经皮冠状动脉腔内成形术对冠心病患者心室晚电位的影响

为观察经皮冠状动脉腔内成形术（ＰＴＣＡ）对心室晚电位（ＶＬＰ）的影响，对３８例冠心病患者ＰＴＣＡ前、后的信号平均心电图（ＳＡ－ＥＣＧ）进行定性、定量分析和随访观察。时域分析发现，３例ＶＬＰ阳性中的１例ＰＴＣＡ术后ＶＬＰ消失，有５．７％（２／３５）ＶＬＰ阴性患者术后ＶＬＰ转为阳性；频谱时间标测发现，４例ＶＬＰ阳性中的２例术后ＶＬＰ消失，有１１．８％（４／３４）ＶＬＰ阴性患者术后ＶＬＰ转为阳性；全组患者中，ＰＴＣＡ前、后ＳＡ－ＥＣＧ参数的变化无显著性（Ｐ＞０．０５）。术后随访１０．９±２．５（４～１４）个月，未发生心律失常事件。提示ＰＴＣＡ可使ＶＬＰ阳性的部分患者转阴；使很少部分患者ＶＬＰ阴性转为阳性，提示再灌注可能改善冠心病患者的预后     

心率变异预测急性心肌梗死预后的价值

为探讨急性心肌梗死（ＡＭＩ）预后与心率变异（ＨＲＶ）的关系及ＨＲＶ与左室射血分数（ＬＶＥＦ）、心室晚电位（ＶＬＰ）联合应用对心律失常事件的预测价值，对８４例ＡＭＩ后两周的患者进行ＨＲＶ时域及频域分析和ＶＬＰ检测，并进行长期随访。平均随访１６．７５±７．７４（４～２９）个月（１２例失访）。结果表明：①发生严重心律失常事件的ＡＭＩ患者（１５例）的ＨＲＶ较无严重心律失常事件者（５７例）明显下降〔ＳＤ：３．８７９±０．３５５ｌｎ（ｍｓ）ｖｓ４．０７７±０．２８１ｌｎ（ｍｓ），Ｓｔ．Ｇｅｏｒｇｅｓ指数：３．６７７±０．５６９ｖｓ３．９２９±０．３５８，ＬＦ：４．３９９±１．１７９ｌｎ（ｍｓ２／Ｈｚ）ｖｓ５．０４１±０．９１２ｌｎ（ｍｓ２／Ｈｚ），Ｐ均＜０．０５〕。②ＨＲＶ对严重心律失常事件预测的敏感性为４６．７％，高于ＬＶＥＦ（３３．３％）及ＶＬＰ（２６．７％）；阳性预测值为３０．４％，与ＬＶＥＦ（３１．２％）及ＶＬＰ（３０．８％）相近。③ＨＲＶ分别与ＬＶＥＦ、ＶＬＰ合用，可明显提高阳性预测值（依次为６０％和５０％）。提示ＡＭＩ后心律失常事件的发生及心脏性猝死与ＨＲＶ有密切关系。     

经皮冠状动脉腔内成形术对不稳定型心绞痛患者心率变异的影响

应用长程心电图分析系统对１６例不稳定型心绞痛患者（ＵＡＰ组）入院后第２日、经皮冠状动脉腔内成形术（ＲＴＣＡ）后第１，３，３０日以及１４８例健康中、老年人（对照组）２４ｈ心电图进行心率变异（ＨＲＶ）分析。结果：ＵＡＰ组２４ｈ连续正常ＲＲ间期的标准差（ＳＤＮＮ）、２４ｈ内连续５ｍｉｎ节段平均正常ＲＲ间期的标准差（ＳＤＡＮＮｉ）、相邻ＲＲ间期差的均方根（ｒＭＳＳＤ），相邻两个正常心动周期差值大于５０ｍｓ个数占总搏数的百分比（ＰＮＮ５０）、低频功率（ＬＦ）及高频功率（ＨＦ）均明显低于对照组（分别为９２．７±１４．３ｍｓｖｓ１２８．９±１７．８ｍｓ、７８．８±１０．６ｍｓｖｓ１１８．６±１９．１ｍｓ、１９．３±７．７ｍｓｖｓ２９．８±１２．７ｍｓ、３．６±１．７％ｖｓ６．５±５．５％、３１７．２±１４８．３ｍｓ２ｖｓ４７６．５±２８７．３ｍｓ２，Ｐ均＜０．０５），而ＬＦ／ＨＦ高于对照组（３．５±１．３ｖｓ２．４±１．１，Ｐ＜０．０５）。ＰＴＣＡ术后３０天ＵＡＰ患者ＨＲＶ逐渐恢复正常。结果提示ＵＡＰ患者交感神经和迷走神经张力下降，而以后者更明显；ＰＴＣＡ后ＨＲＶ逐渐恢复，说明ＰＴＣＡ能改善ＵＡＰ患者的ＨＲＶ。     

