Results
The median period from consciousness of palpitations to CA was 1.9±2.6 years (median, 0.42 years; IQR, 0.17-3.42). Table 1 shows the patients’ baseline characteristics. The average age was 69.3±7.2 years and 20 (54.1%) were male. The average LA diameter was 46.9 ± 7.7 mm.
The types of surgery and outcome are listed in Table 2 . Among the 37 consecutive cases, the following procedures were performed: CryoMaze, 21; Maze III, 4; Kosakai’s Maze, 2; Maze IV, 4; right atrial (RA) Maze, 3; LA Maze, 3. Forty-nine mappable ATs were induced in all cases, of which 42 (85.7%) were related to the Maze procedure and 47 (95.9%) reached endpoint at first session.
Figure 1 shows the characteristics of 59 atrial arrhythmias, in which 49 were mappable ATs and the remaining 10 were AF. Mappable AT divided into 37 macroreentrant-ATs and 12 non-macroreentrant-ATs. Macroreentrant-ATs divided into 22 peri-mitral atrial flutter (M-AFL) (20 gap-rerated), 11 cavotricuspid isthmus dependent atrial flutter (T-AFL) (10 gap-rerated), and 4 RA AT (4 gap-rerated). Non-macroreentrant-ATs were divided into 4 septal AT (2 gap-rerated), 4 LA appendage (LAA) AT (4 gap-rerated), 2 LA AT (2 gap- related), and 2 RA AT (0 gap-rerated).
Figure 2 shows all gaps after the Maze procedure. In total, there were 88 gaps (2.4±1.2 gaps/patient), of which 42 (47.7%) were associated with AT. Among the 42 gap-related ATs, 20 (47.6%) were M-AFL and 11 (26.2%) were T-AFL. Nineteen of 37 consecutive cases (51.4%) had gaps in the PV isolation (PVI) line, but only 2 (10.5%) were associated with PV gap reentry AT.
Figure 3 shows representative case 7. This figure shows lines of the CryoMaze2 procedure performed in our institution, and 3 forms of gap related ATs after CryoMaze procedure.
Table 3 shows the number of AT and AF cases after the Maze procedures. The number of ATs induced was 1.6±0.8 per case. Most of ATs were macro reentry tachycardia of the LA. In some cases, LA AT or AF occurred after RA Maze.
Table 4 shows the relationship among the PV gap, the occurrence of PV gap related AT and AF, and the Maze procedure. Almost half of the cases had PV gap and gap-related AT or AF in each Maze procedure. The relationship between cut-and-sew method and the PV gap was not significant different (P=0.44), and also the relationship between incidence of AF or gap related-AT and cut-and-sew methods (P=0.15). The incidence of gap related-AT and AF was significantly higher with more gaps in PV (P=0.003).