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ObjectiveBased on ultra performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry（UPLC-Q-TOF-MS）， to evaluate the establishment of a mouse model of liver Yin deficiency by thyroid tablet suspension combined with 10% carbon tetrachloride（CCl4） from the perspective of non-targeted metabolomics， in order to lay the foundation for the establishment of a traditional Chinese medicine（TCM） syndrome model. MethodA total of 24 mice were randomly divided into blank group and model group. The model group was given thyroid tablet suspension（0.003 2 g·kg-1） by gavage for 14 consecutive days， and 10% CCl4（5 mL·kg-1） was intraperitoneally injected once a week to establish a liver Yin deficiency model， while the blank group was injected with an equal amount of olive oil intraperitoneally and gavaged with an equal amount of distilled water， and was fed with normal feed. After the modeling was completed， 6 mice in each group were randomly selected， the levels of alanine aminotransferase（ALT）， aspartate aminotransferase（AST）， cyclic adenosine monophosphate（cAMP）， cyclic guanosine monophosphate（cGMP）， interleukin（IL）-6， IL-10， tumor necrosis factor-α（TNF-α）were measured in the mice serum， and malondialdehyde（MDA）， superoxide dismutase（SOD）， total protein（TP）， hydroxyproline（HYP） and other indicators were measured in the mice liver. Liver tissue sections were taken for hematoxylin-eosin（HE） staining and observing pathological changes. The remaining 6 mice in each group were subjected to UPLC-Q-TOF-MS combined with principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to screen differential metabolites in the liver Yin deficiency mouse model， Kyoto Encyclopedia of Genes and Genomes（KEGG） database was used to analyze the corresponding metabolic pathways of differential metabolites. ResultCompared with the blank group， mice in the model group showed liver Yin deficiency manifestations such as reduced body weight， fatigue and sleepiness， disheveled and lusterless hair， irritability. The levels of ALT， cAMP/cGMP， IL-6， AST， MDA， cAMP， TNF-α significantly increased（P<0.05， P<0.01）， while the levels of SOD， IL-10 and cGMP significantly decreased（P<0.05， P<0.01）， and the changes of HYP and TP were not statistically significant. Hepatic steatosis and distortion of the radial arrangement of the liver plate cells were seen in the section images of the model group， endogenous substances were clearly separated， and 252 differential metabolites were identified in the serum samples， which were mainly involved in the metabolic pathways of purine metabolism， steroid hormone biosynthesis and pyrimidine metabolism. A total of 229 differential metabolites were identified in the liver samples， mainly involving nucleotide metabolism， purine metabolism， steroid hormone biosynthesis， pyrimidine metabolism， antifolate resistance， insulin resistance， primary bile acid biosynthesis， prostate cancer， sulfur relay system， arachidonic acid metabolism and other metabolic pathways. ConclusionThe successful establishment of liver Yin deficiency model in mice by CCl4 combined with thyroid hormone is evaluated through the investigation of serum and liver metabolomics， combined with biochemical indicators， which provides a biological basis and experimental foundation for the Yin deficiency syndrome model of TCM.
