这项研究是由国家机构的资助护理研究R21 NR-011202（MMP），R21 NR-009716（MGC）。 想感谢德比Ganchan的，RN，BSN为她细心周到的数据收集。我们还要感谢圣玛丽医院的护士和医生在医院纷纷慷慨解囊，提供援助与研究的。

1。患者准备<ol><li>获得知情同意书。 </li><li>确定土地的标记准确的导管放置在胸前。为了尽量减少心电图神器和噪声梅森-Likar的电极配置，其中使用肢体引线电极被放置在躯干四肢的前端（ 图2），而不是23 </li><li>准备用酒精准备垫的躯干和皮肤干燥轻快地用纱布垫，以确保最佳的皮肤电极接触。 </li><li>如果有必要，在具体的躯干位置，以使有足够的接触与皮肤电极夹胸毛。执行此步骤谨慎，因为这名病人的人口接受抗凝治疗，因此容易出血。 </li><li>如果可能的话，使用不褪色墨水，以纪念网站，以确保皮肤电极电极返回到正确的位置，在该事件中，他们脱落或删除程序（ 即 echocardiogrAMS，胸部透视等）。 </li><li>在女性中，电极V3应被放置在顶部的乳房组织和V4和V5的电极应放在正下方下垂的乳房，使乳房位于电极的顶部上，以确保精确的安置和防止运动伪影。 </li><li>双监视用于在这项研究中，医院床边监视器和研究动态心电记录。因此，两个心电图皮肤电极被施加到躯干。 </li><li> ECG导线连接到皮肤电极之前，将病人的胸部，以防止不必要的压力的chest.Radiolucent皮肤电极上的电极施加为了避免除去射线照相程序。 </li><li>输入动态心电图设备，并开始心电监护病人的唯一的研究识别码（确定）。 </li><li>将动态心电记录在显示器袋，并通过绳绕颈或在长袍的口袋里。 </li><li>获取位置ECGs的过程中使用的心电图数据的离线分析。包括三个位置:1）仰卧，2）右侧，和3）左侧卧。 </li><li>评估病人至少每2小时时，研究人员是在医院，并在年底的一天，时移，以确保在夜间保持监测。护士，辅助人员（ 如X-射线，超声心动图，与导尿技术人员）的工作人员的教育工作，以确保皮肤更换电极如果需要拆除的过程。正确的电极放置一个的躯干图与留在床边的资源，使工作人员能够更换皮肤如果必要的，也是多余的皮肤电极的电极。 </li><li>如果病人进入心导管实验室，将透亮的引线连接到皮肤的电极，这样可以保持心电图监测在导管插入过程中，以确保连续监测。 </li><li>当监测完成，该设备具有抗菌湿巾清洁。 </li></ol> 2。心电图分析程序<ol><li>在完成监测（持续时间可能会有所不同），闪卡阅读器H-抄写员科研计算机上加载的紧凑型闪存卡的动态心电记录仪。 </li><li>准备的数据进行分析，识别和标记每个QRS波群正常，心室，室上性或工件与H-抄写心律失常分析软件。 </li><li>的心电图数据进行初步评估没有临床数据知识，以减少偏见。 </li><li>的H-抄写软件编程，使用标准的定义，识别性心肌缺血，ST的偏差（抬高或压低）≥100微伏≥2个导联（S）持续≥60秒32在这项研究中，ST段偏移过去，在60毫秒的测量J点。 </li><li>符合这些条件的ST段变化进行识别和标记的H-抄写，并表示在肛门ysis总结。人的监督，以验证是否存在缺血必须做的任何一台计算机生成的事件，以确保正确识别假阳性ST段变化。这个过程将在下面描述。 </li><li> ST段趋势变化提示急性缺血评估小时的连续获取的ECG数据（图3）的一个有效的方法进行评估。 </li><li>为了找出真正的心肌缺血，任何获得3心电图提示急性心肌缺血的评估趋势: <ol class="ualpha"><li>基线ECG之前认定为"事件前心电图的ST段变化， </li><li>心电图认定为"最大的事件心电图ST段偏移，在最高点" </li><li>认定为"事件后心电图心电图ST段偏移彻底解决，" </li></ol></li><li>评估的三个心电图的ST段改变，以确保不因假阳性的变化（ 例如 ，加速ventr要约，要约节奏，间歇性的心室起搏节奏，间歇性束支传导阻滞，或体位改变）。 </li><li>缺少的ECG数据，质量不足的和假阳性ST改变的数据从分析中排除。这些问题都可以最小化使用的一些策略。这些包括:（1）用透亮的心电电极，无需取出电极的X-射线;（2）高品质的护肤准备，由研究护士在一开始就进行监测;（3）四舍五入各地的病人每2小时天;（4）可用性的电话，回答疑虑或问题，从护理和医疗人员。此外，研究小组护理和医疗人员定期进行通信。 </li><li>一旦心电数据进行分析，用于识别病人的医疗记录日期/时间的治疗，药物治疗和症状监测期间。 </li><li>心电图分析验证，确保具有第二专家分析ECG数据使用相同的方法在一个指定的比例的样品如上所述。我们的团队这例患者的20％。 </li><li>用于研究目的，存档的心电数据，以确保适当的数据被保存到外部硬盘驱动器和/或网络驱动器上。 </li></ol>

