心室晚电位

心室晚电位(Ventricular late poten-tials)是与心室某些病变区域存在的缓慢传导有关而延迟除极所出现的舒张期碎裂电活动,因这种晚电位(LPs)通常晚于 QRS 波而出现在 QRS 终了处并延伸至ST 段内,故得名。目前认为 LPs 是预测、预报严重室性心律失常和心脏性猝死的信号。     

心室晚电位

心室晚电位(Ventricule eate potentialVLp)又称迟电位,是指在体表检测时,出现在QRS波终末部份或ST段内的高频低振幅的破碎电活动,Durrer等于1961年首次在狗实验性心肌缺血的心外膜直接记录到VLp,1978年Berbari等采用信号平均技术,即高分辨信息叠加心电图技术,从实验性心肌梗塞(MI)狗和室速病人体表记录到QRS波后有低振幅高频的多形性尖波向ST段内延伸,他称此低振幅电位为VLp。随后的研究证实了从心脏表面记录到的延迟破碎电位和从体表记录到的VLp是相关的,VLp的发现引起了许多学者的关注和研究,目前认为它是预报预测严重心律失常和心源性猝死的信号.     

931例体表心室晚电位检测分析

目的:为探讨心室晚电位(VLP)在正常人及心脏病病人的阳性发病率,以及心室晚电位在合并室性心律失常的临床意义,尤其对猝死的预测价值。方法:931例包括正常心脏组207例及心脏病组724例。二者心室晚电位检测结果进行X~2检验。结果:心脏病组VLP总阳性检出较正常组为高,有显著性差异(P<0.01)。对169例阳性患者治疗后作随访追踪,一年后复查,有47例仍呈阳性,其余转阴性。47例仍呈阳性者为心肌梗塞或伴严重室性心律失常。其中5例猝死。结论:心脏病患者出现室性心律失常与心室晚电位阳性二者有很大的相关性,特别是Last40ms<20uV时,要积极治疗,以防心脏意外事故的发生。     

冠心病心室晚电位与左室功能的关系

目的：观察心室晚电位（ＶＬＰ）、心律失常事件（ＡＥ）与左室功能之间的关系。方法：１４５例冠心病患者均进行信号平均心电图（ＳＡ－ＥＣＧ）检测和２４小时ＨＯＬＴＥＲ监测，同期进行冠状动脉造影和左室造影及随访观察。结果：１１４５例冠心病患者（心绞痛５５例、陈旧性心肌梗死９０例），随访１４１±７１（４－３６）月，发生ＡＥ７例。２ＶＬＰ阳性组左室射血分数（ＬＶＥＦ）显著降低（Ｐ＜００５）。３发生ＡＥ组ＬＶＥＦ显著降低（Ｐ＜００５）。结论：左室功能障碍者ＶＬＰ阳性率高、容易发生ＡＥ。     

老年冠心病患者心室晚电位5年随访观察

老年冠心病患者心室晚电位５年随访观察王卫东徐岩心室晚电位（ＶＬＰ）是出现在ＱＲＳ波终末或ＳＴ段的高频低幅碎裂电位，临床多用来预测冠心病心肌梗死（ＭＩ）的心律失常事件。缺血性心脏病可以发生持续性室速、室颤和猝死，为观察ＶＬＰ检测在预测无ＭＩ病史老年心绞...     

Single-beat analysis of ventricular late potentials in the surface electrocardiogram using the spectrotemporal pattern recognition algorithm in patients with coronary artery disease