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Objective:To assess the left ventricular (LV) myocardial mechanical dysfunction in patients with cirrhosis using ultrasonic layer-specific strain imaging and to explore its value in clinical application.Methods:A total of 80 consecutive cirrhosis patients without cardiovascular diseases were prospectively enrolled from October 2020 to March 2021 in Sichuan Provincial People′s Hospital, 39 of whom were assigned to the compensated group and 41 were assigned to the decompensated group according to the occurrence of portal hypertension. Forty-three healthy volunteers during the same period were randomly recruited as the control group. Transthoracic echocardiography was performed to assess the LV configuration and functional parameters. LV global longitudinal strain in endocardial, middle and epicardial myocardium (GLSendo, GLSmid, GLSepi), and longitudinal strain (LS) in basal, middle and apical segments, and peak strain dispersion (PSD) were obtained using ultrasonic layer-specific strain imaging. ΔLS was calculated by the formula of GLSendo-GLSepi. Then, the differences of related parameters among three groups were compared.Results:①Conventional echocardiography: compared with the control group, the interventricular septum end-diastolic thickness (IVSTd), left ventricular posterior wall end-diastolic thickness (LVPWd), left ventricular mass (LVM) and LVM index (LVMI) were increased in compensated and decompensated groups (all P<0.05), while no significant differences in conventional echocardiographic parameters were identified between the two cirrhosis groups (all P>0.05). ②Global layer-specific strain: compared with the control group, GLSendo, GLSmid, GLSepi and ΔLS were decreased and PSD was increased in compensated and decompensated groups (all P<0.05); Moreover, the decompensated group showed a more impaired GLSendo, GLSmid and GLSepi than compensated group (all P<0.05), whereas there were no significant differences of ΔLS and PSD between the two groups(all P>0.05). ③Segmental layer-specific strain: compared with the control group, LS values of three layers in compensated and decompensated groups were reduced at basal, middle and apical levels (all P<0.05); Compared with the compensated group, LS values of three layers in decompensated group tended to be reduced at above there levels, but only apical segments had significant differences (all P<0.05). Conclusions:There are different degrees of LV mechanical dysfunction in patients with variable severity of cirrhosis. Ultrasonic layer-specific strain imaging has the potential to quantitatively assess the state of cardiac involvement in patients with cirrhosis and to provide visual evidence for the early and accurate diagnosis of myocardial injuries.
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Objective To assess the clinical ultrasound value of layer‐specific strain in evaluation of left ventricular systolic myocardial dysfunction of uremia patients after long‐time dialysis at different time . Methods A total of 68 uremia patients accepted maintenance hemodialysis ( M HD ) were enrolled . T he patients were divided into two groups according to the dialysis duration :dialysis time ＜3 years ( group B , n＝31) and dialysis time ≥3 years ( group C , n ＝37) . T he age and sex mached healthy cases were selected as control group ( group A , n ＝ 30 ) . T he standard dynamic two‐dimensional echocardiographic viewes of apical four‐chamber ,three‐chamber ,two‐chamber and the short‐axis view at three levels of mitral valve , papillary muscle and apex were acquired for three cardiac cycles . T he highest value of peak systolic longitudinal strain ( LS ) ,circumferential strain ( CS ) at different levels ,left venrticular global longitudinal strain ( GLS ) and global circumferential strain ( GCS ) were respectively assessed from endocardium ,mid‐myocardium and epicardium using GE EchoPAC workstation . T he comparisons of those parameters were performed among the 3 groups for differences . T he efficacies of GLS and GCS at different myocardial layers in diagdosing the left ventricular systolic function of M HD patients were analyzed by the ROC curve . Results ① Global transmural parameters :compared with those in group A ,the values of GLS at three myocardial layers in both M HD groups were significantly decreased ( all P ＜ 0 .01 ) ,the value of GLS at three myocardial layers in group C was also decreased ,and was statistically different from that in group B ( P＜0 .01) . Compared with those in group A ,the values of GCS at mid‐myocardium in group B and three myocardial layers in group C were also decreased ( all P ＜0 .01) . T here was no significant difference of GCS between group B and C ( P ＞0 .05) . ②Longitudinal transmural parameters at different levels :the values of LS at three myocardial layers of mitral valve ,papillary muscle and apex were decreased in group B and C compared with those in group A ( P ＜0 .05 or P ＜0 .01) ; T he values of LS at three myocardial layers of mitral valve ,papillary muscle and apical levels were also decreased in group C compared with those in group B ( P ＜0 .05 or P ＜0 .001) . ③Short‐axis transmural parameters at different levels :compared with those in group A ,the value of CS at mid‐myocardium of mitral valve level was decreased in group B ( P ＜0 .05) ,the values of CS at three myocardial layers of the mitral valve level and mid‐myocardium of papillary muscle level and apical level were decreased in group C ( P ＜0 .05 or P ＜0 .01) . Besides ,compared with those in group B ,the values of CS at mid‐myocardium and epicardium of mitral valve level were also decreased in group C ( P ＜0 .05) . ④ROC curve showed that determining left ventricular systolic dysfunction in M HD patients using GLS ,GCS at different myocardial layers ,when the area under the curve ( AUC ) of GLS of intima was 0 .851 ,the cut‐off value was －21 .45% ,the sensitivity was 72 .7% ,and the specificity was 93 .3% ; when the AUC of GCS of mid‐myocardium was 0 .683 ,the cut‐off value was －17 .08% , the specificity was 58 .5% , and the specificity was 83 .3% . Conclusions T he left ventricular systolic myocardial function is progressively damaged with the extended dialysis duration time . Ultrasonic layer‐specific strain technology could be used to quantitatively evaluate left ventricular systolic transmural myocardial dysfunction and might contribute to the evaluation of the severity of left ventricular myocardial dysfunction clinically for a more accurate intervention .
