Electrocardiographic predictors of cardiovascular events in patients at high cardiovascular risk: a multicenter study

Background There are limited data on the prevalence of electrocardiographic (ECG) abnormalities, and their value for predicting a major adverse cardiovascular event (MACE) in patients at high cardiovascular risk. This study aimed to determine the prevalence of ECG abnormalities in patients at high risk for cardiovascular events, and to identify ECG abnormalities that significantly predict MACE. Methods Patients aged ≥ 45 years with established atherosclerotic disease (EAD) were consecutively enrolled from the outpatient clinics of the six participating hospitals during April 2011 to March 2014. The following data were collected: demographic data, cardiovascular risk factors, history of cardiovascular event, physical examination, ECG and medications. ECG was analyzed using Minnesota Code criteria. MACE included cardiovascular death, non-fatal myocardial infarction, and hospitalization due to unstable angina or heart failure. Results A total of 2009 patients were included, 1048 patients (52.2%) had established EAD, and 961 patients (47.8%) had multiple risk factors (MRF). ECG abnormalities included atrial fibrillation (6.7%), premature ventricular contraction (5.4%), pathological Q-wave (Q/QS)(21.3%), T-wave inversion (20.0%), intraventricular ventricular conduction delay (IVCD)(7.3%), left ventricular hypertrophy (LVH)(12.2%), and AV block (12.5%). MACE occurred in 88 patients (4.4%). Independent predictors of MACE were chronic kidney disease, EAD, and the presence of atrial fibrillation, Q/QS, IVCD or LVH by ECG. Conclusions A high prevalence of ECG abnormalities was found. The prevalence of ECG abnormalities was high even among those with risk factors without documented cardiovascular disease.

Coordination of Multi-leaders and Multi-followers in Supply Chain of Value-Added Telecom Services

In order to study supply chain of the telecom value-added service,a multi-leaders and multi-followers Stackelberg game model with multiple telecom operators and multiple service providers whose income is composed of information fee division and advertisement was constructed.Then a demonstration was simulated,and the results were compared with the situation of service providers' income only from information fee division.The simulated and compared results indicate that,the enterprises in the supply chain have the nature of pursuing the maximum profits in capital markets;meanwhile,first-mover advantages and some enterprise can get more profits with the information asymmetry.

Arterial hypertension and electrocardiographic diagnosis of left ventricular hypertension in the group of geriatric patients with coronary heart disease living in the far north

As a result of research, high prevalence of arterial hypertension has been identified in the group of patients with coronary heart disease aged 60 and older. Most often, occurring form of arterial hypertension among geriatric patients is isolated systolic arterial hypertension (ISAH). The comparison of two ethnic groups of the population has showed higher levels of systolic and diastolic blood pressure (SBP and DBP) in the group of patients of non-indigenous nationality, rather than Yakut patients. Correlation was recorded in the group of non-indigenous patients as they age. Significant increase in the level of SBP was identified in the group of senile and long-livers than in the elderly. Detection of ECG signs of LVH showed the lowest specificity of Cornell voltage criterion comparing to Sokolow-Lyon criterion with its more often occurrence. ECG-signs of left ventricle hypertrophy are significantly more often established by Sokolow-Lyon criterion for men, Cornell voltage—for women. Correlation has been found between the presence of LVH and combination of Cornell voltage criterion with both Gubner-Ungerleider and Sokolow-Lyon criteria.

Validity of electrocardiographic criteria for increased left ventricular mass in young patients in the general population

AIMTo investigate validity of electrocardiographic(ECG)criteria for left ventricular hypertrophy(LVH)in young adults.METHODS Retrospectively,echocardiograms showing LVH and concomitant electrocardiograms were collected in patients 18 to 39 years old.A control group of patients without LVH was collected.Using echocardiogram as the gold standard,electrocardiograms were analyzed using common voltage criteria.RESULTS Study included 100 subjects(52%male,mean age=28±6.8 years,96%Hispanic or African-American)with 50%LVH prevalence.Sensitivity and specificity for SokolowLyon criteria were 24%(95%CI:13.5%-38.4%)and 88%(95%CI:74.9%-95%).For Cornell criteria,sensitivity was 32%(95%CI:19.9%-46.8%)and specificity 98%(95%CI:87.9%-99.8%).For R in a VL criteria,sensitivity was 12%(95%CI:4.9%-25%)and specificity 100%(95%CI:91.1%-100%).CONCLUSION In young adults common ECG voltage criteria have low sensitivities and high specificities similar to other age groups.Low sensitivities preclude these ECG criteria from serving as effective screening tests.

