Esophageal electrocardiography: a new technology revives an old technique

This study evaluates the clinical use of an easily swallowed bipolar electrode for recording an esophageal electrocardiogram (ECG). Fourteen patients were selected for bedside diagnosis (ECG group) because of arrhythmias difficult to evaluate using a standard 12-lead ECG. A second group of 27 non-selected patients scheduled for routine 24-hour ambulatory electrocardiographic recordings (ambulatory ECG group) had an esophageal ECG recorded as the "third channel." All 14 patients (100%) in the ECG group had excellent-quality tracings, and the esophageal ECG was diagnostic in 12 cases (86%). Of 27 patients in the ambulatory ECG group, 19 (70%) had fairly good to excellent-quality 24-hour esophageal pill tracings, with the esophageal ECG contributing to correct arrhythmia diagnosis in 11 patients (41%). It is concluded that this easily swallowed esophageal electrode provides an excellent-quality short-term ECG and often permits proper arrhythmia diagnosis in selected patients with arrhythmias. Good-quality 24-hour esophageal ambulatory electrocardiographic recordings can also be obtained that contribute to arrhythmia diagnosis in a limited number of unselected patients, and should be even more clinically useful in carefully selected patients.     

心电图在高血钾临床诊断价值中的研究

目的为了探讨心电图对诊断高血钾的临床价值，尽早诊断、治疗高血钾这一l临床急症。方法对48例高血钾患者的心电图与血清钾浓度进行对照分析。结果显示血清钾高低与心电图改变并不呈绝对平行关系，排钾困难所致的高血钾心电图改变与血清钾测定有较好的一致性。不同程度的高血钾在心电图上有不同的特征表现，而细胞内钾外移所致的高血钾在心电图上无高血钾改变。结论心电图对高血钾改变的反应比血清钾测定更准确，可作为诊断高血钾，判定其程度和观察疗效的重要指标。     

高血钾症的心电图诊断价值

目的 探讨心电图对诊断高血钾的临床价值。方法对48例高血钾患的心电图与血清钾浓度进行对照分析。结果血清钾高低与心电图改变并不呈绝对平行关系,排钾困难所致的高血钾心电图改变与血清钾测定有较好的一致性。不同程度的高血钾在心电图上有不同的特征表现,而细胞内钾外移所致的高血钾在心电图上无高血钾改变。结论心电图对高血钾改变的反应比血清钾测定更准确,可作为诊断高血钾,判定其程序和观察疗效的重要指标。     

12导联同步动态心电图在冠心病心肌缺血诊断中的应用

目的探讨12导联同步动态心电图（DCG）在冠心病心肌缺血诊断中的价值,进一步推广在基层医院中的应用。方法选取本院就诊中疑诊为冠心病的250例作为研究对象,同时行12导联和3导联同步DCG24h监测,收集相关信息,进行统计学分析。结果 12导联同步DCG对心肌缺血诊断的阳性率明显高于3导联者,两者之间有显著差异（P〈0.05）;12导联同步DCG对下壁、侧壁心肌缺血的诊断优于3导联同步记录。结论 12导联描记在冠心病心肌缺血诊断上明显优于3导联记录,可以减少冠心病的漏诊率。     

Recognition algorithm in electrocardiographic syndrome of atrial hypertrophy

A system was developed for automatic ECG analysis, which involved a screening program and algorithms for syndrome ECG diagnosis. The principles for synthesizing algorithms for syndrome diagnosis are exemplified by the decision rule of identifying a ECG syndrome of atrial hypertrophy. The specificity of the proposed algorithm was more than 90%. Severe left and right atrial and moderate right atrial hypertrophies were well recognized. The findings suggest that the developed rules might be useful in the system of automatic ECG analysis.     

Impact of a clinical scenario on accuracy of electrocardiogram interpretation

To examine the effect of clinical history on the electrocardiogram (ECG) interpretation skills of physicians with different levels of expertise, we randomly allocated to an ECG test package 30 final-year medical students, 15 second-year internal medicine residents, and 15 university cardiologists at university-affiliated teaching hospitals. All participants interpreted the same set of 10 ECGs. Each ECG was accompanied by a brief clinical history suggestive of the correct ECG diagnosis, or the most plausible alternative diagnosis, or no history. Provision of a correct history improved accuracy by 4% to 12% compared with no history, depending on level of training. Conversely, a misleading history compared with no history reduced accuracy by 5% for cardiologists, 25% for residents, and 19% for students. Clinical history also affected the participants' frequencies of listing ECG features consistent with the correct diagnosis and features consistent with the alternative diagnosis (all p values < .05). For physicians at all levels of expertise, clinical history has an influence on ECG diagnostic accuracy, both improving accuracy when the history suggests the correct diagnosis, and reducing accuracy when the history suggests an alternative diagnosis.     

