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Objective:To explore the prognostic predictive value of deep neural network (DNN) assisted myocardial contrast echocardiography (MCE) quantitative analysis of ST-elevated myocardial infarction (STEMI) patients after successful percutaneous coronary intervention(PCI).Methods:A retrospective analysis was performed in 97 STEMI patients with thrombolysis in myocardial infarction-3 flow in infarct vessel after primary PCI in Renmin Hospital of Wuhan University from June to November 2021. MCE was performed within 48 h after PCI. Patients were followed up to 120 days. The adverse events were defined as cardiac death, hospitalization for congestive heart failure, reinfarction, stroke and recurrent angina. The framework consisted of the U-net and hierarchical convolutional LSTMs. The plateau myocardial contrast intensity (A), micro-bubble rate constant (β), and microvascular blood flow (MBF) for all myocardial segments were obtained by the framework, and then underwent variability analysis. Patients were divided into low MBF group and high MBF group based on MBF values, the baseline characteristics and adverse events were compared between the two groups. Other variables included biomarkers, ventricular wall motion analysis, MCE qualitative analysis, and left ventricular ejection fraction. The relationship between various variables and prognosis was investigated using Cox regression analysis. The ROC curve was plotted to evaluate the diagnostic efficacy of the models, and the diagnostic efficacy of the models was compared using the integrated discrimination improvement index (IDI).Results:The time-cost for processing all 3 810 frames from 97 patients was 377 s. 92.89% and 7.11% of the frames were evaluated by an experienced echocardiographer as "good segmentation" and "correction needed". The correlation coefficients of A, β, and MBF ranged from 0.97 to 0.99 for intra-observer and inter-observer variability. During follow-up, 20 patients met the adverse events. Multivariate Cox regression analysis showed that for each increase of 1 IU/s in MBF of the infarct-related artery territory, the risk of adverse events decreased by 6% ( HR 0.94, 95% CI =0.91-0.98). There was a 4.5-fold increased risk of adverse events in the low MBF group ( HR 5.50, 95% CI=1.55-19.49). After incorporating DNN-assisted MCE quantitative analysis into qualitative analysis, the IDI for prognostic prediction was 15% (AUC 0.86, sensitivity 0.78, specificity 0.73). Conclusions:MBF of the area supplied by infarct-related artery after STEMI-PCI is an independent protective factor for short-term prognosis. The DNN-assisted MCE quantitative analysis is an objective, efficient, and reproducible method to evaluate microvascular perfusion. Assessment of culprit-MBF after PCI in STEMI patients adds independent short-term prognostic information over qualitative analysis.It has the potential to be a valuable tool for risk stratification and clinical follow-up.
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Objective:To detect the abnormal changes of myocardial blood perfusion in patients with hypertrophic cardiomyopathy(HCM) by myocardial contrast echocardiography (MCE) combined with adenosine stress test.Methods:Fifteen adult patients with HCM who were treated in Fuwai Central China Cardiovascular Hospital from May 2021 to March 2022 were prospectively selected as the HCM group, and eighteen healthy volunteers matched by gender, age and body surface area during the same period were chosen as the control group. All subjects underwent routine echocardiography, rest and adenosine stress MCE. The MCE images were analyzed by QLab software to obtain the myocardial perfusion parameters: peak signal intensity (A value), rising slope of the curve (β value) and A×β value, and the differences of above parameters between the two groups were compared.According to whether the end-diastolic wall thickness ≥12 mm, the myocardial segments in the HCM group were divided into hypertrophic segments and non-hypertrophic segments. The differences in myocardial perfusion parameters were compared among control group segments, hypertrophic segments and non-hypertrophic segments of the HCM group. The correlations of stress myocardial blood flow with maximal left ventricular wall thickness (MLVWT), left ventricular mass index (LVMI) and left atrial volume index (LAVI) in the HCM group were analyzed.Results:Compared with the control group, the A value, β value and A×β value of whole myocardium, hypertrophic segments and non-hypertrophic segments in the HCM group were significantly decreased in the rest and adenosine stress state, and the differences were statistically significant (all P<0.05). In the stress state, the A value, β value and A×β value of the hypertrophic segments were significantly lower than those in the non-hypertrophic segments in the HCM group, and the detection rate of abnormal perfusion segments in the HCM group was significantly higher than that in the rest state(all P<0.05). Compared with the control group, the myocardial blood flow reserve of whole myocardium, hypertrophic segments and non-hypertrophic segments in the HCM group were significantly decreased, and the differences were statistically significant(all P<0.05). The stress myocardial blood flow in the HCM group was negatively correlated with MLVWT, LVMI and LAVI ( r=-0.815, -0.805, -0.742; all P<0.05). Conclusions:Myocardial blood perfusion abnormalities can occur in both hypertrophic and non-hypertrophic myocardial segments in patients with HCM, and adenosine stress MCE can significantly improve the sensitivity of detecting myocardial perfusion abnormalities. The stress myocardial blood flow in patients with HCM is negatively correlated with MLVWT, LVMI and LAVI.
