Effects of Electroconvulsive Therapy (ECT) on St. Jude Medical Implantable Cardiac Rhythm Devices


Electroconvulsive therapy (ECT) is a procedure in which electric currents are passed through the brain, deliberately triggering a brief seizure. This is thought to cause changes in brain chemistry that can alleviate symptoms of certain mental illnesses. ECT can interfere with the normal operation of pacemakers and implantable cardioverter defibrillators (ICDs). Response can vary from total inhibition to inappropriate therapy. The electrical impulses from the ECT therapy may be interpreted as “electrical noise” in ICDs and cause a noise reversion. During a noise reversion the device will not deliver therapy (therapy includes ATP pacing, cardioversion and defibrillation). If ECT impulses are misinterpreted as cardiac events in an ICD, inhibition of bradycardia pacing and/or inappropriate arrhythmia detection and therapy delivery are possible.

In addition, it is possible for unipolar pacemakers to be inhibited by myopotentials from the seizure activity. This is also a transient effect and will cease to be a factor when the involuntary muscle contractions stop. The electrical current should not cause damage to a pacemaker or ICD. It has been documented that in rare cases ECT can induce tachyarrhythmias.

Potential effects

A summary of potential effects is provided in the table below and is based on device testing at St. Jude Medical, clinical experience and/or a review of the scientific literature.

Potential Effect Estimated Frequency
  Pacemakers ICDs
Single-beat inhibition of pacing Uncommon  Rare
Asynchronous pacing/noise reversion Uncommon Uncommon
Inappropriate therapy delivery Not applicable  Uncommon
Failure to deliver needed therapy Not applicable  Rare
Arrhythmia induction Rare Rare  



Per the 2011 HRS perioperative consensus committee, pacemaker-dependent patients who are programmed to unipolar sensing should have their devices programmed to an asynchronous pacing mode1. For devices whose magnet response is programmed on, asynchronous pacing can also be induced by placing a magnet over the pacemaker.


  • For ICDs, a magnet can be placed over the device during ECT to prevent inappropriate therapy in most devices. During magnet placement detection and therapy are disabled in the ICD. Once the treatment session is completed, the magnet should be removed.
  • ECG monitoring or pulse oximetry is recommended any time the ICD is suspended. If an arrhythmia is observed, removal of the magnet will restore detection and device therapy.
  • Should a change in ICD function be suspected during the course of the therapy, a follow-up should be performed.

If you have any questions on this topic, please contact CRM Technical Services.

PDF Effect of Electroconvulsive Therapy (ECT) on St. Jude Medical Implantable Cardiac Rhythm Devices (107kb)

Rev. 03/16

1. Crossley, G., Poole, J., et al.: The Heart Rhythm Society Expert Consensus Statement on the perioperative management of patients with implantable defibrillators, pacemakers and arrhythmia monitors: Facilities and patient management. Heart Rhythm, 2011.