无创心电学指标预测猝死的价值_曲秀芬.ppt

曲 秀 芬 哈尔滨医科大学附属第一医院,无创心电学指标预测猝死的价值,猝死,弗拉明翰前瞻性研究,心律失常,非心律失常,VT 62%,Bradycardia 17%,Torsades de Pointes 13%,Primary VF 8%,心律失常猝死的基本原因,？,无创心电学技术,心性猝死,Heart Rhythm. 2008;5(10):e1-21. Circulation. 2008;118(14):1497-1518.,AHA/ACC/HRS Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death,综合各项无创技术的检测能力,BRS,LVEF,ECG,AECG,Exercise test,无创技术,预测心性猝死的无创技术,预测心性猝死的无创技术,左室射血分数 以心电图为基础的技术 QRS 宽度 QT 间期, QT 离散度， QT间期变异性 信号平均 心电图 短程心率变异性 压力感受器敏感性,以长程动态心电图为基础的技术 室早和非持续性室性心动过速 心率变异性（长程和短程） 心率震荡 运动试验/功能状态为基础的技术 运动能力 和 NYHA分级 运动后心率恢复和 恢复期室性早搏 微伏极T波交替,预测心性猝死的无创技术,以心电图为基础的技术,ECG- QRS波宽度,室内或室间传导延 迟或阻滞的简单指标,测定心室激动时 间的简单方法,重复性较好, 变异率 5%,ECG- QRS 波宽度,QRS波宽度 120 ms, 左束支传导阻滞,SCD预测指标,QRS波宽度 120 ms 是ICD治疗获益重要的预测指标,1. 心室激动的非同步可以抑制心脏功能 2.心室激动的缓慢传导及其相关的心室复极离散度增加可直接激发室性心律失常.,ECG- QRS 波宽度,机 制,一定数量的资料表明QRS波增宽时, SCD的风险增高,但有些资料并不一致。,不推荐QRS波时限增宽用于心衰患者SCD的危险 分层。,ECG- QRS 波宽度,ECG- QT 间期和 QT 离散度,QT 间期代表心室动作电位的时程,2.QT 间期测量结果的重复性好,3.QT 间期测量受测量导联和QRS波增宽的影响,1.QT 间期延长:QT 间期 440 ms,QT 离散度是体表心电图 QT 间期的最大差值,CAMP指南认为其基础值4060ms，100ms以上或超过基础值1倍，认为是危险信号。,Padmanabhan S等观察2265例左室射血分数低于40%患者中发现，QT 间期延长的患者死亡率高.,注意 有心性猝死的患者并没有长QT综合症.,ECG- QT 间期和 QT 离散度,Am Heart J. 2003;145:132138.,Gang Y等观察有症状心衰患者，发现QT 间期延长无预后价值。,Pacing Clin Electrophysiol. 2003;26:394400,QT 间期变异性是QT/R-R间期的比值变化,Chevalier P等长期随访观察结果表明，心肌梗死后心性猝死和死亡率与QT 间期变异性增加有关.,ECG-QT 间期变异性,J Cardiovasc Electrophysiol. 2003;14:227233.,QT 间期变异性阴性预测价值较低,Prog Cardiovasc Dis. 2000;42:359 384.,QT 间期延长、QT 离散度大和QT间期变异性增加是心室肌去极化不稳定的指标，与自发室速、室颤、SCD风险的增加有关。,机 制,ECG- QT 间期和 QT 离散度,部分资料认为心脏复极异常和SCD的增加有关,尚不能用QT间期、QT离散度、QT间期变异性对SCD进行危险分层,ECG- QT 间期和 QT 离散度,ECG- 信号平均心电图,心室晚电位是指QRS波结束后的低幅信号，经减少噪声的信号平均技术可提高增益的放大和滤波作用，并在体表心电图的记录中显示晚电位。,心室晚电位有三个时域指标: QRS 波时限 低幅信号时限 QRS波终末40 ms 电压的均方根,.,中等的重复性,机 制,ECG- 心室晚电位,心梗后，梗死或瘢痕区心室肌激动传导延迟，使QRS波后持续存在低幅的电活动，其与碎裂电位有关，并能成为折返的基质，与室速、室颤的发生相关。,ECG- 心室晚电位,心室晚电位不适用或少用于有左和右束支传导阻滞病人,Savard P等在一个大型的研究中发现：心肌梗死后患者 QRS 波时限延长(114 to 120 ms)和预后相关性最强. 低幅信号时限和QRS波终末40 ms 电压的均方根与心肌梗死心律失常事件不相关。,Circulation. 1997;96:202213,ECG- 心室晚电位,预测猝死或心律失常事件的灵敏度为30% -76% 但阴性预测值高，特异度超过95%。,ECG- 心室晚电位,大量结果显示晚电位可识别心梗后SCD的高危患者，阴性预测值高，识别低危患者非常有效。,常规使用晚电位识别SCD高危患者的证据尚不充分。,ECG- 短程心率变异性（HRV）,记录自主呼吸或屏气时2, 5或8 min的心电图 进而评估HRV,评价指标: 1.自主呼吸时，低频与高频乘方的比值减小 2.屏气时， RR间期标准差 15 ms 3.低频乘方减小等为高危指标,ECG- 短程 HRV,正常人的重复性为中等 心衰患者可重复性差,ECG- 短程 HRV,机 制,短程HRV的分析能推测自主神经对心脏，尤其静息状态下的影响，这些影响在室速、室颤的病理生理发生中能起重要作用,ECG- 短程 HRV,La Rovere MT和同事在慢性心衰患者研究中发现 自主呼吸或屏气时8分钟静息心电图记录中低频与 高频乘方的比值减小、RR间期标准差 15 ms、 低频乘方减小是心律失常性死亡的独立预测因子。,Circulation. 2003;107:565570.,Ann Noninvasive Electrocardiol. 2004;9:113120.,Kuch B等研究发现短程HRV与心律失常性事件无关,ECG- 短程 HRV,但不推荐应用短程HRV行SCD的危险分层,少数资料表明明短程HRV异常与猝死相关,长程动态记录心电图 (Holter),室性心律失常 (室早和非持续性室性心动过速) 长程心率变异性分析 心率震荡,Holter -室早和非持续性室速,指标: 室早10次/小时 非持续性室性心动过速,Holter记录室早和非持续性室性心动过速频数的重复性差 室早和非阵发性室速的自然变异率可高达70%,机 制,自发的室早,非阵发性室速与室速,室颤的发生有关,Holter -室早和非持续性室速,研究证实，Holter记录室早和非持续性室性心动过速的出现是心性猝死的危险因素。,Holter -室早和非持续性室速,早在20世纪70至 80年代, 许多观察性研究证实有心肌梗死病史的病人， AECG记录有室早（室早10次/小时）和非持续性室性心动过速是死亡的危险因素。