An abnormal heart rhythm, or arrhythmia, is caused by a disruption of the normal electrical conduction that occurs in the heart. Some types of arrhythmias may be life-threatening if not promptly and adequately treated. Fibrillation is the most serious form of arrhythmia, characterized by fast, uncoordinated heartbeats that don't pump blood.
Surgeons often treat atrial fibrillation with what is called the MAZE procedure. This surgery creates a "maze" of new electrical routes so electrical impulses can easily move through the heart.