QT间期离散度与JT间期离散度预测急性心肌梗塞室性心律失常发生的临床研究

QT间期离散度(QTd)是指体表12导联心电图不同导联之间最长QT与最短QT间期的差异程度,JT间期离散度(JTd)是指体表12导联心电图不同导联之间最长JT与最短JT间期的差值,它们均能反映心室肌复极化的不均一性。我们观察、分析了急性心肌梗塞(AMI)患者QTd、JTd的变化及其与室性心律失常发生的关系,现报道如下: 1 临床资料和方法 1.1 临床资料:46例AMI系1996年1月～1997年8月间发病后48小时内就诊的住院患者,均为透壁性AMI,确定AMI按1978年WHO诊断标准。早期室性心律失常统计以AMI三天内为限。     

室性心律失常Q—T间期离散度的临床价值探讨

为了评价室性心律失常患Q—T间期离散度(QTd)的临床应用价值，本观察了180例室性心律失常患的QTd，其中持续性室速组(n=55)QTd为10685±28．74ms，并行性室速组(n=60)QTd为3856±2．05ms，频发室早组(n=65)QTd为41．44±1516ms。结果显示持续性室速组QTd显高于并行性室速及频发室早组，差异极显性（P<0．001)。QTd>75ms，持续性室速检出率为94．3％，而QTd≤75ms，持续性室速检出率反为3．9％。两之间差异非常显(P<0.01)。本提示QTd与室性心律失常有一定的关系，能准确反映心室肌复极离散程度，持续性室速患，QTd明蛀增加；QTd增加(>75ms)易发生持续性室速．甚至室颤。认为QTd可作为判断室性心律失常危险性及评估其预后的有效简单的参考指标。     

急性心肌梗死QT离散度增加与早期预后的关系

对６０例急性心肌梗死（ＡＭＩ）病例，在发病４８ｈ内首次描记的心电图（ＥＣＧ）ＱＴ间期离散度（ＱＴｄ）与ＪＴ间期离散度（Ｔｄ）进行了测定。结果显示：ＱＴ间期离散度和ＪＴ间期离散度的增加与ＡＭＩ早期室速和原发性室颤的发生率呈正相关，ＡＭＩ早期室速，室颤患者的ＱＴｄ与ＪＴｄ（１００．４８±２７．６０ｍｓ与１００．５０±２３．１０ｍｓ）显著高于非室速、室颤组（４６．８０±１８．００ｍｓ与４８．４０±１８．     

室性心律失常Q-T间期离散度的临床价值探讨

为了评价室性心律失常患者Q－T间期离散度（QTd）的临床应用价值，本文观察了180例室性心律失常患者的QTd，其中持续性室速组（n＝55）QTd为106.85±28．74ms，并行性室速组（n＝60）QTd为38．56±12．05ms，频发室早组（n＝65）QTd为41．44±15.16ms。结果显示持续性室速组QTd显著高于并行性室速及频发室早组，差异极显著性（P＜0.01）。QTd＞75ms者，持续性室速检出率为94．3％，而QTd≤75ms者，持续性室速检出率反为3．9％。两者之间差异非常显著（P＜0．01），本文提示QTd与室性心律失常有一定的关系，能准确反映心室肌复极离散程度，持续性室速患者，QTd明显增加；QTd增加（＞75ms）易发生持续性室速，甚至室颤。认为QTd可作为判断室性心律失常危险性及评估其预后的有效简单的参考指标。     

磷酸肌酸钠对急性心肌梗死后室性心律失常的影响

目的探讨磷酸肌酸钠对急性心肌梗死（AMI）后室性心律失常的影响,为临床治疗提供依据。方法选择2012年1月至2012年11月住院的AMI患者112例,随机分为两组,各56例。所有患者均给予AMI常规治疗（抗血小板、抗凝、他汀类药物、β受体阻滞剂、血管紧张素转化酶抑制剂、硝酸酯类药物）,有适应证者应用尿激酶溶栓。治疗组在此基础上静脉应用磷酸肌酸钠。观察治疗期间两组患者室性心律失常的发生情况及治疗前后QT间期离散度（QTd）和校正的QT间期离散度（QTcd）的变化。结果治疗组频发室早、短阵室速、持续性室速和室颤发生率均稍低于对照组,但差异无统计学意义（P均﹥0.05）。两组治疗后QTd和QTcd均低于治疗前（P均〈0.05）。治疗组治疗后QTd和QTcd为（64.17±4.14）ms及（71.33±6.52）ms,低于对照组治疗后的（71.30±5.22）ms及（77.82±7.65）ms,差异具有统计学意义（P均〈0.05）。结论磷酸肌酸钠可使AMI患者QTd和QTcd显著降低,能否确实减少AMI后室性心律失常的发生,有待扩大样本量进一步观察。     

