Loading icon
Press enter or spacebar to select a desired language.
Health Information Center


  • Editorial Staff and Contributors
Publication Type:




Cardioversion passes an electric shock to the chest through electrodes or paddles.

External Cardioversion.

Nucleus factsheet imagehttp://services.epnet.com/getimage.aspx?imageiid=76587658si55551745.jpgsi55551745.jpgNULLjpgsi55551745.jpgNULL\\hgfiler01a\intellect\images\si55551745.jpgNULL14NULL2008-12-10264390Copyright © Nucleus Medical Media, Inc.

Reasons for Procedure

This procedure is done to correct a dangerous heart rhythm. The heart should beat in a regular rhythm. Abnormal rhythms can make it hard for the heart to pump blood and oxygen through the body.

Non-urgent cardioversion may be used to treat:

Some abnormal heart rhythms can lead to death if not treated right away. Urgent cardioversion may be used to treat:

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will review some problems that could happen, such as:

  • The procedure does not work
  • A more dangerous heart rhythm develops
  • Damage to the heart muscle
  • Blood clots
  • A stroke

What to Expect

Problems to Look Out For

Call your doctor if you have:

  • Blisters, redness, or open sores on your chest
  • Confusion or lightheadedness
  • A feeling that your heart is:
    • Fluttering (palpitations)
    • Skipping or missing heartbeats, or you have an uneven pulse
  • Cough or problems breathing
  • Lasting nausea or vomiting
  • Pain in the:
    • Chest
    • Left arm or jaw
    • Belly, back, arms, or legs
  • Blood in your urine (pee)
  • Problems with seeing, talking, walking, or movement
  • Drooping face muscles

If you think you have an emergency, call for medical help right away.

Prior to Procedure

The care team may meet with you to talk about:

  • Taking blood thinners for several weeks before the procedure
  • Tests that need to be done before the procedure, such as a transesophageal echocardiography
  • Whether you need a ride to or from the procedure
  • Avoiding food or drink after midnight the night before the procedure
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before the procedure

For urgent cardioversion, there is no time to prepare for the procedure.





  • Al-Khatib SM, Stevenson WG, et al. 2017 AHA/ACC/HRS Guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2018;138(13):e210-e271.
  • Cardioversion of atrial fibrillation. EBSCO DynaMed website. Available at: https://www.dynamed.com/procedure/cardioversion-of-atrial-fibrillation.
  • Direct-current (DC) cardioversion-defibrillation. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/direct-current-dc-cardioversion-defibrillation.
  • Overview of arrhythmias. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/overview-of-arrhythmias.


  • Mark D. Arredondo, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.