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【Subjects】 To investigate the clinical application value of myocardial contrast echocardiography （MCE） in selecting CTO-PCI patients. MethodsFrom February 2019 to March 2020， a total of 50 patients with chronic coronary artery occlusion were consecutively selected as the research subjects. MCE and two-dimensional speck-tracking echocardiography were completed before and 12 months after interventional therapy. The primary end point was major adverse cardiovascular events. Patients were divided into groups according to the preoperative myocardial perfusion level of MCE. The improvement of left ventricular function was evaluated by two-dimensional echocardiography and left ventricular global longitudinal strain. ResultsCompared with the abnormal perfusion group， the improvement of GLS in the normal perfusion group was greater （P=0.028）. The wall motion score index （WMSI） of the abnormal perfusion group before PCI was higher than that of the normal perfusion group （P=0.002）. WMSI in the abnormal perfusion group was higher than that in the normal perfusion group one year after PCI （P<0.001）. The left ventricular GLS（P=0.008）.WMSI（P=0.016） and left ventricular end-diastolic volume（P=0.032） in the normal perfusion group were improved compared with those before operation； The postoperative perfusion score of patients with abnormal perfusion was significantly improved （ P=0.032）. ConclusionMCE has clinical application value in optimizing the selection of CTO-PCI patients. CTO patients with different myocardial perfusion types have different benefits after PCI.
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Objective:To quantitatively evaluate myocardial microcirculation perfusion changes after percutaneous intracardiac septal radiofrequency ablation (PIMSRA, Liwen procedure) in patients with obstructive hypertrophic cardiomyopathy (HOCM) using myocardial contrast echocardiography (MCE) and to further establish the effect of the procedure and predict the long-term prognosis of patients.Methods:A total of 45 patients with HOCM treated by the Liwen procedure in the First Affiliated Hospital of Air Force Medical University (Xijing Hospital) from July 2019 to June 2020 were included. MCE was performed before and 6 months after surgery, respectively. Time-intensity perfusion curve analysis was performed using QLab 10.8 offline software to obtain quantitative parameters of myocardial microcirculation perfusion including myocardial blood volume (A value), myocardial blood flow velocity (β value), and myocardial blood flow (A×β value), then the changes in parameters before and after the procedure were compared.Results:After the Liwen procedure, the mean septal thickness and mean left ventricular free wall thickness were significantly reduced, accompanied by a significant reduction in the left ventricular outflow tract pressure gradient (LVOT-PG) and mitral regurgitation length, and a significant improvement in mitral systolic antegrade motion (SAM) (all P<0.001). In addition, the left ventricular ejection fraction (LVEF) did not deteriorate significantly ( P=0.560) and the E/e′ ratio decreased after the procedure ( P=0.015). Besides, the A values of both the ventricular septum and the left ventricular free wall were not significantly changed compared to those before procedure ( P>0.05), whereas the β values and A×β values were obviously increased ( P<0.05). Conclusions:Myocardial blood velocity and myocardial blood flow in the septum and left ventricular free wall were significantly increased in patients with HOCM after the Liwen procedure, suggesting a significant improvement in myocardial microcirculation perfusion. MCE provides a non-invasive quantitative evaluation parameters of myocardial microcirculation perfusion for the Liwen procedure for the treatment of HOCM.
