Evaluation of the left ventricular remodeling in patients with myocardial infarction after revascularization with intravenous real-time myocardial contrast echocardiography

In order to evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization with intravenous real-time myocardial contrast echocardiography （RT-MCE）, intravenous RT-MCE was performed on 20 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions： homogeneous opacification=l; partial or reduced opaciflcation or subendocardial contrast defect=2; constrast defect=3. Myocardial perfusion score index （MPSI） was calculated by dividing the total sum of contrast score by the total number of segments with abnormal wall motion. Twenty patients were classified into 2 groups according to the MPSI： MPSI≤I.5 as good myocardial perfusion, MPSI〉1.5 as poor myocardial perfusion. To assess the left ventricular remodeling, the following comparisons were carried out： （1） Comparisons of left ventricular ejection fraction （LVEF）, left ventricular end-systolic volume （LVESV） and left ventricular end-diastolic volume （LVEDV） before and 3 months after revascularization in two groups;（2） Comparisons of LVEF, LVESV and LVEDV pre-revascularization between two groups and comparisons of these 3 months post-revascularization between two groups; （3） Comparisons of the differences in LVEF, LVESV and LVEDV between 3 months post-and pre-revascularization （ALVEF, ALVESV and ALVEDV） between two groups; （4） The linear regression analysis between ALVEF, ALVESV, ALVEDV and MPSI. The results showed that the LVEF obtained 3 months after revascularization in patients with MPSI〉1.5 was obviously lower than that in those with MPSI〈1.5. The LVEDV obtained 3 months post-revascularization in patients with MPSI〉1.5 was obviously larger than that in those with M     

心肌声学造影对急性心肌梗死急诊介入术后心肌灌注及预后评估

目的 通过实时心肌声学造影(MCE)评估急性心肌梗死（AMI）急诊介入术后微循环灌注情况及其对AMI预后的评估价值。方法纳入108例AMI且行急诊介入手术患者,术后3～5 d行心肌声学造影,记录患者左室射血分数（LVEF）、室壁运动评分指数（WMSI）、左室收缩末期容量（LVESV）、左室舒张末期容量（LVEDV）、左室舒张末期内径（LVIDd）、二尖瓣E峰速度（MVE）、二尖瓣A峰速度（MVA）、左室质量指数（Lvmassi）及造影剂评分指数（CSI）。出院后1年对108例患者进行电话随访,根据是否发生不良心血管事件（MACE）分为MACE组和非MACE组。结果（1）MACE组患者WMSI、CSI、LVESV更高,而LVEF则较低,两组差异有统计学意义(P<0.05)。（2）前壁心肌梗死MACE事件的发生和更多的心肌灌注缺损有关系。（3）CSI可以作为AMI急诊介入术后MACE事件发生的独立危险因素;（4）CSI≥1.58较 CSI<1.58的AMI患者1年后MACE事件发生率更高(45% vs. 9% P=0.001)。结论MCE能评估AMI急诊介入术后患者微循环灌注情况; CSI能独立预测AMI患者急诊介入术后MACE事件,从而对该类人群进行危险分层,尽早识别高危患者,规避恶性事件发生。     

经静脉心肌声学造影术评价区域性心肌灌注的初步临床研究

目的 探讨经静脉心肌声学造影术（ＩＭＣＥ）的安全性,可行性及临床应用价值。方法 １４例住院病人行ＩＭＣＥ检查、心肌梗死６例,心绞痛６例,可疑冠心病２例。其中８例行冠脉造影术（ＣＡＧ）,７例行单光子发射计算机断层显像术（ＳＰＥＣＴ）检查。ＳＰＥＣＴ、ＩＭＣＥ均采用目测半定量方法（０￣３分）评价心肌灌注。冠脉根据其病变程度分为４组：正常（无狭窄）、中度狭窄（５０％￣７５％）,重度狭窄（７６％￣９９％）     

Real-time three-dimensional myocardial contrast echocardiography in assessment of myocardial perfusion defects