急性心肌梗塞QT离散度增加与室性心律失常的关系

急性心肌梗塞(AMI)早期室性心律失常的发生率较高,且是引起室速、室颤导致猝死的主要原因。本文测定70例AMI心电图(ECG)的QT间期离散度(QTd),目的是分析体表ECG的QTd增加与AMI早期室性心律失常的关系。     

QT,JT间期离散度与急性心肌梗塞预后的关系

QT间期离散度(QTd)是指心电图(ECG)各导联间QT间期的变异程度。其产生与心肌细胞除极后复极不均匀有关。QTd延长与致命性室性心律失常的发生密切相关,而致命性室性心律失常是急性心肌梗塞(AMI)的主要死因,因此将其作为AMI预后的一项指标已越来越受到关注。本文通过对200例AMI患者QTd和JTd的动态观测,探讨如下。     

早期康复治疗对无并发症急性心肌梗死患者QT间期离散度的影响

目的探讨早期康复治疗对无合并症急性心肌梗死 (acute myocardial infarction ,AMI )患者 QT间期离散度( QTd)的影响. 方法 113例研究对象前瞻性随机分为早期康复治疗组 (组 1, 54例 )及对照组 (组 2, 59例 ). 2组主要基线资料具可比性.组 1采用早期康复治疗方案,组 2采用传统康复方案.所有研究对象分别在入院当时 [平均( 9.3± 1.9) h]第 1周末、第 2周末、第 3周末记录标准 12导联心电图. QT 间期的测量从 QRS 波起点至 T波终点,同一导联测量 3个心动周期,取其平均值.不同导联最大减去最小 QT值为 QTd 值. 结果早期康复组入院当时、第 1 周末、第 2 周末、第 3周末 QTd[分别为 (64± 14)ms,(46± 15)ms,(43± 12)ms,(39± 13)ms]与对照组 [分别为 (67± 12)ms,(48± 16)ms,(41± 13)ms,(40± 15)ms]比较统计学上无显著性差异( t分别为 0.81,0.68,0.85,0.38, P >0.05). 结论无合并症 AMI 患者实行早期康复治疗不影响 QTd 值,因而不影响心肌电稳定性,提示该组患者早期康复治疗安全可行.     

早期康复治疗对老年急性心肌梗死患者QT间期离散度和心率变异性的影响

目的:探讨早期康复治疗对老年急性心肌梗死(AMI)患者QT间期离散度和心率变异性的影响。方法:将73例研究对象前瞻性随机分为早期康复治疗组(37例)及对照组(36例)。两组主要基线资料具有可比性。早期康复组采用早期康复治疗方案,对照组采用传统康复方案。所有研究对象分别在入院时、第1周末、第2周末、第3周末记录标准12导联心电图,测量QT间期离散度(QTd)。在发病第2周末行24h动态心电图检查和心率变异性分析。结果:①早期康复组QTd从入院时74.3±14.2ms降低到第3周末的47.3±11.4ms,与对照组比较差异有显著性意义(P<0.05)。②早期康复组HRV各项指标明显好于对照组,其中PNN50为45.0±18.91(%)高能谱为4.55±0.82ln(ms)2,与对照组比较差异有显著性意义(P<0.05)。结论:早期康复治疗对老年AMI患者可降低其QT间期离散度改善心率变异各项指标,不增加恶性心律失常的发生,降低患者猝死率。提示早期康复治疗对老年AMI患者是安全可行的。     

急性心肌梗塞时QT间期离散度对心室颤动的影响

目的:探讨急性心肌梗塞(AMI)时心电图QT间期离散度的改变与心室颤动之间的关系。方法:回顾性分析25例AMI后24小时内发生心室颤动的患者(心室颤动组)和32例未发生心室颤动的AMI患者(对照组),对比分析两组急诊时体表同步12导心电图的QT间期离散度和QTc间期离散度。结果:心室颤动组QTc间期离散度和QT间期离散度均显著高于对照组(分别为76ms±15ms与33ms±16ms和73ms±21ms与40ms±14ms,P<0.001)。结论:AMI时QT间期离散度增加可导致心室颤动的危险性增加。     