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OBJECTIVES@#The high prevalence and high fatality rate of coronary heart disease seriously endanger the safety of human life. The key to its treatment is to restore the perfusion of the narrowed coronary arteries as soon as possible. Two-dimensional echocardiography is limited for assessment of postoperative myocardial function. Myocardial contrast echocardiography (MCE) and 2-dimensional speckle tracking imaging (2D-STI) possess good value in assessing myocardial perfusion and systolic function. We used MCE and 2D-STI to explore the changes of myocardial perfusion and systolic function after percutaneous coronary intervention (PCI) in patients with coronary heart disease, and to evaluate the clinical value of MCE and 2D-STI.@*METHODS@#Twenty patients with coronary heart disease undergoing PCI were selected. MCE was performed before and one day after PCI, and 2D-STI and conventional ultrasound were performed before and a month after PCI. The recovery of left ventricular wall motion was used as a standard to evaluate the ability of MCE semi-quantitative analysis and to predict the recovery of myocardial segment motion.@*RESULTS@#The quantitative value of MCE (signal intensity of contrast medium in plateau phase, slope of curve, and their product) one day after PCI and the contractile function of one month after PCI were significantly improved (all @*CONCLUSIONS@#MCE and 2D-STI can evaluate the improvement of myocardial perfusion and systolic function in patients with coronary heart disease after PCI, and MCE semi-quantitative analysis can effectively predict the ability of ventricular wall recovery.
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Humans , Contrast Media , Coronary Circulation , Coronary Disease/diagnostic imaging , Echocardiography , Myocardial Infarction , Percutaneous Coronary Intervention , Perfusion , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
Background: No reflow phenomenon observed during catheter intervention has been associated with poor cardiovascular outcomes. Assessment of filling defect by myocardial contrast echocardiography (MCE) correlates with no reflow. Limited studies are available for the same. This study was designed to look for impact of type of therapy for revascularization (whether percutaneous coronary intervention or thrombolysis) and its evaluation by MCE and follow up echocardiography parameters.Methods: Total 50 consecutive patients of ST-elevation myocardial infarction (STEMI) were taken study including recent STEMI (within 7 days). After all routine investigations patient underwent coronary angiography and percutaneous coronary intervention (PCI) procedure. Following completion of procedure, thrombolysis in myocardial infarction (TIMI) flow, TIMI frame count, and myocardial blush grade were calculated and noted. Post revascularization contrast echocardiography was done after patient stabilization. Findings were correlated with cath-lab parameters applying appropriate statistical tests. Follow up was planned after 30 days.Results: 50 consecutive patients admitted with acute myocardial infarction (MI) or recent MI (0-7 day) who underwent primary PCI - 82% (n=41) or thrombolysed with various thrombolytic agents - 18% (n=9). Mean age of the study group was 55.02±12.65 years. There was significant association in between TIMI 3 flow and absence of filling defect in MCE (p=0.03), but no significant association found in between revascularization therapy (Either PCI or Thrombolysis) and filling defect in MCE (p=0.08).Conclusions: Our study found good correlation between myocardial contrast score with angiographically measured TIMI flow and improved echocardiographic findings on follow up.
