What is it?

A Maze procedure is a treatment for atrial fibrillation and atrial flutter. If medication, cardioversion and ablation are not effective or if other heart surgery (bypass and/or valve repair or valve replacement) is necessary and atrial fibrillation is present, a Maze procedure is opted for.

For a Maze procedure, the physician applies heat (usually through radiofrequency) or cold to form scar lines in the atrium. The heart tissue is divided into areas this way. These areas are connected to each other and to the valves or openings in the heart so that the signal cannot circle back but continue its path. This way, amaze patternis formed and heart rhythm disturbances can no longer occur. There is no change to the origin of the electrical signals.

What is the process?

The Maze procedure extends a valve replacement procedure or bypass operation by approximately 30 minutes.

Because the heart is stopped during the operation, the heart rhythm is often slow or conduction is interrupted. Before the chest is closed, electrodes (thin metal wires) are attached to the heart. This is always done as a precaution. If the heart were to have a slow heartbeat after the procedure, an external pacemaker can be connected to these electrodes. The wires are removed just before your discharge from the hospital.


Fibrillation may recur after the operation and may sometimes recur in the form of episodes for weeks or months afterwards. This is because the atrial tissue needs to heal after the surgery. It is important that any atrial fibrillation after the surgery is regarded as a new heart rhythm disturbance and is treated aggressively. The final result can therefore only be ascertained after approximately six months.

Atrial fibrillation often occurs after heart surgery, even if it was not observed before the operation.

Centres and specialist areas

Cardiac surgery

Latest publication date: 05/02/2021