Comparative echocardiographic analysis of mitral and tricuspid annular motion:: Differences explained with proposed anatomic-structural correlates

Background: Annular motion (AM) has been shown to occur during all dynamic phases of the cardiac cycle; but little is known regarding comparisons between mitral and tricuspid AM. We elected to use M-mode to examine the extent and timing of mitral and tricuspid AM events. Methods: A complete echocardiogram was obtained in 50 patients [mean age 53 +/- 16 years, mean left ventricular ejection fraction (LVEF) 57 +/- 19%, and mean right ventricular fractional area change (RVFAC) of 49 +/- 20%]. Timing of all AM intervals was corrected for heart rate. Results: A strong linear correlation was noted for both LVEF and maximal mitral annular systolic excursion and for RVFAC and maximal tricuspid annular systolic excursion (r = 0.91, P < 0.0001). The amplitude of both maximal mitral annular descent (1.54 +/- 0.45 cm) and ascent (0.64 +/- 0.23 cm) was significantly smaller than for the tricuspid annulus (2.26 +/- 0.73 and 0.98 +/- 0.37 cm; P < 0.0001, respectively). Furthermore, while it takes longer for the mitral than for the tricuspid annulus (403 +/- 52 ms vs 308 +/- 50 ms; P < 0.0001, respectively) to descend to its lowest point; the duration to reach maximal ascent is shorter for the mitral than for tricuspid annulus (90 +/- 22 ms vs 115 +/- 19 ms; p < 0.0001, respectively). Conclusion: Significant differences exist in both amplitude and timing of AM events between the mitral and tricuspid annuli, likely reflecting intrinsic anatomical and electromechanical differences between both sides of the heart that require further investigation.