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Objective To evaluate the transmural myocardial strain in three specific layers of the left ventricle at the papillary muscle level in short-axis view in SD rats before and after doxorubicin administration usmg myocardial layer-specific strain imaging based on two-dimensional ultrasound speckle tracking imaging (2D-STI),and to demonstrate the myocardial mechanical characteristics of doxorubicininduced early-stage acute cardiac toxicity in rats.Methods Thirty-two SD male rats weighing 300-350 g were randomly divided into a doxorubicin group (DOX group,n=16) and a control group (n=16).In the doxorubicin group,doxorubicin hydrochloride (concentration,2 mg/ml) was injected intraperitoneally at a single dose of 12 mg/kg,while the control group was given equal volume of 0.9％ sodium chloride solution.LVEDD,LVESD,IVSd,LVPWd,FS,and LVEF were measured and derived using two-dimensional gray-scale echocardiography at the left ventricular papillary muscle level in short-axis view at three time points (before administration and 24 and 48 hours after administration).The circumferential strain in the subendocardium,medium,and subepicardium at the left ventricular papillary muscle level in short-axis view were obtained using ultrasonic 2D-STI.The values of FS,LVEF,and the global myocardial circumferential strain in different layers of the left ventricular wall at the papillary muscle level in short axis view at three time points were compared between the two groups.After echocardiographic examinations at 48 h and 72 h,the hearts of three rats in each group were randomly selected,sliced,and HE-stained for myocardial pathological observation.Results In both groups,there was a circumferential strain gradient of the left ventricular wall at the papillary muscle level in the short-axis view:subendocardium ＞ medium ＞ epicardial myocardium.In the DOX group,the circumferential strain in the subendocardial myocardium decreased at 48 hours after DOX administration;the difference was statistically significant between the two groups (-25.13± 10.6 vs -17.04± 2.89,t=2.3,P ＜ 0.05).There was no significant difference in myocardial circumference strain in the three layers,as well as LVEDD,LVESD,IVS,LVPW,FS,or LVEF at three time points between the control group and DOX group (P ＞ 0.05).The pathological changes were mainly myocardial cell edema,vascular degeneration,myocardial nucleus atrophy,dissolution,interstitial edema,and capillary dilatation in the doxorubicin group,which were especially obvious in subendocardial cardiomyocytes.Conclusion 2D-STI technology based layer-specific strain imaging could be used to detect and quantitatively evaluate the deformation damage of the transmural left ventricular wall in SD rats.
