Introduction
Atrial fibrillation (AF) is a common irregular heart rhythm in which the upper chambers (atria) quiver instead of beating in a regular way. It can cause palpitations, tiredness and a higher chance of blood clots and stroke.
In the Maze procedure, the surgeon makes a pattern of small lines of scar tissue in the atria. These lines block the abnormal electrical signals and guide the normal signal along one path, like the paths of a maze, so that the rhythm can become regular.
Why the procedure is needed
Atrial fibrillation that is not controlled well by medicines may cause:
- Palpitations, a racing or irregular heartbeat
- Breathlessness, tiredness, dizziness or reduced stamina
- Higher risk of blood clots forming in the heart and travelling to the brain (stroke)
- Weakening of the heart muscle if the heart beats too fast for too long
- Poor quality of life despite treatment with tablets or procedures
Who may benefit
- People with atrial fibrillation who are having heart surgery for another reason, such as valve surgery or bypass, where a Maze can be added
- People with symptomatic AF in whom medicines or catheter ablation have not worked, or who are not suitable for them
- Selected patients in whom the heart team judges a surgical approach to be appropriate
- Not all patients are suitable — long-standing AF with a very large left atrium may respond less well
Techniques and what to expect
- Cut-and-sew and modern Maze
- The original technique used surgical incisions; today the lines are usually made with energy sources such as radiofrequency or freezing (cryoablation).
- Left atrial appendage
- The small pouch of the left atrium, where clots often form, is often closed or removed to reduce the risk of stroke.
- Alongside other surgery
- It is most often done at the same time as valve or bypass surgery.
- Stand-alone or minimally invasive
- In some centres it can be performed on its own, through smaller incisions, in selected patients.
- Success and medicines
- Many patients return to a regular rhythm, but not all. Blood thinners and rhythm medicines may still be needed for months, and sometimes longer.
Procedure overview
Step 1: Assessment
Rhythm recordings, echocardiography and other tests show the type of AF and the size of the left atrium. Your team discusses the options, including medicines and catheter ablation.
Step 2: Anaesthesia
General anaesthesia is used.
Step 3: Surgical access
The heart is reached through the breastbone (usually with other surgery), or through smaller incisions in selected patients.
Step 4: Creating the lines
Patterns of lines are made in the left and sometimes the right atrium with radiofrequency or cryoablation, or with surgical cuts.
Step 5: Appendage management
The left atrial appendage is usually closed or removed.
Step 6: Recovery and rhythm check
After surgery, heart rhythm is monitored. Rhythm may be irregular for the first weeks while the lines heal. Follow-up rhythm checks decide whether medicines can be reduced.
Clinical advantages
- May restore a regular heart rhythm and relieve palpitations and tiredness
- Closing the left atrial appendage may lower the risk of stroke
- Adds relatively little extra time when done during other heart surgery
- May reduce the need for rhythm medicines in some patients
Risks and considerations
Every operation carries risk. The points below are general; your own risk depends on your health and on the operation you need.
- The risks of the main surgery (bleeding, infection, stroke, rhythm and kidney problems)
- AF may return, and a further procedure may be needed
- Slow heart rate after surgery, which may need a pacemaker in some patients
- Damage to nearby structures such as the oesophagus (very rare) from energy sources
- Blood thinners may still be needed after surgery, with their own bleeding risk
Frequently asked questions
Will the Maze procedure cure my atrial fibrillation?
Many patients become free of AF, but it is not a guaranteed cure. Results vary with the type and duration of AF and the size of the heart chambers.
Will I be able to stop my medicines?
Some patients can reduce or stop rhythm medicines and, in time, blood thinners, but only after follow-up tests and on your doctor's advice. Never stop them yourself.
How is it different from catheter ablation?
Both create lines to block abnormal signals. The Maze is done surgically, usually with other heart surgery, while catheter ablation is done through blood vessels without open surgery.
Why is the left atrial appendage closed?
Clots in AF often form in this small pouch. Closing it may lower the risk of stroke.
Is my rhythm normal immediately after surgery?
Not always. Irregular rhythm can occur in the first weeks while the heart heals. Your team will check your rhythm over the following months.
Patient-friendly summary
The Maze procedure creates lines of scar in the heart's upper chambers to block the abnormal signals of atrial fibrillation. It is most often added to other heart surgery and can help many patients return to a regular rhythm, but it is not a guaranteed cure. A cardiologist and cardiothoracic surgeon can tell you if it is suitable.