Left atrial conduit function for left ventricular filling dynamics in patients with myocardial infarction

This study observed the left atrial function in determining filling dynamics of the left ventricle in patients with myocardial infarction. The study consisted of eight control subjects and ten patients with myocardial infarction. The left ventricular filling volume is considered to be composed of the left atrial passive emptying, active emptying, and conduit volumes. The change of left ventricular filling volume was correlated with that of conduit volume (r = .87, P < .01). However, the change of left ventricular filling volume did not have any correlation to those of left atrial passive emptying and active emptying volumes. These results suggested that the left atrial conduit function was important in determining filling dynamics of the left ventricle.     

急性心肌梗死后的左心房功能与其近期预后的关系

目的探讨左心房功能与急性心肌梗死患者近期预后的关系。方法入选的急性心肌梗死患者184例,观察并发症的发生率和超声心动图下左心房功能各指标。结果预后不良患者左心房功能明显较预后良好者差。(P<0.05)。结论左心房功能是预测急性心肌梗死患者近期预后的较好的指标。     

实时三维超声心动图评价心肌梗死患者左心房功能

目的应用实时三维超声心动图技术评价心肌梗死患者左心房功能改变。方法分别对37例陈旧性心肌梗死患者和50名健康人进行二维超声心动图和三维超声心动图检查。测量左心房射血分数(LAEF)、左心室舒张末容积(LVEDV)、左心室收缩末容积(LVESV)、左心室射血分数(LVEF)、二尖瓣E/e'。采用成组t检验比较两组指标。结果与健康组比较,心肌梗死患者左心室容积、左心房内径、二尖瓣环内径、二尖瓣E/e'和LAEF[(11.5±5.6)kdyne比(4.8±2.7)kdyne]均明显增加(均为P<0.05)。结论实时三维超声心动图技术能够用以评价左心房功能。左心室功能减低的心肌梗死患者表现为左心房收缩功能代偿增强。     

Relation between paroxysmal atrial fibrillation and left ventricular diastolic function in patients with acute myocardial infarction.

The relation between left ventricular filling pattern and the occurrence of paroxysmal atrial fibrillation was evaluated using Doppler echocardiography in a prospective series of 157 patients with acute myocardial infarction. Paroxysmal atrial fibrillation after acute myocardial infarction was often associated with a higher restrictive filling pattern.     

Left atrial conduit function for left ventricular filling dynamics in patient with myocardial infarction

This study observed the left function in determining filling dynamics of the left ventricle in patients with myocardial infarction. The study consisted of eight control subjects and ten patients with myocardial infarction. The left ventricular filling volume is considered to be composed of the left atrial passive emptying, active emptying, and conduit volumes. The change of left ventricular filling volume was correlated with that of conduit volume (r = .87, P less than .01). However, the change of left ventricular filling volume did not have any correlation to those of left atrial passive emptying and active emptying volumes. These results suggested that the left atrial conduit function was important in determining filling dynamics of the left ventricle.     

Assessment of left ventricular function by Doppler tissue imaging in patients with atrial fibrillation following acute myocardial infarction

AIMS: We studied tissue Doppler parameters in patients with atrial fibrillation following acute myocardial infarction, and their relation to P wave durations and P dispersion. METHODS: Echocardiographic examination was performed in 84 consecutive patients with first anterior acute myocardial infarction. In addition to other conventional echocardiographic parameters, the peak systolic (Sm), early diastolic (Em) and late diastolic (Am) velocities were obtained at the lateral corner of the mitral annulus by pulsed wave tissue Doppler. The Em/Am ratio and the ratio of early diastolic mitral inflow velocity to Em (E/Em), which is a marker of diastolic filling pressure, were calculated. Electrocardiogram was recorded from all patients on admission; P wave measurements were also performed. RESULTS: Atrial fibrillation occurred in 20 (23.8%) of 84 patients. The patients with atrial fibrillation had significant reduction of Em (5.6+/-1.5 vs. 8.7+/-2.7 cm/s, p < 0.001), Em/Am (0.61+/-0.27 vs. 0.84+/-0.23, p = 0.001) and Sm (7.1+/-1.0 vs. 8.3+/-1.9 cm/s, p < 0.001) values compared with those without. The E/Em ratio (14.45+/-4.62 vs. 7.47+/-2.79, p < 0.001), P maximum (102+/-11 vs. 95+/-11 ms, p = 0.02) and P dispersion (35+/-7 vs. 26+/-7 ms, p < 0.001) were significantly higher in patients with atrial fibrillation than in those without. In all patients, P dispersion showed significant correlation with Em (r = -0.33, p = 0.002), Sm (r = -0.40, p < 0.001) and E/Em (r = 0.32, p = 0.003). When E/Em > or = 10 was used as cutpoint, atrial fibrillation could be predicted with a sensitivity of 90%, and a specificity of 84%. CONCLUSIONS: The patients with atrial fibrillation following acute myocardial infarction have reduced systolic and diastolic mitral annular velocities and increased E/Em ratio, P maximum and P dispersion values compared to those without. P dispersion is correlated with systolic and diastolic left ventricular function after acute myocardial infarction. The E/Em ratio appears to be a useful parameter for assessing the risk of atrial fibrillation occurrence after anterior acute myocardial infarction.     

