| ObjectiveHypertrophic cardiomyopathy (HCM) is a kind of autosomal dominant inheritance disease, which specified with asymmetrical hypertrophic. The long axis systolic function of HCM has been studied in many researches, its short axis function has been paid closed attention to. The speckle tracking imaging does not have the limit of angle-dependent. By use of the speckle tracking imaging technology, we can learn more about the systolic and diastolic cardic in short-axis. The purpose of this study was to assess the three different pattern of myocardial deformation: radial, circumferential and rotation in short-axis views in patient with hypertrophic cardiomyopathy, and to evaluate regional left ventricular dyssynchrony in hypertrophic cardiomyopathy (HCM) at the same time to analyse the post systolic deformation.MethodsThirty-six healthy subjects (aged from 19-76 years, mean age 51±13 years) and 18 patients with HCM (aged from 21-78 years, mean age 53±14 years) during 2008.1-2008.12 were recruited. Conventional echocardiography was performed to acquire basal, middle, and apical 2D LV short-axis.We obtained the curve of circumferential strain/strain rate and radial strain/strain rate curve in each segment by speckle tracking imaging. In the curve we acquired the radial and circumferential strain of each segment. We also acquired time to radial peak systolic (Trs) and to circumferential peak systolic (Tcs) in each case from these curves, and observe the post systolic deformation phenomenon.In the second part of the study,36 healthy subjects (aged from 19-76 years, mean age 49±15 years) and 24 patients with HCM (aged from 21-78 years, mean age 50±16 years) were recruited during 2008.1-2009.5 to analyzed LV rotation and torsion. We divide these patients with HCM into two sub-group. Group 1 were the patient with hypertrophic segments involved the septum, anterior, lateral and the apical. Group 2 were patients with asymmetrical mid-septum hypertrophy. Conventional echocardiography was performed as described above. Basal, middle, and apical 2D LV short-axis views were acquired to obtain curves of the rotation angle, rotation velocity and torsion.From these curves, the max-torsion angle, time to max-torsion angle(Tmax), the systolic peak of rotation in each segment, time to peak systolic rotation, the rotation angle when the close of aortic valves and open of mitral valves (Tmvo), were analysed, from which the untwisting rate[(Tmax—Tmvo)/Tmax]*100/IVRT was obtained.Results1,Circumferential strain and radial strain in patients with HCMThe peak systolic circumferetial strain was all negative in the health subject and patient with HCM. The circumferential strain in anterior and post septum of basal and middle septum increased as compared to other free wall segments of the same plane (P>0.05). ALL circumferential strain in free wall segments showed no significant difference (P>0.05). The circumferential strain in apical segments showed no significant difference (P>0.05). There was significant difference of circumferential strain in all segments in basal and middle segments in patients with HCM(P<0.05). But there was no significant difference in all apical circumferential strain. And almost all the circumferential strain in each segment of patient with HCM were lower than that in controls except for the inferior wall and inferolateral wall. The peak systolic radial strain all positive in the healthy subject and patient with HCM. All is lower in patient with HCM than in the control (P<0.05). Ther was no significant difference in radial strain of each segment of the plane in the control (P<0.05). There is also no significant difference of radial strain in each segment of the plane in patient with HCM (P>0.05). All radial strains were lower in patients with HCM than those in the controls.The radial and circumferential strains in each segment of patients with HCM were lower than those in controls, especially radial strain. In HCM, radial and circumferential strains in every segments were reduced no matter if it was hypertrophic or not.2,The torsion in HCMThe basal tend to ration clockwise and the apical tend to counter-clockwise in all the subjects. There may be clockwise or counterclockwise in the middle. There is no difference of rotation angle in the basal and apical (P>0.05). And in group 2, it tended to counter-clockwise in the segments in middle which included anterior septum, post septum, anterior, inferolateral (P<0.05). There was no difference of rotation angle in most of the groupl segments compared with the controls (P>0.05). The standard deviation of time to peak rotation was 75.05±10.48 in group2, which was 57.17±4.83 in group 1 and 40.41±4.47 in the controls. It showed there was significant difference in group2 compared groupl and the controls. Untwisting rates were significantly lower in group 1 (0.22±0.11%/ms, P<0.05) and group 2 (0.22±0.1%/ms, P<0.05) compared with the controls (0.43±0.19%%/ms)3,The synchronization of the systolic and post-systolic shorting in HCMThe Tcs in HCM groups and the controls was 398±28msVs378±57ms(p<0.05), The Tcs in HCM groups and the controls was 418±52msVs370±51ms (p<0.001). All were prolonged in HCM, no matter in hypertrophic segment or not. Compared with the controls, the Ts-18SD were also increased in both circumferential deformation[80±27Vs48±18 (p<0.001)] and radial deformation [91±19Vs41±14(p<0.001)]. The proportion of PSS been observed in circumferential deform and radial deform is 17%and 10%, which was 31% and 34% in patients with HCM. In HCM, the post-systolic shorting (PSS) are increased than that of the controls, especially in the basal and apical segments. The hypertrophic segments have more PSS than non-hypertrophic segments in patients with HCM.Conclusions1,The radial and circumferential strains are reduced in patients with HCM.2,The change in rotation in HCM may be related with the difference phenotype. And the untwisting rate is lower in patients with HCM. 3,There are more dyssynchrony and post systolic deformation in patients with HCM.4,Speckle tracking imaging contributes the better methods to identify the regional function in HCM. |
PDF Full Text Request