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Objective:To evaluate the diagnostic value of exercise stress echocardiography combined with left ventricular two-dimensional speckle tracking layer-specific strain technique in evaluating subclinical myocardial damage and reserve function in patients with hypertension.Methods:A total of 51 healthy subjects(control group) and 55 hypertensive patients (hypertension group) were enrolled in the treadmill exercise stress test in Sichuan Provincial People′s Hospital from October 2018 to January 2020. According to the European Guidelines for the Prevention and Treatment of Hypertension, the inclusion criteria for patients with hypertension were: blood pressure≥140/90 mmHg or who explicitly took antihypertensive drugs, and related cardiovascular diseases were excluded. The conventional parameters of resting and peak exercise, including left ventricular mass index, left ventricular end-diastolic volume index and left ventricular ejection fraction et al, were analyzed by speckle tracking software in two groups. According to the standard images in the resting and peak exercise, the endocardium /mid-myocardium /epicardium of left ventricular (three-, two-, four-chamber and global) longitudinal strain and circumferential strain (papillary muscle level) were compared respectively in two groups. The characteristics of strain differences and the systolic function reserve between the resting and peak exercise were evaluated.Results:There were significant differences in conventional ultrasound parameters between resting and peak exercise period in hypertension group, except E/A and e/a ratio (all P<0.05), and E/e value increased significantly(12.1±0.38) during peak exercise, indicating impaired diastolic reserve function. The longitudinal and circumferential layer-specific strain values from endocardial to epicardial were gradually decreased in both two groups. Compared with the control group, the resting longitudinal and circumferential endocardial strain values in hypertensive group were decreased, and the differences were more obvious at peak status, for instance global longitudinal endocardium strain at rest[control group (24.4±1.5)%, hypertension group (20.4±2.3)%], peak status[control group (30.8±2.8)%, hypertension group (22.8±2.9)%]( P<0.05). There were no significant differences of the partial layer-specific strain values between the peak exercise and resting status in hypertension group, while peak layer-specific strain of the control group were all significantly increased, suggesting that the left ventricular systolic reserve function of hypertension patients was lower than that of the control group. Conclusions:Left ventricular layer-specific strain can effectively evaluate the myocardial function in patients with hypertension, especially the endocardial strain can be used as an indicator parameter, and the peak exercise stress state is more sensitive. The systolic and diastolic reserve function of the left ventricle in patients with hypertension at the peak period are reduced to different degrees. Exercise stress echocardiography combined with left ventricular layer-specific strain technique can be used as a new method for detection of myocardial function impairment in patients with hypertension.
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Objective To evaluate left ventricular ( LV ) myocardial mechanical transmural longitudinal displacement ( LD ) and radial displacement ( RD ) with contrast agent and different power irradiation in open‐chest Beagle canines by ultrasound velocity vector images ( VVI) workstation . Methods T he anesthetized open‐chest Beagle canines were assigned into two groups randomly :Group A ( n ＝6) for baseline ,diagnostic ultrasound power irradiation ( 300 mW) 5 min ,combined with contrast agent irradiation 5 min and contrast agent 20 min conditions ; Group B ( n ＝ 6 ) for baseline and intensity ultrasound irradiation ( 1 W ,2 W and 3 W ,5 min respectively) conditions . T he standard short‐axis and long‐axis gray‐scale view s during three complete cardiac cycles in open‐chest Beagle canine models were acquired . T he peak LD subendomyocardium ( LD‐subendo) ,LD subepimyocardium ( LD‐subepi) ,RD subendomyocardium ( RD‐subendo) and RD subepimyocardium ( RD‐subepi ) of LV were analyzed using a dedicated Syngo VVI method . Results In group A ,the LV LD‐subendo ,LD‐subepi ,RD‐subendo and RD‐subepi in the most of segments showed increasing trend in diagnostic power irradiation ,contrast agent irradiation 5 min and contrast agent 20 min compared with baseline condition ,however the differences were not significant ( P ＞0 .05 ,respectively) . T he peak LD‐subendo and LD‐subepi ,RD‐subendo and RD‐subepi of LV in group A with the same condition were significant different ( all P ＜0 .05) . In group B ,LV LD‐subendo in ultrasonic power 3 W was lower than baseline condition ( P ＜ 0 .05 ) ,LV RD‐subendo was higher compared with baseline condition ( P ＜0 .05) . T he peak LD‐subendo and LD‐subepi ,RD‐subendo and RD‐subepi of LV in group B with the same condition were significant different ( all P ＜ 0 .05) . Conclusions On ultrasonic power 3 W ,LV LD‐subendo is decreased resulting to negative inotropic effect and RD‐subendo is increased to maintain the normal heart work .LV LD and RD on diagnostic ultrasound power irradiation 5 min , combined with contrast agent irradiation 5 min ,contrast agent 20 min conditions ,ultrasonic power 1 W and 2 W are not prominent changes .
