Left Atrial Appendage Function Analyzed by Tissue Doppler Imaging in Mitral Stenosis: Effect of Afterload Reduction after Mitral Valve Commissurotomy

Abstract

This study sought to investigate the relative load dependence of left atrial appendage (LAA) tissue Doppler velocities in patients with mitral stenosis after percutaneous mechanical mitral commissurotomy (PMMC). LAA tissue Doppler velocities were obtained in 34 patients with mitral stenosis (20 with sinus rhythm and 14 with atrial fibrillation) before and after PMMC by transesophageal echocardiography. Standard ultrasound studies were also performed for mitral valve orifice area, transmitral pressure gradient, and LAA blood flow velocity measurements. PMMC resulted in a significant increase in mitral valve area (P < .001) and decrease in mean transmitral pressure gradient (P < .001). LAA tissue Doppler velocities consisted of a triphasic velocity profile: SLAA and ELAA occurring during left ventricular contraction and relaxation, respectively, and ALAA occurring after the atrial contraction. After PMMC, ELAA and ALAA velocities consistently increased (4.8 +/- 1.2 to 7.9 +/- 2.6 cm/sec [P < .001] and 6.6 +/- 2.9 to 8.1 +/- 4.2 cm/sec [P < .05], respectively). The mean transmitral pressure gradient was significantly correlated with ALAA before and after PMMC (r = .65). In mitral stenosis, tissue Doppler velocities illustrated improvement of regional LA function after PMMC, in relation to decreased transmitral pressure gradient.