Impact of single chamber and dual chamber permanent pacemaker implantation on left ventricular function:An observational study

BACKGROUND Permanent pacemaker implantation has the potential to impact left ventricular(LV)function and hence quality of life(QoL)in the long term.AIM To assess the effect of single-and dual-chamber pacing on LV function and QoL.METHODS This study included 56 patients who underwent permanent pacing:Dual pacing,dual sensing,dual responsive and rate responsive(DDDR)for the initial 3 months,ventricular sensing,inhibited response and rate responsive(VVIR)for the next 3 months,and DDDR mode for the last 3 months.Throughout the study period,various echocardiographic parameters,functional status,and QoL were measured to assess the impact of pacing on LV function compared with baseline and at every 3 months interval.RESULTS A significant change appeared in cardiac function after VVIR pacing which was in diastolic properties of LV as shown by increase in isovolumic relaxation time from(85.28±9.54 ms)to(89.53±9.65 ms).At the 3-,6-,and 9-month follow-up,reduction in LV ejection fraction was observed to be 62.71±4.66%,61.07±4.41%,and 58.48±3.89%,respectively.An increase in the QoL scores was noted at every follow-up visit.CONCLUSION An apparent depressant effect on LV function due to right ventricular pacing,with a higher incidence of adverse outcomes in the VVIR mode.In addition,an upsurge in QoL scores for the study population was noted,which indicates improvement in the QoL of patients post-pacing,irrespective of the mode.Generally,the DDDR mode is a highly preferable pacing mode.

Application of three-dimensional speckle tracking technique in measuring left ventricular myocardial function in patients with diabetes

BACKGROUND Diabetic cardiomyopathy is considered as a chronic complication of diabetes mellitus(DM).Therefore,early detection of left ventricular systolic function(LVSF)damage in DM is essential.AIM To explore the use of the three-dimensional speckle tracking technique(3D-STI)for measuring LVSF in DM patients via meta-analysis.METHODS The electronic databases were retrieved from the initial accessible time to 29 April 2023.The current study involved 9 studies,including 970 subjects.We carried out this meta-analysis to estimate myocardial function in DM compared with controls according to myocardial strain attained by 3D-STI.RESULTS Night articles including 970 subjects were included.No significant difference was detected in the left ventricular ejection fraction between the control and the diabetic group(P>0.05),while differences in global longitudinal strain,global circumferential strain,global radial strain,and global area strain were markedly different between the controls and DM patients(all P<0.05).CONCLUSION The 3D-STI could be applied to accurately measure early LVSF damage in patients with DM.

Deep learning echocardiographic intelligent model for evaluation on left ventricular regional wall motion abnormality

Objective To observe the value of deep learning echocardiographic intelligent model for evaluation on left ventricular(LV)regional wall motion abnormalities(RWMA).Methods Apical two-chamber,three-chamber and four-chamber views two-dimensional echocardiograms were obtained prospectively in 205 patients with coronary heart disease.The model for evaluating LV regional contractile function was constructed using a five-fold cross-validation method to automatically identify the presence of RWMA or not,and the performance of this model was assessed taken manual interpretation of RWMA as standards.Results Among 205 patients,RWMA was detected in totally 650 segments in 83 cases.LV myocardial segmentation model demonstrated good efficacy for delineation of LV myocardium.The average Dice similarity coefficient for LV myocardial segmentation results in the apical two-chamber,three-chamber and four-chamber views was 0.85,0.82 and 0.88,respectively.LV myocardial segmentation model accurately segmented LV myocardium in apical two-chamber,three-chamber and four-chamber views.The mean area under the curve(AUC)of RWMA identification model was 0.843±0.071,with sensitivity of(64.19±14.85)%,specificity of(89.44±7.31)%and accuracy of(85.22±4.37)%.Conclusion Deep learning echocardiographic intelligent model could be used to automatically evaluate LV regional contractile function,hence rapidly and accurately identifying RWMA.

