The Maze Procedure is most commonly done at the same time as open heart surgery or during valve replacement surgery. Surgeons perform a Maze Procedure if the patient has a history of an irregular heartbeat that cannot be controlled by other treatments. It is used when the electrical system of the heart is not working correctly, which causes the irregular heartbeat. A healthy heart beats between 60 and 80 times a minute, while irregular heartbeats can beat 300 or more times a minute, which can increase the risk of a stroke. A Maze Procedure corrects the irregular heartbeat by fixing the electrical system in the heart. Specialized equipment and instruments are used for this type of procedure.