体表信号叠加心电图对急性心肌梗塞的临床意义探讨

应用体表信号叠加心电图(SAECG)对60例急性心肌梗塞症状出现后第1,3,7,14,30天系列检测心室晚电位(LP)。检出LP阳性17例(28.3％),80％LP在梗塞后1周内开始出现,40％LP呈间歇出现。阳性组频发室性早搏和室性心动过速检出率(35.7％和21.4％)约为阴性组(17.1％和11.4％)之2倍,但无统计学意义。住院期发生心律失常事件8例(13.3％),7例为LP阳性患者。LP预测事件发生的敏感性87.5％(7/8),特异性80.8％(42/52),阳性准确率41.2％(7/17),阴性准确率97.7(42/43)。     

对Brugada综合征患者晚电位的监测

采用信号平均心电图(SAECG)分析22例Brugada综合征和11例正常人的心室晚电位(LP)。结果Brugada综合征Ⅰ型组LP阳性率比Brugada综合征Ⅱ型或Ⅲ型组和正常对照组高,RMS40较对照小,LAS较对照大(P均<0.05)。结论:Brugada综合征Ⅰ型患者晚电位阳性率很高。     

伴有心功能不全的肺心病患者心室晚电位记录的临床价值

本文对48例伴有心功能不全的肺心病(CP)患者进行时域及三维频谱心室晚电位(VLP)记录分析,并以30例正常人作对照.结果表明,时域VLP和三维频谱的阳性检出率CP组明显高于正常组.VLP阳性者高级别的室性心律失常发生率明显高于VLP阴性者(P<0.001).提示VLP阳性对CP患者心脏事件有较好的预测价值.     

溶栓疗法对急性期心肌梗死心室晚电位的影响

为探讨溶栓对急性心肌梗死心室晚电位的影响,观察84例急性心肌梗死患者心室晚电位、室性心律失常及猝死的情况.结果溶栓组(n=47)与非溶栓组(n=37)心室晚电位阳性率分别为15%、35%,室性心律失常发生率分别为13%、32%,死亡率分别为2%、13%,差异均有显著意义(P<0.05).溶栓再通组(n=28)与未再通组(n=19)心室晚电位阳性率分别为7%、26%,室性心律失常发生率分别为4%、26%,差异均有显著意义(P<0.05).提示溶栓治疗能降低心肌梗死患者的心室晚电位附性率、室性心律失常发生率及死亡率.     

原发性高血压左心室肥大伴室性心律失常与心室晚电位关系探讨

为探讨心室晚电位与原发性高血压左心室肥大伴室性心律失常之间的关系,检测66例合并及94例不合并左心室肥大原发性高血压患者的心室晚电位和动态心电图.结果心室晚电位阳性率13.1%,合并或不合并左心室肥大者分别为20.6%和7.6%(P<0.01);室性心律失常检出率为82.3%和38.4%(P<0.01).心室晚电位阳性的左心室肥大伴室性心律失常、复杂室性心律失常及室性心动过速检出率(100%、64.5%、28.5%)均高于心室晚电位阴性的左心室肥大者(76.9%、47.1%、15.4%,P<0.05)及无左心室肥大的心室晚电位阳性者(71.4%、28.6%、14.3%,P<0.05).提示心室晚电位对原发性高血压的室性心律失常,尤其是复杂性室性心律失常有一定预测价值.     

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。     

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。     

心室晚电位预测急性心肌梗死预后10年回顾

目的探讨心室晚电位(LP)对急性心肌梗死(AMI)患者病死率的预测价值。方法对1997年12月至1999年12月因AMI入院连续243例患者的临床资料进行回顾性总结。收集患者的临床特征、梗死血管开通情况、无创心脏检查结果和预后资料等进行统计分析。结果 243例患者男180例(74.1%),年龄37～79岁,平均(62±11.4)岁,接受血运重建治疗的患者146例(60%)。分成LP阳性83例(34%)和LP阴性160例(66%)两组。主要联合终点事件为严重心律失常、心源性猝死和心力衰竭死亡,次要联合终点事件为联合严重心律失常和心源性猝死.在平均随访(10±0.83)年期间,LP阳性与LP刚性两组比较主要终点事件累计发生率[18.1%比11.9%,相对风险比(HR)4.19,95%可信区间(CI)2.50～7.02,P<0.0001]和次要终点事件累计发生率(7.0%比2.1%,HR7.64,95% CI2.02～20.75,P<0.0001)均明显增高;Kaplan-Meier生存曲线分析,无主要终点事件累计生存率LP阳性较LP阴性组明显减低,分别为47.0%和81.9%(P<0.0001)。LP阳性组的生存曲线随时间延续呈明显下降趋势(P<0.0001)。Cox风险比例回归模型多因素分析,评判影响主要终点事件的各因素预测能力,LP阳性的风险度明显强于其他已知风险预测变量,其相对危险性依次为LP阳性(HR 3.57,95% CI 1.87～6.81,P<0.0001)、复杂室性心律失常(HR 2.75,95% CI 1.32～5.71,P=0.007)、左心室射血分数<40%(HR 2.44,95%CI1.25～5.71,P=0.009)、未开通梗死血管(HR 1.95,95% CI 1.05～3.59,P=0.033)、年龄(HR 1.04,95% CI 1.00～1.07,P=0.034)。结论 LP阳性是AMI后不良事件和死亡的独立预测指标。     