高频心电图与心率变异在儿科疾病中的联合应用

目的 探讨高主电图（ＨＦＥＣＧ０与心率变异（ＨＲＶ）联合应用小儿心肌炎的辅助诊断意义。方法 对８９例按诊断分４组（Ａ１、Ａ２、Ａ３、Ａ４）进行ＨＦＥＣＧ、短程ＨＲＶ、心肌酶５项检查，并与２１０例正常对照组（Ｂ组）分析。结果 ＨＲＶ时域值在病毒性心肌炎（Ａ１）组，疑似心肌炎（Ａ２）组、呼吸道感染组（Ａ３）稍偏低，ＳＤＮＮ依次为（３３．４±２２．０、３５．８±１５．４、３６．５±１７．５）ｍｓ；Ａ１￣     

急性心肌梗塞患者心率变异性及其临床意义

采用心率变异性（ＨＲＶ）时域指标──２４ｈ心电图中全部窦性Ｒ－Ｒ间期标准差（ＳＤＮＮ），研究急性心肌梗塞（ＡＭＩ）患者ＨＲＶ改变及其与肌酸激酶同功酶（ＣＫ－ＭＢ）、心功能和住院期间病死率的关系。结果显示：ＡＭＩ后２～３ｄ的ＳＤＮＮ（６０．５３±２０．６０ｍｓ）较正常对照组（１３０．２０±３０．４１ｍｓ）显著降低（Ｐ＜０．００１），并与ＣＫ－ＭＢ峰值呈显著负相关（ｒ＝－０．４８，Ｐ＜０．０５）；服用美多心安者的ＳＤＮＮ显著高于未服者（６１．２７±１３．４４ｍｓＶＳ４７．５３±１１．２５ｍｓ，Ｐ＜０．０５）；心功能Ⅱ～Ⅳ级者ＳＤＮＮ显著低于Ⅰ级者（４９．７１±１８．１０ｍｓＶＳ６８．５２±１８．８０ｍｓ，Ｐ＜０．０１）；住院期间死亡者ＳＤＮＮ显著低于存活者（４２．２５±６．４５ｍｓＶＳ６２．５６＋２０．６３ｍｓ，Ｐ＜０．０１）；ＳＤＮＮ＜５０ｍｓ者的住院病死率显著高于＞５０ｍｓ者（３１％ＶＳ０，Ｐ＜０．０５）。提示ＡＭＩ早期心脏交感神经活动增强而迷走神经活动受抑制，其改变的程度与心功能损害和梗塞面积相关；ＡＭＩ早期测定ＨＲＶ可获得重要临床信息和有助于对患者作早期危险性的分层。     

长效二氢奎尼丁、普罗帕酮、美托洛尔对心室晚电位影响的临床研究

通过短期观察信号平均心电图（ＳＡ－ＥＣＧ）的重复性及比较心室晚电位（ＶＬＰ）阳性患者服药前后ＳＡ－ＥＣＧ指标变化，以了解长效二氢奎尼丁（ｓéｒéｃｏｒ）、普罗帕酮、美托洛尔对ＶＬＰ阳性患者ＳＡ－ＥＣＧ指标的影响，及是否具有逆转ＶＬＰ的作用，结果表明：（１）ＳＡ－ＥＣＧ各定量指标的重复性良好，ＶＬＰ阳性组自然转阴率仅为７．７％。（２）ｓｅｒｅｃｏｒ不能逆转ＶＬＰ，而具有选择性延长ＱＲＳ终末部４０μＶ的低振幅信号持续时间（ＬＡＳ）的作用。（３）普罗帕酮不能逆转ＶＬＰ，仅延长滤波后ＱＲＳ－时限（ＱＲＳ－Ｄ）。（４）美托洛尔显著逆转ＶＬＰ，使ＱＲＳ－Ｄ、ＬＡＳ缩短，综合导联滤波的ＱＲＳ终末４０ｍｓ处综合向量电压（ＲＭＳ_（４０））增加。讨论了三种抗心律失常药物对ＶＬＰ影响的不同效应。     