<ol>
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J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency,+duration,+magnitude,+and+consequences+of+myocardial+ischemia+during+intracoronary+ultrasonography.">Frequency, duration, magnitude, and consequences of myocardial ischemia during intracoronary ultrasonography.</a> Am. Heart J. 134, 474-478 (1997).</li><li>Drew, B. J., Pelter, M. M., Adams, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency,+characteristics,+and+clinical+significance+of+transient+ST+segment+elevation+in+patients+with+acute+coronary+syndromes.">Frequency, characteristics, and clinical significance of transient ST segment elevation in patients with acute coronary syndromes.</a> Eur. Heart J. 23, 941-947 (2002).</li></ol>

作者们没有竞争的金融利益申报。

在这篇文章中描述的研究方法，使用Holter记录，捕捉连续12导联心电图记录。虽然计算机辅助软件工程ST段短暂性脑缺血检测，准确分析，需要仔细，专家的监督。在分析过程中考虑的重要因素包括:（1）神器，（2）的一致性和准确性放置电极，（3）身体姿势的变化，（4）药物的影响，以及（5）突然波形的变化。 总之，连续12导联心电图监测，这是既便宜又非侵入性，可识别短暂的心肌缺血发作的前兆MI，即使在无症状。10,12,33,34，12导联心电图监测医院的做法是不常见的，相反，只有两条引线，通常被监控。 12导联心电图监测获得的信息可能会提供有用的信息，决定与ACS患者的最佳治疗。然而，随机临床试验评估缺血的临床反应，以确定需要的价值，这种技术识别高风险的患者可能受益于更积极的管理策略，在ACS。

