| Objective To assess the change of the left ventricular early diastolic flow propagation velocity (Vp) in patients with hypertrophic cardiomyopathy, and to discuss the relation between Vp and left ventricular regional diastolic function as well as myocardial hypertrophy and the clinical application value of Vp in evaluating left ventricular diastolic function in patients with hypertrophic cardiomyopathy. Methods We studied 52 patients with hypertrophic cardiomyopathy and 30 healthy volunteers matched with age. The thickness of twelve myocardial segments of interseptal, lateral, inferior and anterior left ventricular wall was measured ar mitral, papillary muscle and apical level from a cross sectional image in the parasternal short axis view by transthoracic two-dimensional echocardiography to calculate left ventricular wall thickness index (WTI) and left ventricular wall asymmetry index (WAI). From the apical four chamber view, the image of mitral inflow was obtained and early diastolic peak flow velocity (E), late diastolic peak flow velocity (A), the ratio of E/A and deceleration time of E wave were measured. From the apical four chamber and two chamber view, the basical segment and middle segment of interventricular septal, left ventricular lateral wall, anterior wall and inferior wall were obtained by tissue Doppler imaging. Early diastolic myocardial motion velocity (Em) and displacement (De), late diastolic peak myocardial motion velocity(Am) and displacement (Da), and the ratio of Em/Am were measured. The mean value of parameters and left ventricular wall relaxation asynchrony index (RAI) were calculated. From the apical four chamber view, left ventricular early diastolic flow propagation velocity (Vp) was measured by color M-mode echocardiography. Results WTI was significantly higher in the HCM group than in the control group, 154.56+23.81 and 92.94+8.88, respectively (t= -11.69, P<0.0001) . WAI was also significantly higher, 0.36+0.11 and 0.07+0.01, respectively (t= -14.04, p<0.0001) . There were no significant differences in E, A, E/A and DT between the control and HCM groups (t= -0.99-2.23, P>0.05). Em, Am, Em/Am, De, Da, mean Em, mean Am, mean Em/Am, mean De and mean Da were significantly lower in the HCM group than in the control group ( t= 0.09-14.13, P<0.0001) . The value of RAI were 0.11+0.02 and 0.04+0.01 in the control group and HCM group respectively and there was a significant difference ( t= -3.67. P<0.0001 ) . The value of Vp were 38.54+ 10.08 cm/s and66.20+ 17.50 cm/s in the control group and HCM group, respectively, and there was a significant difference ( t= 8.42, p<0.0001) . Multinomial linear regression analysis showed WTI, RAI, WAI and LVEF were determinant to Vp in HCM group. According to various degrees of left ventricular diastolic dysfunction, hypertrophic cardiomyopathy group (52 cases) was divided into three subgroups: damaged left ventricular effective relaxation subgroup, pseudonormal filling pattern subgroup and restrictive filling pattern subgroups. The values of Vp in different left ventricular diastolic function groups were(66.20+ 17.50) cm/s, (42.44+9.17) cm/s, (34.85+9.99) cm/sand (21.86+5.48) cm/s, respectively. There was a decreasing gradually trend and a significantly difference(F= 29.80, P<0.001) . Spearman rank correlation analysis showed the correlation between the change of Vp and the degrees of left ventricular diastolic dysfunction was excellent (r= 0.41, p<0.001) . The mean Em and mean Em/Am decreased gradually significantly in the control group, damaged left ventricular effective relaxation subgroup, pseudonormal filling pattern subgroup and restrictive filling pattern subgroup (F= 5.05-66.93, P<0.001) . Spearman rank correlation analysis showed the values of the mean Em, mean De and mean Em/Am decreased gradually, and there were significant differences (F= 5.05-66.93, p<0.001) . Spearman rank correlation analysis showed there were excellent correlation between the changes of the mean Em, mean De, mean Em/Am and the degrees of left ventricular dias...
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