Individualized anti-thrombotic therapy for acute myocardial infarction complicated with left ventricular thrombus: A case report

BACKGROUND Presently,there is no established standard anti-blood clot therapy for patients facing acute myocardial infarction(AMI)complicated by left ventricular thrombus(LVT).While vitamin K antagonists are the preferred choice for oral blood thinning,determining the best course of blood-thinning medication remains challenging.It is unclear if non-vitamin K antagonist oral blood thinners have different effectiveness in treating LVT.This study significantly contributes to the medical community.CASE SUMMARY The blood-thinning treatment of a patient with AMI and LVT was analyzed.Triple blood-thinning therapy included daily enteric-coated aspirin tablets at 0.1 g,daily clopidogrel hydrogen sulfate at 75 mg,and dabigatran etexilate at 110 mg twice daily.After 15 d,the patient’s LVT did not decrease but instead increased.Clinical pharmacists comprehensively analyzed the cases from the perspective of the patient’s disease status and drug interaction.The drug regimen was reformulated for the patient,replacing dabigatran etexilate with warfarin,and was administered for six months.The clinical pharmacist provided the patient with professional and standardized pharmaceutical services.The patient’s condition was discharged after meeting the international normalized ratio value(2-3)criteria.The patient fully complied with the follow-up,and the time in the therapeutic range was 78.57%,with no serious adverse effects during pharmaceutical monitoring.CONCLUSION Warfarin proves to be an effective drug for patients with AMI complicated by LVT,and its blood-thinning course lasts for six months.

Off-Pump Coronary Artery Bypass Grafting in Patients with Left Ventricular Dysfunction: Short-Term Results from a Single Center in Bangladesh

Background: Off-pump coronary artery bypass grafting (OPCAB) is considered a safer alternative to on-pump surgery, especially in patients with left ventricular dysfunction (LVD). Objectives: This study assessed short-term outcomes and functional improvements in LVD patients post-OPCAB. Methods: The study included 200 coronary artery disease patients who underwent isolated off-pump coronary artery bypass grafting (OPCAB) at the National Heart Foundation Hospital and Research Institute between January 2019 and June 2020. Patients were categorized into Group 1, with a left ventricular ejection fraction (LVEF) of 30% - 39%, and Group 2, with an LVEF of 40% or higher. Echocardiographic assessments of left ventricular dimensions and ejection fraction were performed preoperatively, at discharge, and one month postoperatively. Results: In Group 1, preoperative left ventricular internal dimensions during diastole (LVIDd) and systole (LVIDs) were 53.48 ± 4.40 mm and 44.23 ± 3.93 mm, respectively, with a left ventricular ejection fraction (LVEF) of 35.28% ± 2.26%. At discharge, these values improved to 51.58 ± 4.04 mm (LVIDd), 41.23 ± 5.30 mm (LVIDs), and 39.25% ± 3.75% (LVEF). One month postoperatively, further improvements were observed: 46.29 ± 3.76 mm (LVIDd), 37.45 ± 3.68 mm (LVIDs), and 43.22% ± 4.67% (LVEF). Group 2 showed similar positive outcomes, with preoperative values of 47.09 ± 5.06 mm (LVIDd), 35.11 ± 5.25 mm (LVIDs), and 50.13% ± 7.25% (LVEF), improving to 42.37 ± 4.18 mm (LVIDd), 31.05 ± 4.19 mm (LVIDs), and 55.33% ± 7.05% (LVEF) at one month postoperatively. Both groups demonstrated significant improvements in left ventricular function and NYHA class, with most patients moving from class III/IV to I/II. Complications were minimal, and no mortality was observed. Conclusion: OPCAB is safe and effective for patients with LVEF 30% - 39% and LVEF ≥ 40%, providing significant short-term functional improvements without increased risk.

Effect of PTCA and stenting on left ventricular diastolic function in patients with CHD

Objective The aim of this study was to determine the effect of successful coronary revascularisation on left ventricular diastolic function.Methods We consecutively studied the diastolic function by Doppler echocardiography in 125 patients with one vessel disease before and 48 hours after selective coronary angioplasty. The following parameters of left ventricular diastolic function were evaluated: peak early (VE, m/s) and peak late diastolic (VA, m/s) flow velocity, E/A ratio, acceleration time (AT, ms), deceleration time (DT, ms) and isovolumetric relaxation time (IVRT, ms). Ejection fraction (EF; %) was determined and used to characterise systolic left ventricular function. Results All of the patients were initially successful treated with coronary angioplasty (residual stenosis <40% ). In 98 patients( 78.4% ) stents were used to improve an inadequate result after coronary angioplasty. Both patient groups (27 patients with coronary angioplasty and 98 patients with combined coronary angioplasty and stent implantation) showed no relevant differences concerning sex, age, atherosclerotic risk factors, exercise capacity and results of exercise electrocardiography. All patients who underwent stent implantation showed an early improvement of left ventricular diastolic function 48 hours after revascularisation. Surprisingly there was no significant short term improvement (48 hours) of diastolic function in patients with initially successful angioplasty.Conclusions We suppose that stent implantation might normalize coronary blood flow faster than that of coronary balloon angioplasty.