<html>根据最近的美国心脏协会的统计数据，冠状动脉疾病（CAD）， ​​估计是负责120万的住院治疗，治疗是最昂贵的医疗条件。1超过半数的医院停留CAD患者之间谁也逗留期间接受经皮冠状动脉介入治疗（PCI）或冠状动脉旁路移植术（CABG）。由于CAD的患病率，在医院工作的医生有可能经常会遇到这些病人。这篇稿子的目的是描述的ECG应用程序和分析方法的比较研究（电Çardiographic中为例缺血中号 IA COM P O N环进行投资，以PHAŕmacological TRËatment的一个西伯;（R21 NR-011202） ，这可能被利用的其他研究，探索这个临床问题。 T"每年近70万美国人将有一个新的冠心病发作，或急性冠脉综合征（ACS）。1 ACS的病理生理涉及动脉粥样硬化斑块破裂，因此，治疗的目的是稳定斑块，以防止细胞死亡然而，有相当大的临床医生的辩论中，哪些是最好的治疗途径:早期浸润性经皮冠状动脉介入治疗（PCI /支架）时表示，一个保守的方法（ 即药物治疗或PCI /支架如果出现复发症状）。 -5 在三种类型的ACS有三种类型:ST段抬高心肌梗死（STEMI），非ST段抬高心肌梗死（NSTEMI）和不稳定型心绞痛（UA）。6，NSTEMI / UA是近四倍，作为共同的STEMI。7 ，8 NSTEMI / UA的处理决定主要是根据症状和休息或运动心电图（ECG）。然而，因为动态的和不可预知的Natu重新动脉粥样硬化斑块，这些方法往往是在检测心肌缺血，因为症状是不可靠的，和/或持续心电监护，尚未动用。 NSTEMI / UA的表现形式包括:（1）症状（胸部，手臂，下巴或颈部疼痛，出汗，恶心），（2）释放NSTEMI的情况下，心脏生物标志物（肌钙蛋白I，肌钙蛋白T，或creatnine的激酶MB）和（3）心电图（ECG）的变化（间歇性ST段抬高/抑郁，或T波倒置）。虽然症状可能发生在ACS，这是有据可查的，短暂的心电图检测缺血发作是在70％以上的患者无临床症状。9-12重要的是，许多研究都发现，患者的心电图检测心肌缺血，患者相比，没有这样的事件，因此在短期内11-13和长期不利结果 ​​的风险较高。14-16，症状是在NSTEMI / UA，这是一个不可靠的指标缺血治疗早期侵入性策略或服药初期战略决策问题，因为病人的症状往往是2-5此外，生物标志物识别NSTEMI / UA的患者为时已晚，因为他们的存在表明，血清中细胞死亡已经发生。 表示缺血的心电图变化发生在几秒钟内冠状动脉的血流量减少。10,17复杂的心电图变化在急性缺血性ST段的三个点之一，这是衡量的部分，（1）J点， （2）J点，加上60毫秒（msec）的，或（3）J点加80（毫秒）（ 图1）。 12导联心电图识别MI，它是非侵入性的，廉价的，如果持续保持可识别短暂性脑缺血，甚至当它是无临床症状症状和生物标志物的重要优势。虽然12导联心电图监测是理想的，因为亩ltiple地区的心脏进行评估，典型的医院实践结合的监测，只有两个导联。两个心电图导联的护士在医院环境中最常用的监控V1和II。不幸的是，这两根导线用于检测在许多ACS患者短暂性脑缺血是不敏感的。10,19因此，缺血外发生的这两个监控线索将被错过。 使用12导联心电图监测比较研究的目的是评估的频率和过性心肌缺血的临床后果，NSTEMI / UA患者早期侵入性的初始保守的方法，其中包括药物单独管理的PCI /支架治疗，过渡到PCI /支架以下症状反复发作。在我们的研究中，连续12导动态心电记录仪是用来捕捉缺血。本描述性研究的目的是评估的频度和临床后果的反刻度心肌缺血，NSTEMI / UA患者的治疗无论是早期介入治疗PCI /支架或保守治疗（药物治疗或PCI /支架后，症状反复发作）。 方法上的挑战虽然计算机辅助软件工程ST段短暂性脑缺血检测，准确分析，需要仔细，专家的监督。在分析过程中考虑的重要因素包括:（1）神器，（2）的一致性和准确性放置电极，（3）身体姿势的变化，（4）药物的影响，和（5）突然波形的变化。这些因素都将在下面讨论。 工件:由于临床显着的ST段变化小为100微伏（一个小盒子上的心电图纸），噪声信号的肌肉刺激可显着阻碍分析。大部分文物是皮肤准备不当有关。的问题CAN是很容易解决病人的躯干与细致的皮肤准备在一开始监测，并根据需要在整个监测期间21日至23日的皮肤准备应包括在网站电极去除毛发，大力清除皮肤油/碎片，使用醇制备焊盘和/或毛巾。23,24 电极位置的一致性和准确性假阳性ST段电极移动或删除时，在监控过程中可能发生的变化。20这种可管理的网站监测，以确保电极在一开始就用不褪色墨水标记每个电极都将重新应用到正确的位置，如果他们脱落或删除程序（ 例如 ，超声心动图，X-射线）。25我们建议的评估，以确保病人的躯干，至少每4小时皮肤电极在胸前。 体位的变化:udies使用连续ST段监测表明，一些患者可在体位改变（ 即 ，左，右侧卧），可被误诊为心肌缺血的表现伴随QRS波群和ST段振幅的变化。26,27我们的研究小组发现，假阳性ST段报警，体位改变是最常见的原因。使用超声心动图，Feldman和同事28发现，当患者从仰卧到左侧卧位，左心室移近侧胸壁。这有一个直接的影响从胸部电极的左心室的距离上，并导致在心电图中的R波的振幅的增加导致移到该心肌领土。这些变化已经证实了别人。26,27一般情况下，位置心电图变化怀疑时，心电波形的幅度增加，同时ST段变化。一个有用的策略是获得"位置的模板心电图假设与患者仰卧，左，右侧卧的位置时，开始监测，为以后进行比较分析。 药理作用:即使在治疗剂量的药物可影响心电波形。药物改变ST段是特别重要的，因为它们会导致误诊为心肌缺血。29这些药物包括洋地黄，抗心律失常药，吩噻嗪类。 "洋地黄效应"是用来描述特征的ST段和T波改变可能出现的这种药物，包括"拱形"ST段压低，扁平的T-波和短QT间期的时间间隔。等30个其他药物，作为抗心律失常药物（ 如奎尼丁，索他洛尔和胺碘酮）30，吩噻嗪，用于治疗精神分裂症/精神障碍，增加QT间期，减少T波振幅31 Ňevertheless，服用这些药物的患者可以监视可能表明急性心肌缺血急性ST段变化。项目的基线异常的药物是慢性看到，因此任何ST段偏移（压低或抬高），应评估患者的基线ST段电平发生急性心肌缺血。 突然波形变化:瞬态条件，如心律失常，右或左束支传导阻滞（BBB），以及间歇性的心室节奏的节拍，可以扭曲的ST段和导致假阳性缺血诊断。20 总之，连续ST段监测识别性心肌缺血疑似ACS患者是一个很好的工具。然而，这种方法要求仔细的电极中的应用，并导致电线进行在开始和整个监测。这种方法也需要认真的人监督为了消除假阳性ST段的改变。 步骤分步方法在比较研究中，数字动态心电图记录仪（H12 +，莫仪器，密尔沃基，威斯康星州），它记录了在4毫秒的间隔超过10秒采样，以确定中位数拍的电势。全部12导联（I，II，III，AVR，AVL，aVF导联V1-V6），同时获得一个数字采样速率为每秒1000个样本每通道存储到一个紧凑的闪存卡。此外，H12 +电极阻抗测量，以确保正常的皮肤前的准备工作开始动态心电图记录。的显示器指示如果一个心电导联线已成为分离的，还提供了一个用于记录日记事件的内部时钟。从动态心电图监测烧录卡的数据被下载到H-抄写员，脱线动态心电分析系统（莫仪器，密尔沃基，威斯康星州）。该软件允许连续心电图记录分析INGS来确定的信号的质量，心律失常的存在下，和局部缺血。 研究助理工作经验的心脏病患者人口的动态心电数据收集。会议在研究开始的培训计划，以确保研究方案的质量和一致性。一个培训课程，包括心电监护程序，包括如何应用心电监护设备，启动/保持科研计算机上的心电监护，并下载动态心电数据。回示威活动进行间信度完成整个研究过程中，通过随机评估10％，目前在读的科目。双周研究小组会议的招聘目标，面临的挑战进行了讨论，并间信度测试的结果可以共享。 在比较研究的研究方法有两个重要的步骤，病人准备和立东北心电图分析。这两种方法都将在随后的部分中的一步一步的方式解释。