Association between ventricular repolarization variables and cardiac diastolic function: A cross-sectional study of a healthy Chinese population

BACKGROUND Diastolic electromechanical couple, a well-described phenomenon in symptomatic heart failure, has not been well studied in healthy people. We hypothesized that ventricular repolarization variables, such as the QT interval,Tpeak-to-Tend(Tpe) interval and Tpe/QT ratio, are associated with cardiac diastolic function in the healthy Chinese population.AIM To assess the relationship between ventricular repolarization variables and cardiac diastolic function in apparently healthy Chinese individuals.METHODS This was a community-based cross-sectional study conducted in Shenyang,China. A total of 414 healthy subjects aged 35-91 years were enrolled. All subjects underwent standard 12-lead electrocardiography(ECG) and comprehensive echocardiography. ECG enabled the measurement of QT and Tpe intervals and Tpe/QT ratio. echocardiographic parameters, such as the ratio of mitral early diastolic inflow velocity(E) and late diastolic inflow velocity(A), E-wave deceleration time, left atrial volume(LAV) and LAV index, were measured to assess diastolic function. E/A < 0.75 was considered to indicate reduced diastolic function. ECG and echocardiography results were analyzed separately and in a blinded fashion. Correlation and regression analyses were applied to determine associations.RESULTS Ventricular repolarization variables, such as the QTc interval(393.59 ± 26.74 vs403.86 ± 33.56; P < 0.001), Tpe interval(72.68 ± 12.41 vs 77.26 ± 17.86; P < 0.01),Tpec interval(76.36 ± 13.53 vs 83.32 ± 21.25; P < 0.001) and Tpe/QT ratio(0.19 ±0.03 vs 0.20 ± 0.04; P < 0.01), were significantly different between the normal diastolic function group and the reduced diastolic function group. Significant associations were found between repolarization variables and diastolic function.After adjusting for all other possible confounders, the QTc and Tpe_c intervals were significantly associated with the E/A ratio(P = 0.008; P = 0.010). In men, the QTc interval was associated with abnormal diastolic function, and compared to the third QTc tertile, in the second QTc tertile, the odds ratio was 0.257(95%CI:0.102–0.649; P = 0.004).CONCLUSION Repolarization variables are associated with cardiac diastolic function even in healthy people. Moderate levels of the QTc interval exert a protective effect on diastolic dysfunction in men.     

甲状腺功能亢进性心脏病左心结构与功能临床研究

目的探讨甲状腺功能亢进（甲亢）性心脏病（HHD）病人左心功能与结构的改变和早期诊断。方法应用彩色多普勒超声显像仪检测31例单纯甲亢和65例HHD病人左、右心室舒张末期内径（LV、RV）,舒张末期左心室后壁及室间隔的厚度（IVS、LVPW）,收缩末期左、右心房横径（LA、RA）;测量左心室舒张早期（E峰）及舒张晚期（A峰）二尖瓣最大血流速度,左心室射血分数（EF）。计算左心室质量（LVM）、左心室质量指数（LVMI）及舒张早晚期的最大血流速度比值（E/A）,并与30例正常对照组比较。结果HHD病人早期LVMI明显高于对照组和单纯甲亢组,二尖瓣血流频谱E/A比值明显低于对照组和单纯甲亢组（F=5.47、20.32,q=4.93～5.10,P〈0.01）,而早期EF与对照组比较差异无显著性（P〉0.05）。HHD病人早期左心房、左心室大于单纯甲亢组和对照组,右心房、右心室无明显的变化,晚期右心房、右心室大于HHD早期和单纯甲亢病人。HHD晚期EF低于对照组,差异有显著性（F=5.03,q=4.87,P〈0.01）,单纯甲亢病人EF高于对照组,差异有显著性（q=5.02,P〈0.01）。结论甲亢病人左心室收缩功能增强。HHD病人早期出现左心舒张功能不全,收缩功能正常,晚期出现收缩功能不全。HHD病人先左心扩大,晚期全心扩大。LVMI结合E/A可早期诊断HHD。     

Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice

Malignant cardiac arrhythmias which result in sudden cardiac death may be present in individuals apparently healthy or be associated with other medical conditions. The way to predict their appearance represents a challenge for the medical community due to the tragic outcomes in most cases. In the last two decades some ventricular repolarization(VR) markers have been found to be useful to predict malignant cardiac arrhythmias in several clinical conditions. The corrected QT, QT dispersion, Tpeak-Tend, Tpeak-Tend dispersion and Tp-e/QT have been studied and implemented in clinical practice for this purpose. These markers are obtained from 12 lead surface electrocardiogram. In this review we discuss how these markers have demonstrated to be effective to predict malignant arrhythmias in medical conditions such as long and short QT syndromes, Brugada syndrome, early repolarization syndrome, acute myocardial ischemia, heart failure, hypertension, diabetes mellitus, obesity and highly trained athletes. Also the main pathophysiological mechanisms that explain the arrhythmogenic predisposition in these diseases and the basis for the VR markers are discussed. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients.     

急性冠状动脉综合征患者的QT间期变异性与室性心律失常的相关性分析探讨

目的现已明确急性冠状动脉综合征（acute coronary syndrome，ACS）患者发生猝死与恶性室性心律失常密切相关，本文旨在探讨ACS患者QT间期变异性与发生室性心律失常的相关性。方法采用动态心电图分析54例ACS室性心律失常患者24h QT间期变异性。结果ACS室性心律失常患者24h QT间期变异性明显减低。结论ACS室性心律失常患者24h QT间期变异性较正常人明显减低，其发生心律失常的可能性将明显增加。     

陈旧性心肌梗死患者T波峰末间期的检测及其与室性心律失常的关系

目的检测陈旧性心肌梗死患者T波峰末间期（Tpe）及T波峰末间期离散度，并探讨其与室性心律失常发生的关系。方法对31例陈旧性心肌梗死患者（分为室性心律失常亚组与无室性心律失常亚组）及40例对照组患者，测量其同步12导联动态心电图的Tpe间期和Tpe离散度（最长Tpe减最短Tpe之差），计算校正的T波峰末间期（Tpe√RR）、心率校正的Tpe离散度（Tpe离散度√RR），并进行比较。结果心肌梗死组的Tpe/√RR、Tpe离散度√RR均较对照组组明显延长（P〈0．01），而心律失常亚组的Tpe／√RR、Tpe离散度／√RR亦较无心律失常亚组延长（P〈0．05）。结论心肌梗死组的Tpe间期、Tpe离散度延长有显著统计学意义，Tpe间期、Tpe离散度延长与室性心律失常的发生关系密切。     

R EDUCTION OF THE C ALL -R ESPONSE I NTERVAL WITH A MBULANCE B ASE P AGING

Objective. To determine whether the call-response interval for an emergency medical services (EMS) system would be decreased through the introduction of ambulance base paging. Methods. The study community included a mixture of urban and rural areas with a total population of approximately 400,000. The EMS system is composed of two ambulance services and one central ambulance communication center with computer-aided dispatching capabilities. Approximately 30,000 calls are responded to yearly by the combined ambulance services. A before-and-after study design was used. In a retrospective review of one ambulance service, there were 224 calls collected in the period before base paging and 200 calls collected in the period after base paging was introduced. In the other ambulance service, there were 571 calls captured in the period before base paging and 515 calls captured in the period after base paging. Results. The call-receipt-to-crew-notified interval was reduced from the before period to the after period in both ambulance services: Cambridge—61.8 to 49.8 seconds (p < 0.0001); Kitchener—66.6 to 46.2 seconds (p < 0.0001). The crew-notified-to-vehicle-mobile interval was reduced from the before period to the after period in both ambulance services: Cambridge—91.8 to 73.2 seconds (p < 0.0001); Kitchener—80.4 to 66.0 seconds (p < 0.0001). Conclusions. The introduction of ambulance base paging reduced components of the call-response interval in this EMS system. Overall, the reduction in time was approximately 30 seconds, which was found to be statistically significant.     