Electrocardiographic Safety of Daily Hydroxychloroquine 400 mg Plus Azithromycin 250 mg as an Ambulatory Treatment for COVID-19 Patients in Cameroon

Objective: To determine the early electrocardiographic changes in a cohort of ambulatory cameroonian COVID-19 patients treated with hydroxychlo- roquine and Azithromycin. Design: Prospective study. Setting: Treatment centres of the city of Yaounde, Cameroon, from May 7th to 24th 2020. Participants: We enrolled 51 consecutive confirmed COVID-19 on RT-PCR who having mild forms of COVID-19 and treated by hydroxychloroquine 200 mg twice daily during seven #days plus Azithromycin 500 mg the first day and 250 mg the remaining 4 days as per national standard. Main Outcomes Measures: The primary end-point was the change in QTc interval between day 0 (D0), day 3 (D3) and day 7 (D7). Secondary endpoints were changes in all other cardiac electrical conductivity patterns and the occurrence of clinical arrhythmic events during the course of treatment. Results: The population (29 men and 22 women) was aged 39 ± 11 years (range 17 to 61 years). Mean Tisdale score was 3.35 ± 0.48. No significant change from baseline (D0) of QTc was observed at D7 (429 ± 27 ms at D0 versus 396 ± 26 ms at D7;p = 0.27). A reduction of heart rate was observed between the D0 and D7 (75 ± 13 bpm versus 70 ± 13 bpm, p = 0.02) with increased QRS duration between D0 and D7 (95 ± 10 ms versus 102 ± 17 ms, p = 0.004). No symptomatic arrhythmic events occurred during the treatment course. Conclusions: No life-threatening modification of the QT interval was observed in non-severe COVID-19 patients treated ambulatory with hydroxychloroquine and azithromycin. Studies are needed in critical-ill and older patients.

Remote electrocardiograph monitoring using a novel adhesive strip sensor: A pilot study

The increase in health care costs is not sustainable and has heightened the need for innovative low cost effective strategies for delivering patient care. Remote monitoring holds great promise for preventing or shortening duration of hospitalization even while improving quality of care. We therefore conducted a proof of concept study to examine the quality of electrocardiograph (ECG) recordings obtained remotely and to test its potential utility in detecting harmful rhythms such as atrial fibrillation. We tested a novel adhesive strip ECG monitor and assessed the ECG quality in ambulatory individuals. 2630 ECG strips were analyzed and classified as: Sinus, atrial fibrillation (AF), indeterminate, or other. Four readers independently rated ECG quality: 0: Noise; 1: QRS complexes seen, but P-wave indeterminate; 2: QRS complexes seen, P-waves seen but poor quality; and 3: Clean QRS complexes and P-waves. The combined average rating was: Noise 12%; R-R, no P-wave 10%; R-R, no PR interval 18%; and R-R with PR interval 60% (if Sinus). If minimum diagnostic quality was a score of 1, 88% of strips were diagnostic. There was moderate to high agreement regarding quality (weighted Kappa statistic values; 0.58 to 0.76) and high level of agreement regarding ECG diagnosis (ICC = 0.93). A highly variable RR interval (HRV ≥ 7) predicted AF (AUC = 0.87). The monitor acquires and transmits diagnostic high quality ECG data and permits characterization of AF.

Electrocardiographic Manifestations of Endocrine and Metabolic Disorders

Endocrine dysfunction has an adverse impact on the cardiovascular system that may be due to an endocrine abnormality that leads to electrocardiogram (EKG) changes. The EKG changes due to endocrine disorder can be reversible and irreversible and treating underlying disease can reverse EKG changes in some cases. In this article, we review the electrocardiogram manifestations of various endocrine disorders.

Experimental and Finite Element Analysis for Multi-lead Rubber Bearings:A Comparative Study

The mechanical properties of multi-lead rubber bearings （MLRBs） were investigated by experiment and finite element analysis. First, the vertical stiffness, horizontal stiffness and yielded shear force were tested for four MLRB specimens and two specimens of the single-lead rubber bearings （ SLRBs）. Then, the MLRBs were modeled by the explicit finite element analysis software ANSYS/ LS-DYNA, in order to evaluate the horizontal force-displacement hysteretic curves under static vertical and dynamical horizontal loadings. The disagreement between the tested and theoretical values was less than 11.4%, and MLRBs and SLRBs were similar in vertical stiffness, pre-yield stiffness and yield stiffness.