缺血性心脏病患者心率变异性研究

应用Ｈｏｌｔｅｒ，测定４０～４９，５０～５９，６０～６９以及７０岁以上４个年龄段的缺血性心脏病患者的心率变异性（ＨＲＶ）并与相应年龄的对照组进行比较，指标为时域法的２４ｈ平均正常Ｒ－Ｒ间期标准差（ＳＤＮＮ）。结果：缺血组与对照组各年龄段比较有显著性差异，分别为：１４１．５２±２８．９２ｍｓＶＳ９３．７２±２７．５４ｍｓ；１３２．４２±２７．６３ｍｓＶＳ９３．１９±３３．１８ｍｓ；１２１．８４±２７．８７ｍｓＶＳ７４．５０±２４．０１ｍｓ；１１０．３１±２３．９６ｍｓＶＳ６３．９３±２３．７３ｍｓ，Ｐ均＜０．０１；对照组及缺血组的ＨＲＶ均随年龄增长呈下降趋势（组内比较，Ｐ均＜０．０１），呈完全负相关（ｒ（对照组）＝－０．９５，ｒ（缺血组）＝－０．９８）。随访发现缺血组中ＨＲＶ≤５０ｍｓ患者发生心源性猝死（ＳＣＤ）９例和室性心动过速１例；＞５０ｍｓ者发生ＳＣＤ２例。     

经食管电生理检查中的交替文氏现象

在５６１例经食管电生理检查中，检出各类交替文氏现象（ＡＷ）８１例，共１３７例次，占１４．４％，其中Ａ型、Ｂ型、ＡＢ混合型、三层房室ＡＷ分别为４４，６０，１８，６例次，分别占３２．１％、４３．８％、１３．１％、４．４％；房室结双径路间、束支、房室旁束的ＡＷ分别为５，２，２例次，分别占３．６％、１．５％、１．５％。将７９例ＡＷ者（Ａ组）与８０例无ＡＷ者（Ｂ组）的电生理资料进行比较，显示：①窦性心率（ＳＲ），Ａ组较Ｂ组慢（７２±１４．２ｂｐｍｖｓ７８±１２．６ｂｐｍ，Ｐ＜０．００１）。②房室相对不应期（ＡＶＲＲＰ）、房室功能不应期（ＡＶＦＲＰ）、房室有效不应期（ＡＶＥＲＰ），Ａ组分别为６０９．０±１１９．４，４９６．６±９６．０，３６０．０±８８．０ｍｓ，与Ｂ组（５４６．０±６８．９，４２９．３±６１．５，３０７．０±５１．３ｍｓ）比较差异有高度显著性，Ｐ均＜０．００１。③心房有效不应期（ＡＥＲＰ），Ａ组与Ｂ组比较无显著差异（２６５．０±４２．３ｍｓｖｓ２６５．０±３７．３ｍｓ，Ｐ＞０．０５）。④随Ｓ１Ｓ１刺激间距缩短，Ａ组的房室传导顺序为：１１→文氏型→２１→交替文氏型→３１或心房Ｐ波脱漏；Ｂ组的房室传导顺序则?     

房室结传导的加速性、疲劳性对房室结功能不应期的影响

房室结传导的加速性、疲劳性对心室免于各种类型的室上性心动过速包括心房颤动的影响起决定作用，但对房室结功能不应期（ＡＶＮ－ＦＲＰ）的影响不明。旨在通过对离体兔心施以多种方案电生理刺激以阐明两者的相互关系。实验结果表明：①房室结传导的加速性使ＡＶＮ－ＦＲＰ缩短（Ｂ方案１４６±３．３ｍｓｖｓＡ方案１５９±３．５ｍｓ，Ｐ＜０．０１，ｎ＝６），疲劳性使ＡＶＮ－ＦＲＰ延长（Ｃ方案１８７±４．９ｍｓｖｓＡ方案１５９±３．５ｍｓ，Ｐ＜０．０１，ｎ＝６）；②加速性和疲劳性诱导的ＡＶＮ－ＦＲＰ的变化是在１１房室传导范围内产生的，并在快速频率下达到它的最大效应（１００％频率下，Ｂ方案１５４±６．０ｍｓ、Ｃ方案１８７±８．３ｍｓ分别与Ａ方案１６８±６．９ｍｓ相比，Ｐ均＜０．０１，ｎ＝６）。结论：ＡＶＮ－ＦＲＰ受房室结传导之加速性、疲劳性相互作用的共同影响，ＡＶＮ－ＦＲＰ的变化可以用来反映房室结的传导功能     

