Effects of balloon mitral valvuloplasty on left atrial function in mitral stenosis as assessed by pressure–are relation

Objectives. This study sought to investigate the changes induced on the pressure–are relation of the left atrium in patients with mitral stenosis after percutaneous balloon mitral valvuloplasty. Background. Left atrial (LA) function is influenced by changes in L afterload. The latter is increased in mitral stenosis as result of increased resistance to blood flow imposed by the stenotic mitral valve. Methods. We studied the effects of acute alterations of L afterload induced by retrograde nontransseptal balloon mitral valvuloplasty (RNBMV) on L function in patients with mitral stenosis. L pressure–are relations were obtained in 15 patients with mitral stenosis (8 with sinus rhythm, 7 with atrial fibrillation) before and after valvuloplasty, as well as in 15 normal subjects. L pressure was recorded by catheter-tipped micromanometer introduced retrogradely into the left atrium while L are was recorded simultaneously using acoustic quantification. The areas of the and V loops of the pressure–are relation as well as the L chamber stiffness constant were calculated. Results. Balloon valvuloplasty resulted in significant increase in mitral valve are (p < 0.001) and substantial reduction of the mean transmitral pressure gradient (p < 0.001) and mean L pressure (p < 0.001). The are of the loop in patients with sinus rhythm and the are of the V loop in those with atrial fibrillation increased significantly after completion of the procedure (p < 0.001). Furthermore, L stiffness decreased in both groups. Conclusions. After RNBMV, there is significant increase in L pump function in patients with sinus rhythm, significant increase in L reservoir function in patients with atrial fibrillation and significant reduction in L stiffness in all patients. Marked alterations of the configuration of the L pressure–are relation occur immediately after successful RNBMV in patients with mitral stenosis.