急性心肌梗死后存活心肌对梗死相关血管晚期血运重建术后左室功能的影响

目的探讨存活心肌对急性心肌梗死(AMI)后梗死相关血管(IRA)晚期血运重建术后远期左室功能以及左室重构的影响.方法69例AMI未接受早期再灌注治疗者,于发病10～21 d行IRA经皮冠状动脉血运重建(PCI)术,术前于AMI发病后5～10 d应用小剂量多巴酚丁胺(5和10μg·min-1·kg-1)超声心动图负荷试验检测存活心肌,并分别测定和计算给药前后左室腔大小、左室射血分数(LVEF)以及室壁运动积分(WMS).按有无存活心肌分为存活心肌组和无存活心肌组,超声心动图随访术后6个月时两组左室腔大小、LVEF和WMS的变化.结果157个运动异常节段中89个节段(57%)有存活心肌,有存活心肌组26例(占38%),无存活心肌组43例(占62%).存活心肌组术后6个月LVEF较术前明显提高(P＜0.05),收缩末期容积指数(LVESVI)和WMS明显降低(P＜0.05和P＜0.01);而无存活心肌组LVEF较术前明显降低(P＜0.01),LVESVI和左室舒张末期容积指数(LVEDVI)较术前明显增加(P＜0.05),WMS无明显变化.存活心肌组多巴酚丁胺负荷时的LVEF和WMS明显改善,且与6个月时的测定值相近;而无存活心肌组PCI前应用多巴酚丁胺LVEF和WMS均无明显变化.结论AMI后有存活心肌者晚期血运重建有利于改善远期左室功能和减少左室重构.心肌梗死后早期小剂量多巴酚丁胺负荷状态下左室收缩功能的提高预示晚期血运重建术后心功能改善.     

糖尿病和非糖尿病急性前壁心肌梗死晚期成功血运重建术后左室功能的变化及其与存活心肌的关系

目的:比较糖尿病和非糖尿病前壁急性心肌梗死(AMI)晚期成功血运重建术对心肌梗死后远期左室功能和预后的影响以及与存活心肌的关系.方法:选择依据病史、心电图和心肌损伤标志物等检查证实为首次发作的前壁AMI,并于发病后2周左右接受冠状动脉介入治疗术(PCI)的患者共计125例,其中参照WHO诊断标准确诊为并发糖尿病者(A组)43例,未并发糖尿病者(B组)82例.PCI前行超声心动图检查,了解左室功能和梗死相关区域存活心肌的情况.详细分析和记录PCI前后冠状动脉造影的结果.并分别于PCI前和术后6 h、24 h采取静脉血检测血清CK-MB和肌钙蛋白T水平.术后6个月重复超声心动图检查,了解左室功能和室壁活动异常的变化,并随访其间主要心血管事件的发生情况.结果:冠状动脉造影显示,与B组相比,A组PCI后即刻靶血管TIMI 2级血流所占的比例较多,TIMI 3级较少(分别为P<0.05和P<0.01).术后CK-MB和肌钙蛋白T增高者A组明显多于B组(25.6%∶9.8%,P<0.05).小剂量多巴酚丁胺超声负荷试验结果示A组中62.8%和B组中56.1%的患者有存活心肌,2组相比差异无统计学意义(P>0.05).急性期2组左室射血分数(LVEF)、左室舒张末期容积指数(LVEDVI)、收缩末期容积指数(LVESVI)以及室壁运动积分(WMS)基本相同(均P>0.05).术后6个月随访,B组WMS明显减少,LVEF明显增高;而A组LVEF和WMS均无明显改善,LVEDVI反而增加;2组相比LVEDVI、LVESVI、LVEF和WMS均有明显差异(分别P<0.05和P<0.01).随访期间2组主要心血管事件的发生率差异无统计学意义(18.6%∶11.0%,P>0.05).结论:糖尿病AMI晚期成功血运重建对远期左室功能的改善作用较非糖尿病者差,其结果可能与糖尿病患者晚期PCI后缺血心肌未能得到有效再灌注或再灌注加重心肌损伤有关,而术前存活心肌可能不是影响其疗效的主要原因.     

