Mayo Clinic Care Network Content
Tests and Procedures

Maze procedure

Risks

The risks of atrial fibrillation ablation vary depending on whether you are undergoing a catheter ablation or open-heart surgery, which is less common. Risks include:

  • Bleeding or infection at the surgical site or where your catheter was inserted
  • Damage to your blood vessels
  • Puncture of your heart
  • Damage to your heart valves
  • Damage to your heart's electrical system, which could worsen your arrhythmia and require a pacemaker to correct
  • Blood clots in the legs or lungs (venous thromboembolism)
  • Stroke or heart attack
  • Narrowing of the veins that carry blood between your lungs and heart (pulmonary vein stenosis)
  • Death in rare cases

Discuss the risks and benefits of atrial fibrillation ablation with your doctor to understand if it's right for you.

How you prepare

Your doctor will examine you and order several tests to evaluate your heart condition. He or she will discuss with you the risks and benefits of your atrial fibrillation ablation procedure. Let your doctor know about allergies or reactions you've had to medications. And tell him or her if you're pregnant or planning to become pregnant.

You'll need to stop eating and drinking the night before your procedure. If you take any medications, ask your doctor if you should continue taking them before your procedure. In some cases, you'll be instructed to stop taking medications to treat a heart arrhythmia several days before your procedure.

If you have an implanted heart device, such as a pacemaker or implantable cardioverter-defibrillator, talk to your doctor to see if you need to take any special precautions.

Overview

The maze procedure is a treatment for an irregular heartbeat called atrial fibrillation (AFib). A surgeon uses heat or cold energy or a scalpel to create a pattern of scar tissue in the upper chambers of the heart. The pattern is called a maze. The heart's electrical signals can't pass through the scar tissue. So the maze can block faulty heart signals that cause AFib.

Why it's done

The maze procedure is done to treat atrial fibrillation (AFib), a type of irregular heartbeat. An irregular heartbeat also is called an arrhythmia. Your healthcare team may suggest the maze procedure if you have AFib that doesn't get better with medicines or other treatments.

What you can expect

You'll have tests to check your heart health to determine if the maze procedure is right for you.

During the procedure

The maze procedure most often is done with medicines that put you in a sleep-like state. This is called general anesthesia.

During the maze procedure, a surgeon creates several specific lines in the heart using one or more of the following:

  • A sharp tool called a scalpel.
  • Heat energy, also called radiofrequency energy.
  • Cold energy, also called cryothermal energy.

The pattern of lines created is called a maze. It scars over time. The scar tissue blocks or redirects the incorrect heart signals that cause irregular heartbeats.

There are different ways to reach the heart to do the maze procedure.

Surgical maze

This is a type of heart surgery. You are put on a heart-lung machine. The machine keeps blood and oxygen flowing through your body.

Another name for surgical maze is the Cox-maze procedure. It's the preferred AFib treatment in those who need another heart surgery, such as heart valve surgery.

Surgical maze may be done in two ways:

  • Open-heart surgery. The surgeon makes a long cut in the chest through the breastbone to reach the heart. This is called a sternotomy. Then the surgeon uses a scalpel, heat energy or cold energy to create the maze.
  • Minimally invasive robotic surgery. Very small cuts and robotic technology are used to reach the heart. With this method, only heat energy or cold energy is used to create the maze pattern.

Surgeons can do other heart treatments or place a pacemaker, if needed, during the procedure.

Catheter ablation maze

This treatment uses thin, flexible tubes called catheters. The surgeon makes a cut to reach a blood vessel, usually in the groin area. The catheters go into the blood vessel. Then, they are moved to the appropriate area in the heart. Sensors on the end of the catheters give off heat or cold energy. The energy is used to create a pattern of scar tissue that blocks or redirects the faulty heart signals.

Mini-maze

Sometimes both surgery and catheter methods are used to create the maze. This is called a mini-maze procedure or a hybrid approach.

Results

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

If your heartbeat becomes too slow after the maze procedure, your healthcare team might suggest a pacemaker.