Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy

Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy.

Cardiac and non-cardiac causes of T-wave inversion in the precordial leads in adult subjects: A Dutch case series and review of the literature

AIM: To describe the electrocardiographic(ECG) phenomena characterized by T-wave inversion in the precordial leads in adults and to highlight its differential diagnosis. METHODS: A retrospective chart review of 8 adult patients who were admitted with ECG T-wave inversion in the anterior chest leads with or without prolongation of corrected QT(QTc) interval. They had different clinical conditions. Each patient underwent appropriate clinical assessment including investigation for myocardial involvement. Single and multimodality noninvasive, semi-invasive and invasive diagnostic approach were used to ascertain the diagnosis. The diagnostic assessment included biochemical investigation, cardiac and abdominal ultrasound, cerebral and chest computed tomography, nuclear medicine and coronary angiography.RESULTS: Eight adult subjects(5 females) with a mean age of 66 years(range 51 to 82) are analyzed. The etiology of T-wave inversion in the precordial leads were diverse. On admission, all patients had normal blood pressure and the ECG showed sinus rhythm. Five patients showed marked prolongation of the QTc interval. The longest QTc interval(639 ms) was found in the patient with pheochromocytoma. Giant T-wave inversion(≥ 10 mm) was found in pheochromocytoma followed by electroconvulsive therapy and finally ischemic heart disease. The deepest T-wave was measured in lead V3(5 ×). In 3 patients presented with mild T-wave inversion(patients 1, 5 and 4 mm), the QTc interval was not prolonged(432, 409 and 424 msec), respectively.CONCLUSION: T-wave inversion associated with or without QTc prolongation requires meticulous history taking, physical examination and tailored diagnostic modalities to reach rapid and correct diagnosis to establish appropriate therapeutic intervention.

The Relationship between T-Wave Alternans and Adverse Cardiac Events in Patients with Congenital Long QT Syndrome:A Systematic Review and Meta-Analysis

Background:T-wave alternans(TWA)is a risk factor of ventricular arrhythmias or sudden cardiac death(SCD)in patients with ischemic cardiomyopathy.Nevertheless,the relationship between TWA and adverse cardiac events(ACE)in patients with congenital long QT syndrome(LQT)remains controversial.Methods:A systematic electronic search of PubMed,Embase and the Cochrane Library was conducted from database inception dates to 28 April 2021 and assessed the relationship between TWA and ACE in patients with LQTS.Sub-group analysis evaluated the association between microvolt TWA(MTWA)and ACE in different monitoring models and ECGlead numbers.Results:A pooled analysis of seven studies of 625 patients with LQTS showed that TWA was significantly associated with ACE(OR 3.16,95%CI 1.86–5.37,P<0.001).Advanced analysis showed that macroscopic TWA was significantly related to ACE(OR 6.01,95%CI 2.96–12.21,P<0.001),while MTWA did not(OR 0.92,95%CI 0.37–2.30,P=0.85).Sub-group analysis showed that MTWA recorded in 24 h continuous ECG(OR 6.79,95%CI 0.80–57.75,P=0.08)might have a stronger association with ACE than recorded in stress ECG(OR 0.28,95%CI 0.07–1.10,P=0.07).No difference was observed between MTWA measured in multi-lead ECG and limited ECG leads(P=0.15).Conclusions:Macroscopic TWA was significantly related to ACE in patients with LQTS.In terms of MTWA,MTWA recorded in 24 h continuous ECG might have a stronger association with ACE than stress ECG,but still deserves further evaluation.

