Selective coronary angiography is regarded as a gold standard for the diagnosis of coronary atherosclerotic cardiopathy(coronary heart disease), but not all the hospitals are qualified for the testing, and additionally, it is risky in some extent and relatively expensive. At present, non-invasive-testing methods for diagnosis of coronary heart disease include electrocardiogram(ECG), ambulatory electrocardiography, and treadmill exercise test, especially surface ECG which is convenient, rapid and low cost, and shows characteristic changes in cases of stable angina pectoris, acute coronary syndrome, etc. At the occurrence of acute myocardial infarction, culprit vessels position can be prejudged through ECG changes, and therefore surface ECG is vital in diagnosing coronary heart disease.

ST-segment change is an ECG manifestation which is commonly seen in clinical practice and easily misdiagnosed. The reason is that ST-segment is mainly descriptive in ECG report and it is difficult to measure the end of S wave and the beginning of T wave accurately. All of -T changes are not caused by myocardial ischemia since many factors contribute to ST-T changes. It has vital clinical significance to accurately identify predictive ST-T changes for ECG's important diagnostic value on myocardial ischemia. This paper reviews the related basic concepts, generalizes four determining methods of ST-segment depression, summarizes its correspondence analysis and several common ST-depression of special types, analyzes its prognosis and risk stratification, and explains the mechanism, so as to provide concise thinking of analysis and diagnosis for more clinicians.

With deepening understanding of the graphic mechanism of Lorenz plot, the related concepts and terminologies have been increasing rapidly and their connotations require to be expounded. This paper focuses on explaining several common clinical concepts at present, including RR interval difference Lorenz plot, tRR scatterplot, electrocardioattractor, big data, “two ends, two lines, and eight regions”, “four diagnostic essentials” for arrhythmia (number of subgraphs, graphic shapes, locations of graphs, and B linear slope), preceding point of premature beat, main point of premature beat, following point of premature beat, preceding block point, following block point, homogeneous attractors with the same origin, homogeneous attractors with different origins, etc.

变异型心绞痛又称血管痉挛性心绞痛，由冠状动脉一过性痉挛收缩引起，心电图ST段可抬高或压低，可伴有心律失常。本文报道一例变异型心绞痛患者静息、发作及PCI术后心电图改变及其临床诊治过程。

ObjectiveTo observe the effects of anesthetics and other different kinds of reagents on ECG in mice .Methods Healthy ICR mice were randomly divided into 5 groups and respectively received intraperitioneal injection of one of the following anesthetics: pentobarbital sodium solution(PS)of 0.4% or 0.6%,10%ethyl carbamate(EC), 3% chloral hydrate(CH),2.5% tribromoethanol(TBE). Anesthetic effects were observed and compared between groups. Anesthetic inhibition effect on heart rate were compared between groups, or with those before administrating and of simultaneous normal saline(NS) group. Under the situation of CHinduced anesthesia, the effects of three kinds of adrenoreceptor agonists(adrenaline,noradrenaline and isoprenaline) on heart rate were observed and compared with that both of simultaneous NS group and before administrating. The drugs and reagents with the effects of inhibition to cardiomyocytes, including βadrenegic antagonist propranolol, sodium channel blocker lidocaine, lactic acid and potassium chloride were used to test their effects on ECG in mice.Results Three anesthetics of 0.6% PS, 3% CH and 2.5% TBE exhibit their satisfactory anesthetic effect, especially for 3% CH and 2.5% TBE ，which got a further more steady effect. Compared with those before administrating, the three anaesthetics mentioned above could significantly slow the heart rate(P<0.05) . These phenomenon could not be altered even though adrenoreceptor agonists were given intraperitoneously. Besides, it was found that both adrenaline and noradrenaline could significantly suppress heart rate, while resecptively compared with the situation before administrating(P<0.05 or <0.01) . The heart rates after administrating in certain concentration of propranolol, lidocaine, lactic acid and potassium chloride were slower than those before administrating(P<0.05 or <0.01) and, at the same time, the administration could also lead to various kinds of arrhymias. ConclusionAnesthetics could significantly inhibit cardic electrophysiological activity in mice and disturb the pharmacological effects of cardiovascular active medicines. ECG observations on conscious mice were of great importance not only for cardic electrophysiological, pharmacological and toxicological researches but also for preclinical and clinical medicine experimental teaching

