Atrial fibrillation (AF) is a frequent complication in patients affected by mitral valve disease, causing systemic embolism, cardiac chamber dilation and decreased cardiac output. Cox et al. have designed the maze procedure as a surgical treatment for patients with AF in whom conventional therapy has failed and their lesion set is nowadays currently performed with different energy sources in order to surgically treat such supraventricular arrhythmia. In particular, the original maze was designed with three specific goals in mind: 1) the permanent AF ablation 2) the restoration of atrioventricular synchrony and 3) the preservation of atrial transport function (1). If , by one side, the efficacy of the procedure in reaching the first two goals are widely known, the restoration of the sinus rhythm does not always accompany the corresponding recovery of atrial mechanical "kick". If the atrial transport function fails to recover, benefits deriving from arrhythmia abolition might only be marginal, since, by one side, blood stasis in the atria persist, thus maintaining unchanged thromboembolic risk and, by the other side, heart hemodynamic performance is still impaired resulting from the loss of atrial contribution to cardiac output. Despite its relevant role for judging maze comprehensive success, atrial contractility outcome and clinical importance have not been deeply investigated. The purposes of this study were to evaluate by serial transthoracic echocardiography temporal modality of biatrial contractility restoration, predictive factors of atrial transport recovery and its possible relationship with cardiac chambers dimensions and function evolution after radiofrequency (RF) maze during mitral surgery.