心肌缺血预适应对急性心肌梗死心电图ST段形态的影响

目的　探讨心肌缺血预适应 (IP)对急性心肌梗死 (AMI)心电图ST段形态的影响及其可能的机制。方法　 10 3例初发AMI患者按入院时心电图AMI相关导联ST段抬高的形态分为 2组 ,凹面向上抬高组 (A组 =4 6 )与凸面向上抬高组 (B组 =5 7) ,根据AMI发生前 2 4h至少出现 1次典型心绞痛的症状为标准 ,比较A组与B组各占的频率。结果　A组梗死前 2 4h内出现心绞痛 34例 ,占 73 91% ;B组为 14例 ,占 2 4 5 6 %。梗死前无心绞痛A组 12例 ,占 2 6 0 9% ;B组 4 3例 ,占 75 4 4 %。 2组比较差异有显著性 (P <0 0 1)。结论　心肌缺血预适应是AMIST段凹面向上抬高的机制之一 ,根据心电图ST段凹面抬高的AMI推断其梗死前存在缺血预适应 ,以及由于缺血预适应产生的心肌保护作用对临床有重要意义。     

不同形态ST段抬高前壁AMI患者的临床特征

将发病12h内的前壁急性心肌梗死（AMI）患者分为ST段凹面抬高（A组）和ST段凸面抬高（B组）两组,观察两组心肌酶峰值、出现Q波和ST段抬高导联数,发病4周时左室射血分数（LVEF）、侧支循环情况、心肌梗死前24h心绞痛,以及发病半年时的心血管事件发生率。结果A组心肌酶峰值、Q波和ST段抬高导联数及半年时心血管事件的发生率均低于B组（P〈0．05）,梗死前24h心绞痛发生率和LVEF高于B组（P〈0．05）,侧支循环建立情况好于B组（P〈0．05）。提示与ST段凸面抬高的前壁AMI比较,ST段凹面抬高患者的心肌梗死范围小,心功能恢复和远期预后较好。     

急性非ST段抬高性心肌梗死患者冠状动脉病变特点及其临床意义

目的分析急性非ST段抬高性心肌梗死患者冠状动脉病变特点及其临床意义。方法选择冠状动脉造影资料与临床资料完整的急性非ST段抬高性心肌梗死83例,以及同期急性ST段抬高性心肌梗死109例,分别就冠状动脉病变支数、狭窄程度、侧枝循环形成情况及临床特征进行对比分析。结果急性非ST段抬高性心肌梗死患者单支病变较ST段抬高性心肌梗死患者少(P<0.05),非ST段抬高性心肌梗死患者三支病变较ST段抬高性心肌梗死患者多(P<0.05),非ST段抬高性心肌梗死患者≥90%的狭窄病变较ST段抬高性心肌梗死患者多,但<90%的狭窄病变较ST段抬高性心肌梗死患者少(P<0.05),而两组间血管100%闭塞情况相似(P>0.05);非ST段抬高性心肌梗死患者Ⅱ级以上的侧枝循环较ST段抬高性心肌梗死患者多见(P<0.05);非ST段抬高性心肌梗死患者既往心绞痛与陈旧性心肌梗死病史多见(P<0.05),肌酸激酶同工酶峰值较ST段抬高性心肌梗死组明显要低(P<0.01),急性肺水肿、心源性休克、致死性心律失常等严重急性并发症比ST段抬高性心肌梗死组明显要少(P<0.05),左心室射血分数、住院期间死亡率和随访3年的冠心病死亡率与ST段抬高性心肌梗死组相似(P>0.05),而梗死后心绞痛比ST段抬高性心肌梗死组则明显增多(P<0.05)。结论急性非ST段抬高性心肌梗死冠状动脉病变相对复杂,多支及严重狭窄病变多,发作前多已有缺血预适应,且侧枝循环多见,这是心肌梗死形成非ST段抬高的主要原因,也决定了非ST段抬高性心肌梗死患者的临床特征。     

