[Anatomic atrial remodeling after mitral valve surgery in permanent atrial fibrillation]

Mitral valve pathology is frequently associated with atrial dilation and fibrillation. Mitral surgery allows immediate surgical atrial remodeling, and in those cases in which sinus rhythm is achieved, it is followed by late remodeling. The aim of this study was to investigate the process of postoperative atrial remodeling in patients with permanent atrial fibrillation who undergo mitral surgery.

In a prospective randomized trial, 50 patients with permanent atrial fibrillation and dilated left atrium, repaired surgically, were divided into two groups: group I, 25 patients with left atrial reduction and mitral surgery, and group II, 25 patients with isolated valve surgery. The characteristics of both groups were considered homogeneous in the preoperative assessment.

After a mean follow-up of 31 months, 46% of the patients in group I versus 18% in group II regained sinus rhythm (p = 0.06). Atrial remodeling with shrinkage occurred in patients who recovered sinus rhythm, with larger changes in group II (-10.8% left atrial volume reduction in group I compared to -21.5% in group II; p < 0.05). The atrium became enlarged again in patients whose atrial fibrillation did not remit (+16.8% left atrial volume increase in group I versus +8.4% in group II; p < 0.05).

Mitral surgery produces a postoperative decrease in atrial volume, especially when reduction techniques are used. Late left atrial remodeling was influenced by the type of atrial rhythm and postoperative surgical volume.