Maze Procedure (Surgical Ablation) for AFib

Written by Matt McMillen, Susan Bernstein
Medically Reviewed by Shruthi N, MD on March 24, 2025
9 min read

If you have an irregular heartbeat caused by atrial fibrillation (AFib), you may need surgery to restore your normal heart rhythm. This is called the maze procedure, a type of surgical ablation in which your surgeon creates a maze-like pattern of scars. Your doctor may refer to them as lesions or ablation lines. These scars block abnormal electrical signals while allowing normal signals to control your heart’s rhythm.

The procedure has been modified several times since it was first done in 1987. Known formally as the Cox-maze procedure (Cox was the name of the doctor who developed it), the current version surgeons perform is called Cox-maze IV.

“The locations of the ablation lines have been standardized over years of research and evaluation,” says Matthew Henn, MD, a cardiac surgeon and assistant professor of surgery at The Ohio State University Wexner Medical Center and College of Medicine in Columbus, OH. “When the full Cox-maze IV lesion set is utilized, it is the most successful and durable treatment available for atrial fibrillation.”

The maze procedure has an 80%-90% success rate.

It’s usually a treatment your doctor will try if other things, such as medications, cardioversion therapy, or catheter ablation, have not worked. Most people who have AFib will not need the maze procedure. If you require heart surgery for another reason, such as a coronary artery bypass graft, your doctor will likely suggest that you undergo a maze procedure at the same time. This is called a concomitant ablation, and it can help lower your risk for stroke and premature death.

“Oftentimes, we perform the Cox-maze IV procedure in a concomitant fashion — meaning we are performing heart surgery for another reason and the Cox-maze IV is added to the procedure to treat atrial fibrillation,” Henn says.

 

The maze procedure blocks abnormal electrical signals. That prevents episodes of AFib, during which those electrical signals cause your heart to beat erratically and too fast. Instead, the maze pattern your surgeon creates during the procedure allows normal electrical signals to pass through your heart, keeping it beating in a proper rhythm.

By preventing AFib episodes, you will no longer experience the symptoms those episodes cause, such as fatigue, shortness of breath, heart palpitations, and dizziness.

“Some of my patients feel they have a new lease on life after surgery,” says Frank Manetta, MD, the chief of cardiac surgery at North Shore University Hospital in Manhasset, NY.

The procedure has benefits beyond helping you feel better. It can also save your life. When your heart is in AFib, it can’t pump blood normally. Some of that blood pools in your heart’s upper chambers — the right atrium and left atrium. Clots can form in those pools. If one of those clots gets into your bloodstream, it can travel to your brain, block blood flow, and trigger a stroke.

The maze procedure allows your heart’s rhythm to remain normal so that blood flows through and out of your heart as it should. This reduces your risk of clots and stroke.

That means that correcting AFib with the maze procedure improves your life expectancy as well as your symptoms, Manetta says.

Your doctor will access your heart through your chest. They will make small cuts in the heart tissue, causing scars to form. They make a path for normal electrical signals in your heart to follow. The goal is to restore your heartbeat to normal.

Different types of maze surgery include:

Open-heart maze procedure. If you need valve or bypass surgery for heart disease and you have AFib, your surgeon may do a maze procedure during your open-heart surgery. Your surgeon will break your breastbone, open your chest, and stop your heart to perform this surgery. The doctor will put you on a heart-lung machine to support you during this procedure. This is the most common type of surgical ablation.

Minimally invasive maze surgery. Many people with AFib can have this type of surgery. It involves small cuts called keyholes so your surgeon can get to your heart. They will use energy, either heat or cold, to make scar tissue on your heart. This procedure can be done while your heart is still beating. Your surgeon may use a tiny video camera to help see inside your heart while making cuts and scar tissue.

Robotically assisted maze surgery. This is a type of minimally invasive maze surgery. Your surgeon may use a robotic tool to help do the ablation. These tools are slightly different from the ones used in minimally invasive surgery.

Before you undergo a maze procedure, you will have a thorough medical examination and will have to make a few changes to your daily routine.

Testing before the maze procedure

 In addition to blood tests, your doctor will order several tests before your procedure, including:

Transthoracic echocardiogram (TTE). This is a noninvasive or minimally invasive imaging test that uses sound waves (ultrasound) to create pictures of your heart. Your doctor uses these pictures to examine your heart’s functioning and structure.

Chest X-rays and chest CT. These noninvasive imaging tests create pictures of your heart. A CT scan is a type of X-ray that offers more detailed images than standard X-rays. It can help your doctor spot blood clots present in your heart, which would make surgery too dangerous. “You’ll come back once the clot has been resolved,” Manetta says.

Electrocardiogram (ECG or EKG). This is a noninvasive test that records your heart’s rhythm.

Holter monitor. This is a wearable device that records your heart’s rhythm for one or two days. You’ll wear it at all times. Some can be worn while bathing or swimming. With others, you have to avoid bathing or swimming or any contact with water while wearing it.