数字心电图机计量检定心率显示问题的探究

数字心电图机是在临床上被广泛使用的一种医疗设备,是通过心电图的方式,对心肌梗死、心绞痛、心律失常等疾病进行初步诊断,但设备使用频率增加,会降低其准确度。因此,为避免心电导联规则不一致导致的误判,确保其量值的准确性和可靠性,本文针对不同厂家数字心电图机心率显示的计量特性的检定方法进行研究,并提出了相应的解决方案。

手持式心电采集仪的使用技巧

手持式心电采集仪是一款简易的双极单导联心电图记录设备,只需双手拇指紧捏正、负两极,就能方便地记录出标准Ⅰ导联心电图,多用于监测心律失常。它属于家用医疗器械,颇受广大中老年朋友的欢迎。基于单极导联与双极导联的本质及其内在联系,本文衍生出标准导联与加压单极导联的记录方法;同时,在深入探究CR导联与Wilson导联内在联系的基础上,创造性地提出了手持式心电采集仪直采CR胸导联心电图的方法。理论和实践均表明,加压单极肢体导联的等效记录法与CR胸导联的双极记录法不仅能满足临床需要,而且还有其独到之处。该方法能充分发挥家用医疗器械的医用价值,值得推广普及。

心音心电检测仪电磁兼容问题的测试分析及整改方法

现代医疗器械更偏向于高精确度、高敏感度和小型化,其所处的电磁环境越来越复杂。外界电磁干扰对医疗设备会产生影响,严重时甚至影响医生的诊断。本文结合心音心电检测仪,基于医疗器械测试标准对传导发射测试、辐射发射测试和静电放电这3个测试项目进行了研究,提出了壳体整改,增加滤波电路、磁环、电荷释放电路等整改方法。对其他类型相关医疗器械的电磁兼容问题分析和整改,有一定的参考借鉴作用。

心电图参数对冠状动脉重度病变评估价值

目的 探讨心电图参数对冠心病患者冠状动脉重度病变评估价值。方法 选取2022年1月至2023年9月郑州大学第二附属医院收治的冠心病患者364例,根据Gensini评分将患者分为重度病变组(n=123)和非重度病变组(n=241),比较两组患者基线资料和心电图参数差异。采用logistic回归分析重度病变的影响因素及心电图参数评估效能,绘制心电图参数评估重度病变列线图,计算心电图参数联合增量价值及评估重度病变的ROC曲线下面积。结果 与非重度病变组相比,重度病变组年龄、肌酸激酶同工酶、氨基末端脑钠肽前体、QRS时限、额面QRS-T夹角大,吸烟、高血压、糖尿病、病理性Q波、左心室高电压、碎裂QRS波占比大,高密度脂蛋白胆固醇、射血分数低,差异有统计学意义(P <0.05)。logistic回归分析显示病理性Q波(OR=3.71,95%CI:1.93~7.15,P <0.001)、左心室高电压(OR=5.05,95%CI:1.66~15.41,P=0.004)、碎裂QRS波(OR=2.17,95%CI:1.14~4.11,P=0.018)、额面QRS-T夹角(OR=1.01,95%CI:1.00~1.02,P=0.023)是重度病变的评估因素。心电图参数联合对重度病变增量价值:C-statistic增加0.09(95%CI:0.02~0.16,P=0.009)、NRI 0.37(95%CI:0.20~0.55,P <0.001)、IDI 0.12(95%CI:0.08~0.17,P <0.001)。ROC曲线显示心电图参数联合评估重度病变的AUC为0.79(95%CI:0.74~0.84,P <0.001),灵敏度为63.41%,特异度为85.89%。结论 心电图参数(病理性Q波、左心室高电压、碎裂QRS波、额面QRS-T夹角)联合对重度病变评估具有一定临床价值。

基于自适应参数的心电压缩方法研究

为探究一种适应于临床诊断的高压缩比的心电(electrocardiograph, ECG)压缩方法,本研究提出了一个自适应压缩参数寻优器,基于压缩算法定位出压缩性能最佳的ECG信号参数组。针对算法的普适性,本研究推荐了一组适用于所有ECG信号的参数组,并利用4个指标在MIT-BIH数据库上对压缩性能进行估计。实验结果表明,平均压缩比(compression ratio, CR)达到了26.67,平均百分比均方根误差(percentage root-mean-square difference, PRD)达到了14.64%,压缩一条30 min ECG信号的平均时长为0.125 8 s。本研究改进后的压缩算法在压缩比上表现突出,对临床诊断有应用意义。

