Marui Akira, Saji Yoshiaki, Nishina Takeshi, Tadamura Eiji, Kanao Shotaro, Shimamoto Takeshi, Sasahashi Nozomu, Ikeda Tadashi, Komeda Masashi
Department of Cardiovascular Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
J Thorac Cardiovasc Surg. 2008 Jun;135(6):1297-305. doi: 10.1016/j.jtcvs.2008.02.026. Epub 2008 May 5.
Left atrial geometry and mechanical functions exert a profound effect on left ventricular filling and overall cardiovascular performance. We sought to investigate the perioperative factors that influence left atrial geometry and mechanical functions after the Maze procedure in patients with refractory atrial fibrillation and left atrial enlargement.
Seventy-four patients with atrial fibrillation and left atrial enlargement (diameter > or = 60 mm) underwent the Maze procedure in association with mitral valve surgery. The maximum left atrial volume and left atrial mechanical functions (booster pump, reservoir, and conduit function [%]) were calculated from the left atrial volume-cardiac cycle curves obtained by magnetic resonance imaging. A stepwise multiple regression analysis was performed to determine the independent variables that influenced the postoperative left atrial geometry and function.
The multivariate analysis showed that left atrial reduction surgery concomitant with the Maze procedure and the postoperative maintenance of sinus rhythm were predominant independent variables for postoperative left atrial geometry and mechanical functions. Among the 58 patients who recovered sinus rhythm, the postoperative left atrial geometry and function were compared between patients with (VR group) and without (control group) left atrial volume reduction. At a mean follow-up period of 13.8 months, sinus rhythm recovery rate was better (85% vs 68%, P < .05) in the VR group and maximum left atrial volume was less (116 +/- 25 mL vs 287 +/- 73 mL, P < .001) than in the control group. The maximum left atrial volume reduced with time only in the VR group (reverse remodeling). Postoperative booster pump and reservoir function in the VR group were better than in the control group (25% +/- 6% vs 11% +/- 4% and 34% +/- 7% vs 16% +/- 4%, respectively, P < .001), whereas the conduit function in the VR group was lower than in the control group, indicating that the improvement of the booster pump and reservoir function compensated for the conduit function to left ventricular filling.
Left atrial reduction concomitant with the Maze procedure helped restore both contraction (booster pump) and compliance (reservoir) of the left atrium and facilitated left atrial reverse remolding. Left atrial volume reduction and postoperative maintenance of sinus rhythm may be desirable in patients with refractory AF and left atrial enlargement.
左心房的几何形状和机械功能对左心室充盈及整体心血管功能有着深远影响。我们旨在研究影响难治性心房颤动合并左心房扩大患者迷宫手术后左心房几何形状和机械功能的围手术期因素。
74例心房颤动合并左心房扩大（直径≥60mm）患者在接受二尖瓣手术的同时接受了迷宫手术。通过磁共振成像获得左心房容积-心动周期曲线，计算左心房最大容积和左心房机械功能（增强泵功能、储器功能和管道功能[百分比]）。进行逐步多元回归分析以确定影响术后左心房几何形状和功能的独立变量。
多变量分析显示，与迷宫手术同时进行的左心房缩小手术以及术后窦性心律的维持是术后左心房几何形状和机械功能的主要独立变量。在58例恢复窦性心律的患者中，比较了有（VR组）和没有（对照组）左心房容积缩小的患者的术后左心房几何形状和功能。在平均随访13.8个月时，VR组的窦性心律恢复率更高（85%对68%，P<.05），左心房最大容积更小（116±25ml对287±73ml，P<.001）。仅在VR组中，左心房最大容积随时间减少（逆向重构）。VR组术后的增强泵功能和储器功能优于对照组（分别为25%±6%对11%±4%和34%±7%对16%±4%，P<.001），而VR组的管道功能低于对照组，这表明增强泵功能和储器功能的改善补偿了对左心室充盈的管道功能。
与迷宫手术同时进行的左心房缩小有助于恢复左心房的收缩功能（增强泵）和顺应性（储器），并促进左心房逆向重构。对于难治性心房颤动合并左心房扩大的患者，左心房容积缩小和术后窦性心律的维持可能是理想的。