 As a practical tool, electrocardiogram(ECG) is widely applied in the diagnosis and prognosis evaluation of coronary heart disease, especially ECG with abnormal myocardial repolarization. The repolarization abnormalities mainly manifest in the changes of ST segments, T waves, and QT durations. This paper discusses ST segment, T wave, and QT duration in details, and summarizes those indices clinical values for the diagnosis and prognosis evaluation of coronary heart disease, with the boundedness also analysed. It points in the right direction for the clinical application of those indices. U wave has higher specificity in the diagnosis of ischemic heart disease, however it has been focused by relatively few clinical studies. In addition, T wave electrical alternans and T peak end interval(Tp-Te) are also indicators for myocardial repolarization. However, the two indices were not referred in details in this paper since their application is rarely seen clinically and they mainly associate with malignant arrhythmia.

Lead system is an important part of ambulatory electrocardiography(AECG), which lays the foundation for collecting and analyzing AECG graphs. This paper introduces the invention of AECG and the development of lead system in details, including the development background, electrode placement, clinical application, advantages and disadvantages of each type of lead system, and finally the prospects for development.

Objective    To discuss the clinical application value of telemonitoring ECG(TTECG) information system. Methods    The Holter data of 63 patients were selected which were transmitted from branch hospital to ECG consultation center of central hospital from June 2015 to May 2016. The enrolled patients were divided into network transmission group(31 cases) and artificial transmission group(32 cases). Holter recorder was utilized in collecting Holter data in primary hospital; the data were then transmitted to ECG consultation center artificially or by local area network, respectively; ECG specialist physicians made diagnosis. The starting time of diagnosis was classified into within 1 h, 1-5 h and 5-10 h. During different time periods, the diagnosed cases were made comparison and analysis between the two groups. Results    The starting time of diagnosis in network transmission group was significantly earlier than that in artificial transmission group[(1.2±0.5) h vs. (8.7±2.0) h，P＜0.05]. If the starting time of diagnosis was within one hour, network transmission group diagnosed 26 cases(83.9%) in all while none of the patients was diagnosed by artificial transmission group. If the starting time of diagnosis was 1-5 h, the diagnosed cases were separately 5 cases(16.1%) and 12 cases(37.5%) in the two groups. If the starting time of diagnosis was 5-10 h, none of the patients was diagnosed by network transmission group while artificial transmission group diagnosed 20 cases(62.5%). The difference was statistically significant(P＜0.01). Conclusion    TTECG information system applied in primary hospitals can shorten consultation hours for patients, and realize remote data sharing and consultation. It also has advantage in detecting cardiovascular events in time. It may improve the level of diagnosis and treatment in primary hospitals, and has great clinical practical value.

ObjectiveTo discuss the relationship between blood pressure instant variability(BPIV) and heart rate variability(HRV) of human under respiratory control. MethodsFiftytwo healthy people′s ECG, blood pressure  （BP）and respiration were synchronously recorded and analyzed when respiratory rate were controlled at 51015 times/min and 81216 times/min. ResultsAt respiratory rate of 1015 times/min and 81216 times/min, RR variation trend and BPBP variation trend were fully synchronized with respiratory wave variation trend. Correlation coefficients(r) of center frequency of RF/HR with peak of respiratory（RSP）, BPIV and HRV were 0.924, 0.902 and 0.913, respectively. At respiratory rate of 5 times/min, RR variation trend and BPBP variation trend were desynchronized. ConclusionsAt certain respiratory rate, BPIV is corresponded with the physiological mechanism of respiratory sinus arrhythmia and HRV mechanism caused by respiratory sinus arrhythmia. However, BPIV is not corresponded with the physiological mechanism of HRV mechanism caused by respiratory sinus arrhythmia when respiratory rate is too low.

With the popularity of treadmill graded exercise test and Holter ECG monitoring technology, the probability of mixed wrong connections between upper and lower limb lead wire or left and right hand lead wire of 12 lead simultaneous monitoring ECG increases gradually. Those wrong connection ways are intricate and the graphs are illegible. Taking the limb-lead ECG of a 35-year-old healthy male adult for example, diagrammatize the ECG lead polarity and the tracing order of channels separately in 6 connection ways of lead wire, the right way and 5 wrong ways, especially display the mixed wrong connection ways between the upper and lower limb lead and the ECG representations.

