Prognosis after an initial non-Q-wave myocardial infarction related to coronary arterial anatomy

Eighty-six consecutive hospital survivors (aged less than or equal to 60 years) of a first non-Q-wave acute myocardial infarction (MI) were followed up prospectively. Coronary arteriography was performed a median of 2 weeks after MI. The size of the MI was small (as judged by a mean peak creatine kinase level of 906 IU/liter); 90% were in Killip class I, and the mean left ventricular ejection fraction was 60 +/- 11% (+/- standard deviation). Forty-nine patients had 1 vessel significantly narrowed by disease (greater than or equal to 70% luminal diameter reduction), 19 had 2-vessel, 2 had 3-vessel, 3 had left main (greater than or equal to 50% luminal diameter reduction), and 13 minimal or no coronary artery disease (CAD). Complete occlusion of the MI-related vessel was present in 33 patients. All 33 and an additional 5 patients had collateral vessels to the MI area. During a mean follow-up of 25 months, 1 cardiac death and 4 recurrent infarcts (3 with non-Q-wave MI) occurred. Angina occurred in 53 patients (62%) and responded medically in all but 7 who underwent coronary artery surgery. Angina after MI occurred frequently in patients with severe proximal left anterior descending CAD (greater than or equal to 90%), and in those with CAD (greater than or equal to 50%) in a vessel supplying collaterals to the infarct area. Because angina can be managed medically in most patients and the outcome is good, routine coronary angiography is not indicated in asymptomatic survivors less than or equal to 60 years of a first non-Q-wave MI.     

Relation of coronary arterial patency and left ventricular function to electrocardiographic changes after streptokinase treatment during acute myocardial infarction

One hundred and eighty-eight patients with evolving acute myocardial infarction were treated with intravenous streptokinase. Serial 12-lead electrocardiograms were recorded for 3 hours after treatment and inspected for rapid repolarization changes of the ST segment and T wave. Abrupt electrocardiographic repolarization changes were observed in 106 patients (56%) and were strongly predictive for an open infarct-related coronary artery at a mean of 6 days after treatment (predictive value = 0.92, sensitivity = 0.67). Abrupt electrocardiographic changes were not observed in 82 patients (44%). This absence was not a good predictor of an occluded infarct-related coronary artery (predictive value = 0.4). There was no relation between the presence or absence of abrupt electrocardiographic changes and global or regional left ventricular function after streptokinase treatment. Abrupt repolarization changes after thrombolytic treatment indicate a high probability of an open infarct-related artery. When abrupt repolarization changes do not occur, the patency of the infarct-related coronary artery cannot be predicted with accuracy. Serial electrocardiographic recordings do not provide sufficient information about coronary patency to eliminate the need for coronary arteriography.     

Influence of coronary arterial thrombus location on left ventricular function in acute myocardial infarction

In 238 patients with acute myocardial infarction studied during intracoronary streptokinase therapy, the circumferential extent of left ventricular hypokinesis was measured by 5 methods and correlated with the location of the infarct-related coronary artery segment and with 1-year survival. Of the 5 methods, 1 focused only on the infarct region, and 4 varied in the complexity of the noise filter. Hypokinetic segment length measurements by all 5 methods correlated significantly with the location of occlusion along the left anterior descending coronary artery. No method yielded measurements that correlated with occlusion location along the right coronary artery. Measurements by all methods correlated significantly with survival, but the method that focused on the infarct region performed least well. Thus, the circumferential extent of hypokinesis in patients with acute myocardial infarction is greater for proximal than mid- or distal occlusions of the left anterior descending but not the right coronary artery. Survival is influenced by the function of periinfarct and noninfarct regions and by the function of the infarct region. Complex noise filters provide no advantage over simpler filters in measuring the extent of hypokinesis.     

Changes in coronary anatomy and left ventricular function from the acute to the chronic stage of myocardial infarction

Coronary angiography was performed in the acute stage of myocardial infarction in 65 patients. The infarct-related vessel was occluded in 50 patients; it was narrowed >90% in the remaining 15 patients. Control angiography was performed 55±46 d after acute myocardial infarction in 18 patients. In the chronic stage, five of thirteen previously occluded vessels showed antegrade filling of the distal segment. The narrowing at the site of previous obstruction was 80-95%. In two of five patients with a subtotal stenosis, the lumen of the infarct-related vessel was clearly larger in the chronic stage. The end-diastolic volume index increased significantly from 86±23 ml/m² in the acute stage to 110±35 ml/m² in the chronic stage (p<0.001). The increase in the end-systolic volume index from 42±15 ml/m² to 63±31 ml/m² was also statistically significant (p<0.005). Stroke volume index, ejection fraction, and the length of the akinetic segment (AKS) did not change significantly. There was a weak correlation between the end-systolic volume index and the length of the AKS in the acute stage (r = 0.489, p<0.05) and a better correlation in the chronic stage (r = 0.602, p<0.01). The ejection fraction and the length of the AKS correlated in the chronic stage only (r = 0.795, p<0.001). In contrast to the total group, three patients showed improvement in left ventricular pump function. In all three patients there was a collateral flow to the infarct area during the acute stage of myocardial infarction. In two of these patients there was spontaneous recanalization of the infarct vessel. However, vascularity of the infarct area during the acute stage was also found in eleven patients without improvement of left ventricular pump function. Two of these showed recanalization of the infarct vessel. In all four patients with a proximal occlusion of a major coronary artery and avascularity of the infarct area, there was impairment of left ventricular function and an increase in the length of the AKS.     

