Various patterns of mid-diastolic mitral annular motion may imply different left ventricular (LV) diastolic function and filling pressure. To be a reliable marker in the evaluation of LV diastolic function and filling pressure, these findings must be validated by invasive method. Hence, this study was designed to compare the LV diastolic properties among different patterns of mid-diastolic mitral annular motion by invasive method. Fifty-five patients undergoing elective cardiac catheterization were included. Study subjects were classified into three groups according to mid-diastolic mitral annular motion patterns. Upward and downward La waves were respectively defined as a clear apically- and atrially-directed mid-diastolic annular motion on at least three consecutive beats with the average peak velocity >or=2 cm/s. Subjects with upward La wave, with downward but without upward La wave, and without La wave were categorized as groups 1, 2 and 3, respectively. The time constant of isovolumic LV pressure decline (tau) and LV end-diastolic pressure (LVEDP) were obtained from a micromanometer-tipped catheter. The tau was shorter and LVEDP was lower in group 1 than in groups 2 and 3 (p < 0.047) but these parameters were comparable between groups 2 and 3. In conclusion, patients with upward La wave had better LV relaxation function and lower LVEDP than patients without it. However, these diastolic properties were comparable between patients with only downward La wave and those without La wave. Therefore, mid-diastolic mitral annular motion is a useful and promising marker in the evaluation of LV relaxation and LVEDP.