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.

Objective To investigate the performance of left ventricular torsion (LVtor) or twist with cardiac dysfunction patients by speckle tracking imaging (STI). Methods Standard left ventricular short-axis views images were acquired by rountine two-dimensional echocardiography in thirty-two healthy humans and twenty-four patients with cardiac dysfunction. LVtor angle,left ventricular rotation (LVrot) angle,the peak value and time of LVtor and LVrot were measured respectively. The data were compared and analyzed between the two groups. Results Compared with normal group,the peak of LVtor and LVrot angle was decreased in cardiac dysfunction group at both apical and basal planes (P<0.05). The peak time of LVtor in patients with cardiac dysfunction was delayed (P<0.05). The peak time of clockwise rotation at the apical level segments was longer than control group (P<0.05). Conclusions There is a temporal sequence difference of left ventricular rotation between basal and apical planes during left ventricular contraction and decreased LVtor has been demonstrated to influence left ventricular function.

Objective To evaluate the feasibility of quality intima-media thickness (QIMT) in assessing function of common carotid artery (CCA) though cold pressure test(CPT). Methods Thirty healthy subjects[mean age(24.68±1.73) years old]were underwent 2D and QIMT examination under the normal quiescent and CPT condition respectively. The diastolic and systolic diameters of right-CCA were measured respectively. Corresponding the changed range and rate were calculated. After a week,under the same condition, 10 subjects who were chosen randomly were examination again to accept reproducibility test. Results The maximal and minimal diameters,changed range and rate of diameters were wider when subjects suffered CPT and measured by QIMT(P < 0.05). There was no significant difference of diameters between CPT and quiescent condition which measured by 2D. The maximal diameters measured by QIMT were well concordance [in group: r=0.92, P < 0.0001 :mean difference(0.027±0.012)mm]. Conclusion The function of CCA would be evaluated by QIMT.

Objective To assess the diagnosis safety by detecting the biological character of prenatal fetus rats’nervous tissue exposed to diagnostic ultrasound during earlier period. Methods Cell culture, morphology examining, cell proliferation curve measurement and flow cytometry detection were adopted. Results ①After morphology examining, there are no difference between the treated group and control group. ② We can see from the growth curve, the two groups has identical growth tendency. ③Through flow cytometry detection, results show that there are no significance between two groups. Conclusion Diagnostic ultrasound in early pregnancy have no significant effect on prenatal fetus rats’nervous tissue.

Objective To discuss the feasibility of quantitive tissue velocity imaging(QTVI) to quantify regional myocardial dysfunction induced by acute ischemia and reperfusion.The results derived from this study provide experimental foundation for QTVI in estimating the segment of myocardial ischemia and evaluating viable myocaridium after reperfusion.Methods Note the peak velocity of the systolic wave(Vs) and the peak velocity of the early diastolic wave(Ve) of regional wall segments of seven dogs with left anterior descending coronary artery(LAD) ligated under the different examination time points(i.e.,pre ligation,basic state;post ligation 5 min,15 min,30 min,60 min,120 min and reperfusion) by using QTVI technique.Postoperation, the myocardial specimen was stained by 1% triphenylatetrazolium chlorde(TTC) solution and tissue structure was analyzed by transmissible electrical microscope to identify whether myocardium was necrosis or not.Results Vs,Ve of every segmental myocardium of the dogs at ligation 5 min,10 min falled evidently in comparison with the basic state of the dogs (P

Objective To investigate the changes of mi crovascular endothelial dilatation in stunned myocardium. Methods Thirteen healthy and adult mongrel dogs were randomly organized into two groups, group A (n=6) and group B (n=7). Each dog in group A and B underwent 15 min and 30 min acute ligation at left anterior descending coronary artery (LAD), respectively. Myocardial contrast echocardiography was implemented via intra-femoral vein bolus injection of C 3F 8-exposed sonicated dextrose albumin at different examining time.Peak-intensity (PI) and area under curve (AUC) were derived from time-intensity curve (TIC) after aortic root injection of acetylcholine (ACH) or nitroglycerin (NG),and then PI ratio (PIR) and AUC ratio (AUCR) of pre- to post-ACH or pre- to post- NG were calculated at each of the corresponding examining times. Myocardial endothelium-dependent relaxation (EDR) and non-EDR were analyzed at different examining times. Results ①At baseline (before LAD ligation), PI and AUC in group A and B increased considerably via aortic root injection of ACH and NG. ② After ACH injection,PIR in group A decreased sharply at 5,30 and 60 min, whose P values were less than 0.05 compared with baseline. And all these recovered completely at 120 min reperfusion. However,PIR in group B recovered slowly and reached finally to baseline at 150 min reperfusion. Meanwhile, the variation trends of AUCR in both group A and B were the same as those of PIR. Overall, the dynamic tendencies of PIR and AUCR in these two groups for post-NG at different examining times were much similar to those of post-ACH. ③ The decreased magnitudes of PIR and AUCR in group A and B after ACH injection were bigger than those of NG injection at 5,30 and 60 min reperfusion(P