Left atrial transport function in myocardial infarction. Importance of its booster pump function.

After myocardial infarction (MI), left ventricular (LV) end-diastolic pressure (EDP) is higher than mean pulmonary artery wedge pressure because of powerful atrial contraction. To evaluate the significane of atrial contraction to left ventricular function we studied 10 control (C) patients without cardiac disease and 17 patients from three to six weeks after acute myocardial infarction. Cardiac catheterization with simultaneous left ventricular diastolic pressure (DP) and left ventricular cineangiograms were obtained. Left ventricular volumes and pressure were (mean +/- SD): (SEE ARTICLE). Although left ventricular stroke volume was lower in the patients with myocardial infarction than in the control subjects (46 versus 56 ml/m2), atrial contraction contributed more to left ventricular filling during diastole (which is the same as left ventricular stroke volume) in the patients with myocardial infarction than in the controls (16 versus 10 ml/m2). The average atrial contribution to left ventricular end-diastolic volume was 11.9 per cent (C), 15.4 per cent (MI); to left ventricular end-diastolic pressure 20 per cent (C), 38.7 per cent (MI); and to left ventricular stroke volume 21.7 per cent (C), 35.1 per cent (MI). Atrial contribution to left ventricular stroke volume was 56 per cent in patients with a cardiac index less than or equal to 2.0 liters/min/m2 and 31 per cent in those with a cardiac index greater than 2 liters/min/m2 (p less than 0.01). Atrial contraction contributed 35 per cent to left ventricular stroke volume in patients with normal end-diastolic volume and in those with increased end-diastolic volume and 10 per cent to end-diastolic volume in patients with increased end-diastolic volume (p less than 0.001). In patients with myocardial infarction, atrial contraction made a large contribution to left ventricular filling and stroke volume irrespective of the type of left ventricular functional derangement that was present. The "booster pump" function of the atrium cannot be ignored in assessing left ventricular performance.     

Chemokines and left ventricular function in patients with acute myocardial infarction

BACKGROUND: Leukocytes are activated in the inflammatory process involving locally atherosclerotic lesions through adhesive molecules attaching to the surface of endothelial cells, especially during acute myocardial infarction. The aim of the study was to assess MCP-1, MIP-1alpha, and RANTES serum levels in patients with STEMI and to correlate them with the severity of left ventricle (LV) dysfunction. METHODS: Forty patients were initially divided into two groups, with group 1 having an ejection fraction (EF) above 40% and group 2 an EF of 40% or less. Next, the patients were divided on the basis of wall motion score index (WMSI): group 3 had a WMSI of 1.3 or lower and group 4 had a WMSI above 1.3. A control group of ten volunteers was also included in the study. Serum samples were taken at admission as well as 3, 24, 48, 72 h, and 7 days after. RESULTS: The baseline serum levels of MCP-1 and RANTES in group 1 were significantly higher than in the controls (p<0.05 and p<0.005, respectively). The highest concentrations of chemokines were observed 3 h after admission. The serum levels of MIP-1alpha on admission and 3 h later were significantly higher in group 1 than in group 2 (p<0.03 and p<0.01, respectively). Maximum MIP-1 concentrations were observed 3 h after admission in group 3 and 24 h after admission in group 4 (p<0.006). In group 1, MIP-1alpha 3 h after admission correlated positively with the EF (r=0.444, p<0.05). In group 1 there was a negative correlation between MIP-1alpha concentration 3 h after admission and LV end-diastolic dimension (r=-0.492, p<0.02). CONCLUSIONS: Patients with myocardial infarction with an elevated ST segment had a significant increase in MCP-1, MIP-1alpha, and RANTES serum levels.     