Clinical characteristics of subjects with the Brugada-type electrocardiogram:

INTRODUCTION: The Brugada-type ECG, a terminal r' wave accompanied by ST segment elevation in the right precordial leads, is not a very rare condition. Most of the cases are men in Japan and elsewhere; however, information about the clinical features of these cases is lacking. The aim of this study was to determine the clinical characteristics of subjects with the Brugada-type ECG, specifically Japanese men. METHODS AND RESULTS: We extracted male Brugada-type ECG cases from 3,374 men followed biennially from 1958 through 2001 in Nagasaki, Japan, and compared the clinical characteristics at diagnosis between these cases and four age-matched male controls for each case. A total of 34 cases with the Brugada-type ECG were observed during follow-up. Body mass index (BMI) at diagnosis was significantly lower in Brugada-type ECG cases than in 136 controls (20.2 +/- 2.1 kg/m(2) vs 21.8 +/- 2.8 kg/m(2), P = 0.003). The BMI trend in cases was always lower than that in controls throughout the 8-year observation period (from 4 years before diagnosis to 4 years after diagnosis). Pulse rate at diagnosis was also somewhat lower in Brugada-type ECG cases than in controls (68.9 +/- 7.7 beats/min vs 72.7 +/- 11.1 beats/min, P = 0.038). The significance disappeared after controlling for BMI (P = 0.131) or body weight (P = 0.153). CONCLUSION: The cases with the Brugada-type ECG had lower BMI than controls, leading to a clue to possible basic mechanisms of the Brugada-type ECG with a focus on this association.     

Automated electrocardiographic diagnosis of ventricular hypertrophy in the system of the cardiologic telemetric consultation-diagnostic center

A method and algorithm of automated diagnosis of ventricular hypertrophy is described for electrocardiograms, transmitted by telephone to the remote-control consultative diagnostic centre. The validity of computerized ECG diagnosis was assessed in comparison to roentgenologic, echocardiographic and angiographic diagnosis, on the one hand, and a collective ECG diagnosis made by physicians, on the other. Automated electrocardiographic diagnosis is shown to be only slightly less accurate, as compared to physicians' diagnosis. Left ventricular hypertrophy was diagnosed correctly on the basis of ECG findings in 73.01% by a physicians' counsel, and in 69.8% of cases by the computer; in case of right ventricular hypertrophy, the rates were 55.2% and 44.7%, respectively.     

心电散点图在快速诊断并行心律中的临床应用

目的：探讨心电散点图对快速诊断并行心律的临床价值。方法应用动态心电记录仪记录患者连续24 h的心电信号，分别应用常规心电图分析方法和心电散点图（ RR-Lorenz图、时间RR散点图及其逆向技术）对其进行分析；将分析结果分为窦性并行心律、房性并行心律和室性并行心律3组，分别对诊断结果加以对比分析并比较各组心电散点图形特征。结果对比观察显示，并行心律在心电散点图中有特征性表现，可据此做出快速诊断。结论从心电散点图的特征性表现出发，可以快速有效地鉴别诊断并行心律，其作用优于常规心电图分析方法，值得临床推广应用。     

心电散点图在心律失常快速诊断中的应用

目的通过与诊断结果对比观察,探讨心电散点图在快速诊断心律失常方面的临床应用价值。方法应用动态心电图记录仪记录患者连续24h心电信号,利用计算机自动检测技术,进行心电分析,并同步绘制24h心电散点图。将诊断结果分为窦性心律、室上性早搏、室性早搏、心房颤动、差异性传导5组,分别将4组心律失常结果与心电散点图检测的诊断结果进行对照,计算出二者的符合率及各组的B线斜率,进行分析对比。结果室上性早搏组与室性早搏、心房颤动、差传组差异显著(p<0.001);室性早搏组与室上性早搏、心房颤动、差传组差异显著(p<0.001);心房颤动组与差传组差异不显著(p>0.05)。结论心电散点图在长程大样本心电数据中,快速诊断心律失常,尤其是室上性早搏、室性早搏、心房颤动等时具有较好的临床应用价值。     