Detection of T-wave Alternans in ECG Signals Using FRFT and Tensor Decomposition

T-wave alternans(TWA)refers to the periodic beat-to-beat variation in the amplitude of T-wave in the electrocardiogram(ECG)signal in an ABAB-pattern.TWA has been proven to be a very important indicator of malignant arrhythmia risk stratification.A new method to detect TWA by combining fractional Fourier transform(FRFT)and tensor decomposition is proposed.First,the T-wave vector is extracted from the ECG of each heartbeat,and its FRFT amplitudes at multiple orders are arranged to form a T-wave matrix.Then,a third-order tensor is composed of T-wave matrices of several consecutive heart beats.After tensor decomposition,projection matrices are obtained in three dimensions.The complexity of the projection matrix is measured by Shannon entropy to obtain feature vector to detect the presence of TWA.Results show that the sensitivity,specificity,and accuracy of the algorithm on the MIT-BIH database are 91.16%,94.25%,and 92.68%,respectively.This method effectively utilizes the fractional domain information of ECG,and shows the promising potential of the FRFT in ECG signal processing.

Adaptive Match-Filtering: A Biomedical Application to Identify T-Wave Alternans

T-wave alternans (TWA), consisting in an alternation of the electrocardiographic (ECG) repolarization segment (T-wave), is a promising index of the risk of sudden cardiac death. By definition, it is characterized by a frequency component, termed fTWA, that matches half heart rate. The heart-rate adaptive match filter (AMF) based method is a technique for automatic TWA identification from the digital ECG. Aim of the present study was to provide a complete technical description of the filter able to explain its methodological principles. The AMF is usually realized as a 6th order Butterworth filter with a narrow (0.12 Hz) passing band centered in fTWA. It is applied in a bidirectional fashion, so that final filtering order is 12. While extracting the TWA component, the AMF simultaneously filters out every ECG component including noise and artefacts, and thus results are very robust. Goodness of the technique was tested using 8 synthetic ECG tracings corrupted by typical noisy factors, such as white random noise, baseline wanderings, heart-rate variability, and others. Six ECG tracings were affected by 100 μV TWA, whereas two were not. Results indicate that the AMF-based method is able to prevent false-positive and false-negative detections and, thus, represents a useful tool for a reliable TWA identification.

On the basis of the morphology of the T-wave alternans: A Poincare mapping method research

Presently T-wave alternans (TWA) has become a clinical index of non-invasive diagnosis for heart sudden death prediction, and detecting T-wave alternate accurately is particularly important. This paper introduces an algorithm for detecting TWA using Poincare mapping method which is a technique for nonlinear dynamic systems to display periodic behavior. Sample series of beat to beat cycles were selected to prepare Poincare mapping method. Vector Angle Index (VAI), which is the mean of the difference between θi (the angle between the line connecting the i point to the origin and the X axis) and 45 degrees was used to present the presence or absence of TWA. The value of 0.9 rad ≤ VAI ≤ 1.03 rad is accepted as a level determinative for presence of TWA. VAI via Poincare mapping method (PM) is used for correlation analysis with T-wave alternans voltage (Vtwa) by way of the spectral method (SM). The cross-correlation coefficient between Vtwa and VAI is γ = 0.8601. The algorithm can identify the absence and presence of TWA accurately and provide idea for further study of TWA-PM.

Application of T-Wave Alternans in Evaluation of Prognosis in Patients with Intracerebral Hemorrhage

Objective: To explore the application value of electrocardiograph (ECG) T-wave Alternans (TWA) anomaly in acute stage of intracerebral hemorrhage patients. Methods: We choose 1175 intracerebral hemorrhage patients whose conventional 12-lead ECG has TWA in our hospital from January 2011 to December 2015, 751 patients without TWA in the same period as the control group, compared the volume of intracerebral hemorrhage, bleeding site and mortality between the 2 groups. Results: In TWA group, 247 cases died, 361 cases with massive intracerebral hemorrhage, 298 cases with brain stem hemorrhage;in TWA negative group (control group), 41 cases died, 93 cases with massive brain hemorrhage, 64 cases with brain stem hemorrhage. There are statistical differences between two groups (P Conclusion: The occurrence of TWA is significantly related to the volume of bleeding, the bleeding site and mortality, and can be used as an important parameter in the prognosis of intracerebral hemorrhage.