The reliability and reliable indexes of quantitative assessment of coronary flow reserve (CFR) by using time-intensity curve (TIC) via myocardial contrast echocardiography were investigated. The TIC variables were obtained by employing acoustic densitometry (AD) technique before and after acetylcholine (Ach) injection in 12 dogs. Meanwhile, the correlation between these variables and CFR was analyzed. Among the variables derived from TIC, peak intensity (PI), area under the curve (AUC) and descending slope (DS) were increased significantly (P < 0.05) with the increase of coronary blood flow after Ach injection. Conversely, time-to-peak (TP), half-time of descent (HT), and mean-transit-time (MTT) were decreased remarkably (P < 0.0001). The PI and AUC ratios from post- to pre-Ach injection were strongly associated with CFR with the correlation coefficient (r) being 0.8366 and 0.8824, respectively. It is reliable by using the variables derived from TIC with myocardial contrast echocardiography to quantitatively evaluate regional myocardial CFR. The PI and AUC ratios from post- to pre-Ach injection are the reliable indexes for quantitative assessment of CFR.
Animals ; Blood Flow Velocity ; physiology ; Contrast Media ; Coronary Circulation ; physiology ; Coronary Vessels ; diagnostic imaging ; physiology ; Dogs ; Echocardiography ; methods ; Image Processing, Computer-Assisted ; Observer Variation ; Regional Blood Flow ; drug effects ; physiology ; Reproducibility of Results ; Ultrasonography, Interventional

To evaluate the possibility and accuracy of Doppler tissue image (DTI) on assessment of normal and abnormal ventricular activation and contraction sequence, 9 open chest canine hearts were analyzed by acceleration mode, M-mode, and spectrum mode DTI. Our results showed that: (1) Acceleration mode DTI could show the origin of activation and conduction sequence on line; (2) M-mode DTI revealed that the activation in mid-interventricular septum was earlier than that in mid-left ventricular posterior wall at sinus activation; (3) Spectrum DTI showed the ventricular endocardium was activated earlier than the ventricular epicardium in all segments at sinus rhythm. The earliest site of activation of the normal ventricular wall was at middle interventricular septum; the latest site was at basal-posterior wall; the contraction sequence was different at the different walls; (4) During abnormal ventricular activation, mid-left ventricular posterior wall was activated earliest in accordance with the pacing sites. Abnormal ventricular activation was slower than sinus activation, and the contraction sequence varied at different sites of ventricular wall. It is concluded that DTI can be used to localize the origin of normal or abnormal myocardial activation and to assess the contraction sequence conveniently, accurately and non-invasively.
Animals ; Dogs ; Echocardiography, Doppler ; instrumentation ; methods ; Heart Ventricles ; diagnostic imaging ; Myocardial Contraction ; physiology ; Sinoatrial Node ; physiology ; Tachycardia ; diagnostic imaging ; physiopathology

To evaluate the possibility and accuracy of Doppler tissue image (DTI) on assessment of normal and abnormal ventricular activation and contraction sequence, 9 open chest canine hearts were analyzed by acceleration mode, M-mode, and spectrum mode DTI. Our results showed that: (1) Acceleration mode DTI could show the origin of activation and conduction sequence on line; (2) M-mode DTI revealed that the activation in mid-interventricular septum was earlier than that in mid-left ventricular posterior wall at sinus activation; (3) Spectrum DTI showed the ventricular endocardium was activated earlier than the ventricular epicardium in all segments at sinus rhythm. The earliest site of activation of the normal ventricular wall was at middle interventricular septum; the latest site was at basal-posterior wall; the contraction sequence was different at the different walls; (4) During abnormal ventricular activation, mid-left ventricular posterior wall was activated earliest in accordance with the pacing sites. Abnormal ventricular activation was slower than sinus activation, and the contraction sequence varied at different sites of ventricular wall. It is concluded that DTI can be used to localize the origin of normal or abnormal myocardial activation and to assess the contraction sequence conveniently, accurately and non-invasively.
Echocardiography, Doppler/instrumentation ; Echocardiography, Doppler/*methods ; Heart Ventricles/*ultrasonography ; Myocardial Contraction/*physiology ; Sinoatrial Node/physiology ; Tachycardia/physiopathology ; Tachycardia/ultrasonography

The reliability and reliable indexes of quantitative assessment of coronary flow reserve (CFR) by using time-intensity curve (TIC) via myocardial contrast echocardiography were investigated. The TIC variables were obtained by employing acoustic densitometry (AD) technique before and after acetylcholine (Ach) injection in 12 dogs. Meanwhile, the correlation between these variables and CFR was analyzed. Among the variables derived from TIC, peak intensity (PI), area under the curve (AUC) and descending slope (DS) were increased significantly (P < 0.05) with the increase of coronary blood flow after Ach injection. Conversely, time-to-peak (TP), half-time of descent (HT), and mean-transit-time (MTT) were decreased remarkably (P < 0.0001). The PI and AUC ratios from post- to pre-Ach injection were strongly associated with CFR with the correlation coefficient (r) being 0.8366 and 0.8824, respectively. It is reliable by using the variables derived from TIC with myocardial contrast echocardiography to quantitatively evaluate regional myocardial CFR. The PI and AUC ratios from post- to pre-Ach injection are the reliable indexes for quantitative assessment of CFR.
Blood Flow Velocity/physiology ; Contrast Media ; Coronary Circulation/*physiology ; Coronary Vessels/physiology ; Coronary Vessels/ultrasonography ; *Echocardiography/methods ; *Image Processing, Computer-Assisted ; Observer Variation ; Regional Blood Flow/drug effects ; Regional Blood Flow/physiology ; Reproducibility of Results ; Ultrasonography, Interventional