOT use magnet. Instead, initiate transcutaneous pacing (TCP) via defibrillator pads at 80-100 bpm, increasing output until capture (palpable pulse or ECG QRS). Call for transvenous pacing backup. Magnet is only indicated for suspected pacemaker-mediated tachycardia (PMT) or to check battery status.
   ```
2. **If magnet is used for PMT, apply the magnet firmly over the device for 3-5 seconds to switch to asynchronous mode, then remove. Observe rhythm; if PMT recurs, consider reprogramming.** (80% success)
   ```
   If magnet is used for PMT, apply the magnet firmly over the device for 3-5 seconds to switch to asynchronous mode, then remove. Observe rhythm; if PMT recurs, consider reprogramming.
   ```

## Dead Ends

- **** — VT may be caused by R-on-T from asynchronous pacing; removing magnet may not terminate VT, and defibrillation is needed. Magnet removal only stops asynchronous pacing. (75% fail)
- **** — Magnet strength beyond the reed switch threshold can damage the device circuitry. Standard pacemaker magnet (e.g., Medtronic 9600 series) is sufficient. (90% fail)