Differential Classification of Acute Myocardial Infarction into ST‐ and Non‐ST Segment Elevation Is Not Valid or Rational

Background: The distinction between ST elevation and nonST elevation infarcts is widely accepted and is employed as a guide to management. Aim: This is review of the world literature to assess the basis for this distinction, since the two studies on which it is based are seriously flawed in method and conclusions. Method: Pathologic and clinical studies were reviewed from the world literature. Finding: The pathology of the two subsets is identical as are the morbidity, mortality and clinical course. Non‐ST elevation infarcts are likely to be subsequent, to occur in older patients and to involve the circumflex artery: this subset therefore includes a high‐risk group. ST deviation in any part of the electric field of the heart will predictably be accompanied by reciprocal deviation if the entire field of the heart is mapped. Further, ST deviation of infarction is often transient, resolving in minutes so that infarcts will be predictably misclassified. ST deviation per se is therefore not a rational basis for classification of infarcts. In fact, invasive therapy is indicated in both subsets with identical results. Conclusion: The distinction between ST elevation and non‐ST elevation infarcts is baseless. The high risk subgroup included in the non‐ST elevation infarct set should not be denied the benefit of early invasive therapy. Ann Noninvasive Electrocardiol 2010;15(3):191–199     

Optimal ECG monitoring during percutaneous transluminal coronary angioplasty of the left anterior descending artery

During percutaneous transluminal coronary angioplasty (PTCA) frontal ECG leads are routinely monitored. The detection of ST segment deviation during the procedure is important for decisions regarding guiding catheter seating and the timing of balloon inflation and deflation. ST segment deviation appears on intracoronary electrograms in the absence of changes on the surface ECG in many patients, while the reverse is true in some individuals. When a precordial lead is employed, V5 or V6 is most commonly selected. The surface ECG leads most sensitive for monitoring ischemia during left anterior descending angioplasty are not known. In nine lead surface ECGs recorded during balloon inflation, a small degree of ST segment elevation occurred in leads I, aVL, and V5. Lead V2 demonstrated an increase in ST displacement from 0.0 ± 0.03 mV to 0.29 ± 0.25 mV during coronary occlusion (p<0.01). We conclude that if V5 or V6 is used as a single precordial lead, surface ECG alterations are easily overlooked. During left anterior descending occlusion the most sensitive surface lead is V2. Optimal ECG monitoring during PTCA in some cases should involve surface lead V2 or the intracoronary lead.     

Standards for analysis of ventricular late potentials using high resolution or signal-averaged electrocardiography: A statement of by a Task Force Committee between the European Society of Cardiology, the American College of Cardiology,the American Heart Association and the American college of cardiology

Sufficient data are avaliable to recommend that the high-resolutionor signal-averaged electrocardiogram can be used in patientsrecovering from myocardial infracation without bundle blockto help to determine thier risk for developing sustained ventriculartachyarrhythmias,However, no data are avaliable regarding theextent to which pharmacologic or non-pharmocologic intervationsin patients with late potentials have an impact on the incidenceof sudden cardic death. Therfore,Controlled, prospective studiesare required before this issue can be definitely answered. Asrefinements in techniquens evlove, it is anticipated that theclinical value of high-resolution or signal-averaged electrocrdiographywill continue to increase in the future.     

85例肺栓塞临床心电图分析

目的 分析心电图改变在临床肺栓塞诊断中的作用。方法 病例选自我院1995年1月至2003年2月期间住院的85例经肺CT、灌注／通气扫描或肺动脉造影明确诊断的肺栓塞患者，主要分析患者住院期间的心电图特征以及治疗前后心电图改变的对比。结果 肺栓塞患者出现心电图改变者为98．8％，其中最多见的为QⅢ，达到60．0％，其它SI 55．3％，TⅢ 44．7％，同时具备SⅠQⅢTⅢ占32．9％，右胸导联Vl—V3T波倒置占42．4％，aVR导联出现终末R波占36．5％，右束支阻滞占25．9％，ST段下移改变占25．9％，肺型P波仅占5．9％。结论 心电图在临床肺栓塞的诊断虽然是非特异性和非诊断性的，但有许多特征对提示肺栓塞有一定价值。     