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Objective To evaluate the damage of longitudinal mechanical parameters of left ventricular myocardium by ultrasonic layer‐specific strain imaging in patients with systemic lupus erythematosus ( SLE ) without conventional evidence of cardiovascular system involvement . Methods Seventy‐eight patients suffered from SLE without conventional evidence of cardiovascular system involvement ( SLE group ) and 48 healthy volunteers with age and sex matched ( control group ) were selected for this study . T he left ventricular conventional structure and functional parameters were measured by conventional echocardiography . T hen layer‐specific strain imaging was performed in both groups to obtain left ventricular endocardial myocardial global longitudinal strain ( GLSendo ) ,mid‐myocardial GLS ( GLSmid) ,epicardial GLS ( GLSepi) and basal segment ,middle segment and apex longitudinal strain ( LS) of all three layers of the myocardium . T hen the transmural difference of the GLS ( ΔLS ＝ GLSendo －GLSepi) were calculated . T he related parameters between these two groups were compared for difference and correlation analysis of related mechanical parameters were also made . Results ① T here was no significant difference in the left ventricular ejection fraction ( LVEF ) and left ventricular stroke volume ( LVSV ) between the two groups ( all P ＞0 .05 ) ; Compared with the control group ,the mean E/e in the SLE group was increased and the E/A ,E ,e were decreased ( all P ＜0 .05) ; however ,the incidence of left ventricular diastolic dysfunction in the SLE group ( 2/78 ) was not significantly different from that in the control group ( 0/48 ) ( P ＞0 .05 ) . ② T he myocardial global longitudinal strain( GLS ) of the two groups were decreased from endocardial to epicardial gradient ; the values of GLS and segmental LS of all three layers in the SLE group were decreased ( all P ＜0 .05) ; the ΔLS of the SLE group was decreased compared with the control group ( P ＜ 0 .05 ) ; the value of peak strain dispersion ( PSD ) were increased in SLE patients ( P ＜ 0 .05 ) . ③ T he correlation analysis showed the GLS of each layer of myocardium in SLE patients were negatively correlated with disease duration ( rs ＝ －0 .34～ －0 .36 ,all P ＜ 0 .05 ) and SLE disease activity index ( SLEDAI) ( rs ＝ －0 .25～ －0 .30 ,all P ＜0 .05 ) . Conclusions T he ultrasonic layer‐specific strain imaging can quantitatively detect the damage of mechanical parameters of left ventricle in SLE patients ,w hich is more sensitive than the conventional echocardiography in evaluating left ventricular systolic function . It may provide visual evidence for early diagnosis of cardica dysfunction in SLE patients .
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Objective To evaluate left ventricular myocardial systolic function in patients with obstructive sleep apnea hypopnea syndrome ( OSA HS) with normal left ventricular ejection fraction( LVEF) using three‐dimensional strain echocardiography . Methods One hundred patients with OSA HS were divided into mild group ,moderate group and severe group according to apnea hypopnea index ( A HI) w hile matched with 32 healthy people as control group . T he parameters such as three‐dimensional LVEF ,global longitudinal strain( GLS) ,global circumferential strain( GCS) ,global area strain( GAS) ,global radial strain ( GRS) ,twist and torsion based on standard three‐dimensional echocardiography were measured by three‐ dimensional strain echocardiography , the above parameters among the four groups were compared for difference .Linear correlationship between A HI ,LVEF and the three dimensional strain parameters was analyzed respectively . Results ①T here was no significant difference in three‐dimensional LVEF ,twist and torsion between each groups( P ＞0 .05 ) . ②GLS ,GAS and GRS were lower in mild ,moderate and severe group compared with control group ,decreasing along with the disease severity ( P ＜0 .01 or P ＜ 0 .05 ) . GCS in severe group was lower than that in control group ( P ＜0 .01 ) . ③GLS and GAS in severe group were lower than those in mild group ( all P ＜0 .05) .GRS in moderate and severe group were lower than that in mild group( all P ＜ 0 .05 ) ,GAS ,GRS in severe group was lower than those in moderate group ( P ＜0 .05) . ④T here was a mild correlation between GLS and A HI ( r ＝0 .342 , P ＜0 .01) ,GAS and A HI ( r＝0 .294 , P ＜0 .01) ,GRS and A HI ( r ＝ －0 .411 , P ＜0 .01 ) . T here was a mild correlation between GCS and three‐dimensional LVEF ( r＝ －0 .354 , P ＜0 .01 ) ,GAS and three‐dimensional LVEF ( r ＝ －0 .326 , P ＜0 .01) ,GRS and three‐dimensional LVEF ( r ＝0 .300 , P ＜0 .01) . Conclusions T he left ventricular myocardial systolic function is impaired in all patients with OSA HS even with normal LVEF and the dysfunction is aggravating with the disease severity . Ultrasonic three‐dimensional strain imaging technology can be used to detect the subclinical myocardial systolic dysfunction quantitatively in the early stage of OSA HS patients .