Background Both real-time three-dimensional echocardiography (RT3DE) and myocardial contrast echocardiography (MCE) are novel imaging techniques. The purpose of this study was to confirm the feasibility and accuracy of RT3DE combined with MCE for quantitative evaluation of myocardial perfusion defects. Methods Thirteen dogs underwent ligation of the left anterior descending artery (LAD, n=6) or distal branch of the left circumflex artery (LCX, n=7) under general anaesthesia. Three to four ml of a perfluoropropane (C3F8) microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with a commercially available Philips SONOS-7500 ultrasound system. After removal of the dog hearts, Evans blue dye was injected via the left and right coronary arteries to stain the myocardium at risk. In vitro anatomic measurements of myocardial mass after removal of the animals’ hearts were used as controls. Results Left ventricular (LV) mass determined by RT3DE ranged 36.7-68.9 g ［mean, （54.6±9.6） g］ before coronary artery ligation, and correlated highly (r=0.99) with in vitro measurement of LV mass ［range, 38.9-71.1 g; mean, (55.6±9.3) g］. There was no significant difference between RT3DE and in vitro measurements of LV mass ［range, 36.7-68.9 g; mean, （51.3±12.5） g. Or range, 38.9-71.1 g; mean, （53.7±12.3） g, respectively］ and under-perfused mass ［range, 0-21.4 g; mean, （12.0±6.9） g. Or range, 0-19.8 g; mean, （10.8±6.3） g, respectively］ after the LAD ligation (P&gt;0.05). Likewise, no significant difference was present between RT3DE and in vitro measurements of LV mass ［range, 50.1-65.4 g; mean, （57.5±5.9） g. Or range, 51.5-65.8 g; mean, （57.3±6.4） g, respectively］ and under-perfused mass ［range, 0-25.6 g; mean, （13.3±9.6） g. Or range, 0-22.7 g; mean, （12.8±8.1） g, respectively］ after the LCX ligation (P&gt;0.05). For all the animals with coronary ligation, LV mass measured by RT3DE ranged 35.9-68.6 g ［mean, （54.8±10.0） g］ and there was no significant difference between RT3DE and in vitro measurements of LV mass and under-perfused mass (P&gt;0.05, r=0.99). Further, the under-perfused mass derived from RT3DE ［range, 0-25.6 g; mean, （12.7±8.2） g］ correlated strongly with the in vitro measurements ［range, 0-22.7 g; mean, （11.9±7.2） g］ (r=0.96). Conclusion RT3DE with MCE is a rapid and accurate method for estimating LV myocardial mass and quantifying perfusion defects.     

实时超声心肌声学造影对冠心病患者心肌灌注的临床研究

目的应用实时心肌声学造影半定量评价冠心病患者心肌灌注状况和心肌微循环状况。方法 20例冠脉造影左前降支冠脉狭窄>75%以上的冠心病患者和20例健康对照组行静息状态下实时心肌声学造影检查,并进行左室显影效果评分及造影声像半定量分析,来评价冠心病患者心肌灌注状况和心肌微循环状况。结果 MCE技术不但可对左室显影效果及心肌造影进行直观评价,而且能同时显示心肌增厚率和室壁运动,可以作为评价冠心病患者心肌血流灌注及心肌微血管病变的最佳选择。结论心肌超声造影有望成为冠心病的常规检查方法。     

Quantitative analysis of myocaridal perfusion in rabbits by tansthoracic real-time myocardial contrast echocardiography