誓约的记忆秋之回忆6T-wave

从第一部《秋之回忆》发售至今，已然十年。在这十年中，KID以及它的继承者5pb为我们带来了包括正传、外传和后续故事在内的十三部作品。初代、雪莹、想君和从今以后的巅峰，中断胶片的争议，安可的质疑，无疑不深深刺激着玩家的心里。

Preoperative Atrial Fibrillation and T-Wave Inversion Associated with Postoperative Pulmonary Edema

Background: Atrial fibrillation (AF) and T wave inversion (TWI) are occasionally found on pre-operative electrocardiograms (EKG) of patients with long standing hy-pertension (HTN) associated with left ventricular hypertrophy (LVH). Each of these two pathologies, AF and LVH, can impose negative hemodynamic effects on the car-diac function. Case: We present a case of a patient with AF, TWI and long standing HTN that went into post-operative pulmonary edema. Conclusion: Even returning to base line poorly controlled hypertension, and even more so during a hypertensive cri-sis, their concurrent presence may inflict even more detrimental effect manifested by elevation of pulmonary venous pressure and pulmonary edema.

T/R双模微波功率模块技术及其应用

微波功率模块(MPM)是真空电子器件和固态电子器件组合而成的一种新型微波功率器件,具有频率高、频带宽、功率大、体积重量小等特点,它使常规行波管的应用变得更加便利和广泛。现代战争向雷达、电子战综合一体化方向发展,这就要求功放既能工作在高峰值功率、低占空比的高模工作方式,也能工作在低峰值功率、准连续波的低模工作方式,针对这一需求,结合电子系统收发共孔径的要求,提出了T/R双模MPM技术。T/R双模MPM技术的核心是T/R双模行波管,基于三端口双向T/R行波管,通过在慢波系统的衰减器附近设置一个耦合口,实现行波管的信号反向接收功能;通过T/R双模行波管设计、双模放大均衡组件、双调制栅极电源等技术实现MPM的双模双向功能。T/R双模MPM应用前景广阔,特别是在基于无人机平台的作战应用中的具有明显优势。

第四次浪潮中智慧情报理论探索的摹因呈现

在以智能化为特征的第四次浪潮中,“智慧情报”的理论探索需要在做好谱系扫描工作的基础上才能有效把握研究重点。文章通过“感知时代环境”“厘清要素代差”“品评形势利害”“考较策略路径”“擘画理论教育”梳理所涉及的情报事实,将“智慧情报的学科体系”“情报学术的认知谱系”及“科技安全”“信息安全”“密码工具理论构成”的情报解读等重要对象以摹因形式呈现出来。

汉江流域2021年伏秋连汛降水季内差异特征及成因分析

汉江流域是中国重要的调水水源区,研究其降水特征对防涝抗旱具有重要意义。基于汉江流域62个国家气象站降水资料及美国国家环境预报中心/国家大气研究中心(National Center for Envi⁃ronmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)再分析资料,通过百分位数、相关分析和T-N波作用通量,探讨了2021年伏秋(8—10月)连汛期间汉江降水的季内差异特征及其与大气环流和海温的关系。结果表明:2021年伏秋期间,汉江上游流域出现破纪录降水,极端性强、总量大。降水在伏夏和秋季两个时段均偏多,但秋季的多雨区位置更偏北。伏夏期间,北大西洋经西伯利亚向东频散的Rossby波使得欧亚上空维持“两槽两脊”,冷空气较强,同时西太平洋副热带高压(简称“副高”)强势西伸,通过西南和偏东两支通道向北输送暖湿水汽;冷暖空气在高空急流南侧对峙并辐合上升,导致降水异常偏多。秋季,北太平洋频散的Rossby波使得欧亚上空维持“两槽一脊”,冷空气较弱;副高断裂导致水汽通道偏南,高空急流北抬使冷暖空气辐合上升位置偏北,造成雨区偏北。2021年汉江流域伏夏降水异常受热带东大西洋海温正异常影响,秋季受赤道中太平洋冷海温影响。