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Objective To reveal the early elastic dysfunction of common carotid artery may have occurred in systemic lupus erythematosus( SLE) patients ,the circumferential strain parameters of common carotid artery intima in SLE patients at different serum complement levels were quantitatively evaluated by layer-specific strain imaging . Methods Seventy-two patients suffered from SLE without evidence of atherosclerosis were enrolled ,and the results of laboratory examination of serum complement C 3 in patients with SLE were recorded in detail ,49 cases of SLE patients whose serum C3 was lower than the normal reference range(SLE C3+ group) ,23 cases of SLE patients whose serum C3 was in the range of normal reference value(SLE C3 - group) . And a matched healthy control group ( n =38) were selected . Carotid ultrasound were performed in all three groups ,and the common carotid artery conventional parameters ,such as common carotid artery intima-media thickness ( CCA-IM T ) ,peak systolic velocity ( PSV ) ,end-diastolic velocity(EDV) ,resistance index(RI) and circumferential strain related parameters ,such as circumferential strain of common carotid artery intima(CSendo) and circumferential strain rate(CSr) were measured and derived.Therelatedparametersamongthosegroupswerecomparedfordifference.Results ①Therewas no significant difference in RI among the three groups(all P >0 .05) . The values of CCA-IMT in the SLE C3+ group and SLE C3- group were larger than that in the control group( all P <0 .05) . ②The values of CSendo and CSr in the SLE C3+ group and SLE C3 - group were lower than those in the control group ,the values of SLE C3+ group were significantly lower than those in the control group ( P <0 .001) ,and there was no significant difference between the SLE C3- group and control group( P >0 .05) . ③The CSendo and CSr in the SLE C3+ group were lower than those in the SLE C3- group(all P < 0 .05) . Conclusions CSendo which is provided by new ultrasonic technology of layer-specific strain combined with recent changes in serum complement C3 may provide visual evidence for assessing early elastic disfunction of carotid intima in SLE patients .
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ObjectiveTo evaluate the myocardium damage of myocardial contrast echocardiography (MCE) and the impact on regional left ventricular mechanics by imaging and pathology techniques.Methods Eleven open-chest animal models of Beagle were employed to collect the short-axis views of mitral annular,papillary muscle and apical level of three complete cardiac cycles using gray-scale imaging at the baseline and blank irradiation 5 min later(transmitting frequency 1.7/3.4 M Hz,mechanical index 1.0).After that,5 ml of SonoVue was gotten a shot by intravenous bolus injection,the heart was exposed by ultrasonic wave for 5 min continuously,and then the same images collected were at the point-in-time irradiation immediately,20 min,40 min and 60 min later.The short-axis circumferential strain and strain rate,radial strain and strain rate were measured and calculated by EchoPAC multi-parameter workstation,meanwhile including conventional of cardiac function.All the dogs were killed after the experiments and the myocardium was harvested for HE staining and observed with transmission electron microscope for the tissue microstructure.Results①Conventional parameters of cardiac function:there was no significant difference before and after MCE in the heart rate,blood pressure,ejection fraction,left ventricular end-systolic volume and end-diastolic volume,stroke volume,cardiac output,mitral flow spectrum prior to the E/A,tissue Doppler mitral annular e/a and E/e ( P ＞0.05).During the whole process of experiment,the dogs’ vital signs were stable.②Compared the segmental circumferential strain and strain rate,radial strain and strain rate between baseline and each treatment groups,these parameters had a trend of increase in most segments,but the difference was not statistically significant in most segments (P ＞0.05).③HE staining at the light microscope demonstrated a small amount of myocardial cell infiltration of inflammatory cells near the outer membrane (21.2％),and very few part of the muscle fibers dissolved and fractured (6.1％).④The section of transmission electron microscope showed all the structures were normal except that a small amount of endothelial cells were mild swelling,some red blood cells were leaked,some myofilaments were regional dissolved,the relevance ratio were 28.6 ％,42.9 ％ and 21.4 ％ respectively,and the abnormal area was less than 10％ of the entire field of vision.ConclusionsMCE has no significant impact for the global function of heart and the regional mechanical state,and furthermore there is no serious pathological damage on the myocardium.