To evaluate the feasibility of real-time myocardial contrast echocardiography （RTMCE） by quantitative analysis of myocardial perfusion in rabbits, transthoracic RTMCE was performed in 10 healthy rabbits by using continuous infusion of SonoVue into the auricular vein. The short axis view at the papillary muscle level was obtained. The duration of the time that the contrast took to appear in right heart, left heart and myocardium was recorded. The regional myocardial signal intensity （SI） versus re-filling time plots were fitted to an exponential function： y（t） =A（1–e–β（t–t0）） ＋ C, where y is SI at any given time, A is the SI plateau that reflects myocardial blood volume, and β is the slope of the refilling curve that reflects myocardial microbubble velocity. The A, β and A×β values at different infusion rate of SonoVue were analyzed and the A, β and A×β values in each segment in the short axis view at the papillary muscle level were compared. All the animal experiments were successful and high-quality im-ages were obtained. The best intravenous infusion rate for SonoVue was 30 mL/h. The contrast appeared in right heart, left heart and myocardium at 7.5±2.2 s, 9.1±2.4 s and 12.2±1.6 s respectively. After 16.6±2.3s, myocardial opacification reached a steady state. The mean A, β and A×β value in the short axis view at the papillary muscle level were 9.8±3.0 dB, 1.4±0.5 s-1 and 13.5±3.6 dB×s-1 respectively. A, β and A×β values showed no significant differences among 6 segments. It was suggested that RTMCE was feasible for quantitative analysis of myocardial perfusion in rabbits. It provides a non-invasive method to evaluate the myocardial perfusion in rabbit disease models.     

磁共振心肌灌注成像评价心肌梗死PTCA治疗前后心肌存活

目的 评价磁共振心肌灌注成像(MRMPI) 检测心肌梗死存活心肌的作用. 方法 选择心肌梗死患者51 例.采用1.5 T MR扫描仪,反转恢复快速小角度激励( IR-turbo FLASH) 序列,全部患者均在静脉注射钆喷替酸葡甲胺(Gd-DTPA) 0.1 mmol/kg、MRMPI 首过期及5~30 min 延迟期成像.21 例行静息、负荷99锝单光子发射计算机体层摄影术( single photon emission computed tomography, SPECT) 进行对照研究.首过期行短轴面成像,延迟期行短轴面及长轴面成像.结果 51例心肌梗死患者,42 例(82.3%) 首过期显示灌注减低;50 例(98%) 延迟增强.在21例168个心肌段SPECT诊断无活性心肌段48个,MRMPI 示梗死区均有延迟增强,SPECT诊断存活心肌段120 个,MRMPI 示97段无延迟增强.以静息、负荷99m锝SPECT 作为参考标准,MRMPI 的敏感度、特异度分别为100%、80.8%. 结论 MRMPI 可有效地检测心肌梗死的存活和非存活心肌,以及其程度和范围.     

实时心肌造影对可疑冠心病患者的研究

目的：探索实时心肌超声造影（RTMCE）在可疑冠心病中的左室心内膜边界及心肌显影效果。方法：49例可疑冠心病患者进行了超声心动图检查,并在静息状态下行心肌声学造影后进行冠状动脉造影并与冠状动脉造影对比分析。结果：（1）超声造影后左室心内膜边界显示较造影前明显清晰,显示不清的节段减少,清晰显示的节段增多,记分指数增高（P〈0．05）。（2）49例患者中冠脉造影15例异常,3例冠脉3支病变的患者显示心肌灌注明显下降,12例单支或双支病变的患者中7例表现为相应冠脉供血区心肌灌注下降,5例其相应冠脉供血区未见异常,3-4例冠脉造影正常者中有3例表现为灌注减弱。结论：心肌超声造影有望成为可疑冠心病及冠心病的常规检查方法。     

Hydrogen peroxide myocardial perfusion contrast echocardiography: I. Experimental study

Summary Myocardial perfusion contrast two-dimentional echocardiography (2-DE) is a new method for determining the extent of experimental myocardial ischemia and infarction. 172 aortic root injections of a fresh mixture of 1 ml of 0.75 % hydrogen peroxide (H₂O₂) and blood, and 75 pulmonary wedge injections of 1 ml of 3 % H₂O₂ were given to 24 open-chest dogs before and after ligation of the left anterior descending coronary artery (LAD) and four short-axis and long-axis views of the left ventricle were examined. 164 (95%) aortic root injections and 30 (40 %P< 0.05) pulmonary wedge injections showed homogeneous echocardiographic contrast intensification of normal myocardium before ligation of LAD and distinctly delineated echocardiographic contrast defect after ligation of LAD. When compared with aortic root injection, H₂O₂ pulmonary wedge injection has the adventage of less invasiveness and remains to be further studied. This project was supported by the Science Fund of the Chinese Academy of Sciences     