Aims Post-infarction risk stratification can be ascertained frombeat-to-beat variations in ventricular late potentials. However,gaining such information by conventional late potential analysisusing signal averaging is still not possible. Methods We therefore developed the spectrotemporal pattern recognitionalgorithm in order to detect beat-to-beat variations in latepotentials. Based on the spectrotemporal pattern recognitionalgorithm two-dimensional correlation function, the typicalspectral pattern of late potentials can be identified in spectrotemporalmaps of single beats, even in the presence of noise. Results Surface electrocardiograms of 385 patients after myocardialinfarction (85 with documented sustained ventricular tachycardia(group 1), 100 with fast, polymorphic ventricular tachycardia(>270 cycles.min^–1) or primary ventricular fibrillation(group 2), 200 without ventricular arrhythmias (group 3) and45 healthy volunteers (group 4), were analysed.The spectrotemporalpattern recognition algorithm detected late potentials in singlebeats in 89% of group 1 patients, in 79% of group 2, in 22%of group 3 and in 4% of normals. The spectrotemporal patternrecognition algorithm measured late potential frequency andextension of late potentials into the ST segment, which wassignificantly different between groups 1 and 2.Beat-to-beatvariations in late potentials, with respect to frequency andextension into the ST segment, were markedly higher in patientswith a history of primary ventricular fibrillation. Conclusion Single-beat analysis using the spectrotemporal pattern recognitionalgorithm may improve risk stratification of patients aftermyocardial infarction, and provides information on patientsprone to ventricular fibrillation.     

Ventricular late potentials in patients with and without inducible sustained ventricular tachycardia: a combined analysis in the time and frequency domain

Time and frequency of signal-averaged electrocardiograms from 51 patients and 19 normal subjects were studied. A new filter device was designed to facilitate the analysis of the complete QRS complex, particularly the high-frequency components. All patients underwent electrical programmed stimulation (EPS) with up to three extra stimuli. In 29 patients, sustained ventricular tachycardia (VT) was inducible (group A), whereas in 22, sustained VT could not be elicited (group B). Between A and B, we compared several variables from the signal-averaged ECG as well as clinical data. The variables that differed between the two groups (P less than 0.01) were entered into a logistic regression model to determine which ones could most reliably predict the outcome of EPS. A combination of three variables (number of minima and maxima in the terminal QRS; third of four areas of equal length, divided by the total area below the QRS; maximum of the frequency spectre in the terminal QRS) could predict the inducibility of sustained VT with 82.8% sensitivity and 86.4% specificity.     

心肌再灌注对犬心室晚电位的影响

对犬进行冠状动脉二期结扎,建立心肌梗死模型,应用心表组合电极标测心室晚电位,观察再灌注对其影响。结果发现:心室晚电位阳性再灌犬,晚电位100％转阴。未灌犬无一例转阴。心室晚电位阳性再灌犬恶性心律失常发生率与晚电位阴性再灌犬相比,无显著差异。提示1.再灌注是使心室晚电位转阴的可靠方法;2.心室晚电位与再灌注心律失常无关;3.对急性心肌梗塞后心室晚电位阳性者,应积极进行心肌再灌注治疗。     

冠心病持续性室性心动过速患者的Q—T离散度

为评价Q-T_d对冠心病患者发生室性心动过速的预测价值,观察18例冠心病持续性室性心动过速患者和20例对照组的Q-T_d。结果显示持续型室性心动过速组Q_(Td)(104±28ms)明显大于对照组(61±19ms,P<0.01)。表明Q-T_d的增加可作为预测室性心动过速发生的重要指标。     

Prevalence of ventricular late potentials in patients with obstructive sleep apnea syndrome

BACKGROUND: It is known from various cardiac disorders that the presence of ventricular late potentials (VLP) in the signal-averaged electrocardiogram (ECG) is associated with an increased risk of sudden cardiac death. HYPOTHESIS: In view of the increased cardiovascular mortality of patients with obstructive sleep apnea syndrome (OSAS), we assessed the prevalence of VLP in these patients. METHODS: In all, 118 consecutive patients with polysomnographically verified OSAS were prospectively studied; 21 snorers without evidence of a sleep-related breathing disorder served as a control group. Signal-averaged ECG and 24-h Holter ECG were performed in all patients and controls, and left ventricular function was determined by radionuclide ventriculography in the OSAS group. Furthermore, patients and controls were followed for up to 45.5 months for arrhythmic events, syncopes, or sudden cardiac death. RESULTS: An abnormal signal-averaged ECG was seen in seven patients (5.9%) and in one snorer (4.8%). Patients with and without VLP did not differ with respect to age, body mass index, left ventricular ejection fraction, or ectopic activity in the 24-h Holter ECG, but the former had significantly higher mean (standard deviation) apnea/hypopnea indices [55.4 (25.2)/h vs. 37.4 (22.6)/h; p < 0.05]. Of the 118 patients, 110 could be followed for 26.7 (7.9) months. During this period, two patients had syncopes and one patient had sudden cardiac death. The seven patients with VLP remained free of events during the follow-up period, as did the 21 snorers. CONCLUSIONS: Patients with OSAS have a low prevalence of VLP in the signal-averaged ECG, not exceeding that in normal subjects. Moreover, abnormal signal-averaged ECGs do not appear to be useful as a prognostic marker.     

