Cardioversion is a procedure that uses a device or a medication to alter the rhythm of the heart. It changes an irregular heart rhythm with brief, low-energy shocks, especially beneficial for people experiencing conditions like atrial fibrillation or atrial flutter, or ventricular arrhythmia.

Cardioversion may be advised by your healthcare provider when you experience specific heart rhythm abnormalities, such as atrial fibrillation or atrial flutter. These conditions arise when the usual electrical signals responsible for maintaining a regular heart rate fail to propagate correctly through the upper chambers of the heart. With cardioversion, heart rate and rhythm are restored to their normal state, allowing the heart to function as it should, pumping effectively.

Cardioversion typically works fast to restore a normal heart rhythm. It is typically a planned procedure, although it can also be performed in urgent situations.

Defibrillation, an emergency technique used when the heart stops or beats ineffectively, is different from cardioversion. More powerful shocks are given to the heart during defibrillation to restore its rhythm.


Cardioversion is categorized into two types:

  • Electric cardioversion: A defibrillator delivers shock to the the heart using handheld paddles or electrode patches on the chest and back. A healthcare provider can quickly determine whether electric cardioversion has successfully restored a regular heartbeat. An implanted cardioverter-defibrillator (ICD) may be recommended to regulate the rhythm among people with high risk of developing potentially fatal arrhythmias or whose heart is not functioning properly.
  • Chemical cardioversion: Compared to electric cardioversion, this takes longer to start working. This procedure used oral or intravenous medication to normalize heart rhythm. The medication’s effects may become noticeable within minutes, hours, or sometimes days. Electric shocks will not be performed if one is recommended this procedure.

Reasons for undergoing the procedure

Cardioversion can restore normal heart rhythm and address various fast or irregular heart rhythms, such as:

  • Atrial tachycardia.
  • Atrial fibrillation and atrial flutter.
  • Ventricular tachycardia.
  • Ventricular fibrillation.

Abnormal heart rhythm can cause symptoms that indicate insufficient blood flow from the heart to the body. Even if the symptoms are hardly noticeable, delaying treatment runs the risk of developing more serious issues, such as a heart attack or stroke. Cardioversion can help restore normal heart activity.

Abnormal heart rhythm symptoms include:

  • Breathing problems like shortness of breath
  • Chest discomfort
  • Dizziness
  • Excessive exhaustion
  • A fluttering or pounding sensation in the chest area


Rarely, electric cardioversion complications may include:

  • Dislodged blood clots: Blood clots may develop among individuals with irregular heart rhythms, like atrial fibrillation. Before doing a cardioversion, tests to look for blood clots may be required. Blood thinners may also be administered. This is done due to the possibility that electrical shocks to the heart can potentially dislodge blood clots, leading to serious risks, including strokes or the migration of clots to the lungs.
  • Irregular heart rhythms: This typically happens during or shortly after the procedure. To rectify the heart rhythm, medications or extra shocks can be administered.
  • Skin burns: Electrodes can cause a rash, minor burns, or short-term skin injury.

Other rare complications may include minor skin bruising at the IV insertion point and potential allergic reactions to administered medications. While pregnant, cardioversion can be performed, but it is advisable to monitor the fetal heartbeat throughout the procedure.


Prior to undergoing cardioversion, transesophageal echocardiogram may be required. This test is used to identify blood clots in the heart. Cardioversion has the potential to dislodge blood clots, which can result in critical complications. Your healthcare provider will assess the necessity of a pre-cardioversion test to determine if you have any blood clots in your heart. If one or more blood clots are detected, it is typically recommended to postpone the cardioversion procedure for a period of 3 to 4 weeks. During this waiting period, you will usually be prescribed blood thinners to mitigate the risk of potential complications.

If symptoms of an abnormal heartbeat are severe, emergency cardioversion may be performed. However, in most cases appointments are made in advance.

The actual procedure takes a few minutes, but one should allocate approximately four to six hours in total to account for both the pre-procedure preparations and the post-procedure recovery.

Before the procedure

It is advised to have a regular meal the night before the procedure. But refrain from eating, drinking, or chewing anything after midnight, usually around eight hours prior to cardioversion. This prohibition includes gum, mints, and water, among other items. The healthcare provider will advise on whether to take the usual medications before the procedure.

During the procedure

Electrical cardioversion is a quick procedure, usually lasting just a few minutes. The procedure uses a cardioverter machine or defibrillator which shocks the heart quickly and gently in order to get it back to its normal beat. Several patches, known as sensors or electrodes are attached to the chest and back. The heart’s rhythm is recorded by the device. To restore the heart’s rhythm, it might take a few shocks.

A healthcare provider will place an IV in the hand or forearm and administer sedative drugs to put one to sleep throughout the treatment. The oxygen level, heart rhythm and blood pressure are usually monitored during the procedure. Cardioversion is frequently performed in hospitals.

For chemical cardioversion, drugs are administered through an IV to assist the heart’s rhythm to normalize.

After the procedure

After the procedure, one will slowly awaken, experiencing drowsiness due to the medication. They are usually placed in a recovery room for monitoring. The ability to make decisions may be impacted for several hours after cardioversion. In most cases, one may return home the same day of the electric cardioversion.

Even if there were no blood clots in the heart prior to the treatment, one will need blood thinners. The drugs are typically administered for a few weeks to prevent the formation of clots.

Chest tenderness may also be experienced in the following days, and using hydrocortisone cream can help alleviate any discomfort.


It is important to monitor for recurrence of symptoms. Ensuring scheduled follow-up appointments is essential to monitor one’s response to treatment and assess the effectiveness of any prescribed medications.

To enhance the heart’s health and prevent or cure conditions like high blood pressure that might result in irregular heartbeats, making lifestyle changes may be advised.

To promote a heart-healthy lifestyle, limit or avoid alcohol, reduce salt for better blood pressure, choose whole grains, lean meats, low-fat dairy, and plenty of fruits and vegetables. Minimize sugar, saturated fat, and trans fats, increase physical activity to maintain a healthy weight, quit smoking, and work on managing stress and anger.

Although some individuals require additional measures to maintain a steady heartbeat, most people will immediately have a normal heartbeat after cardioversion.