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Objective To evaluate left ventricular ( LV ) myocardial mechanical rotation and twist with contrast agent and different power irradiation in open-chest beagle canines by ultrasound velocity vector images ( VVI ) . Methods The anesthetized open-chest Beagle canines were assigned into two groups randomly :group A ( n = 6 ) for baseline ,diagnostic ultrasound power irradiation ( 300 mW ) 5 min , combined with contrast agent irradiation 5 min and contrast agent 20 min conditions ;group B ( n = 6) for baseline and intensity ultrasound irradiation ( 1 W ,2 W and 3 W ,5 min respectively ) conditions . The standard short-axis gray-scale views at basal level (BL) ,and apical level( AL) during three complete cardiac cycles in open-chest beagle canine models were acquired . The peak subendomyocardium rotation ( subendo-rot) ,subepimyocardium rotation ( subepi-rot) of BL and AL were analyzed using a dedicated Syngo velocity vector imaging ( VVI) method and LV subendomyocardium twist ( subendo-twi) and subepimyocardium twist ( subepi-twi) were defined as apical subendo-rot/subepi-rot - basal subendo-rot/subepi-rot . Results In group A ,the LV subendo-twi ,subepi-twi ,subendo-rot and subepi-rot of BL and AL in the most of segments were significant different on diagnostic power irradiation ,contrast agent irradiation 5 min and contrast agent 20 min ( P < 0 .05 ) compared with baseline condition ;LV subendo-twi was higher than subepi-twi in group A under the same condition ( P < 0 .05) . In group B ,LV subendo-twi ,subepi-twi and subendo-rot ,subepi-rot of BL and AL on power 1 W ,2 W were higher and subendo-twi ,subepi-twi on power 3 W were lower than those on baseline condition ( P < 0 .05) ;There was no difference in subendo-rot and subepi-rot of LV BL compared with baseline condition ( P > 0 .05) ;subendo-rot and subepi-rot of LV AL were different compared with those on baseline condition ( P < 0 .05) ;LV subendo-twi and subepi-twi in group B under the same condition were significant difference ( P < 0 .05) . Conclusions LV rotation and twist increase on diagnostic ultrasound power irradiation 5 min ,combined with contrast agent irradiation 5 min ,contrast agent 20 min conditions ,1 W and 2 W ;LV twist and AL rotation decrease on ultrasound power 3 W ,but BL rotation is not affected on ultrasound power 3 W .
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Objective To evaluate left ventricular ( LV ) myocardial mechanical synchrony with contrast agent and different power irradiation in open-chest Beagle canines . Methods The anesthetized open-chest Beagle canines were assigned into two groups randomly : Group A ( n = 6 ) for baseline , diagnostic ultrasound power irradiation ( 300 mW ) 5 min ,combined with contrast agent irradiation 5 min and contrast agent 20 min conditions ;Group B ( n = 6) for baseline and intensity ultrasound irradiation ( 1 W ,2 W and 3 W ,5 min respectively) conditions . The standard short-axis gray-scale views at levels of mitral annulus ( MV) ,papillary muscle( PM ) ,and apex( AP) during 3 complete cardiac cycles in open-chest Beagle canine models were acquired . The global radial displacement peak time ( RD-PT) and standard deviation of peak time ( RD-PT SD ) of LV subendomyocardium ( subendo ) and subepimyocardium ( subepi ) were measured and analyzed by using a dedicated Syngo velocity vector imaging ( VVI) method . Results In group A ,compared with baseline condition , the RD-PT and RD-PT SD of subendo and subepi had no significant different among diagnostic power irradiation ,contrast agent irradiation 5 min and contrast agent 20 min ( all P < 0 .05) . There was no significant different in the RD-PT and RD-PT SD between subendo and subepi in A group in all conditions ( all P < 0 .05) . In group B ,the RD-PT and RD-PT SD of subendo and subepi with power 1 W ,2 W and 3 W was higher than those with baseline condition ;the RD-PT and RD-PT SD of subendo were significant different on 2 W compared with those on baseline condition ( all P <0 .05) ;the RD-PT and RD-PT SD of subendo ,subepi were significant different on 3 W compared with baseline condition ( all P < 0 .05) ;the RD-PT and RD-PT SD were significant difference between subendo and subepi in only 3 W condition ( all P < 0 .05 ) . Conclusions Diagnostic ultrasound power irradiation 5 min and combined with contrast agent irradiation 5 min and contrast agent 20 min conditions do not effect the synchrony of LV myocardial mechanics . Power more than 1 W can induce the delay of RD-PT and RD-PT SD of LV subendo and subepi . Power 3 W can result in dyssynchrony of LV myocardial mechanics .