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OBJECTIVES@#To study myocardial perfusion and systolic function in patients with different coronary artery stenosis by myocardial contrast echocardiography (MCE) and two-dimensional speckle tracking imaging (2D-STI).@*METHODS@#MCE, 2D-STI and coronary angiography were conducted in patients with coronary heart disease in our hospital. Myocardial segments were divided into 4 groups according to the degree of coronary artery stenosis: group A (normal group), group B (mild stenosis, 50%-75%), group C (moderate stenosis, 76%-90%) and group D (severe stenosis, 91%-100%). Blood volume, blood flow velocity, blood flow and longitudinal myocardial strain value (SL) in each group were measured by analysis software for MCE and 2D-STI. The differences in blood volume, blood flow velocity, blood flow and SL were evaluated.@*RESULTS@#The blood flow velocity and blood flow in B, C and D groups were decreased gradually, with significant difference (0.05). There were significant differences in SL among the 4 groups (<0.05).@*CONCLUSIONS@#There is a good correlation between coronary stenosis degree and myocardial perfusion or systolic function. The ability of 2D-STI to detect mild stenosis of coronary artery is better than MCE.
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Humans , Coronary Circulation , Coronary Stenosis , Echocardiography , Myocardium , SystoleABSTRACT
Objective To explore the application value of IL-8 monoclonal antibody microbubble combined with ultrsound targeted microbubble destruction ( UTMD) on alleviating myocardial ischemia reperfusion/injury ( MIRI) in rabbits .Methods Forty-two rabbits were randomly divided into closed chest group ( n =7) ,open chest control group ( n = 7) and ischemia-reperfusion ( I/R) group ( n = 28) .I/R group were randomly divided into 30 min reperfusion group( n =7) ,60 min reperfusion group( n =7) ,120 min reperfusion group ( n = 7 ) and 180 min reperfusion group ( n = 7 ) .All rabbits were examined by electrocardiogram , echocardiography and HE staining after MIRI . Targeted myocardial contrast echocardiography ( MCE) was performed and ELISA was used to detect IL-8 content in rabbit myocardium before and after UTMD . Results Electrocardiogram and wall motion returned to normal at 60 min after reperfusion .Targeted MCE showed that with the prolongation of reperfusion after I/R ,the video intensity of myocardium in reperfusion area increased gradually , reaching its peak at 120 min and 180 min after reperfusion .After UTMD ,the video intensity decreased ,and the change rate of video intensity in 30 min reperfusion group was higher than those in other reperfusion groups(all P<0 .05) .The content of IL-8 and its neutralization rate in the ELISA results were consistent with the video intensity and rate of change of targeted MCE .HE staining and scanning electron microscopy showed that myocardial injury was found in I/R group .With the prolongation of reperfusion time ,the degree of myocardial injury was gradually aggravated ,and the injury was alleviated after irradiation .Conclusions IL-8 monoclonal antibody combined with UTMD has the advantages of non-invasive and highly effective in alleviating MIRI .It provides a new way to treat MIRI .
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PURPOSE: Coronary flow reserve (CFR) is recognized as an indicator of myocardial perfusion. The aim of this study was to assess the relationship between CFR in the non-infarcted myocardium and the incidence of major adverse cardiac events (MACEs). MATERIALS AND METHODS: 100 consecutive patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) were enrolled in the present study, and divided into MACE and non-MACE groups according to the incidence of 12-month MACEs. Left ventricular function and CFR were analyzed using two-dimensional echocardiography and myocardial contrast echocardiography at one week after PCI. Cardiac troponin I levels were assayed to estimate peak concentrations thereof. RESULTS: The MACE group was associated with lower CFR, compared to the non-MACE group (2.41 vs. 2.77, p < 0.001). In the multivariable model, CFR in the non-infarcted myocardium was an independent predictor of 12-month MACE (hazard ratio: 0.093, 95% confidence interval: 0.020–0.426, p=0.002) after adjustment for baseline demographic and clinical characteristics. CONCLUSION: CFR in the non-infarcted myocardium is a useful marker for predicting 12-month MACEs in patients with AMI undergoing primary PCI.
