Getting a shock from your ICD: is this normal, and what do I do?

The short answer

A shock can be startling and painful. It means the device acted. Always tell your care team about a shock, and know the signs that mean call 911.Source:NIH (NHLBI)Mayo Clinic

What a shock feels like

A higher-energy shock can be painful and may feel like being kicked in the chest. The pain usually lasts only a second.Source:Mayo Clinic

Low-energy charges are not painful. You may not notice them, or you may feel a fluttering in your chest.Source:NIH (NHLBI)

How many shocks are usual

Usually only one shock is needed to restore a regular heartbeat. Some people have two or more in a 24-hour period.Source:Mayo Clinic

Three or more shocks in a short time is called an electrical storm. Mayo Clinic says to call 911 or get emergency help.Source:Mayo Clinic

Not every shock is needed

An ICD can sometimes send a shock when it is not needed. This is more likely during the adjustment period after surgery. If you think you get shocks too often, talk to your care team about adjusting the device.Source:NIH (NHLBI)

What to do after a shock

If your care team gave you a plan for shocks, follow it. Always call your care team if your device gives you a shock.Source:NIH (NHLBI)

If you feel one or two strong shocks in a short time and the symptoms go away, contact your care team and set up an appointment that day or the next day.Source:NIH (NHLBI)

Learn the warning signs of problems and make an action plan with your care team.Source:NIH (NHLBI)

The worry afterward

A strong shock can startle or distress you, and living with a device can cause anxiety. Some people develop PTSD after surviving cardiac arrest or getting shocks. Tell your care team if you are anxious or low.Source:NIH (NHLBI)

Call 911 if...

You feel several strong shocks in a short time. Mayo Clinic counts three or more as an emergency.Source:NIH (NHLBI)Mayo Clinic
You have symptoms of a heart attack or warning signs of cardiac arrest.Source:NIH (NHLBI)American Heart Association
A shock, and afterward you do not feel well or the symptoms do not go away.Source:NIH (NHLBI)
You faint or nearly faint, have chest pain, or cannot catch your breath, with or without a shock. The NIH lists fainting among the symptoms to call your provider about; after a cardiac arrest, do not wait: call 911.Source:NIH (NHLBI)American Heart Association
You are not sure. If your care team gave you a shock plan, follow it, and if in doubt, call 911.Source:American Heart Association

Call 911

Call your care team the same day if...

Any shock at all, even one, even if you feel fine afterward.Source:NIH (NHLBI)
Dizziness, feeling out of breath, fever or a pounding or skipping heartbeat that worries you.Source:NIH (NHLBI)

Quick answers

Should I call 911 after an ICD shock?

Call 911 if you feel several strong shocks in a short time, if you do not feel well after a shock, or if you have symptoms of a heart attack, chest pain, trouble breathing or you faint. Mayo Clinic counts three or more shocks in a short time as an electrical storm. For a single shock when you feel fine afterward, call your care team and follow the shock plan they gave you. If in doubt, call 911.

Source:Mayo Clinic NIH (NHLBI)

Does an ICD shock hurt?

A higher-energy shock can be painful and may feel like being kicked in the chest. The pain usually lasts only a second. Low-energy charges are not painful.