Diagnosis and treatment of heart failure with preserved left ventricular ejection fraction

Nearly six million people in United States have heart failure.Fifty percent of these people have normal left ventricular(LV)systolic heart function but abnormal diastolic function due to increased LV myocardial stiffness.Most commonly,these patients are elderly women with hypertension,ischemic heart disease,atrial fibrillation,obesity,diabetes mellitus,renal disease,or obstructive lung disease.The annual mortality rate of these patients is 8%-12%per year.The diagnosis is based on the history,physical examination,laboratory data,echocardiography,and,when necessary,by cardiac catheterization.Patients with obesity,hypertension,atrial fibrillation,and volume overload require weight reduction,an exercise program,aggressive control of blood pressure and heart rate,and diuretics.Miniature devices inserted into patients for pulmonary artery pressure monitoring provide early warning of increased pulmonary pressure and congestion.If significant coronary heart disease is present,coronary revascularization should be considered.

Mitochondria and left ventricular hypertrophy

Introduction Left ventricular hypertrophy (LVH) is one of the vicious organ damages of essential hypertension.It contributes a lot to high mortality of essential hypertension due to sudden cardiac death,ventricular arrhythmia and heart failure.Many factors involve in the pathogenesis of hypertension-induced LVH including inherited variants as well as environmental factors.……

Hypoxia training attenuates left ventricular remodeling in rabbit with myocardial infarction

Objective Previous studies showed that hypoxia preconditioning could protect cardiac function against subsequent myo-cardial infarction injury. However, the effect of hypoxia on left ventricular after myocardial infarction is still unclear. This study therefore aims to investigate the effects of hypoxia training on left ventricular remodeling in rabbits post myocardial infarction. Methods Adult male rabbits were randomly divided into three groups： group SO （sham operated）, group MI （myocardial infarc-tion only） and group MI-HT （myocardial infarction plus hypoxia training）. Myocardial infarction was induced by left ventricular branch ligation. Hypoxia training was performed in a hypobaric chamber （having equivalent condition at an altitude of 4000 m, FiO214.9%） for 1 h/day, 5 days/week for four weeks. At the endpoints, vascular endothelial growth factor （VEGF） in the plasma was measured. Infarct size and capillary density were detected by histology. Left ventricular remodeling and function were as-sessed by echocardiography.Results After the 4-week experiment, compared with the group SO, plasma VEGF levels in groups MI （130.27 ± 18.58 pg/mL,P〈 0.01） and MI-HT （181.93 ± 20.29 pg/mL,P〈 0.01） were significantly increased. Infarct size in Group MI-HT （29.67% ± 7.73%） was deceased remarkably, while its capillary density （816.0 ± 122.2/mm2） was significantly increased. For both groups MI and MI-HT, left ventricular end-diastolic and end-systolic dimensions were increased whereas left ventricular ejection fraction was decreased. However, compared with group MI, group MI-HT diminished left ventricular end-diastolic （15.86 ± 1.09 mm,P〈 0.05） and end-systolic dimensions （12.10 ± 1.20 mm,P〈 0.01） significantly and im-proved left ventricular ejection fraction （54.39 ± 12.74 mm,P〈 0.05）.ConclusionHypoxia training may improve left ven-tricular function and reduce remodeling via angiogenesis in rabbits with MI.

Heart failure with reduced,mildly reduced,or preserved left ventricular ejection fraction:Has reasoning been lost?