,Denes P等研究表明室早10次/小时并没有进一步增加死亡率的危险,缺血性心脏疾病,Circulation. 1984;69:250 258,Am J Cardiol. 1991;68:887896,缺血性心脏疾病,GISSI-2研究表明, MI病人中，有室早10次/小时的6个月时死亡率为 5.5% ；少发室早的6个月时死亡率为 2%。,EMIAT研究, 伴有 LVEF40% MI病人中, AECG有频发或复杂室性心律失常的病人与没有频发或复杂室性心律失常的病人相比，死亡率明显增加（20% versus 10%）。,Circulation. 1993;87:312322.,Lancet. 1997;349:667 674.,心梗后室早预测的阳性值5% -15% ,阴性预测值90%;,缺血性心脏疾病预测价值,室早是死亡率增加的独立的预测指标 非持续性室性心动过速不是死亡率增加的独立的预测指标,非缺血性心肌病,有分级较高的室早和非持续性室性心动过速的心肌病病人心性猝死危险性增加。,非持续性室性心动过速和成对室早是死亡率的独立预测因子,Am J Cardiol. 1983;51:507512,Circulation. 1996;94:31983203.,非持续性室性心动过速对心性猝死和全因死亡率的敏感性为 31%-71% 阳性预测价值低，为 20%- 50% 阴性预测价值高，达72% 93%,NSVT的预测价值,大量资料显示,心梗伴心衰患者的室早和非持续性室速和猝死的风险有相关性。,因此,心梗伴心衰患者应用Holter监测为IIb类推荐,应用Holter室早和非持续性室性心动过速进行SCD的危险分层尚不完全明确,Holter -室早和非持续性室速,J Am Coll Cardiol. 1999;34:912948,长程HRV的三种测量方法,Holter - 长程心率变异性（ HRV）,机 制,HRV反映自主神经对心脏的功能及电生理活动 的调节，而多种疾病包括心血管与非心血管疾 病的病理生理均与自主神经功能异常有关，决 定了HRV分析广泛应用于临床研究，包括生理 过程和病理生理过程的研究。,Holter - 长程 HRV,Holter - 长程 HRV,应用 HRV 在不同群体研究，来预测心律失常,心性猝死, 或全因死亡。,贫血 风湿免疫 精神心理 等疾病,HRV 是总体死亡率和心性猝死死亡率的预测指标 且对总体死亡率预测价值更大,大量研究报道， 时域和频域 HRV降低的病人死亡率增加 且频域指标预测死亡等同于时域指标,Holter - 长程 HRV,大量资料表明HRV降低是总死亡率增加的预测因子,预测非心律失常引起的死亡更有价值,HRV 在SCD危险分层中的价值还需进一步确定,HRV的预测价值,Holter - 心率震荡（HRT）,窦性心律震荡是室早后窦性周期的短期波动,指标,心率震荡-,TO (震荡起始) 0为阳性, 0为阴性; TS (震荡斜率) 2. 5 mm / s为阴性, 2. 5 mm / s为阳性,机制,机制不清。推测这一指标可衡量迷走神经的反应性，即室早后可引起动脉血压的轻微变化，进而引起反射性迷走神经的激活而使TO、TS指标变。,心率震荡-,主要应用于心肌梗死后研究,也用于非缺血性扩张型心肌病、慢性心衰、肥厚型心肌病和血管重建治疗的病人等研究，HRT也具有SCD预测价值,Holter - 心率震荡,测量值降低时SCD 的相对危险度增加,是一个有吸引力的危险分层指标，但需进一步明确其在危险分层中的价值,HRT的预测价值,运动试验/功能状态- 运动后心率恢复和 恢复期室性早搏,测量运动试验停止后3060 s的心率下降值,或1 min内12次/分为异常， 或2 min内22次/分为异常， 或卧位状态18次/分为异常,在运动后最初5min 内出现的频发或严重的室性早搏为异常,心衰时交感神经过度激活，迷走神经张力的下降和死亡风险的增加有关，并使运动后心率恢复减慢。,运动后心率恢复和恢复期的室早-机制,运动后心率恢复和恢复期的室早,1 min内，心率下降12次/分时和全因死亡率的增加显著相关，阳性预测值19% ，阴性预测值95%。,在运动后最初5min 内出现的频发或严重的室性 早搏和死亡风险有关,是预测死亡的新指标,但在SCD危险分层中的价值尚未证实,运动后心率恢复和恢复期的室早,运动试验/功能状态 - T 波电交替,1994年, Rosenbaum 等首次谈及 T波电交替和增加的严重心律失常危险有关。晚近可通过Holter技术检测。,T 波电交替,T波电交替是单个细胞水平去极化交替的的反应 。 当心率增快并超过心肌细胞转运细胞内钙离子的能力时则可诱发。,异常T波电交替 ：心率 110次/分则出现1. 9V的交替为阳性,微伏级T波电交替,机制,T 波电交替-,目前认为，局部心肌由钙稳态的异常导致动作电位的振荡，与邻近细胞动作电位的复极，在空间向量上显著离散，出现波形的碎裂和易于折返，临床与实验均证明心肌缺血出现室律失常与动作电位的异常密切相关。,ANE2007;12(2):98-105,重复性中等, T波电交替的重复性为 65% -75%, 甚至高达80% -90%,微伏极T波电交替预测心性猝死和主要恶性心律失常事件可以和电生理检查相姘美。,T波电交替用于评价病人ICD获益程度，是一个较好的指标，优越于QRS 波宽度。,T 波电交替,T波电交替对死亡风险和恶性心律失常事件预测能力等同或优于其它无创指标, 如LVEF、 电生理检查、 信号平均心电图、压力感受器敏感性和HRV,T 波电交替,T波电交替是SCD的危险因素,一定数量的资料提示T波电交替对SCD的危险分层有益，但需要有更多研究,T 波电交替,小 结,无 创 心 电 学 指 标,传导延迟,心室复极不均衡,自主神经张力失衡,室性异位激动,QRS波宽度、晚电位,心率变异性、窦性心律震荡 运动后心率恢复,QT间期、QT离散 度、T波电交替,室早、非持续室速,Thanks!,Xiufen Qu The 1st Affiliated Hospital of Harbin Medical University,The Value of Non-invasive Electrocardiological Markers in the Predication of Sudden Death,Sudden Death,Framinghan prospective study,Arrhythmia,Non-Arrhythmia,VT 62%,Bradycardia 17%,Torsades de Pointes 13%,Primary VF 8%,Underlying Arrhythmia of Sudden Death,？,Non-invasive Electrocardiology Techniques,SCD,Heart Rhythm. 2008;5(10):e1-21. Circulation. 