Early electrocardiographic indices for predicting chronic doxorubicin-induced cardiotoxicity

BackgroundDealing with chemotherapy-related cardiac dysfunction (CTRCD) remains a significant problem complicated by the difficulty in early detection of cardiotoxicity. Electrocardiogram (ECG) is expected to be the most realistic methodology due to lower cost-performance and non-invasiveness. We investigated the long-term visual fluctuations in the ECG waveforms in patients with chronic doxorubicin (DOX)-induced cardiotoxicity to identify ECG indices for the early detection of cardiotoxicity.MethodsWe conducted a retrospective case series study by reviewing the medical records of 470 consecutive patients with malignant lymphoma who were treated with DOX at our institute between January 2010 and December 2017. Of them, 23 (4.9%) patients developed left ventricular dysfunction and were diagnosed with CTRCD using echocardiography. We assessed the ECG indices on 12-lead ECG recordings before and after treatment in 15 patients; eight patients were excluded due to conduction disturbances or atrial fibrillation.ResultsCTRCD was detected at a median of 475 (interquartile range, IQR: 341–1333) days after initiating chemotherapy. The evaluation of ECG indices preceding CTRCD development was performed 93 (IQR: 52–232) days before the detection of CTRCD. In the stage of CTRCD, the most significant ECG change was T-wave flattening in leads V3–V6 (12 patients, 80%). Additionally, QTa prolongation was observed in leads I and aVL (n = 10, 66%), leads II, III, and aVF (n = 9, 60%), and leads V3–V6 (n = 10, 73%). These ECG changes were not observed before the treatment but were detected mildly in the pre-CTRCD stage, which subsequently worsened in the CTRCD stage.ConclusionsThis study indicated that T-wave changes and QTa prolongation may be useful as an early indicator before the onset of CTRCD in patients with DOX-induced cardiotoxicity.     

肥厚型心肌病的心电图改变

目的 探讨肥厚型心肌病患者心电图变化及其临床意义。方法 对44例肥厚型心肌病(Ⅰ型前间隔肥大14例，Ⅱ型前间隔、后间隔均肥大18例，Ⅲ型左心室前壁或／和侧壁、后壁肥大7例，Ⅳ型心尖部肥大5例)行常规12导联心电图检查。结果 心电图异常(ST-T改变、异常Q波、心室肥大等)发生率为93．2％。Ⅳ型ST-T改变多见于前侧壁、高侧壁，具有特殊性。其它三型患者异常Q波、ST-T改变发生率及部位差异均无显著性意义。结论 肥厚型心肌病患者大多存在不同程度的心电图异常，但除心尖肥厚型心肌病外，其他各型心电图改变无特异性。     

肺源性心脏病患者治疗缓解前后心电图参数对照分析

目的观察肺源性心脏病患者感染控制前后的心电图变化。方法对76例肺源性心脏病患者分别在急性感染期和缓解期作常规心电图和动态心电图检查,比较心率、额面心电轴、RV1 SV5电压、肢体导联总电压、PⅡ波电压、房性和室性心律失常。结果急性感染期和缓解期心率(110±11次/min,91±10次/min)、ST-T改变的发生率(78%,46%)、房性心律失常(98%,76%)和室性心律失常(32%,14%)差异均有显著性意义(P<0.05);额面心电轴、RV1 SV5电压、肢体导联总电压和PⅡ波电压差异无显著性意义。结论肺源性心脏病患者感染得到控制后,心电图的部分参数随之好转,心律失常和ST-T能够较敏感地反映病情状况。     

多因素分析急性心肌梗死后临床指标评估劳动能力的意义

目的：探讨临床检测指标评估急性心肌梗死后劳动能力(运动贮量)的意义。方法：34例AMI后病人，住院期间进行了多种临床检测，出院前24～48小时进行心电图踏车运动试验，部分病人进行了冠状动脉造影，最后作统计学逐步回归分析，找出与病人运动量相关的指标。结果：病人发病年龄，静息脉压与休息、运动峰值心率差(心率差)的乘积对运动贮量有负向影响(r分别为-0．5081，-0．7135)；病人出院前的一般状况，心率差与运动贮量有正向影响(r分别为0．4973，0．6325)；在研究的20项因素中，经逐步回归分析，有4项在a=0．05的水准上选入回归模型，所得到的方程为：y=418．67—7．88x1 119．39x6 7．85x10-1．07x12.结论：AMI病人住院时的上述4项指标可以较好的预测其出院时的劳动能力状况。     

Atrial fibrillation signal organization predicts sinus rhythm maintenance in patients undergoing cardioversion of atrial fibrillation.