院前心电图远程实时快速网络传输模式建立

目的探讨心电图实时网络传输的可行性及临床价值。方法社区卫生服务中心和医院间建立心电传输网络,将54份心电图由社区通过网络传输至医院。20名受试者随机分为网络组（n=10）和常规组（n=10）,网络组通过心电传输网络进行心电图诊断,常规组乘车前往医院进行心电图诊断。分析两组心电图的诊断时间。结果54份心电图全部成功完成网络传输,平均传输时间为（45±10）s。两组受试者完成心电图诊断的时间分别为：网络组（10．7±2．8）min、常规组（25．3±4．6）min,网络组显著快于常规组（P〈0．01）,差异主要来源于交通时间。结论通过心电传输网络进行实时心电图传输具有可行性,可减少院前心电图的诊断时间。     

常规导联及头胸导联心电图与核素显像对急性下壁心肌梗死诊断的比较

目的：观察心电图与核素显像对急性下壁心肌梗死（AIMI）定位诊断的价值。方法：以90例冠状动脉造影的资料（其中AIMI患者50例,正常人40例）为标准,与同步记录的常规导联心电图,头胸导联心电图,和核素显像检测的结果进行比较。结果：对AIMI诊断,常规导联心电图的准确率为84.4%,敏感性为86.0%,特异性为82.5%;头胸导联心电图的诊断准确率为97.8%、敏感性为96.0%,特异性为100.0%;核素显像的诊断准确率为94.4%、敏感性为92.0%,特异性为97.5%。头胸导联心电图诊断AIMI的准确率、敏感性和和特异性均明显高于常规导联心电图（P〈0.05）,且高于核素显像但差异无显著性（P〉0.05）。结论：对于急性下壁心肌梗死的定位诊断头胸导联心电图准确率、敏感性和和特异性好于常规心电图,与核素显像无显著差异,但检测方便,有推广价值。     

Smartphone ECG for evaluation of ST-segment elevation myocardial infarction (STEMI): Design of the ST LEUIS International Multicenter Study

In patients experiencing an ST-elevation myocardial infarction (STEMI), rapid diagnosis and immediate access to reperfusion therapy leads to optimal clinical outcomes. The rate-limiting step in STEMI diagnosis is the availability and performance of a 12–lead ECG. Recent technology has provided access to a reliable means of obtaining an ECG reading through a smartphone application (app) that works with an attachment providing all 12–leads of a standard ECG system. The ST LEUIS study was designed to validate the smartphone ECG app and its ability to accurately assess the presence or absence of STEMI in patients presenting with chest pain compared with the gold standard 12–lead ECG. We aimed to support the diagnostic utility of smartphone technology to provide a timely diagnosis and treatment of STEMI. The study will take place over 12 months at five institutions. Approximately 60 patients will be enrolled per institution, for a total recruitment of 300 patients.     

冠状动脉影像学与心电图检查诊断老年冠心病价值的对比研究

目的：比较冠状动脉CT血管造影（CTA）与心电图对老年冠心病（CHD）患者的诊断价值。方法选择拟诊冠心病的老年住院患者148例,分别行冠状动脉CTA和心电图检查。其中有96例同时行冠状动脉造影检查。按冠状动脉造影结果分析冠状动脉CTA及心电图诊断冠心病的敏感度（阳性率）、特异度（阴性率）。结果冠状动脉CTA的敏感度为90.1%、特异度为88.1%、符合率为88.8%。心电图诊断CHD的敏感度为72.0%、特异度为57.1%、符合率为68.8%。冠状动脉造影狭窄程度≥90%的病变,心电图的敏感度最高,假阴性率最低;狭窄程度＜90%者与≥90%者比较,心电图敏感度较低,差异显著（均P＜0.01）。结论冠状动脉CTA发现有意义血管狭窄的敏感度、特异度较高,可作为老年冠心病诊断的有效方法;心电图对老年患者严重冠脉狭窄有一定的诊断价值。     

Accuracy of 22-lead ECG analysis for diagnosis of acute myocardial infarction and coronary artery disease in the emergency department: a comparison with 12-lead ECG.

STUDY OBJECTIVES: To compare a new 22-lead ECG with the 12-lead ECG for diagnosis of acute myocardial infarction (AMI). DESIGN: Prospective study of all consenting patients presenting to the emergency department with chest pain. SETTING: Urban hospital ED. TYPE OF PARTICIPANTS: 163 patients admitted with a cardiac-related diagnosis and complete data sets of 22- and 12-lead ECG results and creatine kinase-MB analysis. INTERVENTIONS: Patient care and existing protocols were unaltered, with the exception of including the new 22-lead ECG. MEASUREMENTS AND MAIN RESULTS: Forty-one of 163 patients had an AMI as defined by creatine kinase-MB analysis. The 22-lead ECG provided a statistically significant improvement in sensitivity (83%) for AMI diagnosis over the 12-lead ECG (51%) with specificities of 76% and 99%, respectively. CONCLUSION: When combined with clinical judgment, the 22-lead ECG could provide a 97.6% sensitivity for AMI diagnosis while reducing unnecessary admissions for "rule-out MI" by 69%.     