<table border="1"><tbody><tr><td> 的试剂/材料名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论 </td></tr><tr><td> 皮肤电极:生物PROTECH的泡沫Radiotranslucent电极</td><td>心脏直接</td><td> SKU:T716C </td><td></td></tr><tr><td> 透亮导联线 </td><td>优势医疗电缆</td><td> LW-3090R48/5A </td><td></td></tr><tr><td> 动态心电记录:H12 +版本3.12，12导联动态心电图记录仪，24小时Compact Flash卡，美国心脏协会10线LeadForm病人电缆</td><td>莫仪器，威斯康星州密尔沃基</td><td> H12PLUS-AAA-XXXXX </td><td></td></tr><tr><td> H-抄写动态心电分析系统 ，版本3.71 </td><td>莫仪器，威斯康星州密尔沃基</td><td> ĤSCRIBE - 咩 - AACXX的</td><td></td></tr></tbody></table>

a research method for detecting transient myocardial ischemia in patients with suspected acute coronary syndrome using continuous st-segment analysis

每年，估计有785,000美国人将有一个新的冠心病发作，或急性冠脉综合征（ACS）。 ACS的病理生理涉及动脉粥样硬化斑块的破裂，因此，稳定斑块的治疗的目的是为了防止细胞死亡。然而，有相当多的临床医生的辩论中，哪些是最好的治疗途径:经皮冠状动脉介入治疗（PCI /支架）时表示，保守的方法（ 即的药物只与PCI /支架如果出现复发症状）早期浸润性。 有三种类型的ACS:ST段抬高心肌梗死（STEMI），非ST段抬高心肌梗死（NSTEMI）和不稳定型心绞痛（UA）。在这三种类型中，NSTEMI / UA是常见的STEMI近4倍，。 NSTEMI / UA的处理决定主要是根据症状和休息或运动心电图（ECG）。然而，因为动态和不可预测性的atherosclerotiÇ斑块，这些方法往往是在检测心肌缺血，因为症状是不可靠的，和/或持续心电监护，尚未动用。 连续12导联心电图监测，这是既便宜又非侵入性的，短暂的心肌缺血发作的前兆MI，即使无症状。然而，连续12导联心电图监测是不平凡的医院的做法，而是只有两条引线，通常监测。 12导联心电图监测获得的信息可能会提供有用的信息，以决定最好的ACS治疗。 目的，因此，利用12导联心电图监测，比较研究（电Çardiographic中为例缺血中号 IA COM P O N账单INV 一个西伯PHAŕmacological数Ëatment）的目的是评估的频度和临床后果的瞬态NSTEMI / UA患者的心肌缺血，无论是早期介入治疗PCI /支架或那些管理保守治疗（药物治疗或PCI /支架以下症状反复发作）。这篇稿子的目的是描述所使用的方法的比较研究。 方法。进行这项研究的医院和大学的机构审查委员会的权限。研究护士识别疑似ACS住院的病人从急诊科和遥测单元。一旦同意，12导联心电图动态心电图监测，病人的整个住院过程中仍然存在。患者也维持在每家医院协议的常规床边心电监护系统。离线心电图进行分析，使用先进的软件和仔细的人的监督。