心肌缺血预适应对急性心肌梗死静脉溶栓冠脉再通的影响

目的探讨心肌缺血预适应对急性心肌梗死静脉溶栓治疗冠脉再通的影响。方法84例急性心肌梗死患者接受尿激酶静脉溶栓治疗,分梗死前有心绞痛组和梗死前无心绞痛组,依据临床间接血管再通标准观察两组再通情况,部分病例进行冠脉造影检查。结果两组再通率分别为74%和29.4%,差异有统计学意义(P<0.01)。结论心肌缺血预适应可提高急性心肌梗死静脉溶栓的冠脉再通。     

两种不同形态ST段抬高的急性心肌梗死临床特征

急性心肌梗死患者的胸前导联可出现两种不同形态的ＳＴ段抬高 ,即凹面向上和凸面向上 ,我们探讨其临床意义。一、资料与方法选择本院收治的急性初发前壁心肌梗死患者 40例 ,年龄 (6 3± 7)岁 ,男 31例 ,女 9例 ,于发病 3～ 10ｈ入院 ,平均(6 0± 1 6 )ｈ。入院心电图无束支传导阻滞、预激综合征的表现。按入院时心电图Ｖ3 导联ＳＴ段升高的形态 ,将患者分为两组 :凹面向上组 (Ａ组 ) 2 2例 ;凸面向上组 (Ｂ组 ) 18例。观察指标 :(1)血清肌酸激酶 (ＣＫ)、肌酸激酶同工酶 (ＣＫ ＭＢ)、乳酸脱氢酶 (ＬＤＨ)、天冬氨酸转氨酶 (ＡＳＴ)峰值 ;(…     

急性前壁心肌梗死下壁导联ST段变化与前降支形态和梗死部位的关系

目的探讨急性前壁心肌梗死时下壁导联ST段的变化与不同前降支形态和梗死部位关系。方法根据下壁导联心电图ST段改变情况,将67例首发急性前壁心肌梗死病例分为ST段压低组,ST段抬高组和ST段无变化组,与冠状动脉造影结果对照,分析各组心电图变化与前降支形态和梗死部位的关系。结果梗死相关部位在前降支近端者ST段压低组中占81.25%,ST段抬高组占20%,ST段无变化组占46.34%(P<0.01);LAD返折支配1/4以上下壁在ST段压低组中占6.25%,ST段抬高组占70%,ST段无变化组占29.27%(P<0.01)。结论急性前壁心肌梗死时下壁导联ST;段变化与前降支梗死部位和形态有关。下壁导联ST段压低提示前降支近端梗死,ST段抬高提示前降支远端梗死且存在前降支返折。     

急性心肌梗死墓碑形ST段抬高的临床意义

目的探讨急性心肌梗死（acute myocardial infarction，AMI）墓碑形ST段抬高的临床意义。方法将86例AMI患者以ST段抬高的特征分为两组，墓碑形抬高组36例、其他形抬高组50例。观察两组的一般临床资料（年龄、有否合并糖尿病），并比较两组AMI的发生部位、PCI前心梗后心绞痛、并发症及死亡的发生率、首次CK值、各项心电指标及PCI后心肌缺血再灌注损伤的发生率。结果两组各项临床指标及心电图指标差异均有统计学意义；墓碑形ST段抬高组PCI后心肌缺血再灌注损伤的发生率亦明显高于其他形ST段抬高组。结论墓碑形ST段抬高患者梗死部位特殊而广泛、并发症多、死亡率高、易出现心肌缺血再灌注损伤，对此类患者应高度重视并积极预防心肌缺血再灌注损伤的发生。     