基于慢性心肌缺血小鼠模型探究心电图T波低平的电生理机制

目的 建立通过稳定的冠心病慢性心肌缺血小鼠模型,初步阐述缺血状态下T波低平的电生理原理。方法 将APOE-/-小鼠随机分为模型组和降脂药(lipid-lowering drug, LLD)组,高脂饮食喂养3个月,同时设立C57BL/6J小鼠作为空白组。检测造模前后小鼠心电图变化,通过核素PET/CT扫描评估心脏血流灌注情况,使用主动脉苏木伊红(hematoxylin-eosin, HE)染色和油红染色评估斑块动脉粥样硬化(atherosclerosis, AS)病理。同时,分离小鼠心肌细胞并记录心肌细胞动作电位。结果 高脂喂养3个月后模型组小鼠的胆固醇(cholesterol, CHO)和低密度脂蛋白(low-density lipoprotein, LDL-C)显著升高,同时主动脉出现脂质斑块。LLD组病变减少,空白组无斑块。心肌核素扫描显示模型组小鼠的心肌血流灌注显著低于LLD组和空白组。小鼠心电图显示模型组和LLD组的T/QRS显著降低,空白组无明显改变。记录心肌细胞动作电位发现,缺血的内层心肌细胞复极速率增加,内外电位差减小是T波低平的主要电生理机制。结论 APOE-/-小鼠可用于慢性心肌缺血小鼠模型,缺血状态下内层心肌复极速率的增加可能是心电图中T波降低的主要原因。

基于漏纵波模式的高频宽带低插损滤波器设计

采用常规的瑞利声表面波设计低插损、大带宽的高频声表滤波器,难以满足设计要求。该文设计了一种基于多层膜结构的漏纵波(LLSAW)的高频宽带低损耗声表面波(SAW)滤波器。确定了激发LLSAW的波导结构,建立器件的二维理论模型;研究了电极各项参数对杂散的影响,在此基础上对电极参数进行了优化设计。研究发现,将串联谐振器的反射栅对数设置为6时,可有效抑制通带内的杂散。设计了镜像T型及镜像π型LLSAW结构滤波器,并进行性能比较分析。结果表明,镜像T型结构更能抑制杂散响应,设计的镜像T型结构LLSAW滤波器的中心频率为3545 MHz,插入损耗为-1.416 dB,-3 dB带宽为274 MHz,带外抑制大于-30 dB。

正交异性钢桥面板声发射波三维谱元法模拟及损伤定位

针对大跨度桥梁正交异性钢桥面板的疲劳损伤评估与结构健康监测需求,开展基于声发射波场谱元法模拟的大型复杂板类结构损伤定位研究。采用Legendre高阶插值三维时域谱元法模拟声发射波在正交异性钢桥面板中的传播过程,验证了其内部显著的反射、衍射和频散现象,并代替人工预断铅实测试验获得大量声发射数据。然后,利用赤池信息准则判定声发射波到达各传感器的时间,通过高斯过程回归建立到达时差与声发射源位置的关系模型,用于未知损伤的定位监测。数值模型实验结果表明,赤池信息准则和高斯过程回归改进的时差图法在正交异性钢桥面板中的平均定位误差为37.3 mm(25 dB信噪比工况),平板的定位精度高于U肋。谱元法模拟有望代替繁琐的预断铅实测试验,提升声发射时差图系列损伤定位方法的实用性。

宽温度范围内折衍混合中波红外消热差光学系统设计

在军事领域应用的红外光学系统,有时需在近200℃的宽温度范围内工作。这一温度范围内,红外光学材料可选的种类进一步减少,系统的热离焦现象也会更为严重,进而导致光学系统难以完成良好的无热化设计。为应对这一挑战,该研究将具有独特消热差和消色差特性的衍射元件加入光学系统设计中,并提出了一种针对二次成像系统的材料选择方法。此方法以理想光学系统为基础,利用等效透镜理论将光学系统中的物镜组和中继镜组均等效成由两个单透镜组成的镜组,进而利用T-C图完成对这两个镜组的材料优选。经过深入的分析与评价,最终确定物镜组采用IRG24和ZnS材料组合为最优方案,而中继镜组的最佳材料组合为IRG22和IRG24。依据此种材料组合和理想光学系统的光焦度分配,该研究设计完成了一套中波红外光学系统。该系统的工作波长为3.7~4.8μm,视场角为10°×8°,F数为2,焦距为55 mm,系统总长约为115 mm,冷阑效率达到100%。在20~220℃范围内,全视场的调制传递函数(MTF)均接近衍射极限,维持了良好的成像性能。