基于元胞自动机的Brugada综合征患者心电信号研究

针对Brugada综合征(Brugada syndrome,BrS)患者的症状发展与其异常CV(conduction velocity,CV)恢复和异常APD(action potential duration,APD)恢复之间的联系仍未明确问题,本文采用元胞自动机模型对其进行研究。首先根据BrS患者心电信号的特点对元胞自动机模型进行量纲化处理,并在模型中考虑CV恢复和APD恢复;然后使用该模型数值模拟不同CV恢复及APD恢复下与心动过速对应的心电信号螺旋波态的演化行为。结果表明:只存在CV恢复时,心动过速只会维持,不会恶化;在CV恢复和无记忆APD恢复共同影响下,心动过速可能消失,也可能转化为心室颤动,其中转化为心室颤动的概率为54%,明显高于临床数据;在CV恢复和带记忆APD恢复共同影响下,心动过速可能消失、维持或转化为心室颤动,其中转化为心室颤动的概率约为35%,与临床数据一致。跟踪观察波头附近的心电信号传导情况,发现BrS患者的症状发展与CV恢复或APD恢复导致的电信号传导阻滞有关,传导阻滞的程度越严重,BrS患者就越容易由心动过速发展为心室颤动。记忆性APD恢复因其记忆效应能降低APD的振荡幅度,所以能降低心室颤动的发生率。

心电图机的电磁兼容检测及整改技术研究

该研究结合心电图机产品结构和工作原理,依据国家标准对注册阶段和临床使用的心电图机进行电磁兼容性测试,分析出现的问题。结果显示,心电图机的辐射发射试验有可能超过标准限值,电快速脉冲群试验等抗扰度试验易受到电磁干扰,采集的图像可能影响正常临床诊断,需要进行整改。因此,在心电图机研发生产过程中需要进行数字信号的采集处理,重视电磁兼容性。

高血压患者颈动脉搏动指数和阻力指数与动态心电血压监测指标的相关性研究

目的 探讨高血压患者颈动脉搏动指数和阻力指数与动态心电血压监测指标的相关性。方法 回顾性分析2021年1月至2022年1月在该院诊治的800例原发性高血压患者,将其纳入研究组,同期300例健康体检者纳入对照组。监测并对比对照组和研究组的颈动脉搏动指数、阻力指数、24 h平均舒张压和收缩压、白昼和夜间平均舒张压和收缩压、24 h舒张压负荷和24 h收缩压负荷。将研究组患者按照搏动指数和阻力指数进行三分位分组,分析高血压患者颈动脉搏动指数和阻力指数与动态心电血压监测指标之间的相关性。结果 研究组颈动脉搏动指数、阻力指数、24 h平均舒张压、24 h平均收缩压、白昼平均舒张压、夜间平均舒张压、白昼平均收缩压、夜间平均收缩压、24 h舒张压负荷和24 h收缩压负荷均高于对照组,差异均有统计学意义(P<0.05)。随着颈动脉搏动指数的升高,高血压患者的24 h平均舒张压、24 h平均收缩压、白昼平均舒张压、白昼平均收缩压、24 h舒张压负荷、24 h收缩压负荷均明显升高,差异均有统计学意义(P<0.05);随着阻力指数的升高,高血压患者的24 h平均舒张压、24 h平均收缩压、白昼平均舒张压、夜间平均舒张压、白昼平均收缩压、夜间平均收缩压、24 h舒张压负荷和24 h收缩压负荷均明显升高,差异均有统计学意义(P<0.05)。相关性分析结果显示,高血压患者颈动脉搏动指数、阻力指数分别与24 h平均舒张压、24 h平均收缩压、白昼平均舒张压、白昼平均收缩压、24 h舒张压负荷和24 h收缩压负荷呈正相关性(r>0.3,P<0.001)。结论 高血压患者颈动脉搏动指数和阻力指数的变化与动态心电血压监测指标24 h平均血压、白昼平均血压、24 h血压负荷呈正相关,随着颈动脉搏动指数和阻力指数的升高,部分动态心电血压监测指标也相应升高。

