急性心肌梗塞静脉溶栓治疗改善左心室功能的作用

为评价急性心肌梗塞（ＡＭＩ）静脉溶栓再灌注对左心室功能及重塑的影响，应用二维超声心动图（２ＤＥ）对６１例ＡＭＩ接受静脉溶栓治疗的患者，分别在急性期及６个月后随访时测量并计算左心室容积（ＥＳＶ和ＥＤＶ），射血分数（ＥＦ），左心室内膜弧长（ＡＳＬ和ＰＳＬ）以及室壁运动指数（ＧＷ－ＭＩ和ＲＷＭＩ）。结果显示，以上各项指标急性期时两组比较差异均无显著性，在６个月后的随访中，再通组ＥＦ值明显高于未通组，再通组左室容量减小、变形减轻。急性期两组的心功能无差异，随访时再通组心功能较未通组显著改善。提示溶栓再灌注能明显减轻左心室的扩张及抑制左心室重塑，改善患者的心功能和预后。     

链激酶溶栓治疗急性心肌梗死对左心室功能的改善作用

为评价链激酶溶栓治疗急性心肌梗死（ＡＭＩ）对左心室功能的影响，应用二维超声心动图对２６例接受链激酶溶栓治疗的ＡＭＩ患者和２７例未溶栓的ＡＭＩ患者，分别在急性期及６个月后随访时测量并计算左心室容积（ＥＤＶ和ＥＳＶ），射血分数（ＥＦ）以及室壁运动指数（ＧＷＭＩ和ＲＷＭＩ）。以上各项指标在急性期时比较各组无显著性差异；在随访期再通组ＥＦ值明显高于未通组和未溶栓组，再通组左室容量减小。急性期各组心功能无差异，随访时再通组心功能较未通组显著改善。提示:链激酶溶栓能明显减轻ＡＭＩ患者的左心室扩张，改善左心室功能和长期预后     

急性心肌梗死患者心肌灌注状况对经皮冠状动脉介入术后心功能的影响

目的采用经冠状动脉超声心肌声学造影(MCE)评价急性心肌梗死(AMI)患者心肌灌注状况对经皮冠状动脉介入术(PCI)后心功能改善的影响,并探讨其相关临床意义。方法 18例AMI患者于PCI前及术后15 min分别经左主干或右冠状动脉注射超声声学造影剂,进行MCE实时显影,以视觉评分方式定性分析PCI前后相应心肌节段灌注状况;术后1个月经二维超声评价左心室室壁运动;利用灌注评分指数(PSI)及室壁运动评分指数(WMSI)分析PCI前后心肌灌注水平对心功能改善的影响。结果术前心肌灌注评分为0分的30个心肌节段中,20个(66.7%)术后1个月室壁运动评分为3~5分;而术前心肌灌注评分为2分的11个心肌节段中,有8个(72.7%)1个月时室壁运动评分为1~2分;统计学分析显示,PCI前心肌灌注与1个月室壁运动状况有关(P0.05)。术后心肌灌注评分为0分的12个心肌节段中,11个(91.7%)术后1个月室壁运动评分为3~5分;而术后心肌灌注评分为2分的22个心肌节段中,有17个(77.2%)1个月时室壁运动评分为1~2分;统计学分析显示,PCI后心肌灌注与1个月室壁运动状况有关(P0.01)。结合WMSI及PSI综合评价术后心肌灌注水平与左心室收缩功能的关系,发现二者存在明显相关性(P0.01)。结论 AMI患者心肌灌注状况对PCI后心功能改善有明显影响;经冠状动脉MCE可较准确的判断AMI患者微循环灌注范围,评估术后心功能,故可能对患者的临床预后判断有一定预测价值。     