急性非Q波心肌梗死与Q波心肌梗死冠状动脉病变特点的比较

目的　比较非Q波心肌梗死 (NQMI)与Q波心肌梗死 (QMI)的冠状动脉病变特点。方法　QMI与NQMI患者入院后 10天内行冠状动脉造影术 ,分析病变类型、范围、狭窄程度及侧支循环。结果　NQMI组的多支病变、>90 %的严重狭窄及侧支循环比率高于QMI组 ,而完全闭塞率低于QMI组 ,二组的病变类型无差异。结论　NQMI的多支病率高于QMI,前者的远期预后有可能较后者差     

老年无Q波心肌梗死患者45例临床分析

随着我国人口老龄化问题的加剧,老年急性心肌梗死（AMI）呈迅速上升趋势,其中无Q波心肌梗死（NQMI）约占老年心肌梗死的1／4。由于NQMI梗死面积小,且在冠状动脉血栓发生过程中可能同时存在自溶现象,所以NQMI与Q波心肌梗死（QMI）患者在临床表现、并发症及预后有很大差别。1991～2004年,我们对146例老年AMI患者的临床资料进行分析,现报告如下。     

心肌存活性对急性心肌梗死后左室重构和左心功能的影响

目的:探讨急性心肌梗死(AMI)患者梗死区心肌存活性对心脏功能的影响.方法:采用回顾性对比研究的方法,62例AMI患者以99mTc-MIBI SPECT静息显像及18F-FDG SPECT心肌代谢显像的检查结果分为梗死区有存活心肌组和无存活心肌组,介入治疗后随访12个月,应用超声心动图评价2组患者的心脏功能.结果:有存活心肌组左室射血分数均显著高于无存活心肌组[术前:(54.25±1.60)%:(47.20±1.83)%,P＜0.01;12个月:(58.09±1.88)%:(50.00±2.06)%,P＜0.01],有存活心肌组左室舒张末期内径均显著优于无存活心肌组[术前:(51.31±0.95)mm:(54.33±1.07)mm,P＜0.05;12个月:(51.65±1.12)mm:(56.10±1.38)mm,P＜0.05].左房内径及舒张期二尖瓣血流速度峰值的比值2组随访时均无显著变化.结论:AMI后梗死区有存活心肌的患者心脏整体收缩功能及左室重构显著优于无存活心肌的患者,但心肌存活性对左心室舒张功能无明显影响.     

老年无Q波心肌梗死患者临床和冠状动脉病变特点

目的　评价老年Q波与无Q波型心肌梗死 (QMI与NQMI)患者的临床和冠状动脉病变的特点。　方法　记录QMI与NQMI患者的高血压、糖尿病病史 ,心肌梗死后的并发症和病死率 ,检测血脂、心肌酶 (CK MB) ,超声心动图测定左室射血分数 (LVEF) ,梗死后 3～ 4周内行冠状动脉造影 ,记录冠状动脉狭窄情况。　结果　两组患者中有高血压、糖尿病及高脂血症的比例相似 ,NQMI组CK MB峰值 (6 8 7± 18 6 )mmol/L明显低于QMI组 (10 8 6± 17 3)mmol/L(P <0 0 1) ,CK MB峰值时间 (17 8± 3 4 )h较QMI组 (2 1 9± 4 8)h提前 ,LVEF(5 6 1± 11 2 ) %高于QMI组(5 0 3± 16 7) % ,均为P <0 0 5 ,心律失常发生率和病死率均低于QMI组 (P <0 0 1) ;QMI组发生心源性休克 3例、心脏破裂 3例、室壁瘤形成 11例 ,而在NQMI组中未出现。单支、双支及 3支血管病变比例两组差异无显著性 (P >0 0 5 ) ;QMI组梗死相关动脉闭塞例数明显高于NQMI组 (P <0 0 1)。　结论　老年NQMI患者急性期预后较QMI患者好 ,梗死相关动脉闭塞率较QMI患者低。     

无Q波心肌梗死

1　名称的由来早年,心肌梗死(MI)分为透壁梗死和非透壁(心内膜下)梗死。一般认为,梗死超过整个心肌厚度靠内一半以上是透壁梗死。左室壁有几层肌肉组织,但心内膜下不存在解剖边缘。有人将心内膜下梗死定为内1/2～2/3的梗死,甚至有人定为内1/2直至内9/10但未完全透壁的梗死。事实上,有的临床诊断为透壁梗死者,尸检却为心内膜下;相反,有的临床诊断为心内膜下者,尸检却为透壁。因而,在80年代早期有专家提出临床应按Q波梗死(QMI)和无Q波梗死(NQMI)分类。这种分类明确反映某些不同的临床表现,包括NQMI有关动脉(IRA)的相对通畅和梗死后持…     