Left ventricular(LV)ejection fraction(LVEF),defined as LV stroke volume divided by end-diastolic volume,has been systematically used for the diagnosis,classification,and management of heart failure(HF)over the last three decades.HF is classified as HF with reduced LVEF,HF with midrange or mildly reduced LVEF,and HF with preserved LVEF using arbitrary,continuously changing LVEF cutoffs.A prerequisite for using this LVEF-based terminology is knowledge of the LVEF normal range,which is lacking and may lead to erroneous conclusions in HF,especially at the higher end of the LVEF spectrum.

Isolated left ventricular apical hypoplasia:Systematic review and analysis of the 37 cases reported so far

BACKGROUND Isolated left ventricular apical hypoplasia(ILVAH),also known as truncated left ventricle(LV),is a very unusual cardiomyopathy.It is characterised by a truncated,spherical,and non-apex forming LV.The true apex is occupied by the right ventricle.Due to the rarity of the disease,just a few case reports and limited case series have been published in the field.AIM To analysing the so far 37 reported ILVAH cases worldwide.METHODS The electronic databases PubMed and Scopus were investigated from their establishment up to December 13,2022.RESULTS The majority of cases reported occurred in males(52.7%).Mean age at diagnosis was 26.1±19.6 years.More than a third of the patients were asymptomatic(35.1%).The most usual clinical presentation was breathlessness(40.5%).The most commonly detected electrocardiogram changes were T wave abnormalities(29.7%)and right axis deviation with poor R wave progression(24.3%).Atrial fibrillation/flutter was detected in 24.3%.Echocardiography was performed in 97.3%of cases and cardiac MRI in 91.9%of cases.Ejection fraction was reduced in more than a half of patients(56.7%).An associated congenital heart disease was found in 16.2%.Heart failure therapy was administered in 35.1%of patients.The outcome was favorable in the vast majority of patients,with just one death.CONCLUSION ILVAH is a multifaceted entity with a so far unpredictable course,ranging from benign until the elderly to sudden death during adolescence.

CLINICAL RESEARCH ON THE EFFECT OF ACUPUNCTURE ON THE LEFT VENTRICULAR CONTRACTION FUNCTION IN SYMPTOMLESS CARDIAC FAILURE PATIENTS

Objective: To observe the effect of acupuncture therapy on the function of myocardial contraction in symptomless cardiac failure patients.Methods: A total of 60 cases of symptomless cardiac insufficiency inpatients were randomly divided into medication and acupuncture groups, with 30 cases in each group. For patients of acupuncture group, Neiguan (PC 6), Ximen (PC 4), Tanzhong (CV 17), Xinshu (BL 15), Jueyinshu (BL 14) and Geshu (BL 17) were punctured, twice daily, with 30 days being a therapeutic course. In medication group, patients were asked to take Capoten 25 mg (t.i.d.). The left ventricular ejection fraction (LVEF) and its fractional shortening (FS) of the minor axis were used as the indexes for assessing the therapeutic effect and detected by using a color ultrasonic Doppler apparatus. Results: After one course of treatment, of the each 30 cases of acupuncture and medication groups, 13 (43.3%) and 16 (53.3%) had marked improvement, 16 (53.3%) and 14 (46.7%) had improvement, and 1 (3.3%) and 0 had no any effect respectively. No significant difference was found between two groups in the therapeutic effect. It shows acupuncture therapy can improve myocardial contraction function. Conclusion: Acupuncture has a similar effect in enhancing the systolic function of the myocardium.

Plasma Norepinephrine and Hemorheology in Essential Hypertensive Patients with Different Patterns of Left Ventricular Hypertrophy

对80例不同类型高血压左室肥厚（LVH）患者的血浆去甲肾上腺素（NE）和血液流变学改变进行观察。结果显示，（1）向心性肥厚组（CH）高切变率下全血粘度（WBV230）显著升高；（2）不对称性室间隔肥厚组（ASH）血浆NE和收缩末期室壁应力（ESS）增高较明显；（3）多元回归分析显示，SBP，ESS和血浆NE是影响相对室壁厚度的重要因素。提示CH是一种对压力负荷过重而产生的代偿形式；ASH的形成除了负荷因素外血浆NE可能起更重要的作用。

Anemia treatment and left ventricular hypertrophy in non-dialysis chronic kidney disease

To this day, the target hemoglobin level that minimizes cardiovascular risk in chronic kidney disease (CKD) patients remains unclear. When one examines the many randomized trials of epoetin therapy in aggregate, enhanced quality of life provides the most cogent argument for hemoglobin levels above 110 g/L. It remains unclear whether treatment of anemia improves longevity, or even a surrogate marker (such as left ventricular [LV] mass index), especially when applied at earlier phases of CKD.