不同介入治疗方案选择对急性心肌梗死患者心功能及心肌组织灌注的影响

目的对接受急诊、易化、延迟介入治疗(PCI)的急诊心肌梗死(AMI)患者心功能及心肌组织血液灌注进行评价。探讨AMI患者行PCI最佳时机和方法。方法69例AMI患者分急诊PCI(A)、易化PCI(B)、延迟PCI(C)三组。术后7d、30d行超声心动图及99 mTc-甲氧基异丁基异晴(MIBI)心肌灌注断层显像(SPECT)评价近期心功能及心肌组织灌注,观察1年期间心血管事件的发生情况。结果(1)三组患者扩张后即刻造影结果管腔残余狭窄率<10%,手术成功率100%。(2)超声心动图30d时A、B两组左心室收缩、舒张末容积指数(LVESVI、LVEDVI)、左心室射血分数(LVEF)均优于C组(。3)SPECT显像放射性缺损面积(MIA),A、B两组低于C组,A、B两组心肌组织血流灌注均优于C组。结论(1)直接PCI、易化PCI可显著提高AMI患者的近期心肌组织血流灌注,缩小心肌梗死面积,保护心功能;(2)延迟PCI宜早期进行。     

Impact of acute hyperglycemia on left ventricular function after reperfusion therapy in patients with a first anterior wall acute myocardial infarction

Objective

This study was undertaken to assess the relationship between acute hyperglycemia and left ventricular function after reperfusion therapy for acute myocardial infarction (AMI).

Methods

This study consisted of 529 patients with a first anterior wall AMI who underwent coronary angiography followed by coronary angioplasty or thrombolysis within 12 hours after the onset of chest pain. Plasma glucose was measured at the time of hospital admission. Acute hyperglycemia was defined as plasma glucose >10 mmol/L.

Results

Although acute hyperglycemia was associated with both lower acute left ventricular ejection fraction (LVEF) (46% ± 12% vs 48% ± 10%, P = .026) and lower predischarge LVEF (51% ± 15% vs 56% ± 15%, P = .001), the difference was more pronounced in the latter and the change in LVEF was significantly smaller in patients with acute hyperglycemia (4.8% ± 11.2% vs 8.0% ± 13.8%, P = .022). Multivariable analysis showed that there was a significant correlation between plasma glucose and impaired predischarge LVEF, even after adjustment of acute LVEF (r = −0.13, P = .005). Thirty-day mortality tended to be higher in patients with acute hyperglycemia than in patients without (7.1% vs 3.5%, P = .06). Multivariable analysis showed that plasma glucose (per 1 mmol/L increase) was an independent predictor of 30-day mortality after AMI (odds ratio 1.12, 95% CI 1.03-1.22, P = .009).

Conclusion

Acute hyperglycemia was independently associated with impaired left ventricular function and higher 30-day mortality after AMI. These results may provide a potential explanation for poor outcomes of patients with AMI and acute hyperglycemia.     

Influence of reperfusion therapy on left ventricular remodeling after acute myocardial infarction

To determine the relation between reperfusion therapy and left ventricular function and remodeling after acute myocardial infarction (AMI), 75 consecutive patients with anterior AMI were studied. The patients were divided into four groups according to the reperfusion outcome and time to reperfusion from onset of MI: 12 patients with spontaneous reperfusion, 18 patients with early (less than 4th) successful reperfusion, 16 patients with late (greater than or equal to 4th) successful reperfusion and 29 patients with unsuccessful reperfusion. The right oblique left ventriculograms (LVG), which was performed early (n = 19) and late after infarction (n = 75) were analyzed to assess left ventricular (LV) volume and global and regional LV function. At the late examination, spontaneous early and late reperfused patients showed smaller LV volume (endo diastolic and endo-systolic volume index) than unsuccessfully reperfused patients LV volume was similar in both early and late reperfused patients. Spontaneous and early reperfused patients showed higher LV ejection fraction (EF) and better regional wall motion (RWM) than unsuccessfully reperfused patients. Both EF and RWM was similar in late and unsuccessfully reperfused patients at the late examination. Endo-diastolic and endo-systolic volume index increased significantly with time in patients with unsuccessful reperfusion (n = 10), as compared with the index found in the early examination. In patients with late reperfusion (n = 5), end-diastolic volume index increased with time, but end-systolic volume index was unchanged. RMW improved in patients with early reperfusion (n = 4), but was unchanged in patients with late and unsuccessful reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

老年急性心肌梗塞溶栓治疗对左心室功能的改善作用

目的 :评价链激酶溶栓治疗老年急性心肌梗塞 (AMI)对左心室功能的影响。方法 :应用二维超声心动图对 2 9例 AMI接受链激酶溶栓治疗和 2 1例未溶栓的 AMI患者 ,分别在急性期及 6个月后随访时测量并计算左心室容积 (EDV和 ESV) ,射血分数 (EF)等参数。结果 :急性各组心功能无差异。随访期再通组 EF值明显增加 ,且明显高于未通组和未溶栓组。结论 :链激酶溶栓能明显减轻老 AMI患者的左心室扩张 ,改善左心室功能和长期预后     

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.     

