Predictors of Sinus Rhythm Restoration after Maze Operation and Relationship between Pre- and Post-operative Left Atrial Volume

Background and Objectives:The Maze operation is known to be an effective measure for restoring sinus rhythm in patients with atrial fibrillation (AF). The purpose of this study was to identify the relationship of preand post-operative left atrial volume (LAV) and diameter (LAD) with successful restoration of sinus rhythm in the Maze operation. Subjects and Methods:The subjects for this study were 28 patients who underwent open-heart surgery in conjunction with the Maze-III operation for chronic AF from October, 2002, to April, 2003. Electrocardiographic and transthoracic echocardiographic studies were done pre-operatively and three months post-operatively. LAV and LAD were assessed and corrected for body surface area (LAV index=LAV/BSA, LAD index=LAD/BSA). Results:Sinus rhythm was restored and maintained in 22 of the 28 patients (78.6%). Between the group with successful restoration of sinus rhythm (Group A;n=22) and the group with unsuccessful restoration (Group B;n=6), there was no difference in age, gender, and NYHA functional class. The duration of AF in group A was significantly shorter than that of B (3.6±2.7 years versus 15.8±7.5 years, p=0.003). Group A and B did not show any difference in pre-operative left ventricular ejection fraction. However, pre-operative LAV index in group A was significantly smaller than that of group B (80.7±22.4 mL/m versus 118.1±42.5 mL/m , p=0.048). In group A, the LAV index (80.7±22.4 mL/m 2 versus 52.8±14.7 mL/m , p<0.001) and LAD index (35.4±5.3 mm/m 2 versus 31.7±4.7 mm/m , p=0.001) decreased significantly three months after the operation. In group B, however, no significant changes are found in the LAV index (118.1±42.5 mL/m versus 89.2±38.9 mL/m , p=0.116) and LAD index (39.1±7.9 mm/m 2 versus 36.2±9.2 mm/m , p=0.144). Conclusion:Pre-operative LAV index measured by echocardiography and the duration of AF were significant predictors of successful sinus rhythm restoration after the Maze operation. Significant reduction of the LAV index after the Maze operation was found in patients whose rhythm was successfully restored and maintained. (Korean Circulation J 2004; 34(6):574-581)