心电图avL导联T波变化对老年冠心病病人冠脉狭窄程度的诊断价值

目的分析心电图avL导联T波变化对老年冠心病(CHD)病人冠脉狭窄程度的诊断价值。方法选择2019年7月至2022年10月就诊于本院的124例老年CHD病人,冠状动脉狭窄程度按照Gensini积分法分为重度组(36例,Gensini评分>40分)、中度组(40例,Gensini评分为21~40分)、轻度组(48例,Gensini评分为1~20分)。所有病人均接受心电图检测。比较3组病人一般资料、实验室指标、avL导联T波改变与其他心电图特征,采用Logistic回归分析老年CHD病人冠脉狭窄程度的危险因素,绘制ROC曲线分析avL导联T波改变对老年CHD病人冠脉狭窄程度的诊断价值。结果左心室舒张末期内径(LVEDD)和血清N末端脑钠肽前体(NT-proBNP)水平在轻度组、中度组和重度组中逐步升高,且3组间差异有统计学意义(P<0.01);3组间avL导联T波改变、ST段抬高、ST段压低、病理性Q波比例相比,差异有统计学意义(P<0.01)。Logistic回归分析显示,NT-proBNP、LVEDD、avL导联T波改变、ST段抬高、ST段压低、病理性Q波是影响老年CHD病人冠脉狭窄程度的独立危险因素;ROC曲线分析表明,avL导联T波改变诊断老年CHD冠脉狭窄程度的AUC为0.701(95%CI:0.603~0.798)。结论心电图avL导联T波改变是老年CHD病人冠脉狭窄程度的独立危险因素,在冠脉狭窄程度诊断中具有一定价值。

Microvolt T-wave alternans complemented with electrophysiologic study for prediction of ventricular tachyarrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy: a long-term follow-up study

Background: The long-term predicted value of microvolt T-wave alternans (MTWA) for ventricular tachyarrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains unclear. Our study explored the characteristics of MTWA and its prognostic value when combined with an electrophysiologic study (EPS) in patients with ARVC. Methods: All patients underwent non-invasive MTWA examination with modified moving average (MMA) analysis and an EPS. A positive event was defined as the first occurrence of sudden cardiac death, documented sustained ventricular tachycardia (VT), ventricular fibrillation, or the administration of appropriate implantable cardioverter defibrillator therapy including shock or antitachycardia pacing. Results: Thirty-five patients with ARVC (age 38.6 ± 11.0 years;28 males) with preserved left ventricular (LV) function were recruited. The maximal TWA value (MaxValt) was 17.0 (11.0–27.0)μV. Sustained VT was induced in 22 patients by the EPS. During a median follow-up of 99.9 ± 7.7 months, 15 patients had positive clinical events. When inducible VT was combined with the MaxValt, the area under the curve improved from 0.739 to 0.797. The receiver operating characteristic curve showed that a MaxValt of 23.5 μV was the optimal cutoff value to identify positive events. The multivariate Cox regression model for survival showed that MTWA (MaxValt, hazard ratio [HR], 1.06;95% confidence interval [CI], 1.01–1.11;P = 0.01) and inducible VT (HR, 5.98;95% CI, 1.33–26.8;P = 0.01) independently predicted positive events in patients with ARVC. Conclusions: MTWA assessment with MMA analysis complemented by an EPS might provide improved prognostic ability in patients with ARVC with preserved LV function during long-term follow-up.