心肌缺血致室性心动过速的发生机制探讨

对冠心病患者心肌缺血（ＭＩ）时伴室性心动过速的１９例病人（Ｉ组）与无室速的４６例病人（Ⅱ组）进行对比分析。结果显示：２组每天ＭＩ总阵次和总时间有非常显著性差异（Ｐ均〈０．０１），Ｉ组全程持续性ＭＩ高于Ⅱ组（Ｐ〈０．０５）；Ｉ组中伴室速发作的ＭＩ持续时间、最大ＳＴ段压低幅度高于无室速的ＭＩ（Ｐ均〈０．０１）；Ｉ组心室晚电位阳性及３级以上室早总发生率均明显高于Ⅱ组（Ｐ均〈０．０１）。提示冠心病患者ＭＩ     

Day to day variations in morphology and duration of fragmented ventricular potentials during the late post-myocardial infarction phase in conscious dogs

The relationship between the inducibility of ventricular tachyarrhythmiasand the presence of fractionated epicardial ventricular electrograms(‘late potentials’) was studied daily between days3 and 8 after experimental myocardial infarction in 15 consciousdogs. Before each programmed stimulation, epicardial infarctzone electrograms were recorded from implanted ‘composite’electrodes during sinus rhythm. There was considerable dailyvariation in the morphology and duration of delayed ventricularactivation, but no significant difference in duration of infarctzone electrograms was seen between studies resulting in ventricularfibrillation (108±62ms, mean±SD), sustained ventriculartachycardia (87±18ms), nonsustained (94 ±41 ms)or no tachycardia (78±5 ms). Although fractionated ventricularelectrograms were commonly recorded early after infarction,their presence and duration could not predict the inducibilityof malignant ventricular tachyarrythmias. Similar limitationsmay apply in clinical practice to the use of surface signalaveraging of ventricular late potentials in the early post-myocardialinfarction period.     

冠心病患者左室功能与心律失常事件关系的研究

目的 研究冠心病患者左室功能、心室晚电位与心律失常事件之间关系。方法 随机选择200例确诊为冠心病患者,进行左室功能、心室晚电位和24小时动态心电图检测及随访观察。结果 冠心病患者左室功能、心室晚电位与心律失常事件之间有非常密切关系。结论 冠心病患者进行左室功能及心室晚电位检测,对预测心律失常事件的发生有重要临床价值。     

Early and late potentials in postinfarction patients.

Injury within the myocardium may cause disturbances of the intraventricular conduction and may be manifested by altered spectrum of the QRS complex. The purpose of this report is to indicate the existence of microvolt early waves appearing at the beginning of the QRS complex in some postinfarction patients with low ejection fraction. The method used incorporated the high resolution ECG recording, where the "pyramid" electrode location was applied. Results indicated a relationship between high frequency potentials, QRS duration time, and ejection fraction, as well as dependence between ventricular tachycardia/fibrillation (VT/VF) occurrence and early and/or late ventricular activity. In patients with secondary VT/VF where early and late potentials were found, the ejection fraction (EF) was the lowest (26 +/- 15%). Early waves appeared more often in patients with secondary VT/VF (30%) compared with those with primary VT/VF (8%). In patients without VT/VF and without myocardial infarction (MI) early potentials were not remarked. In those patients late potentials also appeared less often. It could be concluded that existence of early potentials, late activity, and significant prolonged total ventricular activation time is associated with wide dispersion and nonuniform delay of the electrical activity within the myocardium as well as with serious lowering of the ejection fraction. Therefore, existence of early waves seems to be a significant diagnostic factor for the poor hemodynamic condition as well as a serious warning for the recurrent late ventricular tachycardia/fibrillation.