Early effects of percutaneous mitral valvuloplasty on left atrial mechanical functions.

It has been suggested that successful percutaneous balloon mitral valvuloplasty (PMV) decreases the intensity of spontaneous left atrial contrast, reduces the size of the left atrium, and improves left atrial function in patient with mitral stenosis. However, left atrial mechanical functions immediately after PMV have not been extensively evaluated yet. The aim of this study was to evaluate the effects of PMV on left atrial mechanical functions. Twenty patients with critical mitral stenosis who have normal sinus rhythm (male/female: 4 to 16; mean age: 33 +/- 8 years) were included in the study. Left atrial mechanical functions were evaluated before and after PMV, including left atrial passive emptying volume, LA passive emptying fraction, conduit volume, left ventricular stroke volume, LA active emptying volume, LA active emptying fraction, LA total emptying volume and LA total emptying fraction. PMV resulted in a significant increase in the mitral valve area (p < 0.001) and a substantial reduction in the mean transmitral pressure gradient (p < 0.001) as well as LA diameter (p < 0.002). LA maximal volume, minimal volume and atrial presystolic volumes were significantly decreased after PMV (p: 0.001; p: 0.002; p: 0.001, respectively). The conduit volume was increased and LA total emptying volume was decreased after PMV (p: 0.014; p: 0.035). The other left atrial volumes were not altered after PMV. The early increase in conduit volume and the decrease in left atrial presystolic volume indicate that PMV has favorable effects on atrial reservoir and conduit functions. PMV therefore improves atrial mechanic functions.