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） ...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.展开更多
Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). Methods RT3DE was performed...Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). Methods RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD, n=14) or distal branch of the left circumflex artery (LCX, n=7). A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos-7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal’s heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique.Results Total left ventricular (LV) myocardial mass ranged from 38.9 to 78.5 (mean±SD: 60.0±10.1) g. The mass of perfusion defect ranged from 0 to 21.4 (mean±SD: 12.0±5.0) g or 0 to 27% of total LV mass (mean±SD: 19%±6%). The RT3DE estimation of total LV mass (mean±SD: 59.8±9.9 g) strongly correlated with the anatomic measurement (r=0.98; y=2.01+0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean±SD: 12.3±5.3 g) also strongly correlated with the anatomic measurement (r=0.96; y=-0.10+1.04x) and when expressed as percentage of total LV mass (r=0.95; y=-0.20+1.04x). Conclusions RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.展开更多
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 pe...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 MPSI≤1.5 （P=0.002 and 0.04）. The differences in ALVEF and ALVEDV between patients with MPSI〉I.5 and those with MPSI≤1.5 were significant （P=0.002 and 0.001, respectively）. Linear regression analysis revealed that MPSI had a negative correlation with ALVEF and a positive correlation with ALVESV, ALVEDV （P=0.004, 0.008, and 0.016, respectively）. It was concluded that RT-MCE could accurately evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization.展开更多
The myocardial viability after myocardial infarction was evaluated by intravenous myocardial contrast echocardiography. Intravenous real-time myocardial contrast echocardiography was performed on 18 patients with myoc...The myocardial viability after myocardial infarction was evaluated by intravenous myocardial contrast echocardiography. Intravenous real-time myocardial contrast echocardiography was performed on 18 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. Viable myocardium was defined by evident improvement of segmental wall motion 3 months after coronary revascularization. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions： homogeneous opacification; partial or reduced opaciflcation or subendocardial contrast defect; contrast defect. The former two conditions were used as the standard to define the viable myocardium. The results showed that 109 abnormal wall motion segments were detected among 18 patients with myocardial infarction, including 47 segments of hypokinesis, 56 segments of akinesis and 6 segments of dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascularization which showed homogeneous opacification, 14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronary revascularization which showed partial or reduced opaciflcation or subendocardial contrast defect was improved 3 months after coronary revascularization. In our study, the sensitivity and specificity of evaluation of myocardial viability after myocardial infarction by intravenous real-time myocardial contrast echocardiography were 94.7% and 78.9%, respectively. It was concluded that intravenous real-time myocardial contrast echocardiography could accurately evaluate myocardial viability after myocardial infarction.展开更多
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 con...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.展开更多
Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocar...Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and ResultsMCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7 dogs with constant venous infusions of microbubbles. The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects microvascular cross - sectional area (or myocardial blood volume), and βreflects mean myocardial microbubble velocity. The product of A·β represents MBF. MBF was also obtained by ra-diolabeled microsphere method servered as reference. MBF derived by radiolabeled microsphere - method in the regions of normal, ischemia and infarction was 1.5+0.3, 0.7+0.3, 0. 3+0. 2 mL @ min-1@ g-1 respectively. The product of A·β obtained by MCE in those regions was 52. 46±15. 09, 24. 36±3. 89, 3. 74 ±3. 80 respectively. There was good correlation between normalized MBF and the normalized A·β ( r = 0. 81, P=0. 001). Conclusions MCE has an ability to determine myocardial viability in myocardial infarction canine model.展开更多
Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary micro...Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation,but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography(MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction,respectively,and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall,MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice,but the approval of regulatory authorities is lacking.展开更多
Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry fo...Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry for analysis of LV remodeling after myocardial infarction in daily clinical routine. Methods: 26 patients were investigated directly after interventional therapy at hospital pre-discharge and at 6 month follow-up. Standardized 2D transthoracic native and contrast echocardiography were performed in all patients. Due to methodological aspects the results of LV volumes and LVEF using native echocardiography were compared to the results of LV opacification (LVO) imaging for analysis in mono-, bi- and triplane data sets using the Simpson’s rule. In addition corresponding multidimensional data sets were analyzed. Results: The assessment of LV volumes and LVEF is more accurate with contrast echocardiography. The comparison of LV volumes and LVEF shows significant increases using contrast echocardiography (p < 0.001). Larger left ventricular end-diastolic volumes (LVEDV) are measured at follow up (p < 0.05). Significant differences (p < 0.001) are found for the determination of LVEDV and LVEF relating to apical mono-, bi-, tri- and multiplane data sets. Standard deviations of the triplane approach, however, are significantly lower than using other modalities. Conclusion: Depending on the localization of the myocardial infarction LV volumes and LVEF are less reliably evaluated using the mono- or biplane approach. According to standardization and simultaneous acquisition of all LV wall segments the triplane approach is currently the best approach to determine LV systolic function. In addition, contrast echocardiography is indicated to improve endocardial border delineation in patients using the triplane or multiplane approach. To our knowledge the present study is the first systematic evaluation of all current possibilities for determination of LV volumes and LVEF by native and contrast echocardiography.展开更多
