What Is Cardioversion and How Is It Performed?
Cardioversion is a medical procedure used to restore a normal heart rhythm when the heart is beating too fast or irregularly. Many people with a condition like atrial fibrillation (AFib) or atrial flutter feel uncomfortable symptoms because their heart’s electrical signals are not coordinated properly. Cardioversion helps reset the heart’s rhythm so it can pump blood better to the body. It can be done using medications (chemical cardioversion) or a brief electrical shock (electrical cardioversion) given through pads on the chest, but you are sedated so you don’t feel the shock.
This treatment may be planned ahead or done in an emergency, depending on how severe your symptoms are. Short-term results are often quick, though some people may need repeat treatments if the irregular rhythm returns.
Purpose & Benefits of Cardioversion
● Restores normal heart rhythm to improve how the heart pumps blood.
● Reduces symptoms like palpitations, tiredness, shortness of breath, or dizziness caused by irregular heartbeat.
● May improve exercise tolerance and daily activity levels.
● Helps lower the heart’s extra strain and the risk of long-term heart weakening.
● Can work quickly, often returning a normal rhythm within minutes.
Who May Need Cardioversion?
Cardioversion is recommended for people who:
● Have an irregular heart rhythm such as atrial fibrillation or atrial flutter that does not improve with medicines.
● Experience symptoms from rhythm problems, such as palpitations, fatigue, shortness of breath, or dizziness.
● Are at risk of complications because the irregular rhythm has lasted too long and medicines alone have not restored normal rhythm.
● Have a rhythm problem that could lead to stroke or heart damage if left untreated.
Your doctor will decide if cardioversion is right for you after reviewing your symptoms, heart tests, and overall health.
Types of Cardioversions
Electrical Cardioversion
This type uses a controlled electric shock delivered through patches placed on your chest. The electrical impulse briefly stops the abnormal rhythm, allowing the heart’s natural rhythm to restart correctly. You receive sedation or anaesthesia so you don’t feel pain.
Chemical (Pharmacological) Cardioversion
Here, medicines are given (often through an IV) to help the heart return to a normal rhythm without an electric shock. It may take longer than electrical cardioversion but avoids the need for a shock.
Cardioversion Procedure: Step-by-Step
1. You may be asked not to eat or drink for about 6–8 hours before the procedure. Your doctor may also test for blood clots in the heart and sometimes give blood-thinning medicines before cardioversion.
2. An intravenous (IV) line is placed in your arm or hand. You are given sedation so you are calm and comfortable during the procedure.
3. Medicines are given through the IV to help reset the heart rhythm. The effect may take some time.
4. Soft pads or patches connected to a machine are placed on your chest (sometimes front and back). A quick, low-energy shock is delivered that aims to return your heartbeat to normal.
5. Your heart rhythm is watched immediately after the shock to check if the treatment worked. If the first attempt doesn’t fix the rhythm, a second may be given.
6. You spend about 1 hour in a recovery area where doctors watch you for any immediate complications before going home.
The entire procedure usually takes a few minutes, though the preparation and recovery add more time.
Recovery & Aftercare
After cardioversion:
● You may feel drowsy from the sedation and should not drive or operate heavy machinery for at least 24 hours.
● You can usually eat and drink normally soon after the procedure.
● Your doctor may prescribe blood-thinning medicines for several weeks to reduce stroke risk, even if no clots were found beforehand.
● Your heart rhythm may be checked in follow-up visits to see if the normal pattern is maintained.
● You may be told to rest and avoid strenuous activity for a day or two.
Many people feel much better within hours to a few days after cardioversion as the heart returns to a regular rhythm.
Risks & Possible Complications
Cardioversion is generally safe, but there are some possible risks:
● Blood clots and stroke, especially in conditions like AFib. Doctors often use blood thinners to reduce this risk.
● Minor skin irritation or burns where the pads touch your body.
● Abnormal heart rhythms that may develop during or after the procedure.
● Reaction to sedation or IV medicines.
● The procedure may not restore normal rhythm, or the arrhythmia may return later.
Your care team will explain all the specific risks based on your health before you agree to the procedure.
Cardioversion vs Other Treatments
● Cardioversion vs Medicines Alone: Medicines may slow the heart or help occasionally, but cardioversion can quickly restore normal rhythm when drugs alone have not worked.
● Cardioversion vs Ablation: Cardioversion resets the rhythm temporarily. Catheter ablation is another heart procedure that can reduce irregular rhythms long-term by destroying small patches of heart tissue causing the abnormal signals.
● Cardioversion vs Defibrillation: Cardioversion uses lower-energy shocks on a scheduled basis. Defibrillation uses stronger shocks in emergencies like cardiac arrest.