低硒与Coxsackie B_(3m)病毒感染对BALB/c小鼠肝脏脂质过氧化物代谢的影响

用国产低硒食用酵母合成低硒饲料（硒０．０１３ｍｇ／ｋｇ，ＶＥ含量为２０ｍｇ／１００ｇ）喂养断奶后ＢＡＬＢ／Ｃ雄性小鼠，５周后腹腔接种嗜鼠心肌病毒ＣＶＢ３ｍ１０３ＴＣＤ５００．１ｍｌ，７天后处死建立低硒状态下病毒性心肌炎模型，测定肝脏组织中脂质过氧化物（ＬＰＯ）含量及全血中谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性。结果表明低硒感染ＣＶＢ３ｍ小鼠肝组织中ＬＰＯ含量明显高于常硒病毒感染组及常硒对照组（Ｐ＜０．０１）；低硒感染ＣＶＢ３ｍ病毒组小鼠全血ＧＳＨ－Ｐｘ活力也最低。结果提示：低硒因素加重病毒感染引起ＧＳＨ－Ｐｘ活力降低，ＬＰＯ堆积，降低机体的抗氧化能力     

冠心病心室晚电位与冠状动脉病变的关系

为观察心室晚电位（ＶＬＰ）、心律失常事件（ＡＥ）与冠状动脉病变的关系，对１４５例冠心病患者（心绞痛５５例、陈旧性心肌梗死９０例）进行信号平均心电图的定性分析和２４小时Ｈｏｌｔｅｒ监测，并同期进行冠状动脉造影，并长期随访观察。１１９例（失访２６例）随访１４．１±７．１（４～３６）个月，发生ＡＥ７例。ＶＬＰ阳性者ＡＥ发生率２５％（４／１６），明显高于ＶＬＰ阴性者ＡＥ的发生率２．９％（３／１０３），Ｐ＜０．００１；ＶＬＰ、ＡＥ与冠状动脉病变血管的支数和狭窄程度之间均无明显关系（Ｐ均＞０．０５）。结果提示ＶＬＰ与ＡＥ密切相关，但ＶＬＰ、ＡＥ与冠状动脉病变的范围和程度无明显关系。     

短暂心肌缺血过程中心室晚电位的动态变化

对 38例心肌梗死恢复期的病人 ,应用数字化Holter记录仪 2 4h连续监测心室晚电位 (VLP) ,以判定心肌短暂缺血对VLP的影响。Holter中加强ST段分析软件经人为定标后 ,自动分析记录达到缺血标准的时间及程度 ,其中2 1例在Holter分析中检测出一过性心肌缺血 ,此时VLP参数总QRS波持续时间 (TQRS)、QRS波末期幅度低于 4 0uV信号持续时间 (LAS40 )明显延长 (分别为 10 7.6± 14 .3vs 98.8± 12 .7ms,36 .5± 10 .8vs2 8.4± 9.5ms;P均 <0 .0 0 1) ,QRS波末期最后 4 0ms的均方根电压 (RMS40 )幅值显著减少 (2 8.9± 17.9vs 4 3.5± 2 0 .2uV)。缺血期VLP阳性 14例 ,缺血恢复 2h后VLP阳性 7例。结论 :心肌短暂缺血发作有VLP一过性阳性改变 ,动态心电图技术可捕捉到这一变化     

