Echocardiography On The Assessment Of The Cardiovascular Function In Patients With Subclinical Atherosclerosis In Different Risk Levels

Part 1:Cardiovascular function in patients with subclinical atherosclerosis in different risk stratification Objective To evaluate the cardiovascular function in patients with subclinical atherosclerosis using echo-tracking(ET) techniques and three-dimensional speckle tracking echocardiography(3D-STE), as well as analysis the relationship between carotid arterial stiffness and left heart function. Methods Eighty patients with subclinical atherosclerosis who were found that carotid intimal medial thickness increasing(c IMT?1.0mm) by physical examination from March 2015 to October 2015 in our hospital were involved. All of them were without clinical symptoms or history of ischemic stroke. Three groups were divided according to the Framingham risk score(FRS), named low-risk group(27 cases), middle-risk group(26 cases) and high-risk group(27 cases). Each of them were examined by routine echocardiograph and 3D-STE to obtain the parameters like LV peak systolic global longitudinal strain(GLS) and LV peak systolic global circumferential strain(GCS) for analysis. Conventional high frequency ultrasound was used to measure intima-media thickness(c IMT). ET technology was performed to assess stiffness parameter( ?) and pulse wave conducting velocity(PWV?). Results(1)There were no significant differences among the three groups in sex ratio, age, height, weight, heart rate and blood fats(P>0.05). With increased risk of cardiovascular events SBP showed a significant trend between the three groups(P>0.05).(2) Pressurestrain elastic modulus(Ep) had significantly difference among three group(P<0.05). Compared with low-risk group, c IMT, ? and PWV? were higher in high-risk group(P<0.05).(3) Left atrial volume index(LAV) had significantly difference among three group(P <0.05). Compared with low-risk group, E/e increased and GLS reduced in high-risk group(P<0.05). There were no statistical difference of LVEF and GCS in three groups.(4) ? was positively correlated with age and negatively correlated with GLS(P<0.05),LAV was positively correlated with age?E/e(P<0.05),FRS was positively correlated with ??E/e(P<0.05). Conclusions(1)Superposition of cardiovascular risk factors in patients with subclinical atherosclerosis promotes the increase of carotid artery stiffness and the reduction of reserve capability of left atrium.(2)The left ventricular active diastolic function was decreased and the left ventricular longitudinal strain was decreased in high-risk group, compared with low-risk group.(3) ET combined with 3D-STI could be applied to early and accurately evaluate the function of carotid artery and left ventricular in patients with subclinical atherosclerosis, and to provide scientific bases for establishing intervention policy. Part 2:A preliminary study of left ventricular myocardial wall stress in patients with subclinical atherosclerosis Objective To evaluate left ventricular myocardial wall stress in patients with subclinical atherosclerosis using three-dimensional speckle tracking echocardiography(3D-STE),and investigate the relationship between MWS and Left ventricular remodeling. Methods Objects and images collection of this part were same as part one. LVEDV?LVESV and epicardial volume(Vs) at the end systolic were evaluated by 3D-STE and then calculated the left ventricular myocardial wall stress(MWS) and remodeling index(LVRI). Results(1) The values of MWS among the three groups increased with the risk of cardiovascular events(P<0.01). GLS was higher in high-risk group than that in low-risk group(P<0.05). There were no statistically different between the three group in the value of LVEF, LVRI and GCS(P>0.05).(2) MWS was positively correlated with ? and SBP(P<0.01), negatively correlated with LVEF, GLS and GCL(P<0.01).(3)Stepwise multiple regression analysis demonstrated that MWS have multiple regression relation with SBP, LVEF and LVRI.(4)Bland-Altman showed a high inter- and intra-observer agreement in the measurement of MWS. Conclusions(1) With the increase of FRS in patients with subclinical atherosclerosis, left ventricular MWS increased obviously, which may predispose to LV remodeling in later life.(2) MWS increasing and early systolic dysfunction has existed in middle-risk group before LV pump function showed abnormity. And reduction of MWS and GLS in high-risk group suggests the damage of myocardial contractility.(3) Left ventricular MWS could be used to detect the early systolic dysfunction caused by myocardial load sensitively. Combine left ventricular strain and myocardial wall stress could reflect the biomechanical properties of the myocardium from the aspect of mechanics.