急性前壁心肌梗死后梗死相关血管延迟开通对晚期左室重构的影响

目的　探讨急性前壁心肌梗死(AMI)后延迟经皮冠状动脉介入治疗(PCI)使梗死相关动脉(IRA)开通对AMI晚期左室重构的影响。方法　选择64例急性前壁、前间壁及广泛前壁Q波性AMI后病情稳定,发病2~14天,平均(9 .1±2 .3)天冠状动脉造影证实左前降支完全闭塞者,依据是否成功行PCI,分为成功PCI组和对照组,分别于急性期、术后2个月和6个月应用超声心动图随访左室大小、左室功能和室壁活动异常情况,并观察6个月期间心力衰竭事件的发生情况。结果　AMI后2个月两组左室射血分数、左室收缩末期容积指数、左室舒张末期容积指数和室壁活动异常积分与急性期相比差异无统计学意义,急性期和2个月时两组上述各指标之间差异也无统计学意义。6个月时两组左室射血分数和室壁活动异常积分与急性期和2个月相比差异无统计学意义,但对照组左室舒张末期容积指数和左室收缩末期容积指数较急性期明显增大(P<0 .01, P<0. 05 ),且与成功PCI组相比差异有统计学意义(P<0 .01, P<0 .05)。6个月随访期间心力衰竭事件发生率对照组为19%,成功PCI组为2%,但差异无统计学意义。结论　急性前壁AMI后IRA延迟开通能明显减少AMI后晚期的左室重构,而对AMI后早期左室重构的影响不大。延迟PCI可能有利于减少AMI后远期心力衰竭事件的发生。     

急性心肌梗死后延迟冠状动脉介入治疗对左室重构和远期预后的影响

目的探讨急性心肌梗死(AMI)后延迟经皮冠状动脉介入治疗(PCI)对左室重构(LVRM)和远期预后的影响。方法93例初次AMI患者分为PCI组(47例)和非PCI组(46例)。分别在心肌梗死后(23±10)d(术前)和术后6个月测量左心室容量指数、射血分数(LVEF)和异常室壁运动积分指数,并观察6个月期间主要不良心脏事件的发生情况。结果6个月时两组左室射血分数和室壁活动异常积分与术前相比差异无统计学意义,但对照组左室舒张末期容积指数(LVEDVI)和左室收缩末期容积指数(LVESVI)较术前明显增大(P<0.01,P<0.05),且与PCI组相比差异有统计学意义(P<0.01,P<0.05)。6个月随访期间主要不良心脏事件发生率对照组为11%,成功PCI组为4%,但差异无统计学意义。结论AMI后延迟PCI可抑制左室扩大,延缓慢性期左室重构,并显著减少心脏事件的发生。     

非Q波心肌梗死病人冠脉造影及临床特点分析

目的 探讨非Q波心肌梗死病人冠脉造影及临床特点分析.方法 选择我院1999年1月-2004年12月收治的心肌梗死病人175例.按心电图有无病理性Q波分为Q波心肌梗死(QMI)和非Q波心肌梗死(NQMI).非Q波心肌梗死病人53例,Q波心肌梗死病人122例,对两组病人的性别、年龄、既往心绞痛病史、嗜烟史及合并糖尿病、血压(收缩压、舒张压)血糖、血脂、血清心肌酶、心律失常及冠状动脉造影术等资料进行比较.结果 非Q波心肌梗死组女性、既往心绞痛史、梗死后心绞痛、再梗死、冠脉侧支循环开放、冠脉弥漫型病变与Q波心肌梗死组两者相比较有统计学意义(P<0.05).而非Q波心肌梗死组血清磷酸激酶(CPK)峰值、肌钙蛋白T(cTnT)峰值(1 046 U/L±518 U/L,2.9 ng/mL±1.2 ng/mL)、冠脉单支病变、冠脉完全闭塞率均低于Q波心肌梗死组.结论 NQMI 病人既往心绞痛史、梗死后心绞痛、再梗死率高,而院内恶性心律失常发生率低.冠脉单支病变、冠脉完全闭塞率低,而冠脉弥漫型病变、侧支循环的开放率均高.血清CPK酶峰值、cTnT 峰值低.     

Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function.

OBJECTIVE: To investigate the value of a giant negative T wave (> or = 1.0 mV) in precordial leads of 12-lead electrocardiograms in the acute phase of Q wave myocardial infarction as a predictor of myocardial salvage. METHODS: Coronary angiographic and electrocardiographic findings, left ventricular ejection fraction in the chronic stage, and levels of cardiac enzymes were compared in patients with myocardial infarction with (group GNT, n = 31) and without (group N, n = 20) a giant negative T wave. GNT patients were divided into two subgroups according to the presence (GNT:R[+], n = 10) or absence (GNT: R[-], n = 21) of R wave recovery with an amplitude > or = 0.1 mV in at least one lead that had shown Q waves. RESULTS: The maximum level of creatine kinase and the total creatine kinase were lower in group GNT compared with group N (P < 0.05). The left ventricular ejection fraction was higher in group GNT than in group N (P < 0.05). The maximum creatine kinase and total creatine kinase were lower in GNT:R(+) than in GNT:R(-) (P < 0.01). The left ventricular ejection fraction was higher in GNT:R(+) than in GNT:R(-) (P < 0.01). The frequency of R wave recovery was significantly higher when giant negative T waves appeared within 100 h of myocardial infarction or when the maximum potential was > or = 1.4 mV. The appearance of a giant negative T wave > or = 1.4 mV had a sensitivity of 90%, a specificity of 71.4%, a diagnostic accuracy of 77.4%, a positive predictive value of 60%, and a negative predictive value of 93.8% for prediction of R wave recovery. CONCLUSIONS: The appearance of a giant negative T wave, especially within 100 h of the onset of myocardial infarction, with a maximum potential of > or = 1.4 mV, may predict a reappearance of the R wave and a better left ventricular function in patients in the chronic stage of anterior myocardial infarction.     

Complex ventricular arrhythmias in patients with Q wave versus non-Q wave myocardial infarction

We examined whether or not subsets of patients with complex ventricular arrhythmias after myocardial infarction are at high risk with respect to 1 year mortality after hospital discharge. Based on previous studies showing increased risk for those with non-Q wave infarcts, we hypothesized that complex PVCs (premature ventricular complexes) in this group might be associated with a poorer prognosis than complex PVCs in patients with Q wave infarcts. Seven hundred seventy-seven patients entering our study with acute infarction were followed prospectively for 1 year after undergoing a predischarge 24 hr ambulatory electrocardiographic examination. Patients were classified by electrocardiographic criteria into the following groups: Non-Q wave (n = 191), Q wave anterior (n = 261), and Q wave inferior infarction (n = 325). The following arrhythmias were classified as complex: multiform PVCs, couplets, and ventricular tachycardia. Sixty-two percent of patients with non-Q wave infarcts who did not survive 1 year had complex PVCs, compared with 32% of survivors (p less than .01). No differences were seen in the Q wave subgroup. The survival for patients with Q wave and non-Q wave infarction without complex PVCs were nearly identical at 1 year (93% and 90%), whereas in patients with complex PVCs survival for those with Q wave and non-Q wave infarction was 92% and 76%, respectively (p less than .001). Of those with non-Q wave infarction, only 4% of nonsurvivors were free of any PVCs, as compared with 28% of nonsurvivors in the Q wave group (p less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Early invasive versus ischaemia-guided strategies in the management of non-Q wave myocardial infarction patients with and without prior myocardial infarction; results of Veterans Affairs Non-Q Wave Infarction Strategies in Hospital (VANQWISH) trial.