Scuba diving,patent foramen ovale and heart rhythm disturbances: The role of underwater Holter monitoring—Case report

Patent foramen ovale (PFO) is thought to be a risk factor for decompression illness (DCI). Catheter‐based closure procedure reduces the risk of DCI in selected scuba divers with PFO. Major complication of invasive approach are rare, minor, especially heart rhythm disturbances are reported relatively often. We describe a case of 41‐year‐old diver, who underwent PFO closure due to recurrent DCI events. Afterward, he experienced no DCI symptoms; however, he complained about feeling of the heart beating during a submersion. Arrhythmia should be considered as a life‐threatening for scuba diver, thus we performed underwater ECG monitoring and exclude the arrhythmia.     

子宫肌瘤患者的心电图分析

目的探讨子宫肌瘤患者的心电图表现。方法对200例子宫肌瘤患者心电图资料进行分析,200例健康体检女性作为对照组。结果子宫肌瘤患者心电图异常改变133例(66.5%),正常对照组心电图异常改变为46例(23%),二者差异有统计学意义。子宫肌瘤患者心电图异常以ST-T变化为主。结论子宫肌瘤患者心电图异常发生率较高,多表现为ST-T异常改变。     

High-resolution and signal-averaged electrocardiography to separate post-myocardial infarction patients with and without ventricular tachycardia

High-resolution and signal-averaged ECG, 24 h Holter recordingand ejection fraction were used to separate post-myocardialinfarction patients with and without ventricular tachycardia(VT) among 150 individuals: 26 patients with an old myocardialinfarction and documented sustained VT, 104 patients with anacute myocardial infarction without sustained VT, who were followed-upfor 2 years, and 20 healthy volunteers. Bipolar orthogonal XYZleads were recorded, high-pass filtered at cut-off frequenciesof 25, 40, 60, 80 and 100 Hz, and combined to vector magnitudex² + Y²+ Z². The filtered QRS duration, the root-mean-squarevoltages of different time intervals and the durations of lowamplitude signals under different thresholds, both from theinitial and terminal QRS, were calculated. The sensitivity andspecificity of each parameter alone and in every combinationof two, three and four parameters (17 million different combinations)were computed both from non-averaged and averaged data. Thebest separation was achieved by 12 combinations all includingfour signal-averaged ECG parameters, with a sensitivity of 81%and a specificity of 79%. The parameters represented most were:filtered QRS duration at 25 Hz, RMS voltage of the last 50 msat 25 Hz, terminal LAS duration at 80 Hz, and RMS voltage ofthe last 20 ms at 80 Hz. Parameters of the initial QRS complexdid not improve either the sensitivity or the specificity ofthe method. In logistic regression analysis, the best combinationsof four signal-averaged ECG parameters separated VT patientsbetter (P<0·001) than non-sustained ventricular tachycardiaat Holter (P=0·001); left ventricular ejection fraction(P=0·01) or age (P=0·006). Parameters calculatedfrom averaged data gave better results than parameters calculatedfrom non-averaged data.     

急性下壁心肌梗死患者合并右室梗死的心电图探讨

目的　探讨急性下壁心肌梗死合并右室梗死时的心电图变化。方法　对 118例首次发病后 12h以内急性下壁心肌梗死患者行动态描记心电图 ,并对心电图结果进行分析。结果　合并右室梗死者STV2 与STaVF两者无相关关系 (P >0 .0 5 )。不合并右室梗死者STV2 为 (- 0 .13± 1.73)mm ,STaVF为 (1.37± 1.2 3)mm ,两者之间呈负相关 (P <0 .0 1)。在诊断合并右室梗死方面 ,STV4 R和STV5R >1mm的敏感性为 10 0 % ;STV3R >1mm的敏感性为 86 .7% ;STV1 aVF>0 .5的敏感性为 87.5 % ,特异性为 6 2 .7% ;Ⅱ、Ⅲ导联ST段抬高的敏感性为 87.5 5 % ,特异性为 5 7.8%。合并右室梗死者中冠状动脉造影 6例、尸检 1例均为右冠状动脉近端病变 ,且均合并STV3R～V5R >1mm。结论　不合并右室梗死者胸前导联ST段抬高是aVF导联ST段压低的“镜像”表现 ;而合并右室梗死者“镜像”表现消失。STV4 R和STV5R>1mm诊断右室梗死的敏感性最高。STV3R～V5R>1mm预示右冠状动脉近端病变。     