2008;118(14):1497-1518.,AHA/ACC/HRS Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death,The spectrum of noninvasive methods were reviewed in this statement.,BRS,LVEF,ECG,AECG,Exercise test,Noninvasive Techniques,Noninvasive Techniques for Sudden Cardiac Death,Noninvasive Techniques to Identify the “At Risk” Patient Prior to the Event,Ejection fraction ECG based techniques QRS duration QT interval, QT dispersion, QT-interval variability Signal averaged ECG Short-term heart rate variability Baroreceptor sensitivity,Noninvasive Techniques to Identify the “At Risk” Patient Prior to the Event,Long-term ambulatory ECG (Holter) based techniques Ventricular ectopy and nonsustained VT Long-term HRV Heart rate turbulence Exercise test/functional status based techniques Exercise capacity and NYHA class Heart rate recovery and recovery ventricular ectopy Microvolt T wave alternans,Electrocardiogram based techniques,ECG- QRS duration,a manifestation of intraventricular or interventricular conduction delay or block,a simple measure of the duration of ventricular activation measured on the 12-lead ECG,highly reproducible, a coefficient of variation 5%,ECG- QRS duration,QRS duration 120 ms, left bundle-branch block,indicators for poor outcome,QRS duration 120 ms was an important indicator of which patients were likely to benefit from ICD therapy.,1. Dyssynchronous ventricular activation may cause depression of cardiac function. 2. Slow conduction and the associated increase in dispersion of ventricular recovery directly promote ventricular arrhythmias.,ECG- QRS duration,Mechanism,A moderate amount of data show that increased QRS duration identifies patients at higher risk for SCD. the data are not uniform.,The use of QRS duration to further risk-stratify patients with CHF for SCD is not recommended.,ECG- QRS duration,ECG- QT interval and QT dispersion,The QT interval is a reflection of the summed ventricular action potential durations.,2. highly reproducible,3. influenced factors the leads available for analysis and QRS prolongation,1.QT prolongation:QT interval 440 ms,QT dispersion is the maximal difference between QT intervals in the surface ECG.,CAMP Guidelines: The based value of 40 60ms, 100ms or more, or more than one times the based value are danger signals.,ECG- QT interval and QT dispersion,Padmanabhan S et,al. found QT prolongation has been associated with mortality in patients with depressed left ventricular function.,Individuals with SCD risk do not have long-QT syndrome.,Am Heart J. 2003;145:132138.,Pacing Clin Electrophysiol. 2003;26:394400,Gang Y et,al. found QT dispersion has no prognostic value in patients with symptomatic heart failure.,ECG- QT-interval variability,QT-interval variability is the relation of QT/R-Rinterval.,Chevalier P et,al. observed QT dynamicity and sudden death after myocardial infarction: results of a long-term follow-up study.,J Cardiovasc Electrophysiol. 