AIMS: To compare the role of early invasive vs conservative management strategies in treating patients with non-Q wave myocardial infarction with or without a prior myocardial infarction. BACKGROUND: In patients recovering from non-Q wave myocardial infarction, the prognosis among patients with a first non-Q wave myocardial infarction is significantly better than in patients with a prior myocardial infarction, yet physicians often adopt an early invasive strategy to treat patients with a first non-Q wave myocardial infarction. METHODS: Non-Q wave myocardial infarction patients enrolled in the VANQWISH trial with a history of prior myocardial infarction were compared to those with a first non-Q wave myocardial infarction, for the trial primary end-point of death or myocardial infarction at 1 and 12 months, as well as for the initial randomized treatment strategy. RESULTS: Of the 920 non-Q wave myocardial infarction patients, 396 had a history of prior myocardial infarction and 524 did not. Patients with a history of prior myocardial infarction were older and had a higher incidence of multiple high-risk baseline characteristics than those with a first non-Q wave myocardial infarction. Compared to the group with a first myocardial infarction, the prior myocardial infarction group suffered more events at both 1 month (11% vs 6%, P=0.007) and at 12 months (29% vs 16%, P<0.001). This difference in outcome remained significant even after adjusting for confounding variables (P<0.0001 at 12 months). Among the non-Q wave myocardial infarction patients with a prior myocardial infarction, the frequency of death or recurrent myocardial infarction was similar in both invasive and conservative groups during the first year of follow-up. Among the first non-Q wave myocardial infarction group, those assigned to the conservative strategy had significantly fewer events (3% vs 9%, P=0.009 at 1 month; 12% vs 20%, P=0.016 at 12 months) and mortality (1% vs 5%, P=0.012 at one month; 5% vs 11%, P=0.009 at 12 months) than those assigned to early invasive strategy. CONCLUSION: A history of prior myocardial infarction identifies a moderately high-risk subset of non-Q wave myocardial infarction patients who display similar long-term outcomes regardless of the strategy assignment; however, patients with a first non-Q wave myocardial infarction may fare better with a conservative or ischaemia-guided approach during the first post infarction year.     

Acute non-Q wave myocardial infarction associated with early ST segment elevation: evidence for spontaneous coronary reperfusion and implications for thrombolytic trials

The clinical significance of early ST segment elevation in patients with non-Q wave infarction is unknown. Therefore, 150 consecutive patients with creatine kinase isoenzyme-confirmed acute uncomplicated myocardial infarction who had ST segment elevation of 1 mm or more in at least two contiguous leads on the admission electrocardiogram were analyzed. None received thrombolytic therapy or acute coronary angioplasty. Predischarge angiography, radionuclide ventriculography and exercise thallium-201 scintigraphy were performed 10 +/- 3 days after myocardial infarction. Based on serial electrocardiograms (on days 1, 2, 3 and 10), all 150 infarcts were classified as Q wave (n = 115 [77%]) or non-Q wave (n = 35 [23%]). Although patients with Q wave infarction exhibited greater ST elevation, the amount observed in the non-Q wave group was appreciable, as reflected by the number of leads with ST elevation (3.8 +/- 1.8 versus 3.1 +/- 1.2, p = 0.007) and the sum of the ST elevation (9.6 +/- 7.4 versus 6.2 +/- 6.2 mm, p = 0.016). When compared with the Q wave group, patients with non-Q wave infarction had a shorter time to peak creatine kinase (23.0 +/- 9.1 versus 15.8 +/- 7.9 hours, p = 0.0001), a higher infarct vessel patency rate (24 versus 57%, p = 0.001), lower peak creatine kinase values based on 4 hour sampling (1,372 +/- 964 versus 664 +/- 924 IU/liter, p = 0.0002) and a higher left ventricular ejection fraction (46 +/- 12% versus 54 +/- 9%, p = 0.0003).(ABSTRACT TRUNCATED AT 250 WORDS)     

Initial ECG in Q wave and non-Q wave myocardial infarction

The initial ECGs in 440 patients admitted for suspected acute myocardial infarction were retrospectively analyzed to determine predictive values of these ECGs for acute myocardial infarction and to determine differences in the initial ECG for Q wave and non-Q wave myocardial infarction. One hundred (23%) of the study patients were diagnosed as having an acute myocardial infarction. Acute injury was seen in 47% of these patients (positive predictive value [PPV], 84%; 95% confidence interval [CI], 72% to 92%), ischemia in 15% (PPV, 39%; 95% CI, 24% to 57%), and left ventricular hypertrophy with strain in 11% (PPV, 19%; 95% CI, 4% to 29%). Forty-three patients were diagnosed as having a Q wave infarction and 50 patients as having a non-Q wave infarction. Seventy-two percent of the patients with a Q wave infarction had acute injury as the initial ECG interpretation compared with 38% in the non-Q wave infarction group (P less than .001). In contrast, only 17% of patients with Q wave infarction had an initial ECG interpretation of ischemia or strain as compared with 36% of patients with non-Q wave infarction (P = .03). Because of the relatively high incidence of acute myocardial infarction in patients admitted with an initial ECG interpretation of ischemia or left ventricular hypertrophy with strain, prospective studies must be performed to determine if selective patients with acute ST segment depression or ischemic T wave inversion in the setting of suspected acute myocardial infarction may benefit from early thrombolytic therapy.     

