Analysis of mitral annulus motion measurements derived from M-mode, anatomic M-mode, tissue Doppler displacement, and 2-dimensional strain imaging

Background: Left ventricular longitudinal shortening plays an important role in cardiac contraction and can be measured by the mitral annulus motion (MAM) toward the cardiac apex. MAM can be evaluated by conventional M-mode, anatomic M-mode (AM-mode), tissue Doppler displacement (TDD), and 2-dimensional strain imaging (2DSI). Objective: The aim of the study was to compare these 4 different methods for measuring MAM. Methods: MAM was evaluated in 25 patients by M-mode, AM-mode, TDD, and 2DSI. Two walls (septal and lateral) in apical 4-chamber view were analyzed. Results. The angle correction between M-mode and AM-mode was significantly higher in the lateral wall (septum 2.2+/-1.6 vs lateral 4.1+/-1.6 degrees, P<0.01). However, with angle correction up to 8 degrees, the measurements obtained were not significantly different from those obtained by M-mode. No significant differences were found among 2DSI. M-mode, and AM-mode either, although all of them were significantly higher in comparison with TDD measurements in both septal (M-mode [11.0 +/- 2.4 nun], AM-mode [11.8 +/- 2.4 mm], 2DSI [11.0 +/- 3.4 mm] vs TDD [9.2 +/- 3.3 mm], P<.01) and lateral (M-mode [11.9 +/- 2.3 min], AM-mode [12.4 +/- 2.8 mm], 2DSI [10.4 +/- 3.9 mm] vs TDD [8.9 +/- 3.0 mm], P<.05) walls. The +/- 2SD variation from the mean difference in septal and lateral walls were, respectively, between: M-mode and TDD, -2.4 to 5.9 and -2.2 to 8.2 mm; M-mode and 2DSI, -5.7 to 5.7 and -5.8 to 8.7; AM-mode and TDD, -2.5 to 5.6 and -2.7 to 9.6; AM-mode and 2DSI, -5.7 to 5.87 and -5.9 to 9.8 and TDD and 2DSI, -3.2 to 6.6 and -5.3 to 8.4. Conclusions: AM-mode and M-mode measurements did not differ significantly. Despite the good correlation among all methods they were not interchangeable. TDD measurements were significantly lower than M-mode, AM-mode, and 2DSI measurements. M-mode and AM-mode are angle dependent and can, therefore, underestimate or overestimate MAM. The new method of 2DSI is promising because it tracks natural acoustic markers and is not angle dependent and, therefore, measures the true local tissue motion.