EASI 12导Holter心电图与临床

通常Ｈｏｌｔｅｒ心电图贴 7个电极只能模拟 3个导联的心电图 ,故心脏其它部位的心肌缺血、梗死不能显示。为此我们引进了安捷伦公司生产的ＺｙｍｅｄＨｏｌｔｅｒ ,其仅用 5个电极就能获得同步 12导心电图。5个电极中一个为地线置左上胸 ,另 4个置Ｖ6 与ＲＶ6 ,胸骨柄与剑突上 ,分别构成横面与额面导联轴而衍生了ＥＡＳＩ12导Ｈｏｌｔｅｒ心电图。本文对 14 4例ＥＡＳＩ12导Ｈｏｌｔｅｒ心电图与普通 12导同步心电图进行了对照分析 ,现报道如下。资料与方法选用 2 0 0 1年 5～ 6月的住院病人 14 4例 ,其中男 71例 ,女 73例 ,平均年龄 4 6 …     

EASI 12导联与标准监护Ⅱ导联监测心肌缺血的观察

目的评价目前常规选择的标准监护Ⅱ导联和EASI12导联心电监测对于发现心肌缺血的有效性和敏感性。方法采用诊断试验的评价研究设计，将研究期间收住北京市宣武医院CCU病房的57例有ST段改变的病人作为病例组，43例无ST段改变的病人作为非病例组，选用标准12导联心电图为金标准，评价CCU标准监护Ⅱ导联和EASI12导联发现心肌缺血的有效性和敏感性。两组病人均同时描记标准12导联、EASI12导联和标准监护Ⅱ导联心电图。比较3种心电图中ST段的改变情况。结果标准监护Ⅱ导联心肌缺血检出率明显低于标准12导联心电图，敏感度、特异度、假阳性率和假阴性率分别为24．6％、95.3％、4.7％和75.4％，一致性检验Kappa值仅为0.178。而EASI12导联对心肌缺血的检出率与标准12导联心电图相仿，敏感度、特异度、假阳性率和假阴性率分别为89.5％、97．7％、2.3％和10．5％，Kappa=0．859。结论临床上通常选用的标准监护Ⅱ导联并不能有效地发现心肌缺血，而EASI12导联较标准Ⅱ导联能够更有效地发现心肌缺血，具有较好的敏感度和特异度。     

EASI 3导联衍生的12导联心电图的应用研究

目的在亚洲人群中导出EASI导联和常规12导联心电图的转换系数和方程,比较亚洲人群与北美人群之间导联转换上的差异性,同时观察导联转换是否受年龄、性别、身高和体重的影响。方法627例受试者同步记录常规12导联心电图和EASI导联心电图。同时记录年龄、性别、身高和体重。结论在亚洲人群和北美人群之间,导联转换无显著性差异,年龄、性别、身高和体重对导联转换无显著影响。     

12导同步心电图

１２导同步心电图吴杰在一定意义上讲，心电学的进步史也是心电学检测和分析技术的发展史。本世纪初，Ｅｉｎｔｈｏｖｅｎ创立三角学说，发明第一台弦线型心电图描记器并设计描记出Ⅰ、Ⅱ、Ⅲ标准导联心电图。３０年代至４０年代，Ｗｉｌｓｏｎ根据Ｅｉｎｔｈｏｖｅｎ方程...     

EASI 12导联心电监测系统的临床应用

目的探讨EASI12导联心电监测系统的临床意义。方法对CCU病房的530例（EASI12导联监测系统监测205例、传统单导联监测系统监测325例）患者持续心电监测24～72h，并对监测结果进行比较分析。结果应用EASI12导联监测系统监测的205例中，可见房性心律失常57例（27．8％），室性心律失常79例（38．5％），房室传导阻滞26例（12．7％），心肌缺血性ST段改变85例（41．5％），而应用传统单导联监测系统的325例中，可见房性心律失常56例（17．2％），室性心律失常82例（25．2％），房室传导阻滞22例（6．8％），心肌缺血性ST段改变81例（24．9％），前者检出率显著提高（x^2=6．103、6．898、4．218、10．456，P均〈0．05）。结论EASI12导联监测系统为临床提供了即时和准确的数据，有助于及时发现心律失常和心肌缺血事件。     

EASI导联与常规12导联心电图在心肌缺血诊断中的比较

常规12导联心电图是评估心肌缺血和心律失常的一个重要的无创检测方法。将胸前区6个电极放置在准确部位是获取标准的12导联心电图的基本条件。如果电极位置偏离标准位置10～20mm，QRS波形就能发生显著改变。常规12导联心电图记录需要4个肢体导联电极和6个胸前电极，因其需要将4个肢体导联电极放置于四肢末端，不适于持续心电监测，     