2003;14:227233.,Prog Cardiovasc Dis. 2000;42:359 384.,A poor negative predictive value,ECG- QT interval and QT dispersion,QT interval, QT dispersion and QT-interval variability have been suggested as a marker of repolarization instability that might be linked to arrhythmia susceptibility (VT or VF).,Mechanism,ECG- QT interval and QT dispersion,Some data exist that link abnormalities in QT interval and QT dispersion with an increased risk for SCD.,Further studies are needed to establish whether there is clinical utility of these parameters for risk stratification.,ECG- Signal averaged ECG (SAECG),Ventricular Late potentials refer to low-amplitude signals that occur after the end of the QRS complex.,Three time-domain measures of late potentials: QRS duration, low-amplitude signal duration, and root meansquare voltage of the terminal 40 ms of the QRS,.,The Late potentials is moderately reproducible.,Mechanism,Reentrant circuits haved been found,involved intramural pathways located at the infarct border zone, with delayed conduction in the midmyocardium or subendocardium constituting a critical part of the circuit in patients with healed infarction .,ECG- Ventricular Late Potentials,The Ventricular Late potentials is either not useful or less useful in patients with right and left bundle-branch blocks.,Savard P et,al. observed prolonged filtered QRS duration (114 to 120 ms) appears to be the most robust measure correlated with outcome; low-amplitude signal duration and root meansquare voltage of the terminal 40 ms of the QRS are not associated with arrhythmic events in a large post-MI study.,ECG- Ventricular Late Potentials,Circulation. 1997;96:202213,ECG- Ventricular Late Potentials,For the predication of SCD or arrhythmic events, the sensitiviy of Ventricular Late Potentials has been reported to vary from 30% to 76%, but the negative predicative value is high, and the specificity is more than 95%.,Abundant data show that an abnormal late potentials may identify patients with prior MI at risk for SCD.,Routine use of the SAECG to identify patients at high risk for SCD is not adequately supported.,ECG- Ventricular Late Potentials,ECG- short-term HRV,Recored 2, 5 or 8 min ECG during spontaneous or controlled breathing,and evaluated HRV.,Evaluated indices: 1.Ratio of low frequency power to high frequency power during spontaneous breathing 2.a standard deviation of RR intervals 15 ms during controlled breathing 3.lower frequency power,ECG- short-term HRV,Short-term HRV has moderate reproducibility in normal subjects; But, it is less reproducible in patients with congestive heart failure.,ECG- short-term HRV,Mechanism,HRV provides a surrogate for the autonomic effects in the ventricle that are postulated to be important in the pathogenesis of VT and VF.,ECG- short-term HRV,Circulation. 2003;107:565570.,Ann Noninvasive Electrocardiol. 