Short- and long-term clinical outcome after Q wave and non-Q wave myocardial infarction in a large patient population

Prognosis for patients with non-Q wave myocardial infarction is controversial although a number of studies have shown a less favorable outlook after hospital discharge for patients with non-Q wave than for those with Q wave infarction. Therefore, the in-hospital and 1-year prognosis was investigated in a sufficiently large patient population (n = 2,024) to allow stratification by subgroups, in particular by age and previous myocardial infarction. Patients with non-Q wave infarction (n = 444; 22% of the total study population) were somewhat older (65 vs. 63 years, p less than 0.001) and had an increased incidence of previous myocardial infarction (46% vs. 24%, p less than 0.001) and congestive heart failure (21% vs. 8%, p less than 0.001) than patients with Q wave infarction. In-hospital mortality of patients with non-Q wave infarction was lower (8.1% vs. 11.5%; p less than 0.06), whereas their 1-year mortality after hospital discharge was significantly higher (13.7% vs. 9.2%, p less than 0.05) than for patients with Q wave infarction. However, total mortalities at 1 year were nearly equal. When patients were subgrouped by presence or absence of a previous myocardial infarction, patients in both subgroups exhibited mortality patterns typical of the entire population with Q wave or non-Q wave infarction. However, when stratified by age and previous infarction, in-hospital mortality for patients with non-Q wave infarction was significantly lower only in patients older than 70 years of age. Similarly, the higher mortality after hospital discharge in patients with non-Q wave infarction occurred only in patients older than 70 years of age without previous myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial viability in patients with Q wave myocardial infarction and no residual ischemia.

BACKGROUND. Coronary revascularization in patients with persistent angina after myocardial infarction reduces the incidence of recurrent angina pectoris and myocardial infarction and improves left ventricular function. The results of revascularization after a Q wave myocardial infarction when there is no residual ischemia may depend on myocardial viability. METHODS AND RESULTS. To determine whether there was viable myocardium in the infarct area in the absence of clinical and scintigraphic evidence of myocardial ischemia, 15 asymptomatic patients with a Q wave myocardial infarction, no redistribution on stress 201Tl test, and single-vessel disease (greater than 70% stenosis) with persistent anterograde blood flow were randomized to percutaneous transluminal coronary artery angioplasty (PTCA) or conservative medical treatment. After 2 months of follow-up, mean coronary blood flow measured by Doppler catheter in the infarct-related artery was higher in the PTCA treatment group (33 +/- 6 ml/min, n = 8) than in the conservative treatment group (16 +/- 4 ml/min, n = 7; p less than 0.05 between groups). The 201Tl pathological-to-normal ratios measured on postexercise images did not change in patients treated conservatively during the follow-up period (delta = +1.1 +/- 2.2%; NS from baseline) but increased significantly in patients treated by PTCA (delta = +8.5 +/- 2.3%; p less than 0.01 from baseline; p less than 0.05 between groups). Segmental wall motion improved on left ventricular angiography 2 months after PTCA (delta = +11.5 +/- 2.2%; p less than 0.001 from baseline) significantly more than in the conservative treatment group (delta = +4.1 +/- 1.4%; p less than 0.05 between both groups). Improvements of 201Tl ratios and segmental wall motion indexes correlated significantly (r = 0.73, p = 0.002). The mild improvement of global left ventricular ejection fraction measured in the PTCA treatment group did not differ significantly from changes in the conservative treatment group. CONCLUSIONS. Successful angioplasty of the stenotic infarct artery in patients with a Q wave myocardial infarction and no residual ischemia improved coronary flow, 201Tl uptake in the infarct area, and regional wall motion. Therefore, myocardial viability may last several weeks, as long as residual blood flow persists in the infarct-related artery. Optimal assessment of viability by imaging techniques should identify patients who are most likely to benefit from revascularization.     

