What should I do if my implantable cardioverter-defibrillator (ICD) goes off?

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Last updated: August 2, 2025View editorial policy

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What to Do When Your Implantable Cardioverter-Defibrillator (ICD) Goes Off

If your implantable cardioverter-defibrillator (ICD) delivers a shock, you should seek immediate medical attention by calling emergency services or having someone take you to the emergency department for evaluation, even if you feel fine afterward.

Immediate Steps After an ICD Shock

When your ICD delivers a shock:

  1. Sit or lie down immediately to prevent injury in case you lose consciousness
  2. Stay calm and take slow, deep breaths to reduce anxiety
  3. Note the time and any symptoms you experienced before, during, and after the shock
  4. Call emergency services (911) or have someone take you to the emergency department
  5. Do not drive yourself to the hospital (driving restrictions apply after ICD shocks)

Medical Evaluation After a Shock

A thorough evaluation is necessary after an ICD shock to:

  • Determine if the shock was appropriate (for a dangerous heart rhythm) or inappropriate
  • Check the ICD system for proper functioning
  • Assess your underlying heart condition
  • Adjust medications or ICD programming if needed

What to Expect at the Hospital

  • ECG monitoring
  • Blood tests to check electrolytes and cardiac enzymes
  • Device interrogation to review stored data from your ICD
  • Possible adjustment of medications or ICD programming

Driving Restrictions After ICD Shock

The American Heart Association and Heart Rhythm Society recommend 1:

  • For ICDs implanted for secondary prevention: Avoid driving for 6 months after the last arrhythmic event that caused loss or near loss of consciousness
  • For ICDs implanted for primary prevention: Avoid driving for at least 7 days after implantation

Follow-Up Care

After discharge from the hospital:

  • Schedule a follow-up appointment with your cardiologist or electrophysiologist
  • Your device should be interrogated when ICD therapy is delivered 1
  • Regular follow-up should occur every 3-6 months either remotely or in person 1

Preventing Future Shocks

To reduce the risk of future appropriate or inappropriate shocks:

  • Take all medications as prescribed
  • Avoid activities or situations that trigger arrhythmias (if known)
  • Maintain regular follow-up with your healthcare provider
  • Consider programming changes to minimize inappropriate shocks 1
  • For heart failure patients who receive their first appropriate ICD therapy, a thorough reevaluation of heart failure management is warranted 1

Special Considerations

Multiple Shocks in a Short Period

If you receive multiple shocks in a short period:

  • Call 911 immediately
  • Consider applying a doughnut magnet over the device to temporarily deactivate the shocking function if multiple inappropriate shocks are occurring 1

End-of-Life Considerations

For patients with advanced illness or approaching end of life:

  • Discuss ICD deactivation preferences with your healthcare provider 1
  • These discussions should be proactive and ongoing as your condition changes

Common Pitfalls to Avoid

  • Don't ignore a shock - Always seek medical attention even if you feel fine afterward
  • Don't drive yourself to the hospital after receiving a shock
  • Don't attempt to adjust or disable your device without medical supervision
  • Don't forget to inform all healthcare providers about your ICD before procedures

Remember that your ICD is designed to save your life by detecting and treating dangerous heart rhythms. While shocks can be uncomfortable and frightening, they indicate that your device is working as intended to protect you from sudden cardiac death.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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