平板运动试验时的QT离散度诊断冠心病的价值

为了解ＱＴ离散度（ＱＴｄ）在运动试验中的变化对冠心病心肌缺血的诊断价值，对３０例临床诊断或疑诊为冠心病的病人先后行平板运动试验（简称运动试验）及冠状动脉（简称冠脉）造影检查。１７例运动试验阳性者中１０例确诊为冠心病；１３例运动试验阴性者中１０例冠状动脉正常。运动试验诊断冠心病的敏感性７６．９％、特异性５８．８％、准确性６６．７％。冠心病组与冠脉正常组运动前、中、后ＱＴｄ分别为４６．２５±２０．１３ｍｓ、７１．９２±２０．３７ｍｓ、５１．２５±１４．４８ｍｓ及３２．３５±６．６４ｍｓ、３０．８８±９．２３ｍｓ、２９．３８±８．５４ｍｓ，两者比较，Ｐ均＜０．０１。冠心病组运动前、后与运动中ＱＴｄ比较，差异有显著性，Ｐ＜０．００５；而冠脉正常组ＱＴｄ变化无显著性。以运动中ＱＴｄ≥６０ｍｓ为异常，诊断冠心病的敏感性为９２．３％、特异性１００％、准确性９６．７％。提示运动试验中ＱＴｄ增加可作为诊断冠心病心肌缺血的敏感而特异的指标     

Effects of Right Coronary Artery PTCA on Variables of P‐Wave Signal Averaged Electrocardiogram

Background: P‐wave signal averaged ECG has been used to detect atrial late potentials that were found in paroxysmal atrial fibrillation. Ischemia is supposed to trigger ventricular late potentials, which indicate an elevated risk for ventricular tachycardia. Preexistent ventricular late potentials measured by ventricular signal averaged ECG is supposed to be eliminated by successful PTCA. Methods: We examined the incidence of atrial late potentials in patients with a proximal stenosis of the right coronary artery and new onset of atrial fibrillation. Furthermore, we investigated the anti‐ischemic effect of a successful percutaneous transluminal coronary angioplasty.(PTCA) of the right coronary artery. P‐wave signal averaged ECG from 23 patients who had a PTCA of the right coronary artery (group A) were compared to age, sex, and disease‐matched control subjects (group B) one day before, one day after, and one month after PTCA. Results: A new appearance of paroxysmal atrial fibrillation was presented in eight patients before PTCA (group A1) of group A. Patients with a stenosis of the right coronary artery had a significantly higher incidence of supraventricular extrasystoles in a 24‐hour‐Holter ECG (131.1 ± 45.4 vs 17.1 ± 18.9, P < 0.0002 ). The duration of the filtered P wave was longer (124.8 ± 11.9 vs 118.5 ± 10.1 ms, P < 0.04 ) and the root mean square of the last 20 ms (RMS 20) was significantly lower in group A than in group B (2.87 ± 1.09 vs 3.97 ± 1.12 μV, P < 0.01 ). A successful PTCA caused an increase in RMS 20 (2.87 ± 1.11 vs 4.19 ± 1.19 μV, P < 0.02 ) and a decrease in filtered P‐wave duration (124.8 ± 11.9 vs 118.4 ± 10.4 ms, P < 0.04 ). Preexistent atrial late potentials were found among 15 patients before PTCA. After successful PTCA only 3 out of 15 patients were affected (P < 0.0004) after one day, as well as after one month. All patients with a history of atrial fibrillation did not suffer from an arrhythmic recurrence within the following six months after successful PTCA. Conclusion: A stenosis of the right coronary artery is associated with atrial late potentials. A successful PTCA of the right coronary artery eliminates preexistent atrial late potentials and may reduce the risk of atrial fibrillation.     

美托洛尔对冠心病患者QT离散度的影响

为探讨β－受体阻断剂美托洛尔（Ｍｅｔｏｐｒｏｌｏｌ）对冠心病（ＣＡＤ）患者ＱＴ离散度（ＱＴｄ）的影响，采用随机分组、单盲处理、前瞻性研究的方法，观察６２例ＣＡＤ患者Ｍｅｔｏｐｒｏｌｏｌ治疗前、后ＱＴｄ及ＲＲ间期、心率校正ＱＴ间期离散度（ＱＴｃｄ）、最大ＱＴ间期（ＱＴｍａｘ）、最小ＱＴ间期（ＱＴｍｉｎ）的变化。试验组Ｍｅｔｏｐｒｏｌｏｌ治疗后ＣＡＤ患者ＱＴｍｉｎ延长（３８６±３１．８ｍｓｖｓ３５２±２２．４ｍｓ，Ｐ＜０．０１），而ＱＴｍａｘ无明显改变（４３０±３５．６ｍｓｖｓ４２３±３４．９ｍｓ，Ｐ＞０．０５），ＱＴｄ、ＱＴｃｄ则显著缩小（分别为４４±１２．９ｍｓｖｓ７１±２８．６ｍｓ，４５±１１．５ｍｓｖｓ７９±３４．９ｍｓ，Ｐ均＜０．０１）。对照组治疗前、后ＱＴｄ、ＱＴｃｄ、ＱＴｍａｘ、ＱＴｍｉｎ均无改变（Ｐ＞０．０５）。表明Ｍｅｔｏｐｒｏｌｏｌ通过显著延长ＣＡＤ患者的ＱＴｍｉｎ缩小心肌复极化离散的程度，使心肌复极化趋向同步，这有利于防止恶性室性心律失常的发生     