Determinants of improved left ventricular function after thrombolytic therapy in acute myocardial infarction

Many studies have been performed to evaluate the efficacy of thrombolytic therapy in achieving reperfusion, salvaging myocardium and enhancing survival. This review discusses the concordance between the results of these clinical studies and the observations made in experimental animals of the effect of reperfusion on the recovery of left ventricular function. The evaluation of functional recovery is affected by the timing of the measurement and the sensitivity of the method for detecting regional abnormalities. In addition, the underlying coronary anatomy also determines outcome, so that infarct location, collateral circulation and the degree of coronary obstruction merit consideration. Two factors are of paramount importance in determining the amount of myocardium salvaged, the recovery of left ventricular function and the reduction in mortality. These factors are: the time delay until reperfusion is achieved and the adequacy of the coronary reflow. The close agreement between studies measuring the effect of reperfusion on left ventricular function and studies with mortality as the end point provides indirect evidence that enhancement of survival in patients treated with thrombolytic agents is mediated by recovery of ventricular function.     

Effects of intracoronary thrombolysis therapy on left ventricular function after acute myocardial infarction

To treat the acute phase of myocardial infarction, nitroglycerin and urokinase were injected directly into the infarct-related coronary artery. Left ventricular ejection fraction and regional ejection changes were significantly preserved in the chronic phase, compared with conventional therapy in patients with obstruction at the same site. Comparing left ventricular function in the acute and chronic phases, left ventricular ejection fraction, regional ejection changes and left ventricular end-diastolic pressure were significantly improved in the chronic phase in patients with reperfusion within 6 hours. On the other hand, in patients who had no reperfusion in either the acute or chronic phase, left ventricular ejection fraction deteriorated in the chronic phase. Even in patients with reperfusion in the acute phase, reocclusion later meant a worse left ventricular ejection fraction in the chronic phase. These results suggest that intracoronary thrombolysis with urokinase within 6 hours gives a good chance of recovery from myocardial damage in patients with myocardial infarction.     

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.     

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。     

Early reperfusion therapy improves left ventricular function after acute inferior myocardial infarction associated with right coronary artery disease

Quantitative global and regional ventriculographic analysis was performed acutely and 1 week later in 46 patients undergoing reperfusion procedures within 6 hours of acute inferior myocardial infarction due to right coronary artery disease. While serial improvement in global left ventricular ejection fraction was not demonstrated for the group, infarct zone regional wall motion did improve (-2.7 +/- 0.9 vs -2.3 +/- 1.4 SD/chord, p less than 0.007). Serial improvement in global ejection fraction was demonstrated in the subgroup of patients treated within 2 hours of symptom onset (55 +/- 10 vs 62 +/- 10%; n = 5; p less than 0.03). Infarct zone regional wall motion improved serially only in the subgroup of patients treated within 3 hours of symptom onset (-2.4 +/- 1.1 vs -1.3 +/- 1.7 SD/chord; n = 11; p less than 0.007). Patients with initially patent arteries had a higher ejection fraction on follow-up catheterization than did those with initially occluded vessels (61 +/- 11 vs 55 +/- 7%; p less than 0.02), and patients with patent arteries at follow-up had a higher ejection fraction than did those whose arteries were occluded (60 +/- 9 vs 48 +/- 4%; p less than 0.0001). We conclude that significant improvement in global and regional left ventricular function in patients with inferior myocardial infarction is possible when reperfusion therapy is begun early or when arterial patency is achieved.     

