Electrical Cardioversion for Atrial Fibrillation (AFib)
Cardioversion is a treatment for abnormal heart rhythms (arrhythmias), most commonly atrial flutter or atrial fibrillation (AFib). During the procedure, controlled electrical currents are delivered through pads on the chest and back to restore a normal heart rhythm.
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The content of this page was reviewed by Esseim Sharma, MD,
Cardiac Electrophysiologist, University Hospitals Harrington Heart & Vascular Institute, on March 2026.
Quick Facts
- Cardioversion is a planned, controlled procedure performed under anesthesia.
- Think of cardioversion as a “reset” button. It is used to reset the heart back to normal rhythm.
- To help your heart stay in a steady rhythm afterward, your doctor might also suggest rhythm medicines or a procedure called an ablation to fix the heart’s electrical signals.
- The procedure itself takes minutes; most of the visit is prep and recovery.
- Most patients return to regular activity the same or next day.
Understanding Electrical Cardioversion
Cardioversion is one of several treatment options available to restore normal heart rhythm in patients with AFib. During the procedure, a controlled electrical current is delivered to the heart through special pads placed on the chest and back. This electrical energy helps the heart return to a normal, organized rhythm.
It’s important to understand that cardioversion is different from a defibrillator or pacemaker, which is an implanted device that responds automatically to dangerous rhythms, or ablation, which uses energy to create scar tissue that blocks AFib signals. Cardioversion is a planned procedure designed to give your heart an immediate, controlled reset.
How to Prepare for Your Cardioversion Procedure
Preparation is important to ensure your cardioversion is safe and successful. Plan to spend several hours at the hospital for the procedure, preparation and recovery time.
Before your procedure
- Arrange transportation. Bring someone with you who can drive you home, as sedation effects last several hours.
- Fasting. Do not eat or drink after midnight before your procedure.
- Medication review. Discuss with your healthcare provider which medications you should or should not take the morning of your procedure. If you take diabetes medications or insulin, review your dosing with your doctor. Your care team will discuss whether antiarrhythmic therapy is appropriate and safe for you.
- Anticoagulation timing. Blood thinners are typically started before cardioversion to reduce stroke risk. Your doctor will provide specific instructions about your anticoagulation schedule.
- Skin preparation. Do not apply lotions, powders or ointments to your chest or back, as these interfere with the adhesive on the cardioversion and monitoring pads.
Imaging
Your doctor may recommend a transesophageal echocardiogram (TEE) or CT scan to check for blood clots before proceeding. A TEE is an ultrasound performed by swallowing a small, flexible tube, and is typically performed at the same time as the cardioversion. If your doctor chooses a CT scan, it is usually scheduled as a separate appointment a few days before your cardioversion.
Not sure if you’re a candidate?
Your UH cardiologist or electrophysiologist can evaluate your AFib type, heart anatomy, overall health and treatment history to determine if an electrical cardioversion is right for you. Schedule a consultation to discuss your options.
What Are the Risks of Cardioversion?
Cardioversion is generally a safe procedure, but like all medical procedures, it carries some risks. Your healthcare team will discuss these with you and take steps to minimize them.
Potential risks include:
- Stroke risk. The main risk is that a blood clot could form and travel through your bloodstream. Blood thinners given before and after cardioversion significantly reduce this risk. If your AFib has lasted more than 48 hours, imaging may be performed to check for clots before proceeding.
- Mild skin irritation. The pads used to deliver the electrical energy may cause temporary redness or mild irritation, similar to a slight sunburn. This usually improves within a few days.
- Temporary rhythm irregularity. Some patients experience occasional irregular heartbeats in the hours or days after cardioversion as the heart adjusts. This is usually not a sign of failure.
- Sedation-related effects. You may feel groggy, drowsy or experience mild nausea after the procedure as the sedative wears off. These effects typically resolve within a few hours.
- Other side effects. Very rarely, cardioversion can cause damage to the heart muscle or trigger a dangerous rhythm. Your healthcare team monitors you closely during and after the procedure to prevent and quickly address any complications.
Most patients tolerate cardioversion well with minimal complications, especially when proper anticoagulation and monitoring protocols are followed.
What Happens During the Cardioversion Procedure?
Before the procedure
A nurse will place an IV in your arm to give you fluids and a short-acting sedative to keep you comfortable. Monitoring pads will be attached to your chest to track your breathing and vital signs. Special cardioversion pads will be placed on your chest and back. These are connected to the defibrillator that will deliver the electrical energy. Your anesthesiologist and doctor will be present throughout.