Atrial fibrillation after coronary artery bypass surgery: P wave signal averaged ECG, clinical and angiographic variables in risk assessment.

BACKGROUND: Atrial fibrillation (AF) is a commonly encountered arrhythmia and occurs in up to 40% of patients after coronary artery bypass surgery (CABG). The preoperative signal averaged ECG (SAECG) P wave may be useful indicator of AF after CABG. We prospectively analyzed the predictive value of SAECG P wave compared to clinical variables. METHODS: Fifty-three patients with coronary artery disease undergoing first elective CABG were enrolled. All patients had P wave specific SAECG, standard 12 lead ECG, ejection fraction and left atrial posteroanterior diameter from the echocardiogram within the 24 h before surgery. From the SAECG P wave, filtered P wave duration was measured. Lead II P wave duration, left atrial enlargement and left ventricular hypertrophy were determined from standard ECG. Patients were continuously monitored during their postoperative period and serial ECGs were taken. RESULTS: During an observation period of up to 16 days, 19 (35.8%) patients developed AF 2.8+/-1.3 days after CABG. Patients with AF more often had left atrial enlargement (LAE) on ECG (P = 0.041) and right coronary artery (RCA) lesion (P = 0.0034). The filtered P wave duration on the SAECG was significantly longer in the AF patients than those without AF (129.7+/-13.2 ms versus 113.9+/-9.0 ms, P = 0.001). Logistic regression analysis identified independent predictors, estimated adjusted relative risk (95% confidence interval) of AF: with LAE, the relative risk was 2.72 (1.13-5.82), RCA lesion, the relative risk was 3.06 (1.45-6.45) and SAECG P wave duration >122.3 ms, the relative risk was 4.58 (2.11-9.97). The occurrence of AF was predicted by electrocardiographically determined left atrial enlargement with a sensitivity of 36%, specificity of 88%, positive predictive accuracy of 63%, negative predictive accuracy of 71%. If presence of right coronary artery lesion was evaluated these values were 63%, 79%, 63%, 79% subsequently. P wave duration >122.3 ms had a sensitivity of 68%, specificity of 88%, positive predictive accuracy of 76%, negative predictive accuracy of 83%. If both P wave >122.3 ms and presence of right coronary artery lesion were combined, these values were 47%, 94%, 81%, 76% subsequently. CONCLUSION: The predictors of AF after CABG were left atrial enlargement on standard 12 lead ECG, RCA lesion and SAECG P wave duration. Among these predictors, SAECG P wave duration was the best predictor of AF after CABG.     

心肌缺血和冠状动脉病变对QTc离散度的影响

为探讨ＱＴｃ离散度（ＱＴｃｄ）与心肌缺血和冠状动脉（简称冠脉）病变程度的关系，分析２８例冠脉正常和５７例冠心病患者１２导联心电图的ＱＴｃｄ。结果示：冠心病组ＱＴｃｄ较冠脉正常组显著增大（４６．７±１２．６ｍｓｖｓ２６．３±１０．９ｍｓ，Ｐ＜０．０１）；不稳定型心绞痛ＱＴｃｄ明显大于稳定型心绞痛者（５４．６±１３．７ｍｓｖｓ４２．３±１４．１ｍｓ，Ｐ＜０．０５）；双支病变与单支病变以及三支病变与双支病变相比，ＱＴｃｄ均有显著增大（４８．７±１３．２ｍｓｖｓ３５．７±１１．９ｍｓ及５９．６±１５．１ｍｓｖｓ４８．７±１３．２ｍｓ，Ｐ均＜０．０５）。提示心肌缺血是引起冠心病患者ＱＴｃｄ增大的主要原因之一，ＱＴｃｄ的变化对于判断心肌缺血和冠脉病变程度有一定价值。     

