Cox et al 1–4 developed this procedure—a general outline follows: (1) surgical incisions are performed in such a way that it is impossible for an activation impulse to travel from any point in the atrium and return to the same point without crossing an incision or a cryoablated line, which interrupts the electrical conduction; (2) of critical importance is the fact that the Maze procedure provides a route by which an impulse generated by the sinoatrial node can access the atrioventricular node to drive the ventricle; (3) several blind alleys along this main conduction route are also created to synchronously activate the atria, thus preserving the atrial transport function; and (4) a single pathway is preserved for conduction between the sinus node and the atrioventricular node.