During the procedure
Once you are fully sedated, your doctor will deliver electrical energy to your heart. You will not feel anything during this moment because of the sedation. Sometimes more than one shock is needed to restore your heart to a normal rhythm. Your healthcare team continuously monitors your heart’s response and makes adjustments as needed.
After the procedure
You will wake up in the recovery area feeling groggy with little to no memory of the actual procedure. Your vital signs will continue to be monitored as the sedation wears off. Your doctor will review the success of the cardioversion and discuss any next steps or medication changes with you before you leave.
What to Expect After Cardioversion
- Recovery timeline
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Most patients recover from cardioversion quickly. You’ll spend a few hours in the recovery area as the sedation wears off, and you can usually return home the same day.
- How you may feel
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You may feel drowsy or groggy for several hours after the procedure. Some patients experience mild chest discomfort or tenderness where the pads were placed. These sensations are normal and typically mild.
- Skin care
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The area on your chest and back where the pads were attached may be slightly red or irritated. This usually fades within a few days. An ointment may be applied to soothe the area if needed.
- Activity restrictions
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Avoid driving or operating heavy machinery for at least 24 hours after your procedure to ensure all effects of the sedative have worn off. Light activity and rest are recommended for the first day or two.
- When to contact your care team
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Call your doctor if you experience chest pain, shortness of breath, severe dizziness, or if AFib symptoms return or worsen.
- Follow-up and medication
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Your doctor will schedule a follow-up appointment to confirm that your heart rhythm has remained stable. You may need to continue or adjust blood thinners and other medications based on your response to cardioversion. Your care team will provide specific instructions about any medication changes.
When Cardioversion Is Not Enough
Cardioversion successfully restores normal rhythm in many patients, but AFib can recur. If your AFib returns after cardioversion, your care team will work with you to explore additional treatment options.
These may include antiarrhythmic medications, catheter ablation, or even pacemaker implantation. Cardioversion often serves as a bridge while other treatments are planned or optimized. Your electrophysiologist will discuss which approach is most appropriate based on your AFib type, symptoms and overall health.
Understanding that cardioversion is one step in your AFib management journey — rather than a permanent cure — helps set realistic expectations and keeps you focused on long-term rhythm control strategies.
Frequently Asked Questions About Electrical Cardioversion
- How long does it take to recover from cardioversion?
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Most patients recover quickly from cardioversion. You’ll spend a few hours in the recovery area as the sedation wears off, and you can usually go home the same day. You may feel drowsy or groggy for several hours, but these effects typically wear off completely within a day. You should avoid driving or operating heavy machinery for at least 24 hours. Most people return to their normal activities within a day or two.
- What are the risks of cardioversion?
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Cardioversion is generally safe, but potential risks include stroke (reduced significantly by taking blood thinners before and after), mild skin irritation from the pads, temporary irregular heartbeats as your heart adjusts and sedation-related grogginess or nausea. Serious complications are rare, especially when proper anticoagulation and monitoring are followed. Your healthcare team will discuss your individual risk factors before the procedure.
- Is cardioversion the same as an ablation or pacemaker?
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No, cardioversion, ablation and pacemakers are three different approaches to managing heart rhythm problems. While these treatments all help manage your heart rhythm, they each play a very different role. You can think of a cardioversion as a one-time reset button, performed from the outside while you are asleep, to help your heart find its natural beat again. In contrast, a pacemaker is a small device placed under the skin to prevent a slow heart rate. An ablation is different still, as it is a procedure used to actually fix the electrical short circuits in your heart's wiring by blocking the abnormal signals at their source. Your medical team will recommend the specific approach or combination that best fits your unique heart health needs.
- Can AFib return after cardioversion?
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Yes, AFib can return after cardioversion. Some patients maintain normal rhythm long-term, while others experience recurrence within weeks or months. If AFib recurs, your doctor will discuss additional treatment options such as antiarrhythmic medications, catheter or surgical ablation, or other rtreatment strategies. Cardioversion is often part of a broader AFib management plan rather than a permanent solution.
- How many times can you have a cardioversion?
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There is no set limit on how many cardioversions a person can have. However, if AFib recurs repeatedly after cardioversion, your doctor will likely recommend additional or alternative treatments such as medications or ablation to address the underlying cause of AFib rather than relying on repeated cardioversion alone.
- What activities should you avoid after a cardioversion?
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Avoid driving or operating heavy machinery for at least 24 hours after your procedure. Do not engage in strenuous activity or heavy lifting for the first few days as your body recovers from sedation. Follow your doctor’s specific instructions about medications, especially blood thinners and any new prescriptions. If you experience chest pain, shortness of breath or severe dizziness, or if AFib symptoms return, contact your care team immediately.