Placed in patients with VF or VT, long QT, HOCM (if VT or VF), post-MI (if EF < 30%), dilated cardiomyopathy. When a magnet is placed some will beep or emit continuous tone signifying anti-tachycardia function is disabled. Magnets usually do not effect anti-bradicardia functions. Different manufacturers’ devices respond slightly differently to magnet (hence “some” and “usually”), best practice is to interrogate the device (or call manufacturer). All ICD’s should be interrogated prior to elective surgery, and normally turned off (with pacing function left intact or modified as appropriate). Bovie (or monopolar electrosurgical unit, ESU) may be interpreted as VT or VF causing non-pacing in pacer dependent patients. If ICD is off for surgery must have external defib/cardioversion equipment available. No special anesthetic for ICD/pacer patients.