Cardioversion vs. Ablation for AFib

Medically Reviewed by James Beckerman, MD, FACC on June 28, 2022
4 min read

Atrial fibrillation (AFib) is a kind of irregular heartbeat, or arrhythmia. A problem with the electrical signals that control your heart’s pumping action causes it to beat too fast in a pattern that isn’t steady.

The goal of AFib treatment is to get your heart to beat normally and lower the chances that your irregular heartbeats will cause a stroke.

You’ll probably get some kind of medication for AFib. Two common nondrug treatments are cardioversion and cardiac ablation. You may get one or both. Doctors use them both to control your heart rhythm, but they work differently.

Cardioversion. This procedure gives you a mild electric shock to reset your heart to a regular rhythm. You may get it soon after you’re diagnosed with AFib. You may also have it after you’ve had the condition for a while if your symptoms are causing problems for you. Sometimes it’s done as an emergency procedure if AFib causes your blood pressure to drop dangerously.

It’s also used for a related condition called atrial flutter.

Cardiac ablation. This procedure destroys small parts of tissue inside your heart to keep faulty electrical signals from triggering irregular beats. You may not have one unless medicines or cardioversion doesn’t work. But it’s becoming more of a first-choice treatment.

It can also treat atrial flutter.

You’ll schedule this procedure a month or so ahead unless it’s an emergency.

  • It’s usually an outpatient procedure, so you won’t spend the night in the hospital.
  • You’ll get anesthesia to put you to sleep.
  • Electrodes are placed on your chest and sometimes your back.
  • A mild electrical charge is passed between the electrodes to break up faulty electrical signals and let your normal heart rhythm start again.

Cardioversion can cause a blood clot to move through your bloodstream. To prevent that, you may take blood thinners for several weeks before and after the procedure. You may also have an imaging test called a transesophageal echocardiogram to see whether you already have blood clots in one of your heart chambers that could get loose during the procedure.

The kind most often used for AFib is called catheter ablation.

  • You may spend the night in the hospital for this procedure.
  • You’ll get anesthesia so you don’t feel pain and you may be put to sleep completely.
  • Your doctor will insert several thin hollow tubes into a vein, usually in your leg, and thread them up to your heart.
  • They’ll then pass special tools through the tubes.
  • Your doctor will locate the parts of your heart that faulty electrical signals are coming from.
  • They’ll then create scar tissue to disable the problematic areas, either by burning or by freezing.

Sometimes the abnormal electrical signals are coming from a part of your heart called the AV node, which coordinates the pumping of the upper and lower heart chambers. If your doctor has to disable this area during the ablation procedure, you’ll have a permanent pacemaker implanted.

Ablation can also raise your chances of a blood clot, so you’ll probably take blood thinners for up to several months after the procedure. You may also need drugs to control your heart rhythm for a few weeks while the treatment takes full effect.

Ablation can also be done surgically, but you’ll likely only get that if you’re also having another heart operation. A surgeon makes a pattern of cuts on the outside of your heart that forces the electrical signals to follow the correct path. Or they might burn or freeze a pattern of scars to accomplish the same goal.

Both procedures can cause serious complications, although the risks are low if you’re in overall good health. Either procedure can dislodge a blood clot, which can lead to a stroke or a pulmonary embolism.

Cardioversion can also cause:

Other possible complications of cardiac ablation include:

  • Bleeding, infection, or pain from the catheter insertion
  • Damage to the heart, blood vessels, or esophagus
  • Narrowing of the pulmonary veins
  • Nerve damage

Ablation can “cure” AFib, meaning you won’t need to take medicines to control your heart rhythm. But it may take several tries. It works best if your AFib is what’s called paroxysmal, with episodes lasting a week or less. If you have persistent Afib, with episodes that last longer than a week, you’ll most likely have cardioversion.

Cardioversion gets your heartbeat back to a normal rhythm, but it isn’t usually a permanent solution for AFib. You may need to have it done more than once. And you’ll probably have to take medication or have another procedure like an ablation to keep a normal heart rhythm.

Doctors have found better results if you have an ablation earlier rather than later in the disease process. The longer you have AFib, more areas of your heart can start to make faulty electrical signals. That makes the abnormal heartbeat harder to fix.