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Aged , Female , Humans , Male , Middle Aged , Coronary Circulation/physiology , Echocardiography , Fractional Flow Reserve, Myocardial , Myocardial Infarction/diagnostic imaging , Myocardial Perfusion Imaging , Myocardium/pathology , Percutaneous Coronary Intervention , Proportional Hazards Models , Treatment Outcome , Ventricular Function, Left/physiologyABSTRACT
Objective To evaluate the accuracy and value of automatically assessing left ventricular systolic function in rats with myocardial infarction ( MI) by myocardial contrast echocardiography ( MCE) based on neutrosophic similarity score( NSS) algorithm. Methods According to different infarction size (IS),SD rats were divided into large MI (MI-L,IS≥15% ) and small MI (MI-S,IS＜15% ) groups. MCE was performed before MI and at 7,28 days after MI. In vitro study:the automatic segmentation of the endocardial contour based on neutrosophic similarity score algorithm was compared with the manual segmentation boundary. In vivo study:the left ventricular ejection fraction( LVEF) were calculated using the NSS system,biplane Simpson and PV-loop,respectively,and then NSS-LVEF,Simpson-LVEF and PV-LVEF were acquired,respectively. The IS was calculated by Masson and HE staining. The consistency between the two LVEFs was evaluated by Bland-Altman. The intraclass correlation coefficient ( ICC) was calculated to evaluate the reproducibility of MCE analysis system. Results ① The endocardial contour obtained by automatic segmentation had good agreement with the boundary of artificial tracing. ② There was no significant difference among the three LVEFs in same group ( F ＝0.028, P ＝ 0.973),but there was significant difference in different group ( F ＝78.61, P ＜0.01). NSS-LVEF was well consistent with both Simpson-LVEF and PV-LVEF. ③ The ICC of NSS algorithm for inter-observer and intra-observer were 0.96 and 0.98,respectively. ④Compared with before MI and at 7 days after MI,the LVEF in MI-L and MI-S groups at 28 days after MI decreased significantly ( P ＜0.05),especially in MI-L group ( P ＜0.01). There was significantly negative correlation between LVEF and IS ( r ＝ －0.917, P ＜ 0.01). Conclusions Left ventricular endocardium can be identificated automatically and LVEF can be calculated rapidly and accurately by MCE based on neutrosophic similarity score algorithm in rats with myocardial infarction.
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Aim To explore the effect of Shuanglong formula(SLF) on no-reflow in rats with myocardial is-chemia/reperfusion (I/R). Methods The rats were divided into five groups, namely, sham group, I/R group,SLF(5,2.5,1.25 g·kg-1)group. Treatment group received SLF decoction by gavage once a day for five days,while other groups were offered drinking wa-ter by gavage once a day for five days. The rats in I/R group and SLF-pretreated group were induced by iga-tion of left anterior descending coronary artery,and the rats were subjected to ischemia for 4h followed by reperfusion. Sham operation group did not undergo oc-clusion of the coronary artery. After 4 hours' reperfu-sion, real-time myocardial contrast echocardiography was used to monitor regional blood perfusion and cardi-ac functions. Blood was collected from the abdominal aorta and the serum was separated, and the levels of cTnT, CRP, CK and LDH were measured. The myo-cardial no-reflow area and infarction area were assessed by thioflavin S and nitrotetrazolium blue chloride, re-spectively. Results The SLF-pretreated group exhibi-ted significant reductions in the infarct area and no-re-flow area compared with I/R group(P <0.01 or P <0.05). In SLF-pretreated groups, β, A and A·β significantly increased as compared to those in I/R group. The LV anterior wall systolic and diastolic thicknesses (LVAW d/s) were significantly improved in SLF-pretreated group compared with those in I/R group. The LV internal diameter in systole (LVID s) and the LV volume in systole(LV s) were significantly reduced in SLF-pretreated group compared with those in I/R group. The EF, FS and SV were significantly improved in SLF-pretreated group compared with those in I/R group. The comparison between SLF-pretreated group and I/R group showed no significant difference in LDH, CK, cTnT, and CRP levels. Conclusion Shuanglong formula minimizes the sizes of myocardial infarct area and no-reflow area,improving regional my-ocardial blood flow and cardiac function.