心电数据的初步分析，包括使用H-抄写软件的11导联ST段趋势的评估。值得注意的是，aVR导联不上显示的趋势，因为它是一个倒置的铅和不被视为可用于趋势分析，然而，这的铅是可见的12导联心电图打印输出。这种方法是一种快速简便的评估，用于评估小时的心电数据可能存在短暂的心肌缺血。印刷12导联心电图的ST段趋势的改变需要进一步的深入分析之前，期间和之后的趋势变化，将在下面解释。 <img alt="图1" src="/files/ftp_upload/50124/50124fig1.jpg" /> 图1。图 A显示了一个正常的ST段，PR段相比持平;的乙 showsST段抬高，通常显示总的冠状动脉闭塞;C显示ST段压低，通常表示部分冠状动脉闭塞。 ST段偏移也可测得的J点，J点+ 60 + 80毫秒毫秒，或J点。 （来源:M.骤降，M.＆凯里，在AACN重症监护程序手册 （ED韦根林恩·麦克海尔DJ）511-518（爱思唯尔·桑德斯，2011年许可）。 <img alt="图2" src="/files/ftp_upload/50124/50124fig2.jpg" /> 图2的躯干说明使用的的梅森- Likar电极配置的领先位置。右臂（RA）到右肩锁骨下窝，左臂（LA）的左肩锁骨下​​窝，右腿（RL）右下腹部肚脐下方，左腿（LL）左下腹部脐下; V1第四肋间胸骨边境的权利; V2第4肋间左胸骨边境V3之间的中间V2和V4，V4第五，我锁骨中线ntercostal空间; V5 V4腋前线直线距离; V6 V4腋直线。 （来源:M.骤降，M.＆凯里，在AACN重症监护程序手册 （ED韦根林恩·麦克海尔DJ）511-518（爱思唯尔·桑德斯，2011年许可）。 <img alt="图3" fo:content-width="5in" fo:src="/files/ftp_upload/50124/50124fig3highres.jpg" src="/files/ftp_upload/50124/50124fig3.jpg" /> 图3说明 "正常"，或者非缺血性ST段趋势的病人有23个半小时的ST段监测。在Y-轴，11个导联，V1导联显示在顶部和底部，导致III。 0.0在Y-轴表示一个正常的或等电ST段。的X-轴显示一个24小时的时间周期。在这个例子中，心电监护开始就在0900和0800第二天早上结束。在这名病人的ST段保持在0.0点整个监视时段期间（实线），表示有表示瞬态心肌缺血的没有ST段移位。可以从任何时间点在监测期间，通过简单的选择一个特定的时间和打印心电图12导联心电图。它可以保存在任何ECG（S）的研究报告格式文档文件。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50124/50124fig3large.jpg" target="_blank">点击此处查看大图</a> 。 <img alt="图4" fo:content-width="6in" fo:src="/files/ftp_upload/50124/50124fig4highres.jpg" src="/files/ftp_upload/50124/50124fig4.jpg" /> 图4，在这个例子中示出，一个短暂的ST段抬高事件。监测启动之前1200和连续地被保持，直到1000的第二天（X-轴）。在1230中，小于1小时开始监测后，ST段高程被认为是在导 ​​致II，aVF导联和三（见底部3 ST段的趋势）。4A，4B，和4C是12导联心电图的印刷前的事件，在最大的ST段变化，和事后并显示突然ST段抬高Ⅱ导联，aVF导联III暗示的完整的冠状动脉闭塞，1小时后解决。值得注意的是，这名病人是无症状的ST段改变医院的工作人员均未检出。 ST段趋势也显示了两个额外的小，但短暂的ST段变化，这些线索在1500，只是1800年之前的。由于这些ST段的改变不超过100微伏ST的事件，他们不能算作短暂性脑缺血事件的阈值。第二天早上，在0800这个病人的心脏导管插入术实验室，根据他的症状和肌钙蛋白（2.5微克/升）。发现90％病变在右冠状动脉，支架被放置。 ST段抬高结束时的监测期occurred在经皮冠状动脉介入治疗的程序，包括支架置入术，并按照以下步骤解决。4A事件前的短暂性脑缺血事件的心电图。4B。最大ST段抬高的缺血性事件。注ST段抬高的200毫伏中导致II，III，aVF导联。4C，12导联心电图的缺血性事件。需要注意的是ST段抬高的解决线索II，III，aVF导联（箭头）。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50124/50124fig4large.jpg" target="_blank">点击这里查看大图</a> 。 <img alt="图5" fo:content-width="6in" fo:src="/files/ftp_upload/50124/50124fig5highres.jpg" src="/files/ftp_upload/50124/50124fig5.jpg" /> （1）分离的导线或皮肤ELECTR 图5。这个数字说明了两个问题，可以发生在动态心电图监测，中断由于连续监测;诗，和（2）运动伪影。在这两种情况下，心电图数据是不是可用于分析。到1400之前，在所有的引线时，右腿电极（接地电极）脱落ST段趋势消失。当导线被替换了在1600监控恢复。不幸的是，同样的问题发生后的0100，并一直持续到年底的记录。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50124/50124fig5large.jpg" target="_blank">点击此处查看大图</a> 。 在该图中还示出了监控时恢复之前至1600是对ST-趋势的急剧变化。看到了类似的不规则的ST段趋势的变化在约1200，和2030至00年。5A显示了运动伪影的ST段变化的来源，也是源的其他不规则的趋势变化。在一般情况下，突然的或不稳定的ST段趋势的变化往往表示运动伪影或体位改变而变化，而不是心肌缺血。然而，从之前的心电图，期间和之后，ST段趋势的变化，应打印并仔细评估可能的缺血。 <img alt="图6" fo:content-width="6in" fo:src="/files/ftp_upload/50124/50124fig6highres.jpg" src="/files/ftp_upload/50124/50124fig6.jpg" /> 图6。ST段趋势显示假阳性ST段的变化，由于间歇性的心室定速器。之前0100 ST段趋势的变化，V3导联的ST段抬高，V4，V5，II，aVF导联和第三。6A是在0点51分○二秒的12导联心电图之前的趋势变化。值得注意的是，心房的步行者的尖峰可见在过去的4次10秒的节奏条中的铅II（见底部图）。注ST段压低，导致II，III，AVF，V5和V6可能是由于洋地黄类药物，病人服用。这些变化是慢性和本整个监测期间，6B示出了得到的心电图在1点二十○分39秒心室起搏现在本，心房起搏是可见的，以及。心室起搏的结果是从主要负为主阳性，导致V3，V4，V5，II，aVF导联ST段抬高的ST段改变。然而，这些变化是由于缺血，但相当异常的去极化和复与心室步行者的。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50124/50124fig6large.jpg" target="_blank">点击这里查看大图</a> 。