12导动态心电图监测与冠状动脉造影价值的对比分析

为评价24h12导联动态心电图(Holter)对冠心病的诊断价值,选择198例可疑冠心病患者进行24hHolter监测记录心肌缺血及室性心律失常心电图改变,并与选择性冠状动脉造影结果进行对比分析。结果:12导Holter诊断冠心病的灵敏度、特异度分别为62.4%、79.0%;12导联Holter诊断冠状动脉单、双及三支血管病变的灵敏度分别为56.9%、60.0%、91.7%。有无冠状动脉病变者室性早搏检出率和冠状动脉造影单、双及三支病变室性早搏检出率无显著性差异(P>0.05)。结论:12导联Holter监测心肌缺血的敏感性及准确性较高,有一定的临床应用价值。     

12导同步动态心电图

1　定义12导同步动态心电图 (ＤＣＧ)是指随身携带的心电记录器长时间 (2 4ｈ)连续记录 12导同步心电信息 ,再输入计算机处理。在此基础上经过人工编辑分析 ,打印出ＤＣＧ报告。 12导ＤＣＧ实质上是 12导同步心电图连续长时间记录。初步临床应用显示 ,对冠心病、心肌缺血的定位诊断 ,缺血时间 ,缺血程度与冠脉造影结果比较有着极好的相关性。对心律失常的定位诊断与鉴别优于 3导ＤＣＧ。又可以连续观察ＱＴｄ的动态变化 ,为临床提供了大量可靠的心电信息 ,成为临床医、教、研工作的重要工具。其诞生 ,将为临床医学带来重大影响。它将逐步取…     

心得安试验QT离散度变化与QTd本质的研究

目的：研究心得安试验前后QT离散度(QTd)变化，探讨QTd的本质及评价其临床应用价值。方法：于经冠脉造影及其他检查除排除器质性心脏病，静息心电图有T波低平、双向、倒置或有u波的186例思考，观察心得安试验前、后QTd的变化。结果：(假定QTd＞50ms为异常)78例心得安试验阳性QTd异常率试验前、后分别为83．3％，11．5％，有显差异(P＜0．01)；108例心得安试验阴性QTd异常率试验前、后依次为77．8％，74、1％，无显差异(P＞0．05)。两组QTd异常率试验前无显差异，试验后有显差异(P＜0．01)。结论：非器质性心脏病心得安试验QTd变化提示QTd异常不能作为反映心肌复极的不均一性指标，预测恶性心律失常或心脏猝死，而只是反映T波非特异性异常的一个粗浅的量化指标，对QTd的临床应用宜慎重。     

短QT间期的心电图诊断标准探讨

目的用2种已报道的诊断标准研究一组心电图短QT间期者所占比例,并比较2种方法的异同。方法随机选取547例健康人,做常规12导联心电图,准确测量QT间期,根据RR间期(RR)和心率(HR)计算QT间期校正值(QTc)和QT间期预计值(QTp),以QT相似文献   

第45课运动员12导联心电图解释的建议

Electrocardiogram changes in athletes are common and usually reflect structural and electrical remodelling of the heart as an adaptation to regular physical training （athlete＇s heart）. However, abnormalities of athlete＇s ECG may be an expression of an underlying heart disease which carries a risk of SCD during sport.     

The Effects of Intravenous Levofloxacin on the QT Interval and QT Dispersion

The QT dispersion (QT_d) is a non-invasive means of identifying those patients at an increased risk of developing sudden cardiac death (SCD). Although levofloxacin has a minimal effect on the QT_c interval, isolated reports of QT prolongation, polymorphic ventricular tachycardia with a normal QT interval and TdP have been reported. The purpose of this study was to examine the effect of intravenous levofloxacin on the QT interval and QT_d. Of the 50 patients who were deemed candidates to receive intravenous levofloxacin, 29 met the eligibility criteria and were enrolled in this study. A 12-lead ECG was performed before the initiation of levofloxacin (baseline), and on days 3 and 5. The QT^c _min, QT^c _max and the QT_d were calculated. Measurements where made by two independent observers blinded to the patients’ clinical status. The QT_d increased significantly on days 3 and 5 following the initiation of therapy [QT_d (baseline) 33.3 ± 20 ms, QT_d (day 3) 64.4 ± 31.3 ms (p = 0.023), QT_d (day 5) 66.8 ± 20.3 ms, (p = 0.008)]. The increase in the QT_d was significantly longer in men than women. Although women had a shorter baseline QT_d compared to men, this did not achieve statistical significance. Intravenous levofloxacin was found to significantly increase the QT_d, which was more pronounced in men compared to women. Its effect on the QT_d may increase the risk of developing a potentially fatal ventricular arrhythmia. Therefore, care must be taken when prescribing this medication to patients with a pre-existing risk of developing SCD.     

