Behçet's disease and cardiac arrhythmia

Summary Only few cases of cardiac conduction disturbances and arrhythmias have been reported in Behçet's disease. We recently observed the case of a 16-year-old woman with Behçet's disease in whom cardiac arrhythmia became the main clinical symptom. This observation and a review of the literature led us to the conclusion that arrhythmia could represent the clinical manifestation of an underlying myocarditis due to Behçet's disease and can be regarded as a feature of cardiac involvement of the disease.     

Sinoatrial Node Electrogram Studies in Patients with Sick Sinus Syndrome

Sinoatrial node electrogram (SNE) was recorded successfully in recent years, using transvenous electrode catheter. Via SNE and intratrialelectrogram (IEG), one could measure sinoatrial conduction time(SACT) directly, observe sinoatrial node (SN) potential changes in cadiac cycles, diagnose some sinus arrhythmias which couldn't be confirmed by surface ECG. All these could offer accurate evidence for differential diagnosis of sick sinus syndrome (SSS). The authors recommend a modified method for the location of the electrode catheter, by which one can increase success rate of obtaining stable SNE. Using this method, the authors recorded SNE in 10 cases with SSS successfully.     

Ⅱ孔型房间隔缺损直视修补术后心律失常的临床观察

210例Ⅱ孔型房间隔缺损术后发生心律失常90例,14种类型,共292例次,其中,室上性占96%。30例需药物治疗,93%的患者出院时恢复正常。本文着重分析心律失常的特点,讨论影响因素及预防措施。     

益气养阴活血法治疗冠心病心律失常有效性和安全性的Meta分析*

[摘要]目的 系统评价益气养阴活血法治疗冠心病心律失常的有效性及安全性。方法 检索中国知网数据库（CNKI）、维普中文科技期刊全文数据库（VIP）、中国学术期刊数据库（万方）、Cochrane图书馆、Web of Science和PubMed中有关益气养阴活血法治疗冠心病心律失常的临床随机对照试验研究,提取纳入研究的相关数据并进行方法学质量评价。应用RevMan5.3软件进行Meta分析。结果 共纳入26个研究。Meta分析结果显示,益气养阴活血法治疗组在临床总有效率[OR=3.47,95%CI（2.68, 4.48）,P<0.00001]、24h心律失常事件数[WMD=-204.82,95%CI（-228.78, -180.86）,P<0.00001]、中医症候疗效[OR=3.08,95%CI（2.04,4.66）,P<0.00001]、心电图疗效[OR=2.50,95%CI（1.63,3.83）,P<0.0001]、血液流变学指标：全血高切黏度[WMD=-1.02,95%CI（-1.18,-0.85）,P < 0.00001]、全血低切黏度值[WMD=-1.66,95%CI（-2.00,-1.33）,P< 0.00001]、血浆比黏度[WMD=-0.42,95%CI（-0.50,-0.35）,P < 0.00001]、纤维蛋白原[SMD=-1.67,95%CI（-2.06,-1.28）,P <0.00001]及安全性[OR=0.41,95%CI（0.27,0.61）,P<0.001]方面均优于常规西医治疗组。结论 益气养阴活血法治疗冠心病心律失常具有更好的有效性及安全性。由于目前纳入文献数量及质量的限制,期望今后有更多高质量的随机对照试验支持。     

Wertigkeit der EKG-Telefon-Telemetrie in der Erfassung symptomatischer Herzrhythmus-Störungen

Summary The ECG-telephone-transmission (TTM) was used to record an ECG-strip during a typical symptomatic period in patients complaining of symptoms possibly caused by arrhythmias (palpitations, dizziness, paroxysm tachycardia, pulse irregularities; angina and dyspnea only if other reasons could be excluded). Patients complaining of syncope only were not admitted, because of the inability to make a telephon call successfully during such a symptomatic period. The ECG was transmitted to the CCU using a frequency modulation technique. In 60% of 196 patients an ECG-TTM could be achieved during a typical symptomatic period, whereas arrhythmias as cause for the symptoms could be excluded in 51 patients (26%). The remaining 66 patients (34%) demonstrated various arrhythmias ranging from simple SVPB and PVC to total AV-block and sustained VT.TTM, an easy-to-perform and cost-effective method allowed a successful ECG registration during a symptomatic period in almost two-thirds of symptomatic patients. In these patients arrhythmias could be verified or excluded as cause of the symptoms.

