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Clinic Research Of Left Ventricular Motion In Hypertension Patients With Different LV Geometry By STI

Posted on:2012-08-02Degree:MasterType:Thesis
Country:ChinaCandidate:L WangFull Text:PDF
GTID:2154330332999535Subject:Medical imaging and nuclear medicine
Abstract/Summary:PDF Full Text Request
Objective:Left Ventricular Remodeling of Hypertension Patients is a significant independence risk factor for heart events which have compact correlations with cardiac arrhythmia, sudden death, heart failure and so on. So if we find and appreciate the left ventricular remodeling of hypertension Patients is very important for choosing treatment and improving prognosis in the early stage.The speckle tracking imaging can obtain motion information of myocardium by tracking myocardium plaque resonance in 2D dynamic image. Meanwhile, reconstruct the motion and strain of myocardium tissue by using time and space image processing technology.Our research used speckle tracking imaging to estimate torsion and systolic function in longitudinal,radial and circumferential of hypertension patients with different left ventricular geometry. To investigate the clinical application of STI in estimating left ventricular remodeling of hypertension.Method:The study group include 109 EH patients and 36 normal subjects. According to the Ganau classification, hypertensive patients were classified into four groups: normal geometry (group A) had 27 cases; concentric remodeling (group B) had 29 cases; concentric hypertrophy (group C) had 45cases; eccentric hypertrophy (group D) had 15cases. High frame rate two-dimentional (2D) images were recorded from the LV apical four-chamber view, three-chamber view, two-chamber view and the short- axis views at the levels of mitral annulus, papillary muscle and apex of the LV respectively. Acquired the peak systolic strain of each segment, calculated the average strain value of three consecutive cardiac cycles as the peak systolic strain. The average strain values of the three LV long axises and three LV short axises were calculated as the LV global LS, RS and CS. Peak endomembranal rotation, peak membranal rotation, peak bulk rotation, and peak mural torsion of the LV short axis were measured separately,and measured the LV global torsion.Result:(1)LVMI in every EH group were larger than group N (P < 0.05) and consecutive augmented from group A to D;IVS, LVPW and RWT in group B and C were larger than other groups(P < 0.05),but those two group don't have significant difference(P > 0.05); LVEF and FS in group D were most lowest compared with other groups(P < 0.05).(2)As seen from the apex, every group had similar rotation cure at the base level, performed a clockwise rotation and had negative peaks. At the apex level, group N,A,B and C had similar rotation cure, performed a counter-clockwise rotation and had positive peaks,the cure peak in group D were most lowest than other groups,some patients(8%)even performed a clockwise rotation and had negative peaks. The LV longitudinal strain cure,radial strain curve and circumferential strain curve of each segment in EH group were similar with group N,the peak systolic LS and CS values were negative,the peak systolic RS values were positive.(3)At the apex level, endo-rot, bulk-rot, mural-tor and LV-tor in group A were larger than group N (P < 0.05),epi-rot in apex level and every rotation values in basal level of two groups did not had significant difference(P > 0.05);In group A, the average LS values of long axis levels and the LV peak global LS values were lower than those in the group N(P < 0.05),and the peak systolic RS values were higher than those in the group N(P < 0.05). The peak systolic CS values of short axis levels and the LV peak global CS values did not have significant difference between two groups (P > 0.05).(4)Compared with group A, endo-rot, bulk-rot, mural-tor and LV-tor were more larger in group B at both apex and basal levels(P < 0.05),epi-rot at apex level were larger in group B(P < 0.05),but epi-rot at apex level of group B did not significantly increased than those in group A(P > 0.05). In group B, average LS values of long axis levels and the LV peak global LS values were lower than those in the group A (P < 0.05).RS values of basal level and LV peak global RS values significantly increased than those in group A(P < 0.05),RS values of apex and papillary muscle level did not significantly increased(P > 0.05).The peak systolic CS values of short axis levels and the LV peak global CS values did not have significant difference between two groups(P > 0.05).(5)Compared with group B, endo-rot,bulk-rot, mural-tor and LV-tor were larger in group C at both apex and basal levels (P < 0.05),epi-rot at apex level were larger in group C(P < 0.05),but epi-rot at basal level of group C did not significantly increased than those in group B(P > 0.05). In group C, average LS values of long axis levels and the LV peak global LS values were lower than those in the group B(P < 0.05); RS values of every short level and LV peak global RS values decreased than those in group B(P > 0.05),and significant decreased than those in group A and N(P < 0.05);the peak systolic CS values of short axis levels and the LV peak global CS values did not have significant difference between two groups(P > 0.05).(6)Compared with other groups, endo-rot,epi-rot,bulk-rot. mural-tor and LV-tor were significant decreased(P < 0.05);average LS, RS and CS values of each levels and the LV peak global LS,RS and CS values were also significant decreased in group D(P < 0.05).Conclusions:From this research we can get those conclusions: (1) rotation and torsion of left ventricular increased progressively in pace with different LV geometry, and the regional contractile function impaired inordinately. In the eccentric hypertrophy group, left ventricular remodeling can not compensate the highly pressure load, rotation and torsion of left ventricular decreased obviously.(2)The subendocardiac muscle of patients whith different LV geometry impaired firstly and the LS impaired originally.The middle layer cardiac muscle impaired latest and lightest.At the early stage of left ventricular remodeling, highly RS can compensatory lower LS and keep systolic function within normal limits.At the early stage,the CS decreased notobvious; The middle layer cardiac muscle impaired when develop into the eccentric hypertrophy stage, LS, RS and CS all reduced obviously,both global and regional systolic function all decreased significantly.In summary, speckle tracking imaging has the potentiality to be used to evaluate the LV systolic function in hypertension patients with different patterns of left ventricular hypertrophic geometric models. It provided important theory evidence for clinical treatment and prevention ,and had considerable substantial clinical values. Besides, it was also a supplement and development for traditional ultrasound cardiogram.
Keywords/Search Tags:Speckle tracking imaging, left ventricular remodeling, strain, torsion
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