Effects of early myocardial reperfusion on left ventricular function in patients with acute myocardial infarction

The effect of early myocardial reperfusion (within six hours after the onset of symptoms) on left ventricular (LV) function in 106 patients with acute myocardial infarction was studied. The subjects consisting of 26 with conventional therapy, 19 with percutaneous transluminal coronary recanalization (PTCR), 16 with percutaneous transluminal coronary angioplasty (PTCA) after PTCR, 32 with direct-PTCA and 13 with coronary artery bypass graft (CABG) were randomly observed after 1981. In these patients, left ventricular ejection fraction (LVEF), regional wall motion, end-diastolic pressure and the contractility index were measured as the indices of LV function. 1. Compared to the conventional therapy group, LVEF and regional wall motion improved significantly in all groups with reperfusion therapy except in the PTCR group. This LV function in patients with subtotal obstruction or good initial collaterals significantly improved compared to patients with total obstruction and no collateral circulation. Patients with a 75 percent or more residual stenosis after reperfusion therapy had significantly decreased LV function compared to those with residual stenosis of less than 75 percent. These findings support the potential role for reperfusion therapy in patients with acute myocardial infarction.     

心肌梗死前心绞痛对心肌梗死后近远期心功能的影响

目的：探讨梗死前心绞痛对心肌梗死左室功能的影响。方法：129例首次AMI患者，按既往有无梗死前心绞痛分为3组：A组44例，梗死前无心绞痛史；B组40例，梗死前1个月内有心绞痛，且梗死前48h内至少有一次典型心绞痛发作；C组45例，梗死1个月前有心绞痛；监测心肌梗死后12～19个月的左室功能。结果：①C组患者双支以上血管病变多于A组和B组（P〈0．05）；②CK-MB峰值水平B组患者低于A组患者和C组患者（P〈0．01）；③组内比较，所有患者LVDd均降低（P〈0．05），B组患者LVEF增高（P〈0．01），A组和B组患者E／A增高（P〈0．05）；组间比较，B组患者LVEDd低于A组（P〈0．05），B组患者LVEF、E／A均高于A组和C组患者（P〈0．01）；④于3组患者中，梗死后主要心脏事件（除外严重心律失常）B组最少，C组最多（P〈0．05～〈0．01）。结论：梗死前1个月内心绞痛可保护梗死后近期与远期左心室功能、降低梗死后心脏事件发生率。     

Predictors of depressed left ventricular function in patients presenting with ST-elevation myocardial infarction

Early in the course of ST-segment elevation myocardial infarction (STEMI), therapies that may harm patients who develop left ventricular (LV) dysfunction, such as β-blockers, are often administered. The investigators analyzed the ACTIVATE-SF database, a registry of consecutive STEMI activations presenting to 2 medical centers at the University of California, San Francisco. LV dysfunction was defined as an ejection fraction ≤40% on echocardiography. Of 211 patients included in the analysis, 66 (31%) had LV ejection fractions ≤40%. Patients with LV dysfunction were older (63 ± 15 vs 56 ± 13 years, p = 0.002). In multivariate regression models, decreased renal function (reference group, creatinine <1.0 mg/dl; adjusted odds ratio [AOR] creatinine >1.5 mg/dl 6.35, 95% confidence interval [CI] 1.66 to 24.31, p = 0.007), a history of coronary artery disease (AOR 3.12, 95% CI 1.26 to 7.71, p = 0.014), ST-segment elevation >2 mm on 12-lead electrocardiography (AOR 2.78, 95% CI 1.31 to 5.87, p = 0.008), and need for mechanical ventilation (AOR 3.98, 95% CI 1.41 to 11.19, p = 0.009) increased the odds of LV dysfunction. Inferior ST-segment elevations were associated with 88% decreased odds of LV dysfunction (AOR 0.12, 95% CI 0.06 to 0.35, p <0.001). A prediction score using these characteristics stratified patients into low-, intermediate-, and high-risk groups for LV dysfunction; positive likelihood ratios for LV dysfunction in these groups were 0.07, 1.14, and 4.93, respectively. In conclusion, 5 key predictors of in-hospital LV dysfunction after STEMI were identified; a risk score based on these predictors helps to quickly identify patients presenting with STEMI who are at the highest risk for developing significant LV dysfunction and could guide optimal therapeutic choices.     