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Objective: To test the feasibility of drag-reducing polymers (DRP) for improving coronary microcirculation in a canine model in order to provide the experimental basis for treating myocardial microcirculation dysfunction. Methods: A total of 8 dogs received open-chest surgery and they had intravenous injections, in turn, with adenosine (ADN), DRP 250 mg/L and DRP+ADN. The function y=A × (1-e-βt) was used to calculate the myocardium capillary volume (A value), capillary velocity (β value) and myocardial blood lfow (A ? β value) by myocardial contrast echocardiography. Results: With DRP infusion, the A value in experimental canine was similar to the baseline condition,P>0.05; while theβ value and A ? β value were signiifcantly increased as (0.57 ± 0.10) 1/s vs (0.23 ± 0.03) 1/s,P0.05. Conclusion: DRP improved coronary microcirculation primarily by modulating the β value in experimental canine model, and hopefully, this unique hemodynamics could provide a new approach for treating myocardial microcirculation dysfunction.
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Contrast echocardiography is broadly described as a variety of techniques whereby the blood pool on cardiac ultrasound is enhanced with encapsulated gas-filled microbubbles or other acoustically active nano- or microparticles. The development of this technology has occurred primarily in response to the need improve current diagnostic applications of echocardiography such as the need to better define left ventricular cavity volumes, regional wall motion, or the presence or absence of masses and thrombi. A secondary reason for the development of contrast echocardiography has been to expand the capabilities of echocardiography. These new applications include myocardial perfusion imaging for detection of ischemia and viability, perfusion imaging of masses/tumors, and molecular imaging. The ability to fill all of these current and future clinical roles has been predicated on the ability to produce robust contrast signal which, in turn, has relied on technical innovation with regards to the microbubble contrast agents and the ultrasound imaging paradigms. In this review, we will discuss the basics of contrast echocardiography including the composition of microbubble contrast agents, the unique imaging methods used to optimize contrast signal-to-noise ratio, and the clinical applications of contrast echocardiography that have made a clinical impact.
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Contrast Media , Echocardiography , Ischemia , Microbubbles , Molecular Imaging , Myocardial Perfusion Imaging , Perfusion Imaging , Signal-To-Noise Ratio , UltrasonographyABSTRACT
Objective Analysis of myocardial microvascular perfusion in patients with chronic total coronary occlusion (CTO) who underwent a coronary artery bypass graft (CABG) use real-time myocardial contrast echocardiography (RTMCE),to provide an effective method of detecting viable myocardium and a reference for the choice of CABG indications.Methods Twenty-seven patients with CTO underwent RTMCE 1 week before CABG,they underwent follow-up echocardiography and coronary artery 256-slice multislice computed tomography aagiography 1 year after CABG.Myocardial viability was defined as a postoperative ultrasound wall motion significantly improved ≥ 1 point.Semi-quantitative analysis of contrast images,myocardial viability was defined as myocardial perfusion score ≤ 2 points.Viable myocardium by quantitative assessment of myocardial blood flow (MBF) was determined by analyses of receiver-operating characteristic (ROC) curves.Results Patients with LVEF increased significantly after CABG (P ＜ 0.01),Of 259 segments with wall motion abnormality,149 (58％) showed wall motion significantly improved ≥ 1 point after CABG,considered viable myocardium,110 (42％) were not observed in wall motion improved,considered to be non-viable.The viable myocardial segments were significantly greater than non-viable myocardial segments in A,β,A × β value (P ＜ 0.01).Compared with the semi-quantitative analysis,quantitative analysis of MBF increased the sensitivity and accuracy of RTMCE for detecting viable myocardium (P ＜ 0.05).Conclusion RTMCE could accurately assess myocardial viability and provide a strong reference for clinical decision making and judging prognosis.
