Electron Beam Cine CT-Based Evaluation of Left Atrial Function after the Maze Procedure for Mitral Valve Regurgitation

Objective: There has been little investigation of whether atrial function is equally restored by surgery in patients with mitral regurgitation (MR) and atrial fibrillation (AF) compared to patients in sinus rhythm (SR). Patients and Methods: We evaluated left atrium (LA) volume-time curves obtained from electron beam tomography. The study involved 33 patients who had surgical treatment for MR with or without AF and 11 control patients. Results: (1) In patients with SR, LA volume decreased significantly along with a resolution of early regurgitation postoperatively, and the reserve function was well maintained. The LA booster pump function was also well maintained before and after surgery. (2) In patients with AF that resolved after maze surgery, the LA volume was larger than that of the sinus group immediately after surgery, and it did not improve in postoperative periods. These patients had a lower reserve function and a much lower booster pump function despite restoration of SR. Conclusions: The maze procedure is suggested to be unlikely to achieve restoration of atrial function in patients with MR accompanied by AF, even if SR returns postoperatively. Because patients with SR demonstrated the same LA function as the control postoperatively, surgical indication should be considered for patients with severe MR while their atrial function and SR are maintained. (Ann Thorac Cardiovasc Surg 2010; 16: 91-98)