Changes in ventricular function associated with coronary reperfusion in acute myocardial infarction

Currently there is no accepted method for measurement of myocardial infarct size in humans. Analysis of both global and regional left ventricular function provides an indirect indication of extent of myocardial necrosis. Acute coronary occlusion results in cessation of function and in some cases dilatation of the involved myocardial segment. Often there is reciprocal hyperfunction of the non-ischemic segments resulting in little impairment of global ventricular function. Average global left ventricular function does not change from hospital admission through hospital discharge in patients with acute myocardial infarction, treated conventionally. With successful coronary reperfusion, however, both regional and global ventricular function have been reported to improve over several weeks after the initial ischemic insult. Improvement in ventricular function is most likely to occur in patients with collaterals or some preservation of antegrade flow to the involved myocardial segment who successfully undergo reperfusion. Return of function occurs in 82% of patients successfully treated within two hours after onset of chest pain. Approximately 50% of patients successfully treated two to 18 hours after onset of chest pain have demonstrated significant improvement in function. Patients admitted with normal ventricular function are less likely to demonstrate improved global ventricular function than those admitted with ejection fractions less than 45%. Acute PTCA with or without thrombolysis may result in a greater return in function than thrombolysis alone. Delayed revascularization more than 48 hours after successful reperfusion does not appear to affect ventricular function a late follow-up but may improve probability of survival. Patients discharged with ejection fractions greater than 45% clearly have an improved prognosis compared to those with depressed ejection fractions post-myocardial infarction.     

Effect of reperfusion therapy for acute myocardial infarction on ventricular function and heart failure

Thrombolytic therapy reduces mortality and improves ventricular function in acute myocardial infarction. We review the short- and long-term effects of reperfusion after acute myocardial infarction on left ventricular function and heart failure. The beneficial effects of reperfusion may be achieved by immediate limitation of infarct size or through delayed improvement in ventricular remodeling. Infarct size is dependent on the area at risk, the time delay to reperfusion, the completeness and persistence of reperfusion, and collateral blood flow. The main prognostic parameters after myocardial infarction are vessel patency, infarct size, and ventricular volume and function. Initial infarct size and patency of the infarct-related artery are independent predictors of ventricular volume and function, as well as of survival in the long-term following acute myocardial infarction. The beneficial effects of a patent infarct-related artery are only evident if normal flow is achieved and maintained, and are dependent on the degrees of the residual stenosis. Thrombolytic therapy reduces the incidence of in-hospital congestive heart failure, and this improvement is sustained for at least 5 years. As only a fraction of patients with acute myocardial infarction currently receive thrombolytic therapy, heart failure after myocardial infarction can be reduced by administering thrombolytic therapy earlier to more patients with evolving acute myocardial infarction.     

Left ventricular free wall rupture after reperfusion therapy for acute myocardial infarction

We evaluated the clinical significance of angiographic indexes and pericardial involvement in predicting increased risk of free wall rupture after reperfusion therapy and found that Thrombolysis In Myocardial Infarction (TIMI) <3 flow grade after reperfusion therapy was a significant variable related to the free wall rupture. Moreover, pericardial rub was found to be a significant variable related to TIMI <3 grade flow after reperfusion, which indicates that detection of pericardial rub is one of the clinical signs that predicts inadequate anterograde flow of the infarct-related artery after reperfusion and hence, higher risk for free wall rupture.     

