Fragmented QRS – Its significance

Fragment QRS (fQRS) complex is a myocardial conduction abnormality that indicates myocardial scar. It is defined as additional notches in the QRS complex. Though initially fQRS was defined in the setting of normal QRS duration (<120 m s), later it has been expanded to include conditions with wide QRS complexes as in bundle branch block, ventricular ectopy and paced rhythm, when more than 2 notches are present. It is an important, yet often overlooked marker of mortality and arrhythmic events in many cardiac diseases. The significance of fQRS lies in the fact that it just requires a surface ECG for its recording and the value of information about the condition of the heart it dispenses based on the clinical setting. We review the role of fQRS in predicting adverse cardiac events in various conditions.     

QRS波群自动分类技术研究进展

本文综述了QRS波群自动分类技术的关键技术及其研究方向,内容涉及QRS波群的描述方法、分类方法和训练数据集这三个重要影响因素。     

冠心病患者运动致QRS延长的临床意义

为探讨冠心病病人由于急性心肌缺血对ＱＲＳ持续时间变化的影响及其意义。本文收集了５３例病人,均进行运动试验和冠脉造影,其中２０例经冠脉造影排除心病,其他３３例经冠脉造影确定为冠心病。结果运动使冠脉正常者ＱＲＳ持续时间缩短,而使冠心病者ＱＲＳ持续时间延长。     

Fragmented QRS: What Is The Meaning?

Fragmented QRS (fQRS) is a convenient marker of myocardial scar evaluated by 12-lead electrocardiogram (ECG) recording. fQRS is defined as additional spikes within the QRS complex. In patients with CAD, fQRS was associated with myocardial scar detected by single photon emission tomography and was a predictor of cardiac events. fQRS was also a predictor of mortality and arrhythmic events in patients with reduced left ventricular function. The usefulness of fQRS for detecting myocardial scar and for identifying high-risk patients has been expanded to various cardiac diseases, such as cardiac sarcoidosis, arrhythmogenic right ventricular cardiomyopathy, acute coronary syndrome, Brugada syndrome, and acquired long QT syndrome. fQRS can be applied to patients with wide QRS complexes and is associated with myocardial scar and prognosis. Myocardial scar detected by fQRS is associated with subsequent ventricular dysfunction and heart failure and is a substrate for reentrant ventricular tachyarrhythmias.     

呼吸对心电图中QRS波形的影响

通过对20例健康男性Frank导联心电图在不同呼吸阶段的QRS波波形平均和振幅统计,观察到处于不同呼吸阶段的QRS波的振幅有差别。其中QRS波振幅在呼气中期最高在呼气中期最低,根据呼吸运动时肺容积及肺内压变化的规律,认为是由于胸腔压力和心室舒容积的改变,而不是心脏与电极间的相对位置的改变造成了QRS波振幅的变化。     

一种QRS波群实时检测方法

结合模板匹配和改进的导数阈值法,提出了一种QRS波群实时检测方法CT2(combination method of template matching and improved derivative threshold)。首先,预采集一段ECG信号,使用高斯函数构造QRS模板;然后将实时采集的ECG信号使用CT2检测R波位置。为了比较算法检测精度和效率,使用CT2和基于小波模极大值的方法进行了对比。结果表明,CT2检测精度与基于小波模极大值的方法相当,但运算时间大大缩短,适于实时检测。     

心电QRS波的非线性分类方法的研究

阐明了非线性分形维数的计算方法,然后将其应用于ＱＲＳ波分类,实验研究结果表明该算法不仅简单,而且具有很强的抗噪能力,对于ＰＶＢ的检出率高达９７．８％。     

基于QRS波群的心律失常辅助诊断模型研究

基于对QRS波群的特征变量提取。利用减法聚类和自适应模糊神经网络构建心律失常辅助诊断模型,分析不同训练数据集对模型测试结果的影响。实验结果表明。该模型能准确识别不同类型的QRS波群,使用不同训练数据集对诊断结果存在影响,为进一步实现更复杂的心律失常辅助诊断模型提供方法。     

