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Cardiac Arrest Patient's With Internal Defibs

Question#: 642


Should there be any deviation from normal practice when dealing with a patient currently in cardiac arrest.with a confirmed internal defibrillator ? Do we allow the internal shocks to occur or simply follow current guidelines and manage as always?

Thanks Dale


Thank you for your MedicASK submission regarding the management of cardiac arrest patient's with implantable cardioverter defibrillators (ICD's).

There would be no deviation from normal practice when dealing with these patients. It is safe to perform CPR and defibrillation on those who have ICD's/pacemakers as they are typically implanted in the upper left side of the chest and would not interfere with the performance of these skills. The pads should be placed at least one inch away from the ICD and there should be no contact between the two.

There are times when the ICD may deliver one or more shocks but does not succeed in converting to a normal sinus rhythm, or the cardiac arrest may not be cardiac in nature therefore, the ICD would not shock at all.

If you encounter the ICD performing a shock(s) while CPR is in progress, the internal shock(s) will not harm the person performing CPR.

In the event the ICD is successful and the heart is restored to NSR during your resuscitation, you would see this through the externally placed pads during your analysis and act accordingly.

Although these devices are designed to withstand external defibrillation, they can sustain damage and would need to be inspected by a cardiologist during follow up to determine if it needs to be replaced. That being said, lifesaving measures take precedence over potential damage to the device in these patients.

Hope this helps!

Please don't hesitate to reach out should you have any further questions.




08 November 2022



Please reference the MOST RECENT ALS PCS for updates and changes to these directives.