Watch this Scientific Journal Video about A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis at JoVE.

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

连续12导联心电图（ECG）监控可识别性心肌缺血，即使无症状，其中疑似急性冠状动脉综合征（ACS）患者。在这篇文章中，我们描述的方法启动病人监护仪，动态心电图设备，下载的心电图数据进行离线分析，以及如何利用ECG软件，以确定短暂性脑缺血。

研究方法检测疑似急性冠脉综合征患者短暂心肌缺血的连续ST段分析

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture ...

a-research-method-for-detecting-transient-myocardial-ischemia

Nanyang Technological University

Research

JoVE Journal

Medicine

24.2K 次观看.  University of Nevada, Reno. 连续12导联心电图（ECG）监控可识别性心肌缺血，即使无症状，其中疑似急性冠状动脉综合征（ACS）患者。在这篇文章中，我们描述的方法启动病人监护仪，动态心电图设备，下载的心电图数据进行离线分析，以及如何利用ECG软件，以确定短暂性脑缺血。

视频: A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized.  The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed. 

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine heart.

高频超声心动图：非侵入性的反复测量小鼠心脏缺血再灌注心肌劳损，收缩力，二尖瓣关闭不全的第一个证据

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

科研

医学

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking 

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

磁共振衍生的心肌劳损评估使用特征跟踪

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

Ultrasonic Assessment of Myocardial Microstructure

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame&#160;and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Echocardiography is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. We describe an ultrasound-based imaging algorithm that offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