Q波型前壁心肌梗死恢复期开通梗死相关冠脉对左室重构及心功能的影响

为了解Q波型前壁心肌梗死恢复期开通梗死相关冠脉对左室重构(LVRM)及心功能的影响,选择40例近期发生过首次Q波型前壁心肌梗死且造影示供血区供血冠脉闭塞者作为研究对象.试验按前瞻性随机方式进行分组,A组于心梗后4周内行冠脉内支架置入术,B组心梗后不作支架术.所有患者均于梗死后4周和24周进行超声心动图观察,分别测定左室舒张末期容量(LVEDV)、左室收缩末期容量(LVESV)、左室射血分数(EF).结果显示,所有患者于心肌梗死后均发生明显LVRM;A组24周时与4周比较LVEDV与LVESV均减少(P＜0.05),而EF升高(P＜0.05).B组LVEDV、LVESV较术前减少,但差异无显著性(P＞0.05),EF无变化.提示恢复期开通梗死相关冠脉可减轻或逆转Q波型前壁心肌梗死患者的LVRM,明显改善左室功能.     

Relationship between redox state of whole arterial blood glutathione and left ventricular function after acute myocardial infarction

OBJECTIVES: To investigate the role of oxidative stress in left ventricular function after acute myocardial infarction. METHODS: We studied 41 patients with acute myocardial infarction (30 men and 11 women, mean age 61.7 +/- 11.6 years) with Thrombolysis in Myocardial Infarction grade 3 recanalization of occluded coronary arteries within 12 hr after onset. Cardiac catheterization was performed at the time of admission and before discharge. Three markers for oxidative stress were measured: plasma lipid hydroperoxide, plasma creatol and whole arterial blood glutathione at the time of admission. RESULTS: Mean time from onset to recanalization was 5.2 +/- 0.6 hr. The patients were divided into two groups according to the changes in left ventricular wall motion (LVWM); patients who showed improvement in LVWM and those without improvement. There were no significant differences in age, sex, coronary risk factors, severity of coronary artery disease, time from onset to recanalization or ejection fraction between two groups. Maximum creatine kinase and C-reactive protein levels in patients without LVWM improvement were significantly higher than in patients with improvement. Plasma levels of lipid hydroperoxide and creatol did not differ significantly between two groups. On the other hand, reduced glutathione/oxidized glutathione ratio in arterial blood in patients without LVWM improvement was significantly lower than in patients with LVWM improvement (69.8 +/- 3.4 vs 85.5 +/- 2.9, p < 0.05). CONCLUSIONS: Our results suggest that whole arterial blood glutathione is more oxidized in acute myocardial infarction patients without LVWM improvement than in patients with improvement. Redox state of arterial blood can be a predicting factor for left ventricular function after acute myocardial infarction.     

急性心肌梗塞后冠脉内支架植入术对左心室收缩功能的影响

目的：观察心梗后冠脉内支架植入术对左心室功能的影响。方法：75例急性心肌梗塞后患者3s例行冠脉内支架植入治疗（支架组）,40例行静脉内溶栓治疗（溶栓组）,比较两组梗塞相关血管开通率,左室射血分数（LVEF）值。结果：梗塞相关动脉开通率：冠脉内支架术组100％,显著高于溶栓组的60％,P〈0．05。90dLVEF：支架术组（57．5±6．7）％明显高于溶栓组的（42．0±4．3）％,P〈0．05。结论：心梗后冠脉动内植入支架治疗可有效开通梗塞相关动脉,明显改善左心功能。     

Effects of percutaneous coronary arterial thrombectomy during acute myocardial infarction on left ventricular remodeling

The benefit of primary angioplasty for acute myocardial infarction (AMI) is limited by the no-reflow phenomenon, resulting in chronic left ventricular (LV) remodeling. The aim of this study was to evaluate the impact of thrombectomy with the Rescue percutaneous thrombectomy catheter on LV function after AMI. We performed a retrospective study comparing conventional angioplasty with the combination of angioplasty and thrombectomy using the Rescue catheter. The study population was comprised of 109 consecutive patients with AMI who underwent angioplasty and thrombectomy and 86 controls treated with conventional angioplasty. Baseline clinical and lesion characteristics were similar in the 2 groups. Postprocedural restoration of normal flow (Thrombolysis In Myocardial Infarction grade 3) was more frequent in the thrombectomy group (82% vs 69%, p = 0.03). No differences were observed in cardiac events, including death, reinfarction, and target vessel revascularization (thrombectomy vs controls, 27% vs 33%; p = 0.44) or changes in ejection fraction (p = 0.22) during 6-month follow-up. The incidence of LV remodeling, defined as an increase in LV end-diastolic volume index of >20%, was significantly lower in the thrombectomy group (22% vs 44%; p = 0.01). Multiple logistic regression analysis revealed that thrombectomy with the Rescue catheter contributed significantly to reduction of both no-reflow and LV remodeling. In the setting of primary angioplasty, adjunctive pretreatment with a rescue catheter reduces the no-reflow phenomenon and protects against LV remodeling.     