检测冠心病并发室性心动过速患者T波峰末间期的意义—附46例报告

目的：探讨检测冠状动脉粥样硬化性心脏病（冠心病）并发室性心动过速（室速）患者T波峰末间期（Tpeak-Tend interval,Tp-Te间期）的意义。方法：分析46例发生室速（室速组）和23例无室速（非室速组）的冠心病患者的12导联同步动态心电图,测量2组的Tp-Te间期并进行比较。结果：室速组的Tp-Te间期为（114±26）ms,非室速组为（96±15）ms,2组比较差异有统计学意义（P〈0.01）。Logistic回归分析显示,Tp-Te间期改变是冠心病并发室速患者的独立危险因素（比数比为0.95,P〈0.01）。结论：对冠心病患者检测其Tp-Te间期的改变,可识别冠心病患者是否易诱发室速。     

T波峰末间期和心率变异性在冠心病并发室速危险分层的意义

目的明确心电图T波峰末间期(Tpe)和心率变异性在冠心病患者并发室性心动过速(室速)危险分层中的作用。方法选取46例发生室速和23例无室速(对照组)的冠心病患者,分别测量其12导联同步动态心电图的Tpe间期和24 h心率变异性指标。结果两组间Tpe差异有统计学意义(P<0.05);两组心率变异性指标中24 h全部RR间期的标准差(SDNN)差异有统计学意义(P<0.05),Logistic多元回归分析显示Tpe是冠心病患者发生室速的独立危险因素[P<0.05,比值比(OR)为0.9499,5%CI为0.912～0.987]。结论Tpe和心率变异性是冠心病患者并发室速的重要危险因素,且Tpe是独立危险因素。     

ON THE PHYSICOCHEMICAL REGULATION OF THE GROWTH OF TISSUES : THE EFFECTS OF THE DILUTION OF THE MEDIUM ON THE GROWTH OF THE SPLEEN.

It may be concluded that the degree of dilution of the culture medium has a marked influence on the rate of growth of splenic tissue. The maximum acceleration was obtained in a medium composed of three volumes of normal plasma and two volumes of distilled water. The growth in this hypotonic plasma was very much larger than in normal plasma. On the contrary, the growth of the spleen in hypertonic plasma was always less than in normal plasma. In other experiments, we found that in diluted plasma there was also an acceleration of the growth of the skin, the heart, and the liver of chickens. The skin of adult frogs also grew more actively in this plasma. The optimum degree of dilution varied according to the nature of the tissues and to the species of the animals. While the plasma containing two fifths distilled water produced the largest growth of splenic tissue, a slightly less diluted medium was more favorable for the liver and the heart, and generally for the skin also. The action of hypertonic plasma varied also in a large measure. While the spleen did not grow at all in the medium containing 0.0124 and 0.0144 sodium chlorid, the skin, on the other hand, could stand a high concentration of the sodium chlorid. Even its growth was activated in media containing 0.0094 and 0.0124 sodium chlorid and was greater than with normal plasma. The spleen of kittens was very easily affected by the changes of the dilution of the plasma, while the skin of the frog presented its best growth in plasma containing one half distilled water. Marked variations in the sensitiveness of tissues to hypertonic and hypotonic media will probably be observed in animals of different species. From these experiments, three conclusions can be drawn: namely, that certain laws of growth, discovered by Loeb, in lower organisms are true also for higher organisms; that normal plasma is not the optimum medium for the growth of tissue; and that each tissue has probably its optimum medium. The growth of the spleen is, without doubt, considerably modified by the variations of the dilution and perhaps of the osmotic tension of the plasma. It is possible then that the influence of osmotic tension, discovered by Loeb, in the growth of certain organisms, is a general law applicable as well to higher forms of life— frogs, cats, and chickens—as to lower organisms—tubularia and sea-urchins. In placing tubularia in different dilutions of sea-water and distilled water, Loeb found that the greatest rate of regeneration was observed when two volumes of distilled water were added to three volumes of sea-water. But fertilized eggs of sea-urchins were more sensitive to the action of hypertonic plasma, and they all died in a dilution of sea-water with two fifths distilled water. If only one fifth distilled water was added to the sea-water they developed normally. We found that the cells of certain tissues of the chicken follow a similar rule, since the maximal growth of the spleen is obtained in plasma containing two fifths distilled water, while other tissues grow better in a less hypotonic medium. Normal plasma is certainly not the ideal medium for the growth of tissues, since slight modifications of the tension, the alkalinity, or the addition of certain inorganic salts to normal plasma, increase the rate of the growth of tissues.