基于小波变换的QRS综合波的检测

本文描述了基于二进制小波变换（DyWT),ECG信号中QRS综合波的检测。设计－小波它适合于QRS检测,将基于心电信号的特殊的特征的特征为小波的尺度。DyWT较之其它方法最基本的优点为强有力的抑制噪声检测以及在分析随时间变化ECG波形时的灵活性。     

儿童宽QRS心动过速体表12导联心电图分析

目的:探讨儿童宽QRS心动过速的心电图特点.方法:对2006-2009年首都医科大学附属北京儿童医院57例17岁以下宽QRS心动过速儿童心电图分析.结果:儿童宽QRS心动过速以室性心动过速最常见,且多具特异的心电图表现,易引起血流动力学改变.婴幼儿多见室上性心动过速伴室内差异性传导.结论:体表12导联心电图(ECG)是临床诊断宽QRS心动过速的最主要方法;Brugada四步法是鉴别诊断的方法之一.     

ECG 信号QRS 波群检测算法的进展

QRS波群是ECG信号的重要组成部分,是心电信号分析的基础.QRS波群的检测方法已经有很多种实用有效的方法,并逐步地走向成熟,在实际应用中得到实现.本文就QRS波群的检测方法作了具体的整理与分析,较全面的阐述了实际应用中的各种算法,最后作者对检测算法的发展趋势进行了总结和展望.     

强噪声,高基漂下的QRS检测器

本文描述了一种基于两进小波变换（ＤＹＷＴ）的ＱＲＳ波检测器。小波尺度的选择是基于心电信号的频谱的特点,并根据多尺度选择方法判决检测心电ＱＲＳ波,实验结果表明,对于在有强大的噪声和严重的基线漂移干扰下的心电信号能够有效的识别。     

犬心肌缺血再灌注损伤心电图Ⅱ导联QRS波群的演变

目的观察杂种犬心肌缺血再灌注损伤过程心电图(ECG)的动态变化规律,为研究干细胞移植对犬心肌缺血再灌注损伤后的治疗作用提供基础。方法选用杂种犬24只,结扎冠状动脉左前降支中远1/3处,分3组分别于30min、60min、90min后松开。应用MPA-2000生物信号分析系统,在结扎前后及松开后连续动态记录ECGII导联QRS波群的变化。结果在开始结扎阻断冠状动脉血流时,QRS主波向上Rs型;重新开放血流血管再通之初,83.3%(20/24)的犬QRS波表现为主波向下rS型或QS型,伴QRS波增宽,然后r波波幅逐渐增大,逐渐演变成主波向上的Rs型,QRS时程恢复正常。15min、30min和大于30min的演变率分别为25.00%(6/24)、41.7%(10/24)和16.7%(4/24);且演变率与冠脉阻断时间相关。结论犬心肌缺血再灌注后ECG变化有一定规律,QRS波群变化趋势有可能作为心肌细胞功能恢复程度以及心肌保护效果较为直观的判断指标。     