缺血预适应改善急性心肌梗死经皮冠状动脉介入治疗的预后

目的研究梗死前心绞痛对接受PCI治疗急性心梗患者临床预后的影响。方法回顾分析122例首次发生的急性心肌梗死患者。所有患者在发病12h内进行PCI,按梗死前48h有无心绞痛分为2组,即缺血预适应组(56例)和非缺血预适应组(66例)。比较两组患者梗死相关血管PCI后血流TIMI分级、再灌注心律失常情况、心肌酶峰值浓度及出院前心脏事件发生率。结果缺血预适应组患者年龄高于非缺血预适应组(66±12比61±12,P=0.05)。非ST段抬高心肌梗死患者数量缺血预适应组明显多于非缺血预适应组,分别为30.4%和12.1%(P=0.01)。PCI后梗死相关血管无复流发生率在缺血预适应组明显低于非缺血预适应组,分别为4%和15%(P=0.03)。缺血预适应组心肌损伤标志物峰值浓度较非缺血预适应组显著降低,重度左室功能不全(LVEF40%)发生率在缺血预适应组明显低于非缺血预适应组,分别为4%和15%(P=0.03)。结论缺血预适应组急性心梗患者PCI术后心肌酶峰值明显降低,以及梗死相关血管无复流发生率和重度左室功能不全患者比例明显降低,表明缺血预适应对急性心梗患者心脏具有保护作用,改善预后。     

老年急性ST段抬高心肌梗死患者的心肌缺血分级

目的探讨老年急性ST段抬高心肌梗死患者心肌梗死缺血分级。方法选择86例老年急性ST段抬高心肌梗死患者,根据心电图QRS波群进行心肌缺血分级,其中Ⅱ级缺血40例,Ⅲ级缺血46例,并对两组患者入院12 h内进行溶栓治疗,比较两组患者治疗前后的心电图、心功能及心律失常等指标。结果与治疗前相比,两组患者治疗后的ST段抬高幅度均显著下降(P0.05),但Ⅲ级心肌缺血患者治疗前和溶栓2 h后的ST段抬高幅度均显著高于Ⅱ级心肌缺血患者(P0.05),且溶栓2 h后,Ⅲ级心肌缺血患者的ST段回降≥50%的比例显著低于Ⅱ级心肌缺血患者的比例(P0.05);与Ⅱ级心肌梗死患者相比,Ⅲ级心肌梗死患者的心肌梗死面积、肌酸激酶同工酶(CK-MB)峰值、肌钙蛋白(c TNI)峰值、N端-脑纳肽前体(NT-pro BNP)、心律失常等并发症的发生率等均显著增加,但左心室射血分数(LVEF)显著降低(P0.05)。结论加强对心肌缺血分级的研究,对于老年急性ST段抬高心肌梗死患者的临床预后有积极的临床意义。     

尿激酶联合左旋精氨酸治疗急性ST段抬高型心肌梗死的疗效及安全性观察

目的:观察尿激酶溶栓联合左旋精氨酸(L-Arg)治疗急性ST段抬高型心肌梗死的临床疗效及安全性。方法:78例符合溶栓治疗的急性ST段抬高型心肌梗死患者被随机分为常规溶栓治疗组和L-Arg组,每组各39例;L-Arg组于溶栓治疗同时给予L-Arg200mg/kg。分别于治疗前、治疗后24h检测2组患者血浆肌钙蛋白T(cTnT)、乳酸脱氢酶、肌酸激酶同工酶以及超氧化物歧化酶活力;观察2组治疗后的血管再通率和不良事件(梗死后心绞痛、再发心肌梗死、严重心律失常、肺水肿、死亡、出血等)的发生率。结果:L-Arg组血管再通率高于常规溶栓组(76.9%∶71.8%),但差异无统计学意义(P0.05);L-Arg组较常规溶栓组梗死后心绞痛发生率、再发心肌梗死率、严重心律失常发生率显著下降(P0.05);而肺水肿、死亡率和出血发生率2组比较,差异无统计学意义(P0.05)。结论:L-Arg对心肌梗死的缺血再灌注损伤心肌有良好的保护作用,尿激酶溶栓联合L-Arg治疗急性ST段抬高型心肌梗死,能较好的降低冠状动脉再通后并发症的发生。     