Effects and mechanism of different adrenergic receptor antagonists on left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats

Objective: To study the changes of a collagen-binding protein (Colligin) and myosin heavy chain isoform (α/β-MHC) gene and protein in left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats and the effects of three kinds of adrenergic receptor blockers: Carvedilol (CAR) , Metoprolol (MET) and Terazosin (TER) on these changes, and to elucidate the effects and new mechanism of CAR on left ventricular hypertrophy regression. Methods: A model of hypertrophy induced by coarctation of abdominal aorta(CAA)was used in this study. Thirty two male wistar rats were divided randomly into four groups 4 weeks after CAA operation: CAA, CAR, MET and TER. Hemodynamics, ventricular remodeling parameters, expressions of Colligin and α/β-MHC mRNA, protein expressions of Collagen Ⅰ / Ⅲ and Colligin were investigated in the four groups and sham operation group. Results: Left ventricle hypertrophy was observed clearly 16 weeks after operation. The ratio of α/β-MHC mRNA decreased, while expressions of Collagen Ⅰ /Ⅲ proteins and Colligin mRNA/protein increased( P < 0.05). CAR could ameliorate left ventricle hypertrophy prior to MET and TER. CAR could also change the expressions of α/β-MHC, Collagen Ⅰ /Ⅲ and Colligin in both gene and protein levels ( P < 0.05), while MET and TER have no effect on them ( P > 0.05). Conclusion: The effects of CAR on extracellular matrix proteins and MHC isoform shift regression of left ventricle may be due to antiproliferative or antioxidative mechanism, which was independent of beta-adrenergic receptor antagonist.

Calculation of left ventricular diastolic time constant(Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra

OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance, twenty-four animal models(beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB(MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals,(t2–t1) and(t3–t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau(Tau-D)was resolved and compared with catheter-derived Tau(Tau-c).RESULTS There is no significant difference between Tau-D and Tau-c(45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively;P >0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship(r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.CONCLUSIONS This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.

Beneficial Effects of Delayed Opening the Infarct - related Artery on Late Phase Left Ventricular Function in Acute Anterior Myocardial Infarction

Objectives To assess the effect of delayed opening the infarct - related artery (IRA) by percutanous coronary intervention (PCI) on the late phase left ventricular function after acute ante- rior myocardial infarction. Methods 64 patients with initial Q - wave anterior myocardial infarction and the infarct - related arteries were total occluded conformed by angiogram at 2 to 14 days after onset were divided into successful PCI group and control group ( not re- ceiving PCI or the IRA not re - opened). 2 - DE was performed at early phase ( about 3 weeks) , 2 and 6 months after onset of AMI respectively to detect the left ventricular function and left ventricular wall motion ab- normality (VWMA). The total congestive heart failure events were recorded during 6 months follow-up. Re- sults VWMA scores, left ventricular ejection frac- tion (LVEF) , left ventricular end - diastolic and end - systolic volume indices ( LVEDVI and LVDSVI) were similar in 2 groups at early phase and 2 months. There were no differences between early phase and 2 months in each group too. VWMA scores and LVEF did not changed at 6 months in each group compared with the early phase and 2 months ( P > 0. 05 ). But LVEDVI and LVESVI were significantly smaller in the successful PCI group than in the control group (P < 0.01, P < 0. 05). The congestive heart failure events were taken place in 19% of patients in control group com- pared with 2% in successful PCI group ( P > 0. 05 ). Conclusions Although the infarct size does not changed, delayed opening the IRA has beneficial effect to the late phase left ventricular dilatation after acuteanterior myocardial infarction.