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Objective To detect left atrial (LA) function and left ventricular (LV)-LA coupling using vector flow mapping (VFM) and two-dimensional tissue tracking (2DTT) echocardiography in patients with diabetes.Methods A total of 51 patients with type 2 diabetes (DM group) and 38 healthy volunteers (control group) were studied.LA and LV strain were assessed by 2DTT.The energy loss (EL) of LA and LV during ventricular systole (ELs),early diastole (ELed),and atrial contraction (ELac) were measured by VFM.Results LVEL in DM group was significantly increased compared to that in control group (P<0.05).LAELs and LAELed in control group were higher than those in DM group (P<0.05);while LAELac decreased in control group (P<0.05).Multivariate regression analysis identified E and LVELed as independent predictors of LAELed;Peak torsion,LA peak systolic strain and LVELac were independent predictors of LAELac.Conclusions The reservoir and conduit function of LA are impaired in patients with DM,while the pump function increases as a compensation.Abnormal LA-LV coupling also appears in patients with DM.
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Objective To evaluate the left ventricular(LV)myocardial mechanical changes with contrast agent and different power irradiation in open-chest beagle canines.Methods The anesthetized open-chest beagle canines were assigned into two groups randomly:group A(n=6)for baseline,diagnostic ultrasound power irradiation(300 mW)5 min,combined with contrast agent irradiation 5 min and contrast agent 20 min conditions;group B(n=6)for baseline and intensity ultrasound irradiation(1 W,2 W and 3 W,5 min respectively)conditions.The peak circumferential strain(CS),longitudinal strain(LS)and radial strain(RS)of LV myocardial wall were measured and analyzed using a dedicated Syngo velocity vector imaging(VVI)method.Results In group A,the peak CS and LS were increased significantly on diagnostic power irradiation,contrast agent irradiation 5 min and contrast agent 20 min(all P <0.05,respectively) compared with baseline condition;there was no significant difference of the peak RS on diagnostic power irradiation,contrast agent irradiation 5 min and contrast 20 min compared with baseline condition(P >0.05).In group B,the peak CS and LS were higher on power 1 W than on baseline condition(P <0.05), the peak RS was increased gradually on power 1 W than on baseline condition(P >0.05);the peak CS,LS, RS were lower on power 2 W than on baseline condition(P >0.05);the peak of CS,LS were lower on power 3 W than on baseline condition(P <0.05);the peak of RS was decreased gradually without significant changes between power 3 W on baseline condition(P >0.05).Conclusions These findings indicate potential positive inotropic effects with diagnostic ultrasound power irradiation 5 min,combined with contrast agent irradiation 5 min,contrast agent 20 min conditions,power 1 W and negative inotropic effects with power 3 W on LV myocardial CS,LS deformation.LV myofiber deformation reactions appear no significant differences on LV myocardial RS deformation in same disturbed setting.
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Objective To investigate the changes of left ventricular(LV) vortex strength(VS) and distribution during selective cardiac pacing in a phases of cardiac cycle using vector flow mapping techniques ,and associate with LV mechanical performance ,so as to provide basic experimental database for optimizing the sites of the artificial cardiac pacing in clinic conditions .Methods Eight heathy open‐chest Beagle dog models were employed for selective right ventricular apical (RVAP ) ,left ventricular apical (LVAP) and lateral wall pacing (LVLP) .The standard two‐dimensional apical three views with color Doppler flow and dynamic two‐dimensional images were acquired consecutively in three cardiac cycles for further off‐line analysis ,conventional parameters were measured at same time .Results Compared with baseline ,LVSV ,LVEF ,LVCO and dp/dtmax were both reduced ,and the parameters obtained leftside cardiac pacing were lower than that of right ventricular pacing ( P < 0 0.5) ,there′s no significant difference in E/Vp .The vortex pattern ,distribution and vorticity at six typical phases induced by selective cardiac pacing were totally different from those at baseline with sinus rhythm ,and leftside pacing were worsen than RVAP ,the LVAP were most obvious .On multivariable regression analysis ,the VS during ES (VSES ) at baseline was independently related to late‐diastolic VS and longitudinal strain (R2 = 0 6.3 ,P < 0 0.01 and P=0 0.03 ,respectively) .Conclusions The selective cardiac pacing could induce intracardiac vortex changes and differ from that at baseline ,and the persistence of vortex from late diastole into ES is a haemodynamic measure of coupling between diastole and systole .