Maze procedure

Maze is a surgical procedure used to treat an irregular heart rhythm (atrial fibrillation). A surgeon creates a pattern (maze) of scar tissue in the upper chambers of the heart (atria) using a scalpel or a device that delivers heat or cold energy.

Scar tissue doesn't conduct electricity. So the maze interferes with stray electrical heart signals that cause atrial fibrillation.

Why it's done

The maze procedure corrects atrial fibrillation and improves the quality of life of people with this condition.

Your health care provider might recommend the maze procedure if you have atrial fibrillation (A-fib) that doesn't improve with medications or other procedures, or if A-fib returns after treatment. If you're having another heart surgery, such as coronary artery bypass surgery or valve repair, the maze procedure might be done at the same time.

What you can expect

Your health care provider will likely order several tests to get more information about your heart health before determining if the maze procedure is a good option for you. If you're scheduled for surgery, your care team will talk with you about how to prepare and what to bring to the hospital.

During the procedure

For a maze procedure, you are typically given a drug that puts you to sleep (general anesthesia). You are also placed on a heart-lung machine.

During the maze procedure, a surgeon makes an incision in your chest to access the upper chambers of the heart. The surgeon uses heat (radiofrequency energy), extreme cold (cryothermal energy) or a scalpel to make several precise cuts in the heart tissue. The cuts create a pattern (maze) of lines that eventually scar. The scar tissue blocks the faulty electrical signals that cause irregular heartbeats.

While you're on the heart-lung machine, you might also have other needed cardiac surgeries, such as valve repair or pacemaker placement.

Some people undergoing a maze procedure might be treated with a robot-assisted catheter ablation procedure. This procedure can also be done using a combination of surgical and catheter-based interventions. These variations are sometimes referred to as mini-maze or hybrid approaches.


Most people who have atrial fibrillation have an improved quality of life after treatment with a maze procedure. But there's a chance the irregular heartbeat will return. If this happens to you, you might need medication or another maze procedure.

If you develop a slow heart rhythm after your maze procedure, your health care provider might suggest you have a pacemaker implanted.

April 30, 2022
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  3. January CT, et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019; doi:10.1161/CIR.0000000000000665.
  4. Ruaengsri C, et al. The Cox-maze IV procedure in its second decade: Still the gold standard? European Journal of Cardio-Thoracic Surgery. 2018; doi:10.1093/ejcts/ezx326.
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Atrial fibrillation ablation