QT间期及其离散度测定的方法学研究和正常值

报告１００例健康成人同步体表１２导联心电图的ＱＴ间期和ＱＴ间期离散度（ＱＴｄ）：（１）各参数测量结果（±ｓ）：ＱＴｄ、ＱＴｃｄ（矫正ＱＴｄ）、ＪＴｄ（ＪＴ离散度）、ＱＴｐｄ（ＱＴ顶点离散度）、ＪＴｐｄ（ＪＴｐ离散度）、Ｔｐ－ＴＥｄ（Ｔ波顶点至Ｔ波终点间期离散度）、ＱＲＳｄ（ＱＲＳ间期离散度）和Ｏ－Ｑｄ（ＱＲＳ起始时间离散度）分别为２５．６±１１．２，２６．８±１２．６，２６．１±１２．５，２４．６±１４．７，３２．０±１５．６，３１．０±１４．６，２０．６±８．８和１２．５±７．３ｍｓ，其范围均在５～５０ｍｓ以内，与国际上研究结果一致。笔者认为ＱＴｄ的正常值可暂定为＜５０ｍｓ；（２）体表１２导联心电图同步记录方法，比常规非同步记录更能反映ＱＴｄ的实际情况，并且可测量同步１２导联ＱＲＳ起始部时间（Ｑ－ＱＴ）及其离散度（Ｑ－ＱＴｄ）；（３）本文资料由国内和国外三组不同人员测量结果相同，表明ＱＴ、ＱＴｄ测定的可重复性好；（４）性别差异，ＱＴ间期女性比男性长，而ＱＲＳ间期男性比女性长，其机理尚待进一步研究探讨。     

Effects of Epinephrine and Phenylephrine on QT Interval Dispersion in Congenital Long QT Syndrome

Objectives. Measurement of QT interval dispersion during pharmacologic adrenergic stimulation was used to assess the effect of alpha- and beta-adrenergic stimulation on arrhythmic vulnerability in familial long QT syndrome (LQTS).Background. Nonhomogeneity in the ventricular action potential duration causes electrical instability leading to life-threatening ventricular arrhythmias and is markedly increased in LQTS. QT interval dispersion measured from the electrocardiogram (ECG) can be used as an index of nonhomogeneous ventricular repolarization.Methods. Sixteen symptomatic patients with LQTS and nine healthy control subjects were examined at baseline and during epinephrine (mainly beta-adrenergic agonist, 0.05 μg/kg body weight per min) and phenylephrine infusions (alpha-adrenergic agonist, mean 1.4 μg/kg per min). QT interval dispersion was determined from a 12-lead ECG as interlead range and coefficient of variation measured to the end (QT_end) and apex (QT_apex) of the T wave.Results. At baseline QT_enddispersion was greater in patients with LQTS compared with control subjects (mean [±SD] 68 ± 34 vs. 36 ± 7 ms, p = 0.001). QT_enddispersion was markedly increased in patients with LQTS by use of epinephrine (from 68 ± 34 to 90 ± 36 ms, p = 0.002), but remained unchanged in control subjects. Phenylephrine did not affect QT dispersion in either group (all p = NS). Atrial pacing to achieve comparable heart rates during baseline and epinephrine and phenylephrine infusions did not influence the magnitude of QT dispersion in either group. QT_apexdispersion analysis gave congruent results.Conclusions. Epinephrine but not phenylephrine increased QT dispersion, suggesting that beta-adrenergic stimulation provokes arrhythmias in patients with LQTS by aggravating nonhomogeneity of ventricular repolarization, whereas alpha-adrenergic stimulation is less important for arrhythmic vulnerability. The results also suggest that rapid pacing may not reduce vulnerability to arrhythmias in congenital LQTS.     

Comparison of waveforms in conventional 12-lead ECGs and those derived from EASI leads in children

To investigate the possibility of simplifying electrocardiogram (ECG) recording in children, we compared waveforms in conventional 12-lead ECGs to those derived from EASI leads in 221 children of various ages. The conventional 12-lead ECGs and the ECGs using EASI electrode positions were collected simultaneously. We developed and determined the value of age-specific transformation coefficients for use in deriving 12-lead ECGs from the signals recorded at the EASI sites. We compared the results of using age-specific coefficients to the results of using adult coefficients and studied the "goodness-of-fit" between the conventional and the derived 12-lead ECGs. The age-specific coefficients performed slightly better than the adult coefficients, and good agreement was usually attained between the conventional 12-lead ECG and the EASI-derived 12-lead ECG. Our conclusion is that EASI leads in children have the same high levels of "goodness-of-fit" to replicate conventional 12-lead ECG waveforms, as reported earlier in adults.     