Heart transplantation as last resort against Brugada syndrome

We report the first case, to the best of our knowledge, of a patient with Brugada syndrome who required heart transplantation to control multiple "electrical storms."     

A theorem concerning myocardial activation imaging

We present a theorem which is the basis of a new approach to imaging ventricular surface activation. Application of the theorem in realistic simulations and with human data is presented elsewhere in this conference.     

心尖肥厚型心肌病的心电图特征

分析１０例心尖肥厚型心肌病的心电图。９例Ｖ３－Ｖ６Ｒ波异常高大，尤以Ｖ３－Ｖ５，为甚，伴Ｔ波倒置。内８例呈巨大倒置Ｔ波。６例２４小时动态心电图２例活动平板心电图运动试验心率增快时Ｔ波倒置无变化。     

Evidence supporting a new rate threshold for multifocal atrial tachycardia

BACKGROUND: Exacerbation of chronic obstructive pulmonary disease (COPD) is overwhelmingly represented among patients presenting with multifocal atrial tachycardia (MAT) and has been used as a paradigm for such patients. The quasidiagnostic tachycardia threshold for MAT is conventionally set at 100 beats/min. Nevertheless, this threshold has not been demonstrated to be optimal. HYPOTHESIS: Using COPD as a paradigm for MAT, clinical experience led to the hypothesis that MAT with a tachycardia threshold < 100 beats/min could be more closely associated with COPD exacerbation. METHODS AND RESULTS: We reviewed 60 consecutive patients with multifocal atrial arrhythmia (MAA) at any heart rate and found a better association between the incidence of COPD exacerbations and MAT using a tachycardia threshold of 90 beats/min (p = 0.00036) than when using a threshold of 100 beats/min (p = 0.515). CONCLUSION: The rate threshold of MAT should be reduced from 100 to 90 beats/min.     

ST‐Depression with Negative T Waves in Leads V4–V5—A Marker of Severe Coronary Artery Disease in Non‐ST Elevation Acute Coronary Syndrome: A Prospective Study of Angina at Rest,with Troponin,Clinical, Electrocardiographic,and Angiographic Correlation

Background: The significance of ST‐segment depression in acute coronary syndrome has been the subject of debate for many decades. Studies indicate that different manifestations of ST/T changes may have significantly different prognostic implications. Methods and Results: We studied the correlation of ST/T changes in 12‐lead electrocardiography recorded during pain, to clinical and angiographic findings and in‐hospital prognosis, in patients with non‐ST‐elevation acute coronary syndrome and elevated troponin levels. Fifty consecutive patients could be differentiated into two groups: (1) 25 patients with ST‐segment depression and a negative T wave maximally in leads V_4–5, (2) 25 patients with ST‐segment depression and a positive T wave in the precordial lead with maximal ST‐segment depression. Patients in group I had significantly more often left main or left main equivalent coronary artery disease; 76% versus 8% (P < 0.001), heart failure; 40% versus 4% (P = 0.005), and higher in‐hospital mortality; 24% versus 0% (P = 0.02), than patients in group II. The troponin levels did not differ significantly between the groups. Conclusions: In patients with non‐ST‐elevation acute coronary syndrome and elevated troponin levels two subgroups could be identified. Transient ST‐segment depression and a negative T wave maximally in leads V_4–5 during anginal pain predicts left main, left main equivalent, or severe three‐vessel coronary artery disease with high sensitivity and specificity. In patients with ST‐segment depression and a positive T wave, there is a high probability of one‐vessel disease.     