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Objective To observe left ventricular transmural peak radial strain and strain time-to-peak of peri-infarct different layers myocardium using tissue Doppler strain imaging, to assess its mechanical pattern during acute myocardial ischemia.Methods Left anterior descending coronary artery (LAD) were ligated in experimental open-chest Beagle dog models (n = 9),the two-dimensional apical short-axis views of left ventricle in three complete cardiac cycles were acquired and stored in TDI-Q workstation at baseline(the control group of peri-infarc myocardium) and during acute myocardial ischemia respectively.Sampling volume was uesd to measure the peak radial strain and the strain time-to-peak consesquently on the derived M -mode tissue Doppler velocity images at peri-infarct myocardium before and after ischemic segments and different layers(subendocardium, medium, subepicardium).Statistical analies was performed using student's t- test or Pearson's correlations.Results Peak radial strain decreased at peri-infarct subendoeardium (P<0.05) with no significant difference between those at baseline and at peri-infarct medium (P >0.05), the peak radial strain increasd at peri-infarct subepieardium (P < 0.05) ,and the strain time-to-peak at different layers of peri-infarct myoeardium was significantly postponed (P< 0.05).There was a good correlationship of peak radial strain between subendocardium and segment as well as between the medium and segment (r = 0.617, P<0.01 ; r = 0.556, P<0.01).This correlationship disappeared at peri-infarct myocardial segment (r = 0.287, P > 0.05, r = 0.243, P > 0.05).Conclusions The left ventricular transmural mechanical remodeling at peri-infarct myocardium is the integrant of result of mechanical interactions between ischemic and nonischemic myocardium,which might be one of the trigger the structural and fundational remodeling processes involving in the pathophysiological foundation of ischemie cardiomyopathy.
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Objective To evaluate the mechanical characteristics of systolic left ventricular(LV) transmural torsion in different LV electro-mechanical patterns using speckle tracking imaging. Methods Five open-chest canine models were employed for the acquirement of the basal, apical short-axis and four-chamber views of LV during baseline(BASE) and right atrial appendage(RAA), right ventricular apical (RVA), left ventricular lateral wall (LVL) and left ventrieular apical (LVA) pacing. Subendocardial (subend),subepicardial(subepi) and bulk rotation angle(RA) and segmental angle excursion(AE) at basal and apical level were analyzed using a dedicated workstation. LV torsion at different layers and bulk and global LV ejection fraction (EF) were calculated. Results ① There were no significant difference of transmural torsion and RA at basal and apical level between BASE and RAA pacing (P>0.05);② LV torsion of subend, subepi and bulk during RVA pacing were lower than those during RAA pacing(P0.05);LV torsion of subend and bulk during LVA pacing were lower than those during RAA pacing(P0.05);LV RA of subend,subepi and bulk at basal level during RVA and LVA pacing were lower than those during RAA pacing (P<0.05); ③ For normal electro-mechanical pattern, LV torsion of subend were significant higher than that of subepi(P<0.05), there only were a higher tendency for all pacing models (P>0.05); ④AE of segments near the pacing site decreased during different ventricle paeings (P<0.05); ⑤At BASE and during RAA pacing, LV bulk and subepi torsion were positively correlated to EF; RA of subend,subepi and bulk at basal level were positively correlated to EF. Conclusions LV transmual torsion are significantly depressed during RVA and LVA pacing. There is a spatial co-relationship between LV EF and torsion and rotation of bulk and subepi at basal level in normal LV electro-mechanical patterns.