Comparison of the veracity of real-time perfusion, harmonic angio, and ultraharmonic myocardial contrast imaging modes in evaluation of acute myocardial infarction area

Background Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography （MCE） in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index （MI） real-time perfusion imaging （RTPI）, triggered harmonic angio mode （HA）, and ultraharmonic imaging mode （UH） in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion. Methods MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of peffusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride （TTC） staining. Results The infarct area was （15.8-2.4）% by TTC staining; Peffusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches： （16.1-2.7）% by RTPI mode, （15.5-2.9）% by HA mode, and （15.5-3.0）% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94 % for HA mode, and 100%, 75%, and 88% for UH mode. Conclusion All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.     

氟碳微泡经静脉声学造影无创评价缺血和梗死心肌的实验研究

目的 :采用氟碳微泡声学造影剂及间歇二次谐波技术 ,评价心肌声学造影 (MCE)在缺血、梗死心肌诊断中的价值。方法 :建立开胸犬急性心肌梗塞动物模型 ,左前降支 (LAD)结扎 3h后 ,经静脉注射全氟显进行 MCE。于左室短轴乳头肌水平测定正常灌注区与缺血低灌注区心肌视频密度时间 -强度曲线参数及灌注缺损心肌范围。实验结束后心脏行组织学染色 ,比较两种方法所测的左室梗死心肌占左室心肌总面积百分比。结果 :心肌造影时间 -强度曲线中 ,正常灌注区与低灌注区的峰值强度 (PI)、强度减半时间 (T1/ 2 )、曲线下面积 (AUC)参数差异有显著性(13.5± 1.9vs2 2 .5± 2 .4 ;16 .6± 0 .9vs9.7± 0 .5 ;2 31.6± 14.9vs4 0 5 .6± 12 .3,P≤ 0 .0 1)。MCE所测定的左室梗死心肌占左室心肌总面积百分比与组织学染色所测定的实际百分比呈正相关 (r=0 .89,P=0 .0 1)。结论 :经静脉注射氟碳微泡声学造影剂 ,运用间歇二次谐波 MCE可定量心肌血流灌注 ,诊断心肌缺血 ,准确测定心肌梗死范围。     

Real-time myocardial contrast echocardiography and its applications in evaluation for coronary artery disease

It is important to assess myocardial perfusion in the diagnosis, treatment and risk stratification of patients with coronary artery disease. At present, single-photon emission computed tomography (SPECT) is used to evaluate myocardial perfusion, but it is limited by relatively low spatial resolution, the need to inject radioisotopes, and not being able to be performed at the     

Real-time myocardial contrast echocardiography and its applications in evaluation for coronary artery disease

It is important to assess myocardial perfusion in the diagnosis, treatment and risk stratification of patients with coronary artery disease. At present, single-photon emission computed tomography (SPECT) is used to evaluate myocardial perfusion, but it is limited by relatively low spatial resolution, the need to inject radioisotopes, and not being able to be performed at the patient ' s bedside. Using intracoronary injection of ultrasound contrast agent, the potential of myocardial contrast echocardiography (MCE) instead of perfusion assessment has been proved in numerous animal and human studies. Recent improvements in contrast agents have resulted in stable microbubbles that, following intravenous administration, traverse the pulmonary circulation and reach the left heart. Combined with the emergence of contrast-specific imaging modalities along with quantitative analytical method, intravenous MCE is now a feasible and promising noninvasive technique for perfusion assessment.     