AIMS: Electrical remodelling is believed to influence the outcome following cardioversion of patients with persistent atrial fibrillation (AF). However, the results in clinical studies are conflicting. We assessed the hypothesis that non-invasively obtained atrial fibrillatory organization can be used as a predictor of sinus rhythm (SR) maintenance. METHODS AND RESULTS: Fifty-four patients (37 men, age 67+/-11) with persistent AF (median duration 3 months, 1 day to 18 months), without anti-arrhythmic drug treatment, referred for cardioversion were studied. Assessment of the atrial harmonic decay was made by time-frequency analysis of the ECG. At 1-month follow-up, 30 patients had relapsed into AF. The mean harmonic decay at inclusion of those relapsing into AF was 1.5+/-0.3 compared with 1.1+/-0.3 among those maintaining SR (P=0.0004). Using a cut-off value of harmonic decay 相似文献   

急性冠状动脉综合征心电图改变的临床意义

目的 探讨急性冠状动脉综合征心电图改变的临床意义。方法 对104例接受经皮穿刺腔内冠状动脉成形术加支架植入术的急性冠状动脉综合征患者（Ⅰ组Q波心肌梗死54例、Ⅱ组非Q波心肌梗死12例和Ⅲ组不稳定心绞痛38例）的冠状动脉病变和心电图改变进行分析。结果 冠状动脉完全闭塞Ⅰ组占75．55％，Ⅱ组占33．33％，差异有显著性意义（P＜0．05）。Ⅲ组无冠状动脉完全闭塞。3例冠状动脉多支病变差异无显著性意义（P＞0．05）。Ⅰ组：前壁心肌梗死多于下壁（32／54：22／54），发生持续性窦性心动过速、三度房室传导阻滞、室性心律失常、死亡率高。Ⅱ组：广泛持续性ST－T改变或以T波深倒置演变特征或Q波迅速消失，ST－T动态改变。Ⅲ组：胸痛发作时ST－T改变或伪性改善，不发作时ST－T正常或仍有改变。结论 急性冠状动脉综合征心电图表现有多种形式。无Q波心肌梗死并不少见。心电图的易变性是急性冠状动脉综合征的特征之一。     

甲状腺功能减退性心脏病心率变异性的临床研究

目的观察甲状腺功能减退性心脏病（甲减心）患者心率变异性（HRV）的变化。方法采用24h动态心电图分析甲减心患者（39例）HRV的时域指标，并与正常对照组（39例）进行比较。结果甲减心组平均R-R间距（RRI）、24h窦性R-R间期标准差（SD）、5min窦性R-R间期标准差（SDAIDX）、5min窦性R-R间期标准差的均值（SDIDX）、R-R连续差异平方根（rMSSD）、相邻窦性R-R间期差值〉50ms的百分比（PNN50），均明显低于正常对照组，具有非常显著性差异（P〈0．01）。结论甲减心患者交感神经及迷走神经功能均受损，可能为甲减心的发病机制之一。     

心脏性晕厥或猝死的若干高危心电表现

目的 探讨快速性心律失常所致心脏性晕厥或猝死的高危心电图表现。方法 分析入院时或入院后至少发生1次心脏性晕厥或猝死的33例患者发作时与发作前后的常规12导联心电图或持续心电监护心电图。结果 引起心脏性晕厥或猝死的若干高危心电图表现：①长Q—T间期综合征，②Brugada综合征，③异常J波，④复杂性室性期前收缩，⑤冠心病急性心肌梗死呈广泛前壁心肌梗死伴新出现的右束支传导阻滞及弓背抬高的ST段持续不降，或伴ST—T电交替；或广泛前壁心肌梗死伴墓碑样ST段抬高，⑥扩张型心肌病伴进展性QRS波群低电压。结论 心脏性晕厥或猝死存在多种高危心电图表现。     

302例登革热心电图特征研究

目的 分析登革热患者心电图的特征。方法 回顾性分析302例登革热患者（登革热组）和同期300名健康体检者（对照组）的临床资料,对比2组心电图异常情况;进一步分析异常心电图治疗前后的变化及其特点。结果 登革热组存在心电图异常的患者比例（51.32%,155/302）高于对照组（31.00%,93/300）（P < 0.001）;登革热组心电图异常发生频率高于对照组的有ST-T改变（27.81%,84/302）、窦性心动过缓（11.92%,36/302）（P均< 0.05）;有46例心电图异常的患者治疗后复查了心电图,其中窦性心动过缓发生频率较治疗前下降,差异有统计学意义（P < 0.05）;窦性心动过缓的患者共36例,16例（44.44%）合并ST-T改变,高于无窦性心动过缓的患者（25.56%,68/266）,差异有统计学意义（P < 0.05）。结论 登革热患者心电图异常较普遍,主要表现为ST-T改变、窦性心动过缓;窦性心动过缓是登革热最常见的心律失常和较显著的心电图特征,可能有助于诊断登革热。     

Morphological modeling of cardiac signals based on signal decomposition

In this paper a general framework is presented for morphological modeling of cardiac signals from a signal decomposition perspective. General properties of a desired morphological model are presented and special cases of the model are studied in detail. The presented approach is studied for modeling the morphology of electrocardiogram (ECG) signals. Specifically, three types of ECG modeling techniques, including polynomial spline models, sinusoidal model and a model previously presented by McSharry et al., are studied within this framework. The proposed method is applied to datasets from the PhysioNet ECG database for compression and modeling of normal and abnormal ECG signals. Quantitative and qualitative results of these applications are also presented and discussed.