急性心肌梗塞后左室舒张功能影响因素的探讨

为探讨急性心肌梗塞（ＡＭＩ）左室舒张功能的变化及影响因素，我们用脉冲多普勒超声心动图测量了７２例ＡＭＩ患者的左室舒张功能，并用多元逐步回归对其影响因素进行了分析。结果表明，７２例病人中Ｅ／Ａ＜１者４１例，占５６．９％。ＡＭＩ后左室舒张功能除受年龄影响外，梗塞面积的大小直接影响左室舒张功能，但与梗塞部位无关，梗塞前心绞痛可减轻梗塞后左室舒张功能的损害，是通过减小梗塞面积而实现的。溶栓治疗可以改善心肌梗塞后的左室舒张功能。     

Impact of late coronary artery reperfusion on left ventricular function one month after acute myocardial infarction (results from the ISAM study)

To evaluate the impact of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction, findings from 368 patients in the Intravenous Streptokinase in Myocardial Infarction study are presented. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Contrast angiography was performed 1 month after the acute event. The infarct-related coronary artery was patent in 74 of 116 (64%) streptokinase-treated patients and 141 of 252 (56%) patients treated with anticoagulant therapy (placebo group). In all baseline variables, including the actually developed enzymatic and electrocardiographic infarct sizes, there were no differences between the patent- or occluded-artery groups. A patent infarct artery 1 month after infarction was associated with significantly better LV function regardless of the vessel involved and whether or not patients had been treated with streptokinase. Ejection fraction in patients with patent versus occluded artery was 56 +/- 13 versus 50 +/- 14 (p less than 0.0005). Most benefit was noted in patients in whom the proximal left anterior descending coronary artery was affected: ejection fraction was 52 +/- 14 versus 36 +/- 12% (p less than 0.0005). Our data confirm that restoration of adequate flow through an infarct-related coronary artery beyond the time window for actual salvage of ischemic myocardium has a definite beneficial effect on LV function.     

Myocardial contrast echocardiography is superior to other known modalities for assessing myocardial reperfusion after acute myocardial infarction

Background: Angiographic flow measurements do not define perfusion accurately at a microvascular level, so other techniques which assess flow at a tissue level are to be preferred.     

N-末端脑钠尿肽原诊断急性心肌梗死患者左室舒张功能的价值及其判断预后的意义

目的: 利用超声心动图,探讨N-末端脑钠尿肽原（NT-proBNP）对急性心肌梗死(AMI)患者左室舒张功能的评价及其意义。方法: 入选左室收缩功能正常的AMI患者66例,测定血浆NT-proBNP水平。根据组织多普勒超声（TDI）及二尖瓣血流频谱指标评价的左室舒张功能,将患者分为4组:A组:左室舒张功能正常组（n=16）;B组:轻度左室舒张功能减低（LVDD）组（n=21）;C组:中度LVDD组（n=24）;D组:重度LVDD组（n=5）。对患者随访12个月,临床终点是因心衰加重或再梗所致再住院和心源性死亡。结果: NT-proBNP水平随着LVDD的加重而显著增高（P<0.01）。NT-proBNP能够独立于其它影响因素判断LVDD,当其水平为962.1 μg/L时,判断LVDD的敏感性是76%,特异性是75%。12个月后发生终点事件患者的血浆NT-proBNP水平与未发生者相比差异有统计学意义（P<0.05）。结论: AMI后NT-proBNP水平能够独立评价LVDD并判断预后。它可用于对AMI患者危险分层并指导临床治疗。     

Rescue use of abciximab improves regional left ventricular function after early incomplete reperfusion in acute myocardial infarction

BACKGROUND: Abciximab was shown to have important beneficial effects beyond the maintenance of epicardial coronary artery patency. However, it remains uncertain whether abciximab may lead to a better functional outcome in patients with acute myocardial infarction (AMI) and with incomplete reperfusion after primary angioplasty (PA). HYPOTHESIS: The study aimed to evaluate whether rescue use of abciximab may lead to a better functional outcome in such patients. METHODS: The study included 25 patients with first AMI who met the following criteria: (1) total occlusion of the infarct-related artery, (2) PA within 12 h of symptom onset, (3) postprocedural diameter stenosis < 30%, and final Thrombolysis in Myocardial Infarction (TIMI) flow grade 2. Echocardiographic examination was performed before and on Days 7 and 30 after PA. The study population was divided into two groups: Group 1 (usual care, n = 13) and Group 2 (rescue use of abciximab, n = 12). Baseline characteristics were similar between the two groups. RESULTS: Peak level of creatine kinase was higher in Group 1 than in Group 2 (5,800+/-2,700 vs. 3,800+/-2,000 U/I, p < 0.05). At 1 month follow-up, infarct zone wall motion score index (2.71+/-0.26 vs. 2.05+/-0.63, p < 0.01) and left ventricular (LV) volume indices were smaller in Group 2 than in Group 1, whereas LV ejection fraction was higher in Group 2 than in Group 1 (52.1+/-7.8 vs. 42.1+/-6.4, p < 0.01). At 1-month, abciximab was the only independent predictor of wall motion recovery index by multiple regression analysis. CONCLUSIONS: Rescue use of abciximab may reduce the infarct size in patients with AMI and TIMI grade 2 flow after PA, which may improve the recovery of regional LV function.     