心肌微观结构超声波评估

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

急性心肌梗死的猪模型主要成果评估

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the examiners&#39; expertise. Speckle tracking Echocardiography (STE) is a promising but technically challenging method that can be used to quantitatively assess regional and global systolic and diastolic myocardial performance. Myocardial strain and strain rate can be measured in all three dimensions&#160;&#8212; radial, circumferential, longitudinal &#8212; of myocardial deformation. Standard cross-sectional two-dimensional B-mode images are recorded and subsequently postprocessed by automated continuous frame-by-frame tracking and motion analysis of speckles within the myocardium. Images are recorded as digital loops and synchronized to a 3-lead EKG for timing purposes. Longitudinal deformation is assessed in the apical 4-, 3-, and 2-chamber views. Circumferential and radial deformation are measured in the parasternal short axis plane.
Optimal image quality and accurate tissue tracking are paramount for the correct determination of myocardial performance parameters. Utilizing transthoracic STE in a healthy volunteer, the present article is a detailed outline of the essential steps and potential pitfalls of quantitative echocardiographic myocardial deformation analysis.

Speckle tracking echocardiography is an emerging diagnostic imaging technique for the quantitative assessment of global and regional myocardial performance. Standard view echocardiographic motion images are recorded and deformation parameters are subsequently measured by automated continuous frame-by-frame tracking and motion analysis of speckles within the B-mode images of the myocardium.

经胸斑点跟踪超声心动图左室心肌变形的定量评价

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the ...

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality worldwide. In humans, a pathologic occlusion forms in a coronary artery and reperfusion of that occluded artery is considered essential to maintain viability of the myocardium at risk. Although essential for myocardial recovery, reperfusion of the ischemic myocardium creates its own tissue injury. The physiologic response and healing of an ischemia/reperfusion injury is different from a chronic occlusion injury. Myocardial ischemia/reperfusion injury is gaining recognition as a clinically relevant model for myocardial infarction studies. For this reason, parallel animal models of ischemia/reperfusion are vital in advancing the knowledge base regarding myocardial injury. Typically, ischemia of the mouse heart after left anterior descending (LAD) coronary artery occlusion is confirmed by visible pallor of the myocardium below the occlusion (ligature). However, this offers only a subjective way of confirming correct or consistent ligature placement, as there are multiple major arteries that could cause pallor in different myocardial regions. A method of recording electrocardiographic changes to assess correct ligature placement and resultant ischemia as well as reperfusion, to supplement observed myocardial pallor, would help yield consistent infarct sizes in mouse models. In turn, this would help decrease the number of mice used. Additionally, electrocardiographic changes can continue to be recorded non-invasively in a time-dependent fashion after the surgery. This article will demonstrate a method of electrocardiographically confirming myocardial ischemia and reperfusion in real time.

During murine myocardial ischemia/reperfusion surgery, correct placement of the occluding ligature is typically confirmed by visible observation of myocardial pallor. Herein, a method of electrocardiographically confirming ischemia and reperfusion, to supplement observed myocardial pallor, is demonstrated in male C57Bl/6 mice.

小鼠使用表面垫心电图心肌缺血再灌注损伤的确认

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality ...

Quantification of Absolute Myocardial Flow and Resistance by Continuous Thermodilution in Patients with Ischemia and Nonobstructive Coronary Artery Disease (INOCA)

In approximately half of the patients undergoing coronary angiography for angina pectoris or for signs or symptoms suggestive of ischemic heart disease, no obstructive coronary artery disease is angiographically visible. The majority of these patients with angina or ischemia and no obstructive coronary artery disease (INOCA) have an underlying coronary vasomotor dysfunction, and current consensus documents recommend diagnostic invasive coronary vasomotor function testing (CFT). 
During CFT, a variety of vasomotor dysfunction endotypes can be assessed, including vasospastic coronary dysfunction (epicardial or microvascular vasospasm), and/or microvascular vasodilatory dysfunction, including impaired vasodilatory capacity and increased microvascular resistance. The quantification of the continuous thermodilution derived absolute coronary blood flow and resistance might be a better measure compared to the currently used standard physiologic measures. This article provides an overview of this continuous thermodilution method.

Quantification of Absolute Myocardial Flow and Resistance by Continuous Thermodilution in Patients with Ischemia and Nonobstructive Coronary Artery Disease INOCA

Presented here is a protocol to measure absolute myocardial flow and resistance using continuous thermodilution in patients with ischemia and nonobstructive coronary artery disease.

In approximately half of the patients undergoing coronary angiography for angina pectoris or for signs or symptoms suggestive of ischemic heart disease, ...

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of heart reflow and induce secondary myocardial injury. A simple and reproducible model of myocardial infarction and myocardial ischemia-reperfusion injury is a good tool for researchers. Here, a customizable method to create a myocardial infarction (MI) model and MIRI by precision ligation of the left anterior descending coronary artery (LAD) through micromanipulation is described. Accurate and reproducible ligature positioning of the LAD helps obtain consistent results for heart injury. ST-segment changes can help to identify model accuracy. The serum level of cardiac troponin T (cTnT) is used to assess the myocardial injury, cardiac ultrasound is employed to evaluate the myocardial systolic function, and Evans-Blue/triphenyl tetrazolium chloride staining is used to measure infarct size. In general, this protocol reduces procedure duration, ensures controllable infarct size, and improves mouse survival.