心肌缺血预适应对急性心肌梗死影响的观察

目的:探讨心肌缺血预适应对急性心肌梗死(AMI)临床表现及其预后的影响。方法:根据AMI前有无心绞痛发作分为预缺血组和无预缺血组,分组观察AMI患者血清肌酸磷酸激酶(CPK)峰值,住院期间并发症(心衰、心源性休克、严重心律失常),以及住院期间心性病死率。结果:预缺血组血清CPK峰值明显低于无预缺血组(P<0.05),住院期间心源性休克及严重心律失常发生率明显低于无预缺血组(P<0.05)。结论:心肌缺血预适应可减轻心肌坏死程度,缩小梗死面积,并减少AMI并发症的产生。     

Brief repetitive balloon occlusions enhance reperfusion during percutaneous coronary intervention for acute myocardial infarction: a pilot study.

The objective of this study was to determine whether acutely ischemic myocardium may be conditioned during percutaneous coronary intervention for acute myocardial infarction. Ischemic preconditioning is a powerful cardioprotective mechanism that limits infarct size in animal investigations and ischemic sequelae during percutaneous coronary intervention in man. However, the conditioning stimulus in all these studies has been applied prior to the defining episode of ischemia. Seventeen patients undergoing percutaneous coronary intervention for acute myocardial infarction were randomly assigned to a standard ischemic preconditioning protocol (n = 10) or a usual-care control group (n =7). ST segment shift response and Doppler-derived distal coronary velocity data were compared. Despite similar degrees of baseline ST segment elevation, the magnitude of final ST segment elevation in the conditioning group was less than that in controls at the protocol conclusion (conditioning, 1.60 +/- 0.8 mV; control, 4.0 +/- 0.5 mV; P < 0.001). The rate of ST segment resolution was greater in the conditioning group (conditioning, 0.28 +/- 0.1 mV/min; control, 0.12 +/- 0.1 mV/min; P = 0.02). Distal coronary velocimetry indicated significant improvement in coronary flow velocity reserve in the conditioning group at the protocol conclusion (conditioning, 1.8 +/- 0.2; control, 1.4 +/- 0.1; P < 0.008). Brief periods of occlusion and reperfusion during percutaneous intervention for acute myocardial infarction mitigate the extent of ischemic injury and improve distal myocardial perfusion. Such ischemic conditioning represents a potentially useful adjunct to strategies for enhancing reperfusion during acute myocardial infarction.     

Silent myocardial ischemia in unstable angina and acute myocardial infarction. Prospective clinical study

To establish the prevalence and characteristics of silent myocardial ischemia in patients with unstable angina and acute myocardial infarction and its possible correlation with coronary artery lesions; two groups patients were studied, fifteen with unstable angina and fifteen with acute myocardial infarction. In all patients a continuous 24 hours ECG recording was made with a solid state microprocessor for ST variation analysis, and all underwent coronary arteriography and ventriculography, the severity of coronary heart disease was determined by Gensini scoring system and the coronary angiography morphology was studied. In 86% patients with unstable angina ischemic ST changes were found, 90% of these episodes were silent. There were 66% of the patients with acute myocardial infarction and ST ischemic changes of these 75% were silent. There was no correlation with the ischemic myocardium score index, nor with the angiographic morphology or the heart rate. Therefore it can be said that myocardial ischemia is a result not only of anatomic factors but of many others such as vasoconstriction, endothelial, myocardial, systemic and hemorheological alterations.     