Effects of intravenous metoprolol on global and regional left ventricular function after coronary arterial reperfusion in acute myocardial infarction

Coronary reperfusion in myocardial infarction improves infarct zone motion, but its effect on the global ejection fraction has been less consistent. The directional movement of the ejection fraction is determined by the opposing influences of improved infarct zone motion and diminishing hyperkinesia in the noninfarct zone. Noninfarct zone hyperkinesia has been attributed to catecholamine stimulation, the Frank-Starling mechanism or intraventricular interactions that unload noninfarcted segments. To investigate the influence of catecholamine stimulation, 9 men presenting with a first myocardial infarction (mean age 53 +/- 13 years) were studied. Coronary reperfusion was accomplished less than 4 hours after the onset of myocardial infarction. Radionuclide ventriculography was then performed before and immediately after the intravenous administration of 15 mg of metoprolol. End-diastolic volume did not change, but end-systolic volume increased 28% after metoprolol (p = 0.041). The ejection fraction decreased from 55 +/- 13% before metoprolol to 45 +/- 14% after its administration (p = 0.002). There was no effect of intravenous metoprolol on infarct zone motion, whereas motion in the noninfarcted segment decreased (p = 0.002). The patients underwent repeat ventriculography after receiving metoprolol, 100 mg orally twice a day for 9 days. Infarct zone motion improved (p less than 0.002) and the ejection fraction increased to 55 +/- 12% (p less than 0.02). Normal zone motion did not change. Thus, compensatory hyperkinesia is at least in part caused by catecholamine stimulation. Conclusions regarding the effects of reperfusion on global ventricular performance can be influenced by the timing of ejection fraction determinations relative to metoprolol therapy.     

Predictive value of markers of myocardial reperfusion in acute myocardial infarction for follow-up left ventricular function

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R² = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of ≥50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive.     

Time course and characteristics of ventricular arrhythmias after reperfusion in acute myocardial infarction

The time course and characteristics of ventricular arrhythmias were studied in 45 consecutive patients with acute myocardial infarction who received intravenous streptokinase and underwent 24-hour Holter monitoring both after admission and before discharge 8 +/- 3 days later. In 41 of the 45 patients, thrombolytic treatment resulted in reperfusion as determined by characteristic clinical signs, i.e., rapid relief of pain associated with rapid resolution of ST-segment elevation and simultaneous abrupt increase in serum creatine kinase-MB activity. During the first 24 hours after reperfusion, the prevalence of ventricular premature complexes (VPCs) and couplets was nearly 100%, with an average frequency of 67 VPCs (range 1 to 1,336, median 44) and 6 couplets per hour per patient (range 1 to 97, median 4). Ninety percent of patients had an average of 8 runs of accelerated idioventricular rhythm per hour per patient (range 1 to 226, median 5) and 23% of the patients had an average of 2 runs of ventricular tachycardia per hour per patient (range 1 to 22, median 2) during the first 24 hours after reperfusion. The frequency of arrhythmias began to decrease 8 to 12 hours after reperfusion. Except for VPCs, ventricular arrhythmias were rare during the predischarge Holter study. Arrhythmias after reperfusion did not produce clinical symptoms and did not degenerate into ventricular fibrillation even though the patients were not receiving antiarrhythmic therapy. In the 4 patients without signs of reperfusion, the prevalence and frequency of all ventricular arrhythmias during the 24 hours after treatment was lower than in patients with reperfusion, and none had an accelerated idioventricular rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)