Absence of diastolic mitral annular oscillations is a marker for relaxation-related diastolic dysfunction

Although Doppler tissue imaging frequently indicates the presence of mitral annular oscillations (MAO) following the E′ wave (E″ wave, etc.), only recently was it shown that annular "ringing" follows the rules of damped harmonic oscillatory motion. Oscillatory model-based analysis of E′ and E″ waves provides longitudinal left ventricular (LV) stiffness (k′), relaxation/viscoelasticity (c′), and stored elastic strain (x′_o) parameters. We tested the hypothesis that presence (MAO⁺) vs. absence (MAO^-) of diastolic MAO is an index of superior LV relaxation by analyzing simultaneous echocardiographic-hemodynamic data from 35 MAO⁺ and 20 MAO^- normal ejection fraction (EF) subjects undergoing cardiac catheterization. Echocardiographic annular motion and transmitral flow data were analyzed with a previously validated kinematic model of filling. Invasive and noninvasive diastolic function (DF) indexes differentiated between MAO⁺ and MAO^- groups. Specifically, the MAO⁺ group had a shorter time constant of isovolumic relaxation [τ; 51 (SD 13) vs. 67 (SD 27) ms; P < 0.01] and isovolumic relaxation time [63 (SD 16) vs. 82 (SD 17) ms; P < 0.001] and greater ratio of peak E-wave to peak A-wave velocity [1.19 (SD 0.31) vs. 0.97 (SD 0.31); P < 0.05]. The MAO⁺ group had greater peak lateral mitral annulus velocity [E′; 17.5 (SD 3.1) vs. 13.5 (SD 3.8) cm/s; P < 0.001] and LVEF [71.2 (SD 7.5)% vs. 65.4 (SD 9.1)%; P < 0.05] and lower heart rate [65 (SD 9) vs. 74 (SD 9) beats/min, P < 0.001]. Additional conventional and kinematic modeling-derived indexes were highly concordant with these findings. We conclude that absence of early diastolic MAO is an easily discernible marker for relaxation-related diastolic dysfunction. Quantitation of MAO via stiffness and relaxation/viscoelasticity parameters facilitates quantitative assessment of regional (i.e., longitudinal) DF and may improve diagnosis of diastolic dysfunction.