心肌缺血预适应及冠脉侧支循环对急性心肌梗塞患者的保护

目的：探讨心肌缺血预适应（IP）与冠脉侧支循环形成是否独立或协同地对急性心肌梗塞（AMI）患者起保护作用。方法：收集2006年9月~2010年4月择期行冠脉介入治疗（PCI）的103例初发AMI患者的住院资料,按梗塞前24~48 h内有、无心绞痛分为缺血预适应组（IP组,有心绞痛）53例,无缺血预适应组（NIP组,无心绞痛）50例。根据冠脉造影结果,每组再按有无梗塞相关冠脉侧支循环形成分为两个亚组。计算各组在心梗面积,左室射血分数（LVEF）,并发症等方面的差异。结果：①与NIP组比较,IP组的肌酸激酶[CK,（2163.2±962.1）U/L∶（1312.4±681.1）U/L],肌酸激酶同工酶[CK-MB,（292.6±126.7）U/L∶（161.8±58.9）U/L]峰值,心电图QRS积分[（11.6±4.6）分∶（6.9±2.3）分],肌钙蛋白I[cTnI,（29.8±13.4）U/L∶（15.7±6.1）U/L]峰值水平,以及严重心律失常（26.00%∶13.61%）、Killip分级（Ⅱ~Ⅲ）（26.00%∶16.98%）、心源性休克（14.00%∶7.55%）、室壁瘤发生率（12.00%∶5.66%）等显著降低（P均〈0.05）;IP组的LVEF[（55.5±5.6）%]显著高于NIP组[（45.1±6.1）%,P〈0.05];②两组内亚组间相比,有侧支循环亚组的Killip分级、心源性休克、室壁瘤形成率等,显著低于无侧支循环亚组（P均〈0.05）,而有侧支循环亚组的LVEF显著高于无侧支循环亚组（P均〈0.05）;而严重心律失常发生率,两组的两亚组间均无显著差异（P〉0.05）。结论：心肌缺血预适应和冠脉侧支循环形成均能减少急性心肌梗塞患者的心梗面积,阻止室壁瘤形成,改善左室收缩功能,并存在协同保护关系。     

心肌缺血预适应对老年心肌梗死范围和预后的影响

目的研究缺血预适应对老年心肌梗死范围和预后的影响。方法将120例首次老年心肌梗死患者依据梗死前有无心绞痛发作分为缺血预适应组(74例)和非缺血预适应组(46例),通过心电图计分法和磷酸肌酸激酶峰值水平比较最初心肌梗死面积;并统计两组出现并发症和住院期间病死率。结果心肌梗死中确存在缺血预适应,缺血预适应组在最初心肌梗死面积和严重并发症(心源性休克、急性肺水肿和恶性心律失常等)均少于非缺血预适应组(P<0.05)。结论心肌梗死前的心肌缺血预适应对老年心肌梗死患者的心肌有一定的保护作用。     

心肌缺血预适应在急性心肌梗死中的临床意义

目的　探讨心肌缺血预适应在 AMI中的临床意义。方法　 12 0例初发 AMI患者 ,按 AMI发作前 48小时内有无心绞痛分为缺血预适应组 (IP组 n=6 6 )与对照组 (n=5 4) ,测定左心室射血分数 (L VEF)和左心室室壁运动情况、心肌酶 (CPK、CPK- Mb)峰值、心电图 QRS记分 ,观察住院期间心律失常、心功能不全、心源性休克和室壁瘤发生率并进行比较。结果　 IP组 CPK、CPK- Mb峰值、心电图 QRS记分和心功能不全、频发室性期前收缩、VT/VF和 II- III°房室传导阻滞 (AVB)的发生率以及住院期病死率明显低于对照组 (P<0 .0 5 ) ,而 L VEF值明显高于对照组 (P<0 .0 5 )。结论　心肌缺血预适应在 AMI病人中发挥了心脏保护作用 ,有利于减少心肌梗死面积和左心室收缩功能的恢复 ,并减少恶性心律失常的发生率及住院期病死率     

Prognostic significance of transient myocardial ischaemia after first acute myocardial infarction: five year follow up study.

