Left atrial wall tension directly affects the restoration of sinus rhythm after Maze procedure.

OBJECTIVE

The surgical treatment of permanent atrial fibrillation (AF) continues to be a clinical challenge. Increased left atrial (LA) wall tension affected by LA wall thickness and volume has been associated with poor restoration of sinus rhythm after the Maze procedure. This study was designed to investigate the impact of conversion rates to sinus rhythm using LA wall tension reduction techniques in conjunction with aggressive postoperative pharmacological therapy in comparison to a modified Maze procedure alone.

METHODS

From 1999 to 2008, 322 patients with permanent AF and biatrial enlargement, who required mitral valve ± tricuspid valve surgery were exactly randomized into two groups: The study group used biatrial reduction with reef-imbricate suture technique concomitant with the Maze procedure and aggressive postoperative pharmacological therapy; the control group was treated with the Maze procedure alone. LA dimension was measured by transesophageal echocardiogram (TEE) or transthoracic echocardiography (TTE); LA wall thickness was measured by TEE and manually during surgery. Pulmonary artery (PA) pressures were measured by PA catheter or TTE, BNP test and clinical follow-up at discharge, 3 months, 6 months and 1 year. There were 187 woman (58%) and 135 men (42%). Their mean age was 45 ± 9.5 years.

RESULTS

Overall restoration of sinus rhythm was significantly improved in the group with aggressive reduction of LA wall tension during 1-year clinical follow-up (89.3% vs 67.2%, p < 0.001). Calculated LA wall tension was significantly reduced at discharge in the study group versus control group (4.012 ± 1.650 dyn cm(-1) vs 20 384 ± 3313 dyn cm(-1) (p < 0.001)) and at 1-year follow-up (1059 ± 1161 dyn cm(-1) vs 17 139 ± 3170 dyn cm(-1) (p < 0.001)), respectively. Significant differences in changes in LA dimension were detected at discharge and 1-year follow-up in the study group versus control group (43 ± 7 vs 61 ± 11, p < 0.001). LA wall (3.9 ± 1.3 vs 2.3 ± 0.9) thickness also significantly differed at the 1-year follow-up.

CONCLUSION

An aggressive approach to reduce LA wall tension significantly improves restoration of sinus rhythm after the Maze procedure. LA wall tension directly affects sinus conversion. Further studies using pharmacologic intervention to reduce LA wall tension for maintenance of sinus rhythm need to be evaluated.