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Abkürzungsverzeichnis TTM EKG-Telefon-Telemetrie - HF Herzfrequenz - SA-Block sinu-aurikulärer Block - AV-Block atrio-ventrikulärer Block - SVES supraventrikuläre Extrasystole(n) - VES ventrikuläre Extrasysteole(n) - KHK koronare Herzkrankheit - VH-Flimmern Vorhof-Flimmern - parox. paroxysmal - C.C.I.T.T. Internationale Post-Organisation - Ö.P.T. Österreichische Post- u. Telegraphen-Verwaltung - LZ-EKG Langzeit-EKG     

Characterisation of electrocardiogram signals based on blind source separation

Blind source separation assumes that the acquired signal is composed of a weighted sum of a number of basic components corresponding to a number of limited sources. This work poses the problem of ECG signal diagnosis in the form of a blind source separation problem. In particular, a large number of ECG signals undergo two of the most commonly used blind source separation techniques, namely, principal component analysis (PCA) and independent component analysis (ICA), so that the basic components underlying this complex signal can be identified. Given that such techniques are sensitive to signal shift, a simple transformation is used that computes the magnitude of the Fourier transformation of ECG signals. This allows the phase components corresponding to such shifts to be removed. Using the magnitude of the projection of a given ECG signal onto these basic components as features, it was shown that accurate arrhythmia detection and classification were possible. The proposed strategies were applied to a large number of independent 3s intervals of ECG signals consisting of 320 training samples and 160 test samples from the MIT-BIH database. The samples equally represent five different ECG signal types, including normal, ventricular couplet, ventricular tachycardia, ventricular bigeminy and ventricular fibrillation. The intervals analysed were windowed using either a rectangular or a Hamming window. The methods demonstrated a detection rate of sensitivity 98% at specificity of 100% using nearest neighbour classification of features from ICA and a rectangular window. Lower classification rates were obtained using the same classifier with features from either PCA or ICA and a rectangular window. The results demonstrate the potential of the new method for clinical use.     

Changes in tissue optical properties due to radio-frequency ablation of myocardium

The optical properties of pig heart tissue were measured after in vivo ablation therapy had been performed during open-heart surgery. In vitro samples of normal and ablated tissue were subjected to measurements with an optically integrating sphere set-up in the region 470–900 nm. Three independent measurements were made: total transmittance, total reflectance and collimated transmittance, which made it possible to extract the absorption and scattering coefficients and the scattering anisotropy factor g, using an inverse Monte Carlo model. Between 470 and 700 nm, only the reduced scattering coefficient and absorption could be evaluated. The absorption spectra were fitted to known tissue chromophore spectra, so that the concentrations of haemoglobin and myoglobin could be estimated. The reduced scattering coefficient was compared with Mie computations to provide Mie equivalent average radii. Most of the absorption was from myoglobin, whereas haemoglobin absorption was negligible. Metmyoglobin was formed in the ablated tissue, which could yield a spectral signature to distinguish the ablated tissue with a simple optical probe to monitor the ablation therapy. The reduced scattering coefficient increased by, on average, 50% in the ablated tissue, which corresponded to a slight decrease in the Mie equivalent radius.     

模糊ART神经网络在心律失常分析中的应用

本研究提出一种用模糊ART神经网络进行心律失常分析的方法。确定用于描述QRS波群特征的若干属性 ,提取其特征 ,模糊化处理后作为神经网络的输入模式矢量。神经网络为三层结构 ,经过竞争学习 ,对QRS波群进行自动分类。分类结果用MIT -BIH数据库进行了检验 ,证明本方法非常有效 ,30min数据的分析时间小于 2s,满足实用要求     

美托洛尔对室性心律失常患者的心率变异性的影响

目的　研究美托洛尔对室性心律失常的疗效及其对心率变异性的影响。方法　对 36例Holter证实有频繁室性心律失常的患者 ,测定服药前后HRVI ,以统计学方法进行分析。结果　应用美托洛尔治疗后 ,室性心律失常明显减少 ,心率变异指数明显增加 ,较用药前有显著差异 (P <0 0 1)。结论　美托洛尔对室性心律失常疗效显著 ,并使心率变异性增加     

Do antiarrhythmic drugs work? some reflections on the implications of the cardiac arrhythmia suppression trial

Despite major advances in our understanding of the mechanisms of cardiac arrhythmias and how antiarrhythmic drugs appear to work, there remains much doubt whether these agents reduce arrhythmic mortality except in certain subsets of patients. The results of the Cardiac Arrhythmia Suppression Trial (CAST) have indicated that certain antiarrhythmic drugs not only "fail to work" but may substantially increase mortality. The effects of Class Ic agents in CAST and the meta-analysis of randomized antiarrhythmic trials in the survivors of acute infarction suggest that drugs that act primarily by delaying conduction are particularly deleterious in the survivors of acute infarction. Whether these data have a wide applicability in terms of all ventricular arrhythmias is unclear, but beta-blockers remain the only class of agents that in control trials have been shown to reduce sudden death. The effect appears to be related to beta-blockade and not to suppression of premature ventricular contractions (PVCs). Beta blockers appear to act by preventing ventricular fibrillation. It is reasonable to assume that PVC suppression per se is unlikely to produce a reduction in sudden death. Uncontrolled data with amiodarone suggests that it has the potential to prolong survival by controlling arrhythmias. The effects of amiodarone and beta blockers, both significantly attenuating adrenergic stimulation, provide pharmacologic probes to define the crucial determinants of efficacy of a compound for mortality reduction in high risk survivors of myocardial infarction. The focus must now shift from antiectopic and antiarrhythmic agents that delay conduction to those that exert antifibrillatory actions by sympathetic antagonism and those that exhibit the added property of lengthening myocardial refractoriness.