OBJECTIVE--To assess the five year prognostic significance of transient myocardial ischaemia on ambulatory monitoring after a first acute myocardial infarction, and to compare the diagnostic and long term prognostic value of ambulatory ST segment monitoring, maximal exercise testing, and echocardiography in patients with documented ischaemic heart disease. DESIGN--Prospective study. SETTING--Cardiology department of a teaching hospital. PATIENTS--123 consecutive men aged under 70 who were able to perform predischarge maximal exercise testing. INTERVENTIONS--Echocardiography two days before discharge (left ventricular ejection fraction), maximal bicycle ergometric testing one day before discharge (ST segment depression, angina, blood pressure, heart rate), and ambulatory ST segment monitoring (transient myocardial ischaemia) started at hospital discharge a mean of 11 (SD 5) days after infarction. MAIN OUTCOME MEASURES--Relation of ambulatory ST segment depression, exercise test variables, and left ventricular ejection fraction to subsequent objective (cardiac death or myocardial infarction) or subjective (need for coronary revascularisation) events. RESULTS--23 of the 123 patients had episodes of transient ST segment depression, of which 98% were silent. Over a mean of 5 (range 4 to 6) years of follow up, patients with ambulatory ischaemia were no more likely to have objective end points than patients without ischaemic episodes. If, however, subjective events were included an association between transient ST segment depression and an adverse long term outcome was found (Kaplan-Meier analysis; P = 0.004). The presence of exercise induced angina identified a similar proportion of patients with a poor prognosis (Kaplan-Meier analysis; P < 0.004). Both exertional angina and ambulatory ST segment depression had high specificity but poor sensitivity. The presence of exercise induced ST segment depression was of no value in predicting combined cardiac events. Indeed, patients without exertional ST segment depression were at increased risk of future objective end points (Kaplan-Meier analysis; P < 0.0045). These findings may be explained in part by a higher prevalence of left ventricular dysfunction in patients without ischaemic changes in the exercise electrocardiogram (P < 0.05). CONCLUSION--There seem to be limited reasons to perform ambulatory ST segment monitoring in survivors of a first myocardial infarction who can perform exercise tests before discharge. Patients at high risk of future myocardial infarction or death from cardiac causes are not identified. Ambulatory monitoring and exertional angina distinguish a small subset of patients who will develop severe angina pectoris demanding coronary revascularisation during follow up. Patients without exercise induced ST segment depression comprise a high risk subgroup in terms of subsequent objective end points. The role of ambulatory ST segment monitoring performed in unselected patients immediately after infarction when risk is maximal remains to be clarified.     

Effect of intravenous nicorandil and preexisting angina pectoris on short- and long-term outcomes in patients with a first ST-segment elevation acute myocardial infarction

Published reports have indicated that prodromal angina before acute myocardial infarction (AMI) is associated with better outcomes and that nicorandil has cardioprotective effects on ischemic hearts. We compared cardioprotective effects of intravenous nicorandil with preconditioning effects by prodromal angina in patients with AMI who underwent percutaneous coronary intervention (PCI). In total, 368 patients with first ST-elevation AMI who underwent PCI were randomly assigned to receive nicorandil 12 mg or a placebo intravenously just before PCI. Subjects were assigned to 1 of 4 groups: 52 patients with prodromal angina were given placebo, 129 patients without prodromal angina were given nicorandil, 56 patients with prodromal angina were given nicorandil, and 131 patients without prodromal angina were given placebo. Coronary microvascular impairment after PCI was prevented at similar frequencies in groups with prodromal angina and groups on nicorandil. Five-year rates for freedom from major cardiac events were similar across groups with prodromal angina given placebo, without prodromal angina given nicorandil, and with prodromal angina given nicorandil (92.3%, 93.8%, and 92.9%, respectively) but were significantly lower in the group without prodromal angina given placebo (80.2%, p = 0.0019, 0.044, and 0.042, respectively). In conclusion, intravenous administration of nicorandil before PCI exerts pharmacologic cardioprotective effects similar to ischemic preconditioning in patients with AMI.     

急性心肌梗死时心电图不同形态ST段抬高的机制和意义

目的 :探讨急性心肌梗死时心电图不同形态 ST段抬高的机制和意义。方法 :结扎家兔冠状动脉的不同分支制造急性心肌梗死模型。结果 :ST段抬高的形态随心肌缺血时间的延长而呈“下弧形—上斜形—上弧形”的规律性变化。结论 :ST段抬高的不同形态反映心肌损伤的不同时相 ,下弧形抬高提示心肌缺血的早期 ,上弧形抬高提示心肌损伤的晚期 ,上斜形抬高介于二者之间。