Comparison of left atrial function in healthy individuals versus patients with non-ST-segment elevation myocardial infarction using two-dimensional speckle tracking echocardiography

Abstract

Left atrial (LA) function has been associated with adverse outcomes in patients after acute myocardial infarction. The purpose of the current study was to evaluate LA function in patients with non-ST-segment elevation myocardial infarction (NSTEMI) by two-dimensional speckle tracking echocardiography (2D STE). Fifty-one patients with NSTEMI and 40 age-matched normal control individuals were enrolled in this study. Conventional echocardiographic parameters and global longitudinal strain rate (GLSR) were measured at left ventricular (LV) and LA segments. Compared with healthy subjects, patients with NSTEMI had significantly increased LA volumes but significantly decreased LA emptying fraction and GLSR. LA-GLSR had significant correlations with the 2D Doppler echocardiographic parameters of LA function. In particular, global LA peak negative strain rate during early ventricular diastole (LA-GLSRe) was significantly correlated with both LA 2D Doppler echocardiographic parameters and LV contractile function. This could be suggested as a better indicator to evaluate LA function as a preferred parameter of STE.     

急诊血运重建对急性心肌梗死左心室功能的影响

目的应用二维超声心动图及多普勒组织成像（Doppler tissue imaging,DTI）评价急诊血运重建（包括静脉溶栓或者急诊冠状动脉支架置入术）对急性心肌梗死（acute myocardial infarction,AMI）左心室收缩和舒张功能的影响。方法入院后根据AMI患者治疗方法分为常规组和治疗组。常规组30例给予内科常规治疗;治疗组20例在内科常规治疗基础上实施静脉溶栓或急诊冠状动脉支架置入术。应用DTI检测左心室射血分数、二尖瓣血流舒张早期流速峰值（peak velocity at early diastole,VE）和舒张晚期流速峰值（peak velocity at late diastole,VA）比值（VE／VA）,DTI成像模式检测二尖瓣环后间隔、侧壁、前壁、下壁、前间隔和后壁6个节段的收缩期运动速度峰值（peak velocity during systole,Sa）、舒张早期运动速度峰值（peak velocity at early diastole,Ea）和心房收缩期流速峰值（peak velocitv at atrial contraction,Aa）,并计算Ea／Aa比值。各取6个节段的平均值。结果所有AMI患者于发病后1周、3月末左心室射血分数、VE／VA、Sa、Ea和Ea／Aa均较对照组降低;予急诊血运重建的AMI患者于AMI发病后3个月S。和E。较本组发病后1周增高,并较未行急诊血运重建干预组（常规组）发病后3个月增高。结论AMI后左心室收缩和舒张功能受损,实施急诊血运重建可以有效改善心脏功能．应用DTI技术检测二尖瓣环运动速度可以精确反映AMI患者局部节段性心功能的恢复。     

Dynamics of parameters of left ventricular diastolic function in elderly patients with myocardial infarction

Dynamics of parameters of intraventricular filling flows were studied in 83 men (46 older and 37 younger than 60 years) admitted within 12 hours after onset of Q-wave myocardial infarction. Echocardiography was carried out on days 1, 3, 5, and 21 of hospitalization with registration of standard characteristics of left ventricular systolic and diastolic function as well as velocity and time of propagation of intraventricular filling flow. At initial study older patients more often had cardiac failure and ventricular dysfunction. During treatment younger patients had more noticeable decrease of active myocardial relaxation and increase of E/FPV reflecting elevation of intraventricular pressure. Left ventricular remodeling (increases of ventricular diameter and sphericity index) and dilatation were more pronounced in older patients.