Atrial fibrillation is an irregular heart rhythm that leads to a nine times increase risk of stroke and double risk of death. Often, atrial fibrillation can be managed by medications or catheter based procedures. However, sometimes these treatments are ineffective, or a patient with atrial fibrillation is undergoing heart surgery for a different reason. Surgical treatment for atrial fibrillation is called a MAZE procedure. This is because the procedure involves making scars that block abnormal electrical conduction within the heart and form a “MAZE” which channels the electrical signals in the correct direction.
The MAZE procedure can be done at the time of other heart surgery or can be done as a minimally invasive stand-alone procedure. Either heat energy or cold energy is used to create the scars that channel the electrical signals of the heart. In addition to channeling the electrical signals, the left atrial appendage is removed. The left atrial appendage is the source of most strokes from atrial fibrillation. By removing the left atrial appendage, the risk of stroke is significantly decreased.
When done minimally invasively, a video camera is used to work between the ribs and it is not necessary to divide the breastbone. Patients are typically in the hospital for one to three days after the procedure and are discharged without any restrictions. Atrial fibrillation done at the time of other open-heart surgery does not extend the length of the procedure significantly. Patients are typically maintained on anti-arrhythmic medications and anticoagulation for three to six months before an assessment is made about the efficacy of the MAZE procedure.
There is often atrial fibrillation that occurs in the first several months following the MAZE procedure. The occurrence of atrial fibrillation in the post-operative period is not concerning and does not mean that the MAZE procedure did not work. Atrial fibrillation following any surgery in the chest is very common due to the inflammation, irritation, and scarring that occurs on and around the heart following surgery. Patients are given a three to six month period following surgery to allow for healing and resolution of inflammation before the efficacy of the MAZE procedure can be assessed. Once an assessment of the success of the MAZE procedure has been made, consideration can be give to stopping anti-arrhythmic medications and anticoagulation.