Assessment of coronary artery disease with second harmonic myocardial perfusion contrast echocardiography

Objectives To assess the relationship between myocardial regional perfusion using second harmonic myocardial contrast echocardiography (MCE) by venous injection of Levovist and coronary artery stenosis detected by coronary angiography to determine whether MCE can be used to detect coronary artery disease (CAD) and its sensitivity and specificity for detecting CAD.Methods Thirty-six patients who underwent coronary artery angiography and MCE formed the study groups.Ten myocardial segments (5 each in the apical two- and four-chamber views) from the images were scored for detecting myocardial perfusion as follows: 1, normal perfusion; 2, decreased perfusion; and 3, perfusion defect.The arteries were classified as normal or diseased.The diseased arteries were classified into three groups according to the perfusion scores.Results There were significant differences in coronary diameter stenosis among the different perfusion score groups (P&lt;0.001).There were 10 total occluded arteries, and the myocardial perfusion scores were different because of different collateral circulation.In the normal perfusion group (Group A), the coronary diameter stenosis was 65%±12%, and the myocardial perfusion score index was 1±0.00.In the decreased perfusion group (Group B), the average coronary diameter stenosis was 82%±8%, and the myocardial perfusion score was 1.93±0.16.The diameter stenosis was less than 85% in 63 % of the coronary arteries (including diameter stenosis ≤75% in 12% of the vessels).The diameter stenosis was 85%-90% in 22% of the coronary arteries and &gt;90% in 15% of the arteries.In the perfusion defect group (Group C), the average diameter stenosis was 90%±6%, and the myocardial perfusion score index was 2.89±0.24.The diameter stenosis was　≥85% in 94% of the coronary arteries, and the diameter stenosis was &lt;85% and &gt;75% only in 6% of the coronary arteries.The overall sensitivity and specificity of MCE in identifying angiographic coronary diameter stenosis was 67% and 100%, respectively.The false negative rate was 32.6% for the 108 coronary arteries.Further subdivided analysis showed the sensitivities in Groups A, B and C were 0, 100%, and 100%, respectively.The sensitivity increased with increased lumen diameter stenosis of coronary arteries.Conclusions There is a close relationship between coronary artery stenosis and MCE perfusion scores.MCE with venous injection of new generation contrast can define the presence of CAD and lesion graded classifications.Some disagreements between perfusion score and coronary diameter of stenosis may indicate other factors such as different collateral circulation, which should be further investigated.As artery stenosis increases, the sensitivity of MCE is increased.     

Comparison of the veracity of real-time perfusion, harmonic angio, and ultraharmonic mocardial contrast imaging mode sine valuation of acute myocardial infarction area

Background Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography (MCE) in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index (MI) real-time perfusion imaging (RTPI), triggered harmonic angio mode (HA), and ultraharmonic imaging mode (UH) in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion.
Methods MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of perfusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride (TTC) staining.
Results The infarct area was (15.8±2.4)% by TTC staining; Perfusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches: (16.1±2.7)% by RTPI mode, (15.5±2.9)% by HA mode, and (15.5±3.0)% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94 % for HA mode, and 100%, 75%, and 88% for UH mode.
Conclusion All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.

     

实时心肌造影诊断犬冠状动脉狭窄的实验研究

目的探讨实时心肌声学造影（RTMCE）在检测犬冠状动脉狭窄中的实用价值。方法对13只开胸犬冠状动脉左前降支（LAD）在狭窄前、轻度狭窄（血流量减少40%）、中度狭窄（血流量减少70%）、重度狭窄（血流量减少90%）时分别进行心肌声学造影,观察左室乳头肌短轴切面心肌显影情况,应用Real Time MC分析软件进行脱机分析,得出各心肌节段的平台期强度（A）、再充盈平均速度（）及A×值,再对各节段心肌灌注参数进行统计分析。结果在LAD狭窄前分别与LAD轻、中、重度狭窄状态下比较,A值均无统计学意义（〉0.05）;当LAD重度狭窄时,其值与狭窄前比较,两者间差异有统计学意义（〈0.05）,当LAD中度狭窄时,其供血区心肌血流量（A×）低于正常对照区,差异有统计学意义（〈0.05）,当LAD狭窄90%时,其供血区心肌血流量明显减少,显著低于正常对照区,两者间对比明显,A×差异有显著统计学意义（〈0.01）。结论 A×能较好地评价不同程度的冠状动脉狭窄,也是一个探查冠状动脉狭窄存在的理想指标。     