Extracorporeal cardiac shock wave therapy improves left ventricular remodeling after acute myocardial infarction in pigs

OBJECTIVE: We have recently demonstrated that low-energy extracorporeal shock wave therapy improves chronic myocardial ischemia in pigs and humans. In this study, we examined whether our shock wave therapy is also effective at improving left ventricular remodeling after acute myocardial infarction in pigs. METHODS: Acute myocardial infarction was created by surgically excising the proximal segment of the left circumflex coronary artery (n=20). In the early treatment protocol, the shock wave therapy was started 3 days after acute myocardial infarction, whereas in the late treatment protocol, the therapy was started 4 weeks after acute myocardial infarction (n=5 each). The remaining animals were treated in the same manner, but without the shock wave treatment in each protocol (n=5 each). RESULTS: In the early treatment protocol, left ventricular ejection fraction was higher (42+/-1 vs. 32+/-1%, P<0.001) and left ventricular end-diastolic volume was smaller (95+/-1 vs. 99+/-2 ml, P<0.05) in the shock wave group compared with the control group. Furthermore, wall thickening fraction (32+/-1 vs. 28+/-1%, P<0.01), regional myocardial blood flow (1.7+/-0.2 vs. 1.0+/-0.1 ml/min/g, P<0.01), and number of capillaries in the border zone (1348+/-15 vs. 938+/-34 mm2, P<0.0001) were all significantly improved in the shock wave group compared with the control group. By contrast, in the late treatment group, no such beneficial effects of the shock wave therapy were noted. CONCLUSION: These results suggest that our extracorporeal cardiac shock wave therapy is also an effective and noninvasive therapy for improving left ventricular remodeling after acute myocardial infarction when started in the early phase of the disorder.     

T wave positivity in resting electrocardiogram predicts preserved systolic thickening in chronic anterior Q wave myocardial infarction: an echocardiographic study.

AIM: After ST elevation myocardial infarction, ST segment and T wave changes generally resolve, but in some patients T waves keep their negative components for a long time. The aim of this study is to evaluate the pathophysiological implications of persistent negative T waves and restored positive T waves in the chronic stage of Q wave myocardial infarction. METHODS: We studied 30 patients with a previous anterior wall ST elevation myocardial infarction (more than one year follow-up) and presenting Q waves in at least three consecutive precordial leads in the standard 12-lead electrocardiogram at rest. Patients were divided into two groups according to the T wave pattern in leads with Q waves: positive T group consisting of patients in whom all T wave components showed an upright configuration; and a negative T group consisting of patients in whom T waves were are least partly inverted. We used echocardiography to measure systolic thickening of the interventricular septum within the infarction area. Systolic thickening was considered significant when end-systolic thickness was greater than end-diastolic thickness by > 25% in proportion and > 1 mm in absolute value. RESULTS: Significant systolic thickening was demonstrated in 14 (74%) of the 19 positive T patients and in one (9%) of the 11 negative T patients (odds ratio 8.1; 95% CI, 1.2 to 53.5; p = 0.002). CONCLUSION: In the chronic stage of a myocardial infarction, restored T wave positivity predicts preserved systolic thickening, suggesting the presence of viable and normally contracting myocytes within the infarction area. Further studies are needed to establish the prognostic value of T wave characteristics in patients with a past history of myocardial infarction.     

Prognosis after extension of myocardial infarct: the role of Q wave or non-Q wave infarction

We examined whether or not subsets of patients with extension of myocardial infarct were at high risk for early and late mortality. Some data suggest increased risk in patients with non-Q wave infarcts and we hypothesized that infarct extension in this group might be associated with a poorer prognosis than that for patients with extension of Q wave infarcts. A total of 1253 patients with acute myocardial infarction who were included in our data base were followed prospectively. The patients were classified according to electrocardiographic results into the following groups: those with non-Q wave (n = 277) infarcts and those with Q-anterior (n = 462) and Q-inferior (n = 497) infarcts. Extension was diagnosed by two of the following criteria: (1) recurrent chest pain 24 hr or more after admission to the hospital, (2) new persistent electrocardiographic changes, and (3) elevation or reappearance of creatine kinase. By these criteria 85 (6%) patients had extension (8% of non-Q wave infarcts, 6% of Q-anterior infarcts, and 6% of Q-inferior infarcts). Hospital mortality in patients with extension was 15% in those with Q wave infarcts vs 43% in those with non-Q wave infarcts (p less than .01). Nine hundred and fifty-two patients were followed for 1 year. In 24% of those who did not survive 1 year there was extension of infarct; only 6% of survivors had extension (p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)