CT不同成像技术对冠状动脉CTA检查结果的影响

目的:探讨CT不同成像技术对冠状动脉计算机断层扫描血管造影(CTA)检查结果的影响。方法:选取2021年1月—2023年6月于常熟市第二人民医院接受冠状动脉CTA检查的120例患者作为研究对象,采用随机数表法按2∶1将患者分为对照组(n=80)与观察组(n=40)。对照组采用回顾性心电门控技术,观察组采用前瞻性心电门控技术。比较两组心率、扫描时间、辐射剂量[CT容积剂量指数(CTDI_(vol))、剂量长度乘积(DLP)、有效辐射剂量(ED)]、成像质量(解剖结构显示、CT值标准范围、运动造影、图像质地)及患者舒适度(Kolcaba简化舒适状况量表评分)。结果:观察组心率、CTDI_(vol)、DLP、ED低于对照组,扫描时间短于对照组,CT值标准范围、运动造影、图像质地评分、总分及生理、心理、社会、环境评分高于对照组,差异有统计学意义(P<0.05)。结论:前瞻性心电门控技术在冠状动脉CTA检查中相较于回顾性心电门控技术,具有更低的心率、扫描时间和辐射剂量,同时能提供更高的成像质量和更优的患者舒适度。

某型便携式心电图机航空适应性改造技术与应用研究

目的 为提高便携式医疗设备航空适应能力,建立一套系统性的改造工艺与技术方法。方法 以心电图机为例,通过参数对比与摸底试验,获得设备的薄弱环节;基于GJB 150A等标准,开展隔振、加固、电磁兼容等关键改造技术方法研究,并针对玻璃屏幕防护的典型问题开展了压合工艺关键技术研究。结果 经过实验室环境试验、医学鉴定试验与飞行环境试验的验证,心电图机达到了航空适应性要求,并在其他产品上获得了应用推广。结论 该套改造工艺方法与关键技术,可有效解决心电图机的航空环境适应性问题,为便携式医疗设备的航空适应性改造提供借鉴指导。

原发性高血压患者心电图Tp-Te与血压控制效果的关系

目的探讨原发性高血压患者心电图T波峰末间期(Tp-Te)与血压控制效果的关系。方法选取2021年1-3月该院收治的221例原发性高血压患者作为研究对象,根据24 h动态血压监测结果将其分为达标组和未达标组。比较两组患者一般资料、心电图指标。采用多因素Logistic回归分析原发性高血压患者血压控制未达标的危险因素。结果达标组有53例患者,未达标组有168例患者。两组患者年龄、性别、高血压病程、高血压分级、降压治疗规范情况比较,差异均无统计学意义(P>0.05)。未达标组Ⅰ导联Tp-Te、Ⅰ导联校正的Tp-Te(Tp-Tec)短于达标组,V1导联Tp-Te、V1导联Tp-Tec长于达标组,V1导联Tp-Te/QT比值大于达标组,差异均有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,Ⅰ导联Tp-Te缩短、V1导联Tp-Te延长、V1导联Tp-Tec延长、V1导联Tp-Te/QT比值增大是原发性高血压患者血压控制未达标的危险因素(P<0.05)。结论Ⅰ导联Tp-Te缩短、V1导联Tp-Te延长、V1导联Tp-Tec延长、V1导联Tp-Te/QT比值增大是原发性高血压患者血压控制未达标的危险因素,可为研究原发性高血压心电重构与血压控制效果的关系提供新思路。

心电瀑布图结合散点图在诊断房性心律失常中的应用

目的探讨心电瀑布图结合散点图诊断房性心律失常的应用价值及优势。方法分析动态心电图中典型房性心律失常的心电瀑布图及散点图的变化特征,并总结其应用优势。结果不同类型房性心律失常的心电瀑布图和散点图具有不同的表现特征。(1)频发房性早搏:瀑布图特征为间歇性P峰带出现断裂,R、T峰带不变;散点图特征为早搏点位于快加速区。(2)房性自主节律:瀑布图特征为P峰带断裂,PR间期出现变化;散点图特征为该节律可融合于窦性节律集落中,与窦性节律难以区分。(3)间歇性短阵房性心动过速:瀑布图特征为P峰带断裂,出现两个或两个以上的R峰带;散点图特征为集落点可位于快加速区或45°线上,心率范围可与窦性心率区分,但发作时间无法确定。(4)持续性心房颤动:瀑布图特征为P峰带的消失和紊乱,R、T峰带不变;散点图特征为呈扇形图形。(5)心房扑动:瀑布图特征为P峰带断层,出现两个或两个以上的P峰带,并出现相应的PR间期;散点图特征为呈网格状图形。结论通过选择动态心电图上P-QRS-T波群变化明显的导联,并观察心电瀑布图上P、QRS、T峰带的变化特征,再结合心电散点图的变化,就可以准确、快速地判断房性心律失常的类型。