2004;9:113120.,La Rovere MT and co-workers found a diminished ratio of low- to high-frequency power during spontaneous breathing, a standard deviation of R-R intervals 15 ms, and diminished low-frequency power during controlled breathing were univariate predictors of arrhythmic mortality.,Kuch Bet,al. did not find a relation of short-term HRV to arrhythmic events.,ECG- short-term HRV,At the present time, its use for risk stratification for SCD is not recommended.,Limited data link impaired short-term HRV to sudden death.,Long-term Ambulatory Recording ECG (Holter),ventricular arrhythmias (VPBs and NSVT) HRV heart rate turbulence,Evaluated indices: VPBs10 beats per hour NSVT,Holter - VPBs and NSVT,The reproducibility of the frequency of VPBs and NSVT is poor.,Holter - VPBs and NSVT,Mechanism,The presence of VPBs and NSVTis associated with VT and VF.,Holter - VPBs and NSVT,The presence of VPBs and NSVT on Holter monitoring is a well-demonstrated risk factor for SCD.,In the 1970s and 1980s, observational studies demonstrated that VPBs (generally 10 or more VPBs per hour) and NSVT as recorded by an AECG in post-MI patients were risk factors for subsequent mortality.,Data suggest that ectopy beyond 10 VPBs perhour does not convey a further increase in risk.,Ischemic cardiac disease,Circulation. 1984;69:250 258,Am J Cardiol. 1991;68:887896,GISSI-2 study, mortality was 5.5% at 6 months for patients with MI with 10 VPBs per hour compared with 2% in those with less frequent ectopy.,Ischemic cardiac disease,EMIAT study, among postinfarction patients with LVEF 40%, mortality was higher in patients with frequent or complex arrhythmias on AECG than in those without (20% versus 10%).,Circulation. 1993;87:312322.,Lancet. 1997;349:667 674.,The positive predictive value of ventricular ectopy after MI for predicting cardiac arrhythmic events or death generally ranges from 5% to 15%, with a negative predictive value of 90% or more.,The predictive value,VPBs are an independent predictor of mortality. NSVT may not be a predictor of mortality.,Nonischemic cardiomyopathy,Patients with increased risk of SCD frequently have high-grade ventricular ectopy and NSVT.,NSVT and ventricular couplets were independent predictors of mortality.,Am J Cardiol. 1983;51:507512,Circulation. 1996;94:31983203.,The sensitivity of NSVT in relationship to SCD or total death varies among several studies, ranging from 31% to 71%. The positive predictive value is low, ranging from 20% to 50%. The negative predictive value has been cited as 72% to 93%.,The predictive value of NSVT,Holter - VPBs and NSVT,There is abundant information linking the detection of VPBs and NSVT on Holter in post-MI patients with left ventricular dysfunction for risk assessment for SD.,Use of the Holter in this setting has been classified as a class IIb recommendation.,The utility of Holter for risk stratification in this population remains unclear.,J Am Coll Cardiol. 