Vectorcardiography in the diagnosis of the association of inferior necrosis--left intraventricular conduction disorders

The authors study 53 vectorcardiograms (VCG) which demonstrate the association of inferior myocardial necrosis with left intraventricular conduction disturbances (LIVCD) consisting of 44 left anterior hemi-blocks (LAHB), 2 left posterior hemi-blocks (LPHB) and 7 complete left branch blocks (CLBB). In the presence of LAHB, the ECG and VCG diagnosis concur in 37 cases, with a more obvious appearance on the VCG in 16 cases. In 7 cases, only the VCG provided the diagnosis of this association. In the presence of LPHB, the ECG, in one case, only showed signs of necrosis and only the VCG revealed the hemi-block; in the other case, the ECG showed signs of LPHB, but the Q waves did not present the criteria of necrosis. Once again, only the VCG provided the diagnosis of the association. Finally, in the presence of CLBB, the diagnosis were in agreement in only 3 cases. In two cases, only the VCG revealed the necrosis, in one case, the ECG was superior and in the remaining case, the ECG and the VCG were equally ineffective in confirming the inferior necrosis which was nevertheless definitely present. On the basis of these findings, the authors discuss the ECG criteria of the association of inferior necrosis and LIVCD.     

壮族原发性高血压左心室肥厚患者不同心电图诊断指标的应用价值

目的探讨不同心电图诊断指标在壮族原发性高血压患者左心室肥厚临床诊断中的应用价值。方法选择壮族原发性高血压患者100例,以超声心动图检查所得到的左心室质量指数作为左心室肥厚诊断的参考标准,验证Cornell指数、Sokolow-Lyon指数和Romhilt-Estes积分3种心电图诊断指标的临床应用价值。结果以超声心动图诊断的左心室肥厚结果为标准,3种心电图指标均存在敏感性低,特异性高的特点;男性的诊断价值均大于女性;Romhilt-Estes积分高于Cornell指数和Sokolow-Lyon指数(P0.05)。结论 3种心电图指标可以作为诊断左心室肥厚的常规方法。     

Electrocardiographic patterns of patients with echocardiographically determined biventricular hypertrophy.

The numerous criteria proposed for the electrocardiographic (ECG) diagnosis of biventricular hypertrophy (BVH) suffer from inadequate correlative data. We used two-dimensional (2D) echocardiography to identify BVH and analyzed the ECG patterns in these patients. The study group had 69 such patients with BVH and the control group had 22 patients with isolated left ventricular hypertrophy (LVH) demonstrated by 2D echocardiography. The electrocardiograms were analyzed for the presence of established criteria used in the diagnosis of LVH and right ventricular hypertrophy (RVH). Of the 69 patients in the study group, 17 (25%) had ECG findings of BVH, 25 (36%) had LVH, and 14 (20%) had RVH. An S wave in V5/V6 of >7 mm was most the frequent finding in the 17 patients with BVH on the electrocardiogram. The sensitivity of ECG criteria for BVH was 24.6%, specificity was 86.4%, and positive predictive value was 85%. This study reemphasizes the difficulty of ECG diagnosis of BVH. The electrocardiogram has a low sensitivity but satisfactory specificity and positive predictive accuracy for BVH.     

ECG diagnosis of acute myocardial infarction in patients with bundle branch block

The ECG diagnosis of myocardial infarction in the setting of bundle branch block is one that most physicians find difficult and that many erroneously believe to be impossible. Two case reports of a patient with right bundle branch block and of a patient with left bundle branch block are presented to illustrate instances in which the ECG diagnosis of myocardial infarction was both possible and essential. Methods for detecting ECG changes that indicate acute myocardial injury in the patient with bundle branch block are presented and applied to these cases.     

Non-dipole components of the heart electrical field in electrocardiographic diagnosis of combined ventricular hypertrophy

A new method of ECG diagnosis, based on a mathematical model of electrical heart generator as a mobile dipole, was clinically verified in 10 healthy subjects and 2 patients with combined cardiopathy and pronounced bilateral ventricular hypertrophy. Electrocardiograms were recorded in 80 unipolar leads from the body surface; recordings were processed by a computer. The output information were the pathways of the heart electrical centre (dipole) during the heart cycle. The trajectories in patients with combined ventricular hypertrophy markedly differed--even in the absence of ECG changes in standard leads--from trajectories in healthy subjects. The new method of ECG diagnosis consequently offers information which cannot be obtained when using conventional and corrected orthogonal ECG leads.