Assessment of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery by myocardial contrast echocardiography and two-dimensional strain echocardiography

The clinically applied value of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery using real-time myocardial contrast echocardiography （RT-MCE） combined with two-dimensional strain echocardiography was assessed. Twenty patients underwent intravenous RT-MCE by intravenous injections of SonoVue before and after coronary artery bypass surgery. Two-dimensional images were recorded from the left ventricular four-chamber view, two-chamber view and the apical view before, and two weeks and three months after coronary artery bypass surgery, and the peak systolic longitudinal strain was measured. The results showed that myocardial perfusion was significantly increased after coronary artery bypass surgery in about 71.6% segments. In the group that myocardial perfusion was improved, the peak systolic longitu- dinal strain three months after bypass surgery was significantly higher than that before operation [（-15.78±5.91）% vs （-10.45±8.31）%, P〈0.05]. However, the parameters did not change in the group without myocardial perfusion improvement [（-10.33±6.53）% vs （-9.41±6.09）%, P〉0.05]. It was concluded that whether or not the improvement of myocardial perfusion can mirror the recovery trend of regional systolic function, two-dimensional strain echocardiography can observe dynamic change of regional systolic function. The combination of myocardial perfusion with two-dimensional strain echocardiography can more accurately assess the curative effectiveness of coronary artery bypass surgery.     

MR电影判断急性心肌梗死后存活心肌的价值

目的:探讨MR电影心肌运动影像判断急性心肌梗死后存活心肌的价值。方法:分析22例急性心肌梗死患者(急性梗死组)和20例正常对照组的MR电影,判断MR电影对急性心肌梗死后存活心肌检测率。结果:正常对照组心肌各室壁厚度变化一致(P>0.05),梗死心肌节段室壁厚度变化明显小于正常心肌(P<0.05)。室壁厚度变化减小(<2mm)对梗死心肌节段的检测敏感性为77%,特异性为100%;结合首过及延迟灌注异常可将其敏感性提高到91%。结论:MR电影心肌运动影像是MRI诊断急性心肌梗死后存活心肌可靠的指标,可初步判断心肌存活性,行靶区首过心肌灌注可以明显提高检查的敏感性。     

心肌声学造影评价慢性心肌缺血血流灌注的实验研究

目的:探讨经静脉心肌声学造影(MCE)对慢性心肌缺血心肌血流灌注的诊断价值。方法:建立慢性心肌缺血猪模型,经外周静脉持续滴注微泡造影剂,分别于造模前、造模4周后测算A·β、标化A·β,比较造模前后心肌灌注图像及A·β、标化A·β。结果:造模前声学微泡在心肌组织中均匀分布,色泽明亮,A·β、标化A·β分别为49.82±14.07、1.01±0.21;Ameroid环套扎LCX后4周,局部心肌基本无灌注,回声低暗,A·β、标化A·β分别为4.08±3.56、0.13±0.07,明显低于造模前。结论:心肌声学造影可用于量化评估慢性心肌缺血时的心肌血流灌注状态。     

经静脉心肌造影对犬冠状动脉阻断后存活心肌评价的实验研究

目的:探讨经静脉心肌造影(MCE)对犬冠状动脉阻断后存活心肌判定的价值。方法:应用自制声学造影剂,对12条犬于冠状动脉阻断即刻、阻断后1h、4h和再灌注后1h进行经静脉心肌造影研究。结果:当冠状动脉阻断后,所有犬阻断的冠状动脉供血区心肌出现节段性的灌注缺损。阻断即刻与1h的灌注缺损区面积无明显差异,而阻断4h后灌注缺损面积较前两者变小,在阻断早期灌注缺损区域部分变为正常或灌注减低区。灌注减低区对应的氯化三苯四氮唑染色显示为存活心肌。结论:冠状动脉阻断一定时间后MCE可以准确判定存活心肌。