T波形态与急性心肌梗死患者经皮冠状动脉介入术后快速性心律失常发生风险的相关性

目的探讨T波形态与急性心肌梗死(AMI)与经皮冠状动脉介入(PCI)术快速性心律失常发生风险的相关性。方法以成都市中西医结合医院2022年4月至2024年1月收治的169例接受PCI的AMI患者为研究对象。术后48 h根据患者有无发生快速性心律失常分为发生组和未发生组。对比两组患者一般资料、实验室检查指标和T波形态相关参数。采用多因素logistic回归分析影响治疗后心律失常发生的相关因素,绘制ROC曲线并计算曲线下面积(AUC)分析T波形态和心律失常发生风险的相关性。结果入院48 h内,45例(26.63%)发生心律失常。发生组血中性粒细胞/淋巴细胞(NLR)、超敏C反应蛋白(hs-CRP)和左心室收缩末径(LVESD)高于未发生组[(4.46±1.52)比(2.78±0.82)、(2.61±0.71)mg/L比(1.94±0.41)mg/L、(40.54±3.65)mm比(38.25±5.97)mm],左心室射血分数(LVEF)低于未发生组[(45.61±5.31)%比(55.84±6.21)%](P均<0.05);发生组QT间期、Tp-Te间期、校正后Tp-Te间期(Tp-Tec)、校正后QT间期(QTc)、Tp-Te/QT高于未发生组,T波倒置发生率高于未发生组(73.33%比28.23%)(P均>0.05);多因素logistic回归分析示,hs-CRP(OR=19.495,95%CI 1.907~199.292)、NLR(OR=18.807,95%CI 3.871~91.379)、Tp-Tec(OR=1.025,95%CI 1.002~1.049)、QTc(OR=1.357,95%CI 1.096~1.680),Tp-Te/QT(OR=1.025,95%CI 1.002~1.049)、T波形态(OR=8.695,95%CI 3.267~23.139)是心律失常发生的相关因素(P<0.05)。ROC曲线显示,T波形态和心律失常发生风险的AUC为0.726(P<0.05)。结论hs-CRP、NLR、Tp-Tec、QTc,Tp-Te/QT、T波形态是心律失常发生的相关因素且T波形态和术后心律失常的发生具有较高的相关性。

心尖肥厚型心肌病患者超声心电图T波倒置与左心室肥厚特征的关系分析

目的探讨心尖肥厚型心肌病(AHCM)患者超声心电图T波倒置与左心室肥厚特征的关系。方法选取2018年1月至2020年10月辽宁中医药大学附属医院收治的180例心尖肥厚型心肌病患者作为研究对象,根据患者心尖壁增厚程度和类型分为典型AHCM组(n=119)与早期AHCM组(n=61),根据患者心尖肥厚范围分为单纯型AHCM组(n=67)和混合型AHCM组(n=113)。比较各组心电图特征、心尖厚度指标,并分析T波倒置与左心室肥厚特征的相关性。结果典型AHCM组TV5、TI均高于早期AHCM组,Tmax长于早期AHCM组,差异有统计学意义(P<0.05);单纯型AHCM组QRS时限延长、ST段下移发生率均低于混合型AHCM组,TV5、TI均低于混合型AHCM组,Tmax短于混合型AHCM组,差异有统计学意义(P<0.05);典型AHCM组与早期AHCM组、单纯型AHCM组与混合型AHCM组其他指标比较差异无统计学意义。典型AHCM组心尖与后壁基底部室壁厚度比值(ABR)大于早期AHCM组,心尖部最大室壁厚度(APWTmax)、心尖部平均室壁厚度(APWTmean)均厚于早期AHCM组,差异有统计学意义(P<0.05);单纯型AHCM组ABR小于混合型AHCM组,APWTmax、APWTmean均薄于混合型AHCM组,差异有统计学意义(P<0.05)。典型AHCM、早期AHCM和混合型AHCM患者中,APWTmax与Tmax、TV5均呈正相关(r>0,P<0.05),其余指标与T波各特征无明显相关性。结论单纯型AHCM患者APWTmax与超声心电图T波倒置深度密切相关,有利于患者进行影像学筛查和早期诊断。