Coronary collaterals and left ventricular function early after acute transmural myocardial infarction

The coronary collateral circulation and ventricular function,segmental wall motion and infarct size, were investigated fromhemodynamic and angiographic data in 126 patients with acutetransmural myocardial infarction and complete obstruction ofa major coronary vessel. The patients were divided into twogroups: 74 with obstruction of the right coronary artery and52 with obstruction of the left anterior descending artery.The collateral circulation was rated as absent, poor, fair oradequate: two weeks after infarction, collateral vessels wereobserved in only 27% (poor 15.4%, fair 5.8%, adequate 5.8%)of the patients with an anterior myocardial infarction and inonly 35% (poor 13.5%, fair 16.4%, adequate 4.5%) of the patientswith an inferior myocardial infarction. In both groups of patients, the presence of collateral vesselshad no significant influence on the following parameters: leftventricular performance (left ventricular end-diastolic pressure,left ventricular enddiastolic volume, ejection fraction andmean velocity of fiber shortening), extent of abnormally contractingsegment and segmental wall motion. After anterior myocardialinfarction, there was an insignificant trend to lesser myocardialdamage in patients with coronary collaterals. Thus, coronary collaterals are infrequent in patients with acutetransmural myocardial infarction and total obstruction of acoronary vessel; in these patients we conclude that the collateralshave no effect either on left ventricular function or on thesize of the infarction.     

Time course of left ventricular function and coronary patency after saruplase vs streptokinase in acute myocardial infarction

As part of a prospective randomized double-blind trial (PRIMI)to study the early patency rate of the infarct-related arteryafter saruplase (INN for recombinant unglycosylated full-lengthhuman single-chain urokinase-type plasminogen activator) vsstreptokinase in a subgroup of patients, left ventricular functionwas compared between both treatment groups at 90 min and 24h after thrombolysis and at discharge, and ventricular functionwas related to the coronary perfusion grade. Despite a higher patency rate in the saruplase group 60 minafter initiating thrombolysis, neither global ejection fractionnor hypokinesia at the infarct site were significantly differentbetween the treatment groups at any of the three time pointswhen function was measured. Hypokinesia at the infarct siteremained almost equally severe throughout the study in patientswith perfusion grade O, I, and II, and was consistently significantlymilder in patients with perfusion grade III. In contrast, inpatients with perfusion grade II there was a significant dropin hyperkinesia at the opposite wall at 24 h after thrombolysisand before discharge despite unchanged wall motion at the infarctsite. Although patients treated with saruplase had a higher patencyrate in the infarct related vessel shortly after the start ofthrombolysis, no difference was found in left ventricular functioncompared to patients treated with streptokinase. Complete reperfusion(TIMI grade III) seems to be a prerequisite for left ventricularfunction recovery after thrombolysis, whereas only an occludedvessel (TIMI grade O and I) seems to be related to a longerlasting hyperkinesia at the opposite wall.     

心肌梗死患者心功能的预测因素

21世纪,心血管疾病已经超越传染病和肿瘤成为人类健康的头号杀手,其中最为凶险的就是急性心肌梗死。统计资料显示,全球每年有1700万人死于心血管疾病,其中一半以上死于急性心肌梗死。目前研究证实,心梗后约有56％的患者会出现心功能下降,而1／3的患者会发展成为心力衰竭。心力衰竭不但会直接影响患者的生存质量,同时又是介入治疗后晚期血栓形成的重要预测因素,因此,临床工作中全面了解心梗患者心功能的预测因素,积极进行处理事关重要。     

Early intervention with propranolol after acute myocardial infarction: serial left ventricular function determined by M-mode and cross-sectional echocardiography

Fifty patients (mean age 48.6 +/- 9.4 years) with uncomplicated acute myocardial infarction were randomly assigned to propranolol therapy (n = 25) or placebo (n = 25) in a double-blind manner within 24 hours of their presentation with acute symptoms. M-mode and cross-sectional echocardiography were performed at one week and three months to evaluate the left ventricular function. A comparison of the two groups revealed that the group receiving propranolol had higher left ventricular ejection fraction (69% vs 52%, P less than 0.001), fractional shortening (32% vs 24%, P less than 0.01), lower mitral E-point septal separation (6 mm vs 14 mm, P less than 0.001) and wall motion abnormality score (2.5 vs 6.0, P less than 0.001) than the group receiving placebo therapy. At three months there was further significant improvement in wall motion abnormality score (1.1 vs 2.5, P less than 0.001) in the propranolol-treated group as compared to the placebo group, whereas the other parameters remained unchanged. We conclude that the left ventricular function detected by M-mode and cross-sectional echocardiography showed significant improvement in patients with acute myocardial infarction after early intervention with propranolol. This is possibly due to a reduction in the size of infarction.     

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。