直接经皮腔内冠状动脉成形术对急性心肌梗塞QT离散度的影响

目的　研究急性心肌梗塞 (AMI)患者应用直接经皮腔内冠状动脉成形术 (PTCA)对 QT离散度(QTd)的影响。方法　回顾 95例 AMI患者 ,通过测量入院时及入院后不同时间心电图 ,计算校正 QTd(QTcd)。对比分析其中 68例 PTCA再通患者 (PTCA组 )与 2 7例未行 PTCA或溶栓患者 (对照组 )不同时间 QTd与 QTcd的变化。结果　 PTCA组再通即刻 QTd、QTcd较再通前明显延长 (P<0 .0 1 ) ,2小时后恢复到入院时水平 ,4小时后较入院时明显缩短 (P<0 .0 1 ) ,以后 2 4小时内相对稳定。对照组入院后 2 4小时内 QTd、 QTcd变化不大 (P>0 .0 5 )。结论　 AMI患者应用成功的 PTCA治疗可以缩短心室复极的 QTd,但再灌注即刻可加重心室复极的 QTd     

A vector-based, 5-electrode, 12-lead monitoring ECG (EASI) is equivalent to conventional 12-lead ECG for diagnosis of acute coronary syndromes

AIMS: The conventional 12-lead electrocardiogram (cECG) derived from 10 electrodes using a cardiograph is the gold standard for diagnosing myocardial ischemia. This study tested the hypothesis that a new 5-electrode 12-lead vector-based ECG (EASI; Philips Medical Systems, formerly Hewlett Packard Co, Boeblingen, Germany) patient monitoring system is equivalent to cECG in diagnosing acute coronary syndromes (ACSs). METHODS: Electrocardiograms (EASI and cECG) were obtained in 203 patients with chest pain on admission and 4 to 8 hours later. Both types of ECGs were graded as ST-elevation myocardial infarction if at least 1 of the 2 consecutive recordings showed ST elevation more than 0.2 mV, as ACS if one or both showed ST elevation less than 0.2 mV, T-wave inversion, or ST depression. Otherwise, the ECG was graded negative. RESULTS: Final diagnosis was identical in 177 patients (87%; 95% confidence interval [CI], 82%-91%; kappa = 0.81; SE = 0.035). ST-elevation myocardial infarction was correctly identified or excluded by EASI with a specificity of 94% (95% CI, 89%-97%) and a sensitivity of 93% (95% CI, 86%-97%; using cECG as the gold standard). Of 118 patients with enzyme elevations, an almost identical number (72 [61% by EASI] and 73 [62% by cECG]) had ST elevations. Both techniques were equivalent in predicting subsequent enzyme elevation (identical, 108/143; 75% of ACS and ST-elevation myocardial infarction ECGs by EASI and cECG). Thus, both ECG methods had exactly the same specificity of 59% (95% CI, 48%-69%) and sensitivity of 91% (95% CI, 85%-96%) for detecting myocardial injury. CONCLUSION: EASI is equivalent to cECG for the diagnosis of myocardial ischemia.     

Evaluation of QT Interval Dispersion in a Multiple Electrodes Recording System versus 12‐Lead Standard ECG in an In Vitro Model

Background: QT interval dispersion (QTID) as assessed on conventional surface electrocardiogram (ECG) has been used as a clinical tool to identify patients at high risk of ventricular arrhythmia. However, the results obtained have been controversial. The main purpose of this study was to compare QTID measured from an array of 5 × 6 electrodes homogeneously distributed against the values found when the 12‐lead standard ECG was used. Methods: QTID was calculated in a modified Langendorff‐perfused rabbit heart model immersed in a cylindrical chamber. Dispersion in ventricular repolarization was artificially increased by d‐sotalol (60 μ;m) perfusion. Results: All the duration variables measured from any of the lead systems used were significantly increased after d‐sotalol perfusion. The most commonly used variables in clinical studies, such as QTID (maximum ‐ minimum), do not reach a level of statistical significance, except when measured from the 30‐electrodes array or 15 electrodes covering the left or right side of the heart. The standard deviation of the QT interval (QTI) hardly reached a significant level (P = 0.0499) when calculated from the 12‐lead standard ECG. QTID measured at the peak of the T wave exhibited the highest level of significance when calculated from any of the lead systems used. Conclusion: Thirty electrodes homogeneously distributed on the body surface can better discriminate changes in heterogeneity of repolarization. These data further support the importance of multiple recording systems for the evaluation of QTID and may help to provide an understanding of the discrepancies found in clinical applications.