Location of surgery

If below the umbilicus, surgery can be safely performed without reprogramming. Above the umbilicus, electrocautery can cause interference, particularly monopolar.

Timing of interrogation before surgery

For elective surgery, ideal timing of interrogation is within 6 months for ICD and within 6-12 months for pacemaker.

Function of magnet on cardiac devices

ICD

Magnet will turn off anti-tachycardic therapy (i.e. no shock)

Pacemaker

Magnet will convert to asynchronous mode

Combined Pacemaker/ICD

Magnet will turn off anti-tachycardic therapy on ICD but will not affect pacemaker


If a magnet is used, all devices should be reinterrogated as soon as safely possible as the magnet may cause different reprogramming after removal.