Here we describe a simple and reproducible method that can induce myocardial infarction or myocardial ischemia-reperfusion injury in mice by precision ligation of the left anterior descending coronary artery through micromanipulation.

小鼠心肌梗死和心肌缺血再灌注损伤的诱导

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of ...

Real-Time Electrocardiogram Monitoring During Treadmill Training in Mice

Regular physical exercise is a major contributor to cardiovascular health, influencing various metabolic as well as electrophysiological processes. However, in certain cardiac diseases such as inherited arrhythmia syndromes, e.g., arrhythmogenic cardiomyopathy (ACM) or myocarditis, physical exercise may have negative effects on the heart leading to a proarrhythmogenic substrate production. Currently, the underlying molecular mechanisms of exercise-related proarrhythmogenic remodeling are largely unknown, thus it remains unclear which frequency, duration, and intensity of exercise can be considered safe in the context of disease(s).
The proposed method allows to study proarrhythmic/antiarrhythmic effects of physical exercise by combining treadmill training with real-time monitoring of the ECG. Implantable telemetry devices are used to continuously record the ECG of freely moving mice over a period of up to 3 months both at rest and during treadmill training. Data acquisition software with its analysis modules is used to analyze basic ECG parameters such as heart rate, P wave duration, PR interval, QRS interval, or QT duration at rest, during and after training. Furthermore, heart rate variability (HRV) parameters and occurrence of arrhythmias are evaluated. In brief, this manuscript describes a step-by-step approach to experimentally explore exercise induced effects on cardiac electrophysiology, including potential proarrhythmogenic remodeling in mouse models.

Electrocardiogram (ECG) is the key variable to understanding cardiac electrophysiology. Physical exercise has beneficial effects but may also be harmful in the context of cardiovascular diseases. This manuscript provides a method of recording real-time ECG during exercise, which can serve to investigate its effects on cardiac electrophysiology in mice.

小鼠跑步机训练期间的实时心电图监测

Regular physical exercise is a major contributor to cardiovascular health, influencing various metabolic as well as electrophysiological processes. ...

Model of Ischemia and Reperfusion Injury in Rabbits

The protocol here provides a simple, highly replicable methodology to induce in situ acute regional myocardial ischemia in the rabbit for non-survival and survival experiments. New Zealand White adult rabbit is sedated with atropine, acepromazine, butorphanol, and isoflurane. The animal is intubated and placed on mechanical ventilation. An intravenous catheter is inserted into the marginal ear vein for the infusion of medications. The animal is pre-medicated with heparin, lidocaine, and lactated Ringer&#39;s solution. A carotid cut-down is performed to obtain arterial line access for blood pressure monitoring. Select physiologic and mechanical parameters are monitored and recorded by continuous real-time analysis.
With the animal sedated and fully anesthetized, either a fourth intercostal space small left thoracotomy (survival) or midline sternotomy (non-survival) is performed. The pericardium is opened, and the left anterior descending (LAD) artery is located.
A polypropylene suture is passed around the second or third diagonal branch of the LAD artery, and the polypropylene filament is threaded through a small vinyl tube, forming a snare. The animal is subjected to 30 min of regional ischemia, achieved by occluding the LAD by tightening the snare. Myocardial ischemia is confirmed visually by regional cyanosis of the epicardium. Following regional ischemia, the ligature is loosened, and the heart is allowed to re-perfuse.
For both survival and non-survival experiments, the myocardial function can be assessed via an echocardiography (ECHO) measurement of the fractional shortening. For non-survival studies, data from sonomicrometry collected using three digital piezoelectric ultrasonic probes implanted within the ischemic area and the left ventricle developed pressure (LVDP) using an apically inserted left ventricle (LV) catheter can be continuously acquired for evaluating the regional and global myocardial function, respectively.
For survival studies, the incision is closed, a left needle thoracentesis is performed for pleural air evacuation, and postoperative pain control is achieved.

The present study demonstrates a highly reproducible animal model of acute regional myocardial ischemia and reperfusion injury in rabbits using a left mini-thoracotomy for survival cases or a midline sternotomy for non-survival cases.

兔子缺血和再灌注损伤模型

The protocol here provides a simple, highly replicable methodology to induce in situ acute regional myocardial ischemia in the rabbit for non-survival and ...