Using External Defibrillators in Patients with ICDs

Initial Assessment and Approach

The American Society of Anesthesiologists recommends determining if a patient has an ICD by checking for scars, palpating for the device, or reviewing available medical information 1
The American Heart Association suggests allowing 30-60 seconds for the ICD to complete its treatment cycle before attaching an AED if the patient's ICD is actively delivering shocks 2, 3
For patients with ICDs, the American Heart Association recommends that pad/paddle placement should not delay defibrillation if it is clinically indicated 2, 3

The American Society of Anesthesiologists recommends positioning defibrillation pads or paddles as far as possible from the pulse generator (at least 8 cm away) 4, 2
The American Society of Anesthesiologists suggests placing pads/paddles perpendicular to the major axis of the ICD by using an anterior-posterior position whenever possible 4, 1
The American Heart Association recommends avoiding placing pads or paddles directly over the ICD device 2, 3
The American Heart Association states that both anteroposterior and anterolateral pad positions are acceptable in patients with ICDs 2
The American Heart Association recommends using standard adult-sized electrode pads (8-12 cm in diameter) 2, 3

The American Society of Anesthesiologists recommends terminating all sources of electromagnetic interference (EMI) for patients with magnet-disabled ICD therapies 1, 5
The American Society of Anesthesiologists suggests removing the magnet to re-enable the ICD's antitachycardia therapies for patients with magnet-disabled ICD therapies 1, 5
The American Society of Anesthesiologists recommends observing the patient and monitors for appropriate ICD therapy for patients with magnet-disabled ICD therapies 1, 5
The American Society of Anesthesiologists suggests proceeding with external defibrillation using proper pad placement if the above steps fail to restore ICD function for patients with magnet-disabled ICD therapies 1, 5

The American Society of Anesthesiologists recommends using a clinically appropriate energy output regardless of the presence of an ICD 4, 1
The American Society of Anesthesiologists suggests defibrillating the patient in the quickest possible way and being prepared to provide pacing through other routes if needed if it is technically impossible to place the pads/paddles in optimal locations 4, 1
The American Heart Association recommends ensuring the defibrillation pads make good contact with the skin and removing excess chest hair if necessary but not delaying defibrillation 2, 3
The American Heart Association suggests not placing AED electrode pads directly on top of transdermal medication patches, as they may block energy delivery 2, 3

The American Society of Anesthesiologists recommends interrogating the ICD as soon as possible to assess for any damage or programming changes after successful resuscitation 4, 1
The American Society of Anesthesiologists suggests continuously monitoring cardiac rate and rhythm and having backup pacing and defibrillation equipment immediately available after successful resuscitation 4, 1
The American Society of Anesthesiologists recommends restoring all antitachyarrhythmic therapies in the ICD after successful resuscitation 4, 1
The American Society of Anesthesiologists suggests consulting with a cardiologist or pacemaker-ICD service to ensure proper device function after successful resuscitation 4, 1

The American Heart Association recommends not delaying defibrillation in a life-threatening situation due to concerns about the ICD 2, 3
The American Society of Anesthesiologists suggests not assuming the ICD will automatically treat all life-threatening arrhythmias, especially if it has been disabled or is malfunctioning 1, 5
The American Heart Association recommends being aware that pacemaker spikes with unipolar pacing may confuse AED software and prevent proper VF detection 2, 3
The American Society of Anesthesiologists states that the presence of an ICD does not contraindicate the use of an external defibrillator when clinically indicated 4, 1

In cases where the implantable cardioverter‑defibrillator (ICD) is delivering repeated inappropriate shocks that impede assessment or treatment after conversion to a stable supraventricular rhythm, a magnet may be placed directly over the pulse generator to temporarily suspend tachyarrhythmia therapy. This recommendation is based on the 2015 Circulation guideline (American Heart Association). Strength of evidence: not specified. 6

Magnet responses differ markedly among manufacturers and device models; some ICDs exhibit no response to a magnet, while others can be permanently disabled by magnet application. This variability is highlighted in the 2005 Anesthesiology (ASA) guideline. Strength of evidence: not specified. 7
For the majority of ICDs, there is no reliable method to verify correct magnet placement or to confirm that tachyarrhythmia therapy has been successfully suspended, making reliance on magnet use uncertain. This limitation is also noted in the 2005 ASA guideline. Strength of evidence: not specified. 7

Prior to elective surgical procedures, routine magnet placement or ICD deactivation is recommended to prevent inappropriate shocks caused by electromagnetic interference from operative equipment. This recommendation follows the 2024 Circulation guideline (American Heart Association). Strength of evidence: not specified. 8