Viable Myocardium Impact on Left Ventricular Function after Late Revascularization of Infarct-related Artery in Acute Myocardial Infarction

Objectives The long-term benefit of late reperfusion of infarct-related artery （IRA） after acute myocardial infarction （AMI） is controversial, and the benefit mechanisms remain uncertain. Low dose dobutamine stress echocardiography （LDSE） can identify viable myocardium and predict improvement of wall motion after revascularization. Methods Sixtynine patients with first AMI who did not received early reperfusion therapy were studied by LDSE at 5 to 10 days after AMI. Wall motion abnormality and left ventricular size were measured at the same time. Successful PCI were done in all patients at 10 to 21 days after AMI onset. Patients were divided in two groups based on the presence or absence of viable myocardium. Echocardiography was repeated six months later. Results There were 157 motion abnormality segments. 89 segments （57%） were viable during LDSE. 26 patients （38%） with viability and 43 （62%） without. In viable group, left ventricular ejection fraction （LVEF） was increased （P 〈 0.05）, and left ventricular end systolic volume index （LVESVI） and wall motion score （WMS） were decreased （P 〈 0.05 and P 〈 0.01） significantly at 6 months compared with baseline. But in patients without viability, LVEF was decreased （P 〈 0.01）, and LVESVI and left ventricular end diastolic volume index （LVEDVI） were increased （P 〈 0.05） significantly after 6 months, and the WMS did not changed （P 〉 0.05 ）. LVEF increased （P 〈 0.05 ） and WMS decreased （P 〈 0.05） on LDSE during acute phase in patients with viability, but they were not changed in the nonviable group. Conclusions Late revascularization of IRA in patients with presence of viable myocardium after AMI is associated with long-term preservation left ventricular function and less ventricular remodeling. Improvement of left ventricular systolic function on LDSE indicates late phase recovery of left ventricular function after late revascularization.

Short term in vivo thrombosis evaluation of FW-Ⅱaxial blood pump for left ventricular assist

Objective To evaluate in vivo antithrombosis property of optimized FW-Ⅱaxial blood pump and provide evidence for future clinical use. Methods A left ventriclepump-descending aorta bypass model was established in five healthy sheep (60 70 kg) and the circulation ofthese sheep was assisted by FW-Ⅱaxial blood pump for 2 weeks. At preoperative and postoperative day 1,2,3,7。

Assessment of Regional Left Ventricular Myocardial Function in Rats after Acute Occlusion of Left Anterior Descending Artery by Two-dimensional Speckle Tracking Imaging

This study evaluated the change in regional left ventricular myocardial function in rats following acute occlusion of the left anterior descending coronary artery （LAD） by using two-dimensional speckle tracking imaging （2D-STI）. Sixty Wistar rats were randomly divided into two groups, a myocardial infarction （MI） group, in which 50 rats were subjected to LAD occlusion for 30–45 min, and a sham-operated （SHAM） group that contained 10 rats serving as control. Echo-cardiography was performed at baseline and 1, 4 and 8 week（s） after the operation. High frequency two-dimensional images of left ventricular short axis at papillary muscle level were recorded. Peak systolic radial strain （PRS） and circumferential strain （PCS） were measured in the mid-ventricle in short-axis view by using EchoPAC workstation. Left ventricular internal diameter at diastole （LVIDd） and systole （LVIDs）, fractional shortening （FS）, ejection fraction （EF） and left ventricular mass （LVM） were measured by anatomical M-model echocardiography. Infarct size was measured using triphenyl tetrazolium chloride （TTC） staining 1 week and 8 weeks after the operation. Fibrosis of left ventricu-lar myocardium was displayed using Van Gieson staining 1 week after the infarction. In terms of the TTC staining results, the left ventricle fell into three categories： infarcted, peri-infarcted and remote myocardial regions. Compared with those at baseline and in the SHAM group, （1） PRS and PCS in the infarcted, peri-infarcted and remote myocardial regions were significantly decreased in the MI group within 1 week after the operation （P〈0.05） and the low levels lasted 8 weeks; （2） Compared with those at baseline, LVIDd, LVIDs, FS, EF and LVM in the MI group showed no significant dif-ference 1 week after the operation （P〉0.05）. However, LVIDd, LVIDs and LVM were increased sig-nificantly 4 and 8 weeks after the operation （P〈0.05）, and FS and EF were decreased substantially （P〈0.05）. Van Gieson staining showed that fibrosis developed in all the three myocardial regions to varying degrees. It is concluded that 2D-STI is non-invasive and can be used to assess regional func-tion of myocardium with different blood supply in rats following acute occlusion of the LAD, and can be used as a sensitive and reliable means to follow up the process of left ventricular remodeling.