1999;34:912948,Three groups of techniques have been used to quantitatively examine HRV from long-term AECG recordings.,Holter - long-term HRV,The time-domain indices,The frequency-domain indices,nonlinear methods,linear methods,triangular index,Mechanism,There is a pathophysiological link among abnormal HRV, autonomic tone, and arrhythmogenesis.,pathophysiological link,abnormal HRV,arrhythmogenesis,autonomic tone,HRV reflects the autonomic nervous system on cardiac function and its electrophysiological activity regulation. while a variety of diseases , including cardiovascular and non-cardiovascular disease , their pathophysiology are related to autonomic nervous system dysfunction. At present, the HRV analysis is widely used in clinical research, including the physical and pathophysiological processes research.,Holter - long-term HRV,Holter - long-term HRV,The ability of HRV to predict arrhythmic, cardiac, or total mortality has been studied in a variety of different populations.,Respiratory,Kidney disease,Anesthesia,Endocrine disease,HRV application,CAD,Anemia, Rheumatic immune, Psychological disease and so on,HRV was a better predictor of total mortality than of SCD mortality.,A number of studies have reported an increased mortality in patients with low time- and frequency-domain measures of HRV. The ability of frequency-domain measures to predict mortality appears approximately equivalent to that of time-domain measures.,Holter - long-term HRV,Abundant data show that depressed HRV is a predictor of total mortality.,HRV may be a better marker of nonarrhythmic mortality in the present data.,Further studies are needed to establish whether HRV has a role in risk stratification for SCD.,The predictive value of HRV,The short-term fluctuation in sinus cycle length that follows a VPB.,Holter - Heart rate turbulence (HRT),indices,HRT-,TO (turbulence onset) 0 (positive), 0 (negative); TS (turbulence slope) 2. 5 mm / s (positive), 2. 5 mm / s (negative);,Mechanism,After a premature beat and a compensatory pause, there is a typical increase in blood pressure due to the prolonged filling in the cycle of the compensatory pause. Reflex parasympathetic activation ensues and slows the heart rate.,HRT-,Heart rate turbulence has been examined primarily in post-MI patients.,A smaller number of studies of patients with nonischemic dilated cardiomyopathy, chronic congestive heart failure, or hypertrophic cardiomyopathy (HCM) and patients undergoing revascularization have also suggested a predictive value of heart rate turbulence.,HRT,Abnormal heart rate turbulence is associated with increased mortality.,Further studies are needed to establish whether there is clinical utility of this parameter for risk stratification.,The predictive value of HRT,Exercise Test/Functional Status - Heart rate recovery and recovery ventricular ectopy,Immediately after graded exercise, heart rate normally falls with an initial rapid decline occurring during the first 30 seconds to 1