Background No-reflow is associated with an adverse outcome and higher mortality in patients with ST-segment elevation acute myocardial infarction （STEMI） who undergo percutaneous coronary intervention （PCI） and is...Background No-reflow is associated with an adverse outcome and higher mortality in patients with ST-segment elevation acute myocardial infarction （STEMI） who undergo percutaneous coronary intervention （PCI） and is considered a dynamic process characterized by multiple pathogenetic components. The aim of this study was to investigate the effectiveness of a combination therapy for the prevention of no-reflow in patient with acute myocardial infarction （AMI） undergoing primary PCI. Methods A total of 621 patients with STEMI who underwent emergency primary PCI were enrolled in this study. Patients with high risk of no-reflow （no-flow score 〉 10, by using a no-flow risk prediction model, n = 216） were randomly divided into a controlled group （n = 108） and a combination therapy group （n = 108）. Patients in the controlled group received conventional treatment, while patients in combination therapy group received high-dose （80 mg） atorvastatin pre-treatment, intracoronary administration of adenosine （140 ~tg/min per kilogram） during PCI procedure, platelet membrane glycoprotein lib/Ilia receptor antagonist （tirofiban, 101.tg/kg bolus followed by 0.15 ~tg/kg per minute） and thrombus aspiration. Myocardial contrast echocardiography was performed to assess the myocardial perfusion 72 h after PCI. Major adverse cardiac events （MACE） were followed up for six months. Results Incidence of no-reflow in combination therapy group was 2.8%, which was similar to that in low risk group 2.7% and was significantly lower than that in control group （35.2%, P 〈 0.01）. The myocardial perfusion （A= 13） values were higher in combination therapy group than that in control group 72 h after PCI. After 6 months, there were six （6.3%） MACE events （one death, two non-fatal MIs and three revasculafizations） in combination therapy group and 12 （13.2%） （four deaths, three non-fatal MIs and five revascularizations, P 〈 0.05） in control group. Conclusions Combination of thrombus aspiration, high-dose statin pre-treatment, intmcoronary administration of adenosine during PCI procedure and platelet membrane glycoprotein Ⅱ b/Ⅲa receptor antagonist reduces the incidence of no-reflow after primary PCI in patients with acute myocardial infarction who are at high risk of no-reflow.展开更多
文摘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.
文摘Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). Methods RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD, n=14) or distal branch of the left circumflex artery (LCX, n=7). A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos-7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal’s heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique.Results Total left ventricular (LV) myocardial mass ranged from 38.9 to 78.5 (mean±SD: 60.0±10.1) g. The mass of perfusion defect ranged from 0 to 21.4 (mean±SD: 12.0±5.0) g or 0 to 27% of total LV mass (mean±SD: 19%±6%). The RT3DE estimation of total LV mass (mean±SD: 59.8±9.9 g) strongly correlated with the anatomic measurement (r=0.98; y=2.01+0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean±SD: 12.3±5.3 g) also strongly correlated with the anatomic measurement (r=0.96; y=-0.10+1.04x) and when expressed as percentage of total LV mass (r=0.95; y=-0.20+1.04x). Conclusions RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.
文摘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 MPSI≤1.5 （P=0.002 and 0.04）. The differences in ALVEF and ALVEDV between patients with MPSI〉I.5 and those with MPSI≤1.5 were significant （P=0.002 and 0.001, respectively）. Linear regression analysis revealed that MPSI had a negative correlation with ALVEF and a positive correlation with ALVESV, ALVEDV （P=0.004, 0.008, and 0.016, respectively）. It was concluded that RT-MCE could accurately evaluate the left ventricular remodeling in patients with myocardial infarction after revascularization.
文摘The myocardial viability after myocardial infarction was evaluated by intravenous myocardial contrast echocardiography. Intravenous real-time myocardial contrast echocardiography was performed on 18 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. Viable myocardium was defined by evident improvement of segmental wall motion 3 months after coronary revascularization. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions： homogeneous opacification; partial or reduced opaciflcation or subendocardial contrast defect; contrast defect. The former two conditions were used as the standard to define the viable myocardium. The results showed that 109 abnormal wall motion segments were detected among 18 patients with myocardial infarction, including 47 segments of hypokinesis, 56 segments of akinesis and 6 segments of dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascularization which showed homogeneous opacification, 14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronary revascularization which showed partial or reduced opaciflcation or subendocardial contrast defect was improved 3 months after coronary revascularization. In our study, the sensitivity and specificity of evaluation of myocardial viability after myocardial infarction by intravenous real-time myocardial contrast echocardiography were 94.7% and 78.9%, respectively. It was concluded that intravenous real-time myocardial contrast echocardiography could accurately evaluate myocardial viability after myocardial infarction.