It is required by the development of science and technology to introduce computer into interpretation of electrocardiogram(ECG). ECG report will rely more on artificial intelligence diagnosis. At present, the top priority is to construct the countryneeded artificial intelligence ECG diagnosis system which can be applied in medical treatment, health care, teaching and research. The extensive utilization of the system will vigorously propel the development of electrocardiology and elevate the level of disease prevention, early warning, diagnosis, treatment and prognosis evaluation in clinical medicine.

ObjectiveTo explore the relationship between heart rate and the amplitude of P wave.MethodsTwo hundred and fortyfive patients examined by 24 h ambulatory electrocardiography(Holter) in our hospital were randomly selected. Based on their Holter screenshots including the fastest and the slowest heart rate, the heart rates and P wave amplitudes were measured separately, and the average values of P wave amplitudes in different ranges of heart rates were calculated and compared. The reasons for the changes of P wave amplitudes were analysed. ResultsThere was significant difference between the P wave amplitude at a heart rate over 120 beats/min and the one at a heart rate below 120 beats/min. And there was no obvious correlationship between the increase of P wave amplitude and right atrial enlargement or pulmonary artery hypertension.ConclusionWhen heart rate is over 120 beats/min, the increase of P wave amplitude mainly results from elevated autonomic nerve tension.

Objective  To appraise the diagnosis value of Cornell index and Sokolow index by comparing their performance in pediatric electrocardiogram for left ventricular hypertrophy. Methods  One thou-  sand and eighty two cases of children inpatient from 2008 to 2010 in our hospital were divided into three  groups: one months to three years old（232 cases in male and 184 cases in female），three years old to thirteen （198 cases in male and 143 cases in female），thirteen to seventeen（186 cases in male and 139 cases in female）. Each group was divided into normal group and LVH group according to left ventricular diameter  （LVD） detected by echocardiogram. Sensitivity，specificity and accurancy of Cornell index and Sokolow index   were calculated. Results  In the group of one months to three years， the sensitivity， specificity and accurancy of Cornell index were higher than Sokolow index for both sexes. There was no significant difference of the two indexes in the other two groups（>0.95），but the sensitivity and accurancy of Cornell index were higher than Sokolow index for both sexes in the later groups. Conclusion  The effect of Cornell index is more effective than Sokolow index in pediatric electrocardiogram diagnosis for left ventricular hypertrophy. 

There are various kinds of calculation indexes of cardiac chronotropic function, however the majority of the current instruments haven't been equipped with the special detecting function. In this paper, according to the relevant calculation program of cardiac chronotropic detecting, we made a practical and convenient Office Excel measurement table. Through specific examples, we introduced in details how to use the table and matters needing attention in process of detecting.

Severe coronary artery diseases include acute complete or subtotal occlusion of left main coronary artery(LMCA) and 3vessel disease(3vd). Although the patients with acute complete occlusion of LMCA rarely arrive to hospital alive, the specificity and accuracy rate of ST segment elevation in lead aVR are both above 80%. For the patients with acute subtotal occlusion of LMCA and 3 vd, its diagnostic value is higher than that of any other single lead or multiple ones. The higher the amplitude of ST segment elevation in lead aVR is and the longer the duration is, the more serious the patients condition is. This paper reviews the diagnostic criteria of ST segment elevation in lead aVR, electrophysiological mechanism and overseas research progress.

结合对16个图例的分析，详细阐述了起搏器各种频率的基本概念和相应的心电图表现，如频率应答、频率回退、频率平滑、频率滞后、抗心动过缓快速起搏、抗心动过速起搏等。熟悉和掌握这些内容有助于日常起搏心电图或动态心电图的分析和判断，有助于防止误判起搏器功能异常。

的通过与冠脉造影结果对比，探讨平板运动试验可疑阳性在冠心病中的诊断价值。方法 对52例平板运动试验可疑阳性并行冠脉造影者的结果进行回顾性分析。结果 52例运动试验可疑阳性者中15例冠脉造影为阳性，其中男性多见（占80%），37例冠脉造影为阴性，其中女性多见（占75.6%）。平板运动试验中ST段压低的形态及持续时间的长短与冠脉造影的结果有一定的相关性。结论 平板运动试验可疑阳性在冠心病的诊断中具有一定的价值。但其阳性率较低（尤其是女性），需排除多种干扰因素并结合其他检查方法，才能进一步明确诊断。