Clinical implications of precordial ST-segment elevation in acute inferoposterior myocardial infarction caused by proximal right coronary artery occlusion

BACKGROUND: The clinical significance of inferior wall acute myocardial infarction (MI) with combined ST-segment elevation in both anterior and inferior leads, compared with inferior leads alone, is unknown. HYPOTHESIS: Despite having more leads with precordial ST-segment elevation, these patients may have a better outcome due to less posterior involvement, which tends to drag down the precordial ST-segment. METHODS: A total of 158 postinferior MI patients with documented proximal right coronary artery occlusion were retrospectively studied. They were divided into three subgroups according to the magnitude of concurrent ST-segment deviation in lead V2: Group A (n = 19) had ST-segment elevation >/= 2.0 mm; Group B (n = 74) had ST-segment lay between + 2.0 mm and - 2.0 mm; and Group C (n = 65) had ST-segment depression >/= 2.0 mm. The clinical and electrocardiographic characteristics were then compared among these threes subgroups. RESULTS: The baseline demography, prevalence of risk factors, and treatment received were of no difference among the subgroups. However, Group A patients had significantly lower peak creatinine phosphokinase level and more preserved left ventricular function than Group B and C. Moreover, they had lower total sum of inferior ST-segment magnitude, less ST-segment depression in V4-6, and more ST-segment elevation in V(4R) than Group C. Group C patients had highest in-hospital and one-year mortality although it did not reach statistical significance. CONCLUSIONS: Precordial ST-segment elevation in inferior wall acute MI was associated with smaller infarct size and better left ventricular function, probably secondary to occlusion of a less dominant RCA, which did not result in a significant posterior infarction.     

动态心电图对心肌缺血诊断的评价

76例经核素心室造影证实有室壁运动异常的心绞痛患者,进行24h动态心电图检查。结果58例有缺血型ST段异常(76.3%),22例有三级以上室性早搏(28.9%),室壁运动异常区域多者ST段异常发生率、频率、持续时间及偏移程度均较大,室早检出率也明显增高。EF正常组和异常组之间ST段缺血性异常发生率也有显著差异。     

Observational data suggesting there are electrocardiographic abnormalities that strongly suggest the presence of chronic heart failure

Almost nothing is written about the electrocardiographic abnormalities that may suggest the presence of chronic heart failure. Indeed, one often hears that the electrocardiogram does not indicate anything about the function of the ehart. This paper discusses several abnormalities that often predict the presence of chronic heart failure. The information presented is from observations and not from scientific studies. The author urges those who are interested to complete a scientific study based on the premise that such observations may be correct. After all, many scientific studies have been created because of observational data that suggested a certain phenomenon.     

The acute cardiac electrophysiological effects of intravenous sotalol hydrochloride

The cardiac electrophysiological effects of sotalol were studied in ten patients (pts) aged 20--65 years undergoing intracardiac stimulation studies for palpitations (7 pts) or dizzy spells (3 pts). The following measurements were made: 1. basic sinus cycle length (SCL): 2. SINUS NODE RECOVERY TIME (SNRT) following overdrive pacing; 3. intra-atrial (PA), atrio-His (AH) and His-ventricular (HV) conduction intervals during regular atrial pacing; 4. effective refractory periods of the atria (AERP), AV node (AVERP) and ventricular myocardium (VERP). AV nodal functional refractoriness (AVFRP) was also determined. All measurements were repeated 10--15 min after i.v. administration of 0.4 mg/kg of sotalol. Results were analysed by the Wilcoxon Signed Rank test. Significant increases in SCL (p less than 0.01), AH (p less than 0.01). SNRT (p less than 0.01), AVERP (p less than 0.02) and AVFRP (p less than 0.01) were observed. These effects are consistent with the beta-blocking action of sotalol. The acute increase in AERP (p less than 0.01) is, however, not a common property of other beta-blockers and may be related to the 'class III' cellular effect of sotalol. These results are discussed in relationship to the electrophysiological effects of other beta-blocking drugs.