Introduction
Atrial tachycardia (AT) and atrial fibrillation (AF) commonly occur after cardiac surgery (CS), and Maze procedure has been used to treat and prevent such arrhythmias.1 The Maze techniques have been modified over time. Originally, the cut-and-sew technique has been used. In recent years, energy sources, such as radiofrequency (RF), cryo, and Ultrasound (US), have been introduced into the procedure.2-4 Typically, Cox III and Kosakai’s Maze procedures use the cut-and-sew technique4, Maze IV uses RF energy3, and CryoMaze2 uses cryo energy, but Maze technique depends on operators and the facilities. Surgical Maze has been recommended for maintaining sinus rhythm,5 but the failure of the procedure may lead to persistent atrial arrhythmias, which could result in embolism, heart failure, and fatal events.6-8
Previously, the electrophysiological mechanisms of ATs after Maze surgery have been reported by some institutions.3,9 However, few detailed studies have been made on whether there is a relationship between gaps and AT/AF after various Maze procedures. The purpose of this study was to investigate the characteristics, electrophysiological findings, and outcomes of catheter ablation (CA) of atrial arrhythmias after cut-and-sew, RF, or cryo Maze procedures.