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Objective To evaluate the changes of peak segmental and transmural radial displacement (RD) of left ventricle(LV) during acute myocardial ischemia with different LV pacing patterns. Methods Left anterior descending coronary artery (LAD) was ligated to induce acute myocardial ischemia in open-chest Beagle canine models ( n=10). Two-dimensional gray-scale images with overlaid tissue Doppler velocity imaging in three standard LV short-axis views were acquired with different pacing patterns in a randomized sequence in three complete cardiac cycles. Parameters including peak RD, peak RD time(RD-Tc) ,the standard deviation of TC(RD-TSD) of 12 segments and their myocardial layers(subend,mid,subepi) were measured and analyzed using TDI-Q workstation. Results ① There were no significant differences of peak RD between three myocardial layers of LV wall in each different pacing pattern group;There were no significant difference of peak RD from segments and transmural layers among the different LV pacing patterns. ②With acute myocardial ischemia the RD correlation of LV lateral pacing( LVL-P) and LV border pacing(LVB-P) patterns were higher than that of LV apical pacing(LVA-P) pattern between global segment and its subend, mid, subepi. ③ RD-Tc of 12 LV segments and their subend, mid, subepi appeared after T wave and there were no significant differences of RD-Tc among different LV pacing patterns. ④RD-TSD of the corresponding segments during LVL-P,LVA-P and LVB-P patterns were significant lower than those during acute yocardial ischemia(P<0. 05). Conclusions The existed RD correlation of LVA-P between subend.mid, subepi and the segment were lowest among the different ischemic LV pacing patterns; the synchronization of transmural RD could be recovered partly with LVL-P, LVA-P and LVB-P patterns. The echocardiographic study of LV transmural RD might be useful to reveal the segmental and the transmural myocardial mechanical state with different LV pacing patterns during acute ischemia in detail.
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Objective To assess subendocardial systolic circumferential strain(CS),radial strain(RS)and radial displacement(RD)of left ventricle(LV)in short-axis view and LV global systolic function in open-chest canine model with acute myocardial ischemia using velocity vector imaging(VVI),and to establish their spatial correlationships.Methods Left anterior descending coronary artery(LAD)was ligated for 20 minutes to induce acute myocardial ischemia in 12 open-chest canine model.At baseline and 20 minutes after ischemia,two-dimensional dynamic gray-scale images of three standard left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex and the images of LV apical fourchamber and two-chamber view were acquired and transfefred to VVI workstation for off-line analysis.Peak systolic CS,RS and RD of eighteen segments and of three global short-axis sections of LV were measured at subendocardium.and LV ejection fraction(LVEF)and stroke volume(SV)were calculated using Simpson's method.The differences and correlationships were analyzed between them.Resuls Compared with the value at baseline,LVEF decreased significantly(P＜0.05)after ischemia.The peak systolic subendocardial CS,RS and RD of the affected segments,global CS,RD at papillary muscle and apex views and global RS at apex view were significantly lower than those at baseline after ischemia(P＜0.05).There was a good linear correlationship between the peak systolic CS and RD of 17 segments(except the middle segment of LV lateral wall after ischemia)and each global short-axis level before and after ischemia(r=0.662-0.995,P＜0.05,P＜0.01 or P＜0.001),The peak systolic RS of six segments and each global short-axis level(except the apex level at baseline)was correlated with RD(r=0.580-0.916,P＜0.05,P＜0.01 or P＜0.001);There was not statistical correlationship between global RDs and SV as well as LVEF.Conclusions Subendocardial circumferential strain and radial displacement may sensitively reflect the changes of regional and global myocardial systolic function induced by acute myocardial ischemia.The significant correlationship between subendocardial circumferential systolic strain and radial displacement might indicate that circumferential deformation of myocardium result in the changes of the radial displacement mainly.