Left atrial function and deformation in chronic primary mitral regurgitation.

AIMS To study global and regional left atrial (LA) mechanics in chronic primary mitral regurgitation (MR) with echocardiography. METHODS AND RESULTS LA volumes during reservoir, conduit, and contractile phases were measured in 27 MR patients and 25 controls. LA ejection fraction (EF) and ejection force were calculated. Reservoir (SR-R), conduit (SR-C), and contractile phase (SR-A) strain rates, and reservoir phase strain were obtained. LA volumes were higher in MR in all phases. In MR, ejection force was increased (21.5 vs. 12.3 kdynes, P = 0.001); reservoir phase strain (32.91 +/- 14.26%), SR-R (2.65 +/- 0.87), SR-C (-2.02 +/- 0.58), and SR-A (-2.55 +/- 1.31 s(-1)) were increased (23.14 +/- 7.96%, 1.62 +/- 0.53, -1.29 +/- 0.59, -1.98 +/- 0.65 s(-1), in controls, respectively, P < or = 0.004). Regional deformation correlated with corresponding volumetric parameters. Despite enhanced SR-A in MR, LA EF was unchanged (31.34 vs. 29.23%, P = ns), and LA contractile tissue velocity (A') was reduced (-5.39 +/- 1.95 vs. -6.91 +/- 1.80 cm/s, P = 0.006). The LA contractile contribution to left ventricular filling was significantly reduced in MR. CONCLUSION LA deformation is increased in all phases in MR. Unchanged LA EF and reduced A' may reflect the reduced contractile contribution to left ventricular filling.