Although Doppler tissue imaging (DTI) frequently indicates the presence of mitral annular oscillations (MAO) following the E'-wave (E'"-wave, etc.), only recently has it been shown that annular 'ringing' follows the rules of damped harmonic oscillatory motion. Oscillatory model-based analysis of E'- and E'"-waves provides longitudinal 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 was analyzed using a previously validated kinematic model of filling. Invasive and noninvasive diastolic function (DF) indexes differentiated between the MAO⁺ and MAO^- groups. Specifically, the MAO⁺ group had a shorter time-constant of isovolumic relaxation (, 51±13 vs. 67±27 ms, p<0.01) and isovolumic relaxation time (IVRT, 63±16 vs. 82±17 ms, p<0.001) and greater E/A (1.19±0.31 vs. 0.97±0.31, p<0.05). The MAO⁺ group had a greater peak lateral mitral annulus velocity (E', 17.5±3.1 vs. 13.5±3.8 cm/s, p<0.001), LVEF (71.2±7.5 vs. 65.4±9.1%, p<0.05) and lower heart rate (HR, 65±9 vs. 74±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.