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BACKGROUND: It remains unclear whether myocardial contrast echocardiography (MCE) is as accurate as myocardial perfusion imaging with technetium-99m sestamibi (MPI) for the diagnosis of acute coronary syndrome (ACS). We sought to directly compare the diagnostic accuracy of MCE with resting MPI in a head-to-head fashion. METHODS: We prospectively enrolled 98 consecutive patients (mean age; 59+/-9 years, 68 males) who presented to the emergency department with chest pain suggestive of acute myocardial ischemia. Early MCE was performed by using continuous infusion of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) during intermittent power Doppler harmonic imaging. Myocardial perfusion defects observed in at least one coronary territory were considered positive. Sestamibi was injected immediately after MCE and MPI was obtained within 6 hours of tracer injection. RESULTS: ACS was confirmed in 67 patients. There were 32 patients with acute myocardial infarction (AMI) and 35 patients with unstable angina requiring urgent revascularization. The sensitivities of MCE and MPI for the diagnosis of ACS were 72% and 61%, respectively, which were significantly higher than those of ST segment change (24%, p<0.001 vs. MCE and vs. MPI) and troponin I (27%, p<0.001 vs. MCE and vs. MPI), with similar specificities of 90% to 100%. On a receiveroperating characteristics curve demonstrating diagnostic accuracy for ACS, the area under the curve of MCE was significantly larger than that of MPI (0.86 vs. 0.77, respectively; p=0.019). CONCLUSION: MCE and MPI overcome the low sensitivity of routine triage tests for detecting ACS, and MCE is more accurate than MPI for the diagnosis of ACS in the emergency department.
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Humans , Acute Coronary Syndrome , Angina, Unstable , Chest Pain , Early Diagnosis , Echocardiography , Emergencies , Glucose , Myocardial Infarction , Myocardial Ischemia , Myocardial Perfusion Imaging , Perfusion , Prospective Studies , Triage , Troponin IABSTRACT
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 echo-cardiography (RT-MCE) combined with two-dimensional strain echocardiography was assessed.Twenty patients underwent intravenous RT-MCE by intravenous injections of Sono Vue 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 af-ter 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 con-cluded 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 re-gional systolic function. The combination of myocardial perfusion with two-dimensional strain echocar-diography can more accurately assess the curative effectiveness of coronary artery bypass surgery.
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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 Sono Vue 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 refilling 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 images were obtained. The best intravenous infusion rate for Sono Vue was 30 mL/h. The contrast appeared in fight 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.
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Objective To evaluate the relationship between myocardial perfusion and diastolic function with velocity vector imaging (VVI) combined with myocardial contrast echocardiography (MCE) in dog models of coronary artery stenosis at rest and stress. Methods Different stenoses in anterior descending branch were made in 8 dogs. Before and after coronary artery stenosis, VVI evaluation was made on short axis image, then MCE were performed in the left ventricular mastoid muscle section at rest and in the peak dose of dobutamine. The myocardial blood flow A·β value and peak diastolic strain rate (SR_(dia)) on the direction of the circumference of the short view were measured, and the relationship between them was analyzed. Results At rest, no significant difference of A·β value nor SR_(dia) was found between the stenotic bed and normal bed when coronary stenosis was mild or moderate. However, A·β value and SR_(dia) of the stenotic bed were smaller than those in the normal bed when coronary stenosis was severe (P<0.05). At dobutamine stress, A·β value and SR_(dia) of the stenotic bed were already less than those in the normal bed when coronary stenosis was mild or moderate. A·β values and SR_(dia) of the stenotic bed decreased further compared to the normal bed (P<0.05) when coronary artery was severe. At both rest and stress, the standard A·β value was strongly correlated with SR_(dia) (r_(rest)=0.57,r_(stress)=0.72,P<0.01). Conclusion VVI can not only evaluate the diastolic function of myocardial segments on the short axis view, but also reflect changes of myocardial perfusion to a certain extent.
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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=1; 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≤1.5 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 (△LVEF, △LVESV and △LVEDV) between two groups; (4) The linear regression analysis between △LVEF, △LVESV, △LVEDV 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 ΔLVEF and ΔLVEDV between patients with MPSI>1.5 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 △LVEF and a positive correlation with ΔLVESV, ΔLVEDV (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.
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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.