文摘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.
基金This work was supported in part by grants from thescience and technology foundation of China(39870329).
文摘Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and ResultsMCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7 dogs with constant venous infusions of microbubbles. The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects microvascular cross - sectional area (or myocardial blood volume), and βreflects mean myocardial microbubble velocity. The product of A·β represents MBF. MBF was also obtained by ra-diolabeled microsphere method servered as reference. MBF derived by radiolabeled microsphere - method in the regions of normal, ischemia and infarction was 1.5+0.3, 0.7+0.3, 0. 3+0. 2 mL @ min-1@ g-1 respectively. The product of A·β obtained by MCE in those regions was 52. 46±15. 09, 24. 36±3. 89, 3. 74 ±3. 80 respectively. There was good correlation between normalized MBF and the normalized A·β ( r = 0. 81, P=0. 001). Conclusions MCE has an ability to determine myocardial viability in myocardial infarction canine model.
文摘Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation,but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography(MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction,respectively,and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall,MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice,but the approval of regulatory authorities is lacking.
文摘Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry for analysis of LV remodeling after myocardial infarction in daily clinical routine. Methods: 26 patients were investigated directly after interventional therapy at hospital pre-discharge and at 6 month follow-up. Standardized 2D transthoracic native and contrast echocardiography were performed in all patients. Due to methodological aspects the results of LV volumes and LVEF using native echocardiography were compared to the results of LV opacification (LVO) imaging for analysis in mono-, bi- and triplane data sets using the Simpson’s rule. In addition corresponding multidimensional data sets were analyzed. Results: The assessment of LV volumes and LVEF is more accurate with contrast echocardiography. The comparison of LV volumes and LVEF shows significant increases using contrast echocardiography (p < 0.001). Larger left ventricular end-diastolic volumes (LVEDV) are measured at follow up (p < 0.05). Significant differences (p < 0.001) are found for the determination of LVEDV and LVEF relating to apical mono-, bi-, tri- and multiplane data sets. Standard deviations of the triplane approach, however, are significantly lower than using other modalities. Conclusion: Depending on the localization of the myocardial infarction LV volumes and LVEF are less reliably evaluated using the mono- or biplane approach. According to standardization and simultaneous acquisition of all LV wall segments the triplane approach is currently the best approach to determine LV systolic function. In addition, contrast echocardiography is indicated to improve endocardial border delineation in patients using the triplane or multiplane approach. To our knowledge the present study is the first systematic evaluation of all current possibilities for determination of LV volumes and LVEF by native and contrast echocardiography.
文摘Background No-reflow is associated with an adverse outcome and higher mortality in patients with ST-segment elevation acute myocardial infarction （STEMI） who undergo percutaneous coronary intervention （PCI） and is considered a dynamic process characterized by multiple pathogenetic components. The aim of this study was to investigate the effectiveness of a combination therapy for the prevention of no-reflow in patient with acute myocardial infarction （AMI） undergoing primary PCI. Methods A total of 621 patients with STEMI who underwent emergency primary PCI were enrolled in this study. Patients with high risk of no-reflow （no-flow score 〉 10, by using a no-flow risk prediction model, n = 216） were randomly divided into a controlled group （n = 108） and a combination therapy group （n = 108）. Patients in the controlled group received conventional treatment, while patients in combination therapy group received high-dose （80 mg） atorvastatin pre-treatment, intracoronary administration of adenosine （140 ~tg/min per kilogram） during PCI procedure, platelet membrane glycoprotein lib/Ilia receptor antagonist （tirofiban, 101.tg/kg bolus followed by 0.15 ~tg/kg per minute） and thrombus aspiration. Myocardial contrast echocardiography was performed to assess the myocardial perfusion 72 h after PCI. Major adverse cardiac events （MACE） were followed up for six months. Results Incidence of no-reflow in combination therapy group was 2.8%, which was similar to that in low risk group 2.7% and was significantly lower than that in control group （35.2%, P 〈 0.01）. The myocardial perfusion （A= 13） values were higher in combination therapy group than that in control group 72 h after PCI. After 6 months, there were six （6.3%） MACE events （one death, two non-fatal MIs and three revasculafizations） in combination therapy group and 12 （13.2%） （four deaths, three non-fatal MIs and five revascularizations, P 〈 0.05） in control group. Conclusions Combination of thrombus aspiration, high-dose statin pre-treatment, intmcoronary administration of adenosine during PCI procedure and platelet membrane glycoprotein Ⅱ b/Ⅲa receptor antagonist reduces the incidence of no-reflow after primary PCI in patients with acute myocardial infarction who are at high risk of no-reflow.