Changes to make before the maze procedure

In addition to your medical exam and testing, you will need to make some changes to your normal routine. This will include:

Stop smoking. If you smoke, stop smoking for at least two weeks before your heart surgery. It may cause problems with your breathing or blood clotting during or after your procedure.

Stop certain medications. If you take an anticoagulant such as warfarin, your surgeon may have you stop taking it a few days before your procedure. You’ll resume taking it after your surgery. If you take an anti-arrhythmic drug, you may need to stop that as well. Follow your doctor’s instructions regarding which medications to stop and when. You also should review with your cardiologist and surgeon all of the over-the-counter drugs and supplements that you take.

Stop eating and drinking after midnight. You should not eat or drink any foods or beverages after midnight before your procedure, except for a small sip of water to take the necessary medications. Food or drinks in your stomach may cause you to have problems with your anesthesia. It can cause you to vomit and breathe it in.

Bathe. The night before your surgery, bathe or shower. This helps get rid of germs on your skin.

At the hospital, your nurse may test your blood or urine, or give you a chest X-ray to make sure you don’t have any infections or problems that may affect your surgery’s success. You may be given medication to help you relax before the surgery.

You’ll have EKG electrodes attached to your chest and back to keep track of your heartbeat. You will get anesthesia to put you to sleep during the surgery.

After you are asleep, your doctor will connect you to a respirator that has a tube that goes down your throat. This will help you breathe during the operation. You may have a tube inserted into your throat to help collect fluid or air in your stomach during the operation. You may also have a catheter inserted in your bladder to collect urine during the operation.

Your surgeon will cut into your chest during your operation, and they will insert instruments to make the small interior cuts or make lesions on your heart tissue. Depending on the type of maze procedure you have, your surgeon may use tiny video cameras or robotic arms to help perform the operation.

How long does a maze procedure take?

That depends on the type of maze procedure you have, but expect that your surgery will last about two to four hours.

After maze surgery, you will probably have to stay in the intensive care unit of your hospital. After, you may need to stay up to five days in a regular hospital room. There, the staff will monitor your heartbeat and recovery.

After surgery, you may take diuretic drugs to help control fluid in your body. You may also take blood thinners or aspirin to prevent clots.

Open-heart surgery will take the longest to recover from. It can take many weeks to heal. If you have a minimally invasive maze procedure, you may have a quicker recovery than with open-heart surgery. You should be able to leave the hospital in two to four days. You can go back to normal activity after a few weeks.

For about a month after whichever surgery you have, don’t take very hot showers. Avoid soaking in a bath or whirlpool tub. Your surgical wounds may itch or feel numb or tight. You may have chest discomfort for a few weeks as your body heals. If you notice signs of infection around your wounds, such as redness, fever, swelling, or heat, call your doctor.

It may take a few months for your heartbeat to be normal again after the maze procedure. Your doctor will monitor your heartbeat to check how you’re doing. At first, you’ll see them a few weeks after your surgery. Then, you will see them for checkups every few months for the first year. You should see them once a year after that.

Maze procedure recovery time

Expect to feel sore and tired for at least a few weeks after your procedure. However, the length of your recovery will depend on the type of maze procedure you have. Open-heart surgery requires cracking and spreading of your ribs and bigger cuts, which take longer to heal than the cuts made for minimally invasive maze surgery.

“After the minimally invasive procedure, you can resume your regular activities with few restrictions pretty quickly,” Manetta says.

In general, recovery from an open-heart maze should take about six to eight weeks, while recovery from a minimally invasive maze surgery in four to six weeks.

You’re unlikely to have complications from this procedure — experts consider them rare. But like all surgery, the maze procedure does come with risks. These include:

  • Bleeding
  • Blood clots that could cause a heart attack or stroke
  • Buildup of fluids around your lungs (pleural effusion) or around your heart (pericardial effusion) or around your heart (pericardial effusion)
  • The need to have a pacemaker permanently implanted
  • Anesthesia complications, such as nausea and vomiting, sore throat, and chills from a drop in body temperature, as well as more serious complications like a collapsed lung
  • Infection
  • A new arrhythmia
  • Kidney failure

The maze procedure can treat atrial fibrillation effectively, with a success rate of 80%-90%. The procedure restores your heart’s normal rhythm, which eases severe symptoms such as fatigue, shortness of breath, heart palpitations, and dizziness. It also helps prevent potentially deadly strokes.

What is the success rate of the maze procedure?

The maze procedure has a success rate of 80%-90%.

What is the difference between a maze procedure and an ablation?

Ablation refers to any procedure in which abnormal tissue is destroyed in order to treat a medical condition, including arrhythmias, other heart problems, and certain types of cancer. The maze procedure is a very specific type of ablation therapy.

What happens if the maze procedure does not work?

If it does not work or your atrial fibrillation returns, your doctor may suggest medications or a minimally invasive procedure called a catheter ablation to treat it. In this procedure, your doctor will destroy the tissue responsible for the abnormal electrical signals that cause AFib rather than create a maze pattern that blocks those signals.