右室间隔部起搏患者起搏QRS 波时限与心功能的关系

目的:探讨右室间隔部起搏患者起搏QRS波时限与心功能的关系。方法:回顾性分析植入右室间隔部起搏的双腔起搏器患者(111例),起搏器平均植入时间(4.52±3.65)年,通过常规体表心电图测得完全起搏时QRS波时限分为四组:A组为QRS≤120ms(21例);B组为120ms180ms(26例),行心脏彩色多普勒检查获取左房内径(LAD)、收缩末期左室内径(LVESD)、舒张末期左室内径(LVEDD)、室间隔厚度(IVST)、左室后壁厚度(LVPWT)及LVEF,同时检测患者的血清氨基末端脑肭肽前体(NT-proBNP),分析起搏QRS波时限与以上各指标的关系。结果:D组患者LAD、LVEDD、LVESD、IVST及IVPWT较其他三组明显增大,同时LVEF显著下降,NT-proBNP明显升高,有统计学意义(P<0.05)。同时发现随起搏QRS时限的不断增宽,不同组别的LVEF是依次降低(中位值分别为66.5%、60.3%、52.7%和45.8%),而血清NT-proBNP水平是依次增大(中位值分别为143.7 pg/ml、261.8 pg/ml、599.4 pg/m和971.2 pg/ml)。直线相关性分析示起搏QRS波时限与LAD(r=0.141,P<0.05)、LVEDd(r=0.678,P<0.05)、LVEDs(r=0.439,P<0.05)、IVST(r=0.165,P<0.05)及LVPWT(r=0.189,P<0.05)有显著线性关系,呈正相关。起搏QRS波时限与LVEF负相关(r=-0.684,P<0.05),起搏QRS波时限与NT-proBNP的对数正相关(r=0.368,P=0.029)。结论:对于右室间隔部起搏的双腔起搏患者,起搏QRS波时限是一个可初步判断心脏结构和功能的指标,其起搏QRS波时限延长可能会恶化患者的心脏结构及功能,可结合NT-proBNP进行动态观察,对起搏器植入患者的心功能恶化和心衰的预防有一定的临床实用价值。     

基于独立元分析和联合小波熵检测多导联ECG信号的QRS

QRS波群的准确定位是ECG信号自动分析的基础。为提高QRS检测率,提出一种基于独立元分析（ICA）和联合小波熵（CWS）检测多导联ECG信号QRS的算法。ICA算法从滤波后的多导联ECG信号中分离出对应心室活动的独立元;然后对各独立元进行连续小波变换（CWT）,重构小波系数的相空间,结合相空间中的QRS信息对独立元排序;最后检测排序后独立元的CWS得到QRS信息。实验对St.Petersburg12导联心率失常数据库及64导联犬心外膜数据库测试,比较本文算法与单导联QRS检测算法和双导联QRS检测算法的性能。结果表明,该文算法的性能最好,检测准确率分别为99.98%和100%。     

Response to atrial overdrive pacing during narrow QRS tachycardia. What is the mechanism?

A 35-year old lady with no pre-excitation on surface electrocardiogram underwent EP study for recurrent palpitation and documented adenosine responsive narrow QRS tachycardia. Regular narrow QRS tachycardia was induced with critical AH delay on programmed atrial stimulation. An atrial overdrive pacing (AOD) was performed during the tachycardia (Fig: 1 & 2). What is the response to AOD and what is the mechanism of tachycardia?     

Asynchronisme cardiaque chez le sujet à QRS fin. Étude par échocardiographie Doppler tissulaire

ObjectiveTo assess the prevalence of different types of cardiac dyssynchrony by pulsed Doppler ultrasound and Doppler tissue in patients with narrow QRS with or without left ventricular systolic dysfunction.MethodologyProspective, cross-sectional survey at the Institute of Cardiology of Abidjan, from January to April 2012, in subjects with narrow QRS. Group 1: patients with dilated cardiomyopathy with severe left ventricular dysfunction (left ventricular end diastolic diameter greater than 60 mm and/or 30 mm/m² and ejection fraction less than 35% NYHA stage IV). Group 2: normal subjects with normal echocardiography. All patients underwent an evaluation including tissue Doppler search for different types of dyssynchrony (atrioventricular, interventricular and left intraventricular).ResultsPatients in group 1 were significantly older (51.5 ± 15.8 vs. 35.8 ± 7.8, P = 0.03), with larger left ventricular diameters and significantly higher pulmonary systolic pressure. The prevalence of different types of dyssynchrony in group 1 were: atrioventricular dyssynchrony 43.7%, interventricular dyssynchrony 37.5%, left ventricular dyssynchrony 65.6%. Group 2: atrioventricular dyssynchrony 0%, interventricular dyssynchrony 0%, left ventricular dyssynchrony 35%.ConclusionA large proportion of patients with left ventricular systolic dysfunction and narrow QRS have cardiac dyssynchrony and left ventricular dyssynchrony can be found in healthy patients. This raises the problem of the specificity of Doppler ultrasound criteria using cardiac tissue Doppler to assess cardiac dyssynchrony.