Prognosis of patients with frequent premature ventricular complexes and nonsustained ventricular tachycardia after coronary artery bypass graft surgery

Background: Previous studies in small groups of predominantly nongeriatic patients showed that complè ventricular arrhythmias occurring after coronary artery graft (CABG) surgery are of no prognostic significance. The purpose of this study was to compare the prognosis of patients with and without advanced grade ventricular arrhythmias (AGVA) after CABG in a large group of patients. [In this paper, AGVA is used as an abridged definition of frequent premature ventricular complexes (PVCs) and nonsustained ventricular tachycardia (NSVT) which represent advanced grade ventricular arrhythmias.] Methods: Twenty-four hour ambulatory electrocardiographic (ECG) monitoring was performed 3 days after CABG in 185 consecutive patients with and 185 closely matched control patients without AGVA. Of 185 patients with AGVA, 77 had frequent PVCs, 45 had NSVT, and 63 patients had both. The average age of both groups was 65 ± 9.7 years. Patients were followed for 34 ± 10 months, and in 30 patients ambulatory monitoring was repeated at the end of the follow-up. Results: Fifteen AGVA and nine control patients died. In each group seven deaths were noncardiac. Six nonsudden and two sudden cardiac deaths (SCD) occurred in the AGVA group at 2-36 months after CABG and two nonsudden cardiac deaths in the control group at 3 and 35 months after CABG (p = 0.053). Both SCDs occurred 33 months after CABG after new events known to predispose to SCD. In 18 of 30 patients AGVÀ was no longer present when ambulatory ECG monitoring was repeated 36 ± 11 months after CABG. Conclusions: AGVA after CABG was not a marker of an early sudden cardiac death. In 60% of patients not treated with antiarrhythmic drugs, AGVA was no longer present late after operation.     

Is the Change of Late Potential Over Time Related to Enzyme Levels?Ichemic Burden in Acute Myocardial Infarction

Background: The ventricular late potential (VLP) detected using the technique of signal average electrocardiography (SAECG) interacts with several factors, primarily time. Method: In this study, we examined the interaction, over time, of VLP with the initial ischemic burden and enzyme levels in acute myocardial infarction. Patients diagnosed as having acute myocardial infarction were included in the study. On the first day, the patients underwent enzyme analysis and electrocardiography (ECG) follow‐up every 6 hours. A 24‐hour ambulatory ECG was performed on the seventh day in order to determine the ischemic burden. SAECG findings (TQRS, RMS, LAS were obtained on the seventh day, in the first and third months. The study was continued with the patients who did not require angioplasty as decided with angiographic evaluation in the first month. Results: The study included 30 patients with acute myocardial infarction (mean age 51 ± 12, 28 males and 2 females). The initial mean CK‐MB levels and the mean ischemic burden were 98 ± 31 U/L and 44 ± 96 minutes. The TQRS (ms), LAS (ms), and RMS (μV) values (mean ± SD) obtained at day 7, month 1, and month 3 are 97 ± 12, 96 ± 9, 103 ± 11, P = 0.01; 31 ± 10, 31 ± 11, 32 ± 10, P = 0.46; 43 ± 28, 41 ± 26, 33 ± 25, P = 0.01, respectively. We observed that the TQRS and RMS values changed significantly with time, but these levels of significance disappeared when adjusted for the initial ischemic burden and CK‐MB levels (P = 0.06; P = 0.53). The VLP frequency was 33% at day 7 and 23% at month 3. Unlike the CK‐MB level, the initial ischemic burden was significantly different between the patients with and without VLP at month 3 (150.85 ± 149.28, 12.34 ± 26.48, P = 0.001). When tested together with age and gender, it was found that the high initial ischemic burden increased the possibility of VLP (OR: 24, Cl: 2.09–279.52, P = 0.01) at month 3. Conclusion: SAECG findings in patients with myocardial infarction changed with time; however, this change occurred depending on the initial ischemic burden and CK‐MB levels. Of these, only the initial ischemic burden, especially in high levels, was a determinant for the presence of VLP in the late period of myocardial infarction. A.N.E. 2002;7(3):242–246