心肌梗死患者心室晚电位和QT离散度同时检测的临床意义

目的 探讨心肌梗死患者心室晚电位和QT离散度联合检测的临床意义。方法 对86例急性心肌梗死入院第4周后进行同步描记12导联心电图心室晚电位检测后，随即行QT间期检测，测定QT离散度。比较两组心室晚电位阴性与心室晚电位阳性患者的QTd及心律失常、猝死的相互关系。结果 心室晚电位的阴性及QTd在正常范围内的患者无一例猝死，心室晚电位阴性而QTd异常的心肌梗死患者2例猝死，心室晚电位阳性而QTd在正常范围内的患者3例猝死，心室晚电位阳性且QTd异常的患者13例猝死。结论 心室晚电位与QTd联合检测对心肌梗死患者恶性心律失常及猝死有预测意义。     

心室晚电位、心率变异对急性心肌梗死患者心律失常事件发生的预测价值

目的 了解心率变异(HRV)、心室晚电位(VLP)在预测急性心肌梗死(AMI)预后的价值。方法 40例AMI患者HRV(SDNN)、VLP测定,与40例正常人进行对比分析。结果 AMI组SDNN(87.9±25.07ms)与对照组(13.37±35.96ms)比较明显减低(P<0.001),AMI组VLP阳性(11例)与正常组(1例)比较明显增高(P<0.01)。梗塞患者室性心律失常事件组与非事件组HRV(SDNN)、VLP比较相差显著(P<0.005)。对心律失常事件发生预测方面,HRV特异性为93.55％,相对危险性为10.50,VLP敏感性为44.4％。二者结合特异性、相对危险性增加。结论 二项指标均有独立的预测价值,如同时检测可望提高阳性预测值。     

Assessment of markers for identifying patients at risk for life-threatening arrhythmic events in Brugada syndrome

INTRODUCTION: Risk stratification for life-threatening arrhythmic events in Brugada syndrome is not yet established. The aim of the present study was to examine the usefulness of various markers in predicting life-threatening arrhythmic events in the Brugada syndrome. METHODS AND RESULTS: Forty-six patients with Brugada-type ECGs were categorized into the symptomatic (n=28) and asymptomatic (n=18) groups. Statistical analyses were performed with respect to the usefulness of the following markers: SCN5A mutation, pharmacologic challenge, ventricular fibrillation (VF) inducibility by programmed electrical stimulation, and late potential (LP) by signal-averaged ECG (SAECG). Comparison between the two groups revealed a significant difference only in LP positivity (92.6% vs 47.1%, P=0.0004). The symptomatic group had significantly lower RMS40, longer LAS40, and longer fQRSd compared with the asymptomatic group. A significant difference was noted, especially RMS40. The positive predictive value, negative predictive value, and predictive accuracy when setting a cutoff value of 15 microV were 92.0%, 78.9%, and 86.4%, respectively. Furthermore, patients with an RMS40 value <15 microV (n=25) showed significantly higher rates of VF recurrence compared with patients with an RMS40 value > or = 15 microV (n=19, P=0.047). CONCLUSION: Regarding risk stratification for identifying high-risk patients in Brugada syndrome, only LP by SAECG was shown to be useful, suggesting the importance of RMS40 in predicting the history of life-threatening arrhythmic events and the recurrence of VF.     

Role of signal-averaged electrocardiograms for predicting the inducibility of ventricular fibrillation in the syndrome consisting of right bundle branch block and ST segment elevation in leads V1-V3

Right bundle branch block and ST segment elevation (RBBB-STE) in the right precordial leads have been reported as a distinct clinical and electrocardiographic syndrome in patients prone to ventricular fibrillation (VF) in the absence of structural heart disease (Brugada syndrome). The purpose of the study was to investigate the role of signal averaged electrocardiogram (SAECG) in identifying patients at high risk among asymptomatic RBBB-STE patients. Thirteen patients with the RBBB-STE ECG were identified. Symptoms were: syncope (n=3, cases 1, 3, and 11), atypical chest pain (n=3, cases 4, 10, and 12) and palpitations (n=2, cases 6, and 7). The other 5 patients were asymptomatic. SAECG and programmed electrical stimulation (PES) were conducted in all patients. Body surface late potentials (LPs) were present in 7 of 13 patients before PES. Vf was induced in 6 of 7 LP positive patients. Vf was induced in 3 of 6 LP negative patients, but LP became positive in 2 of 3 patients in whom Vf was induced. One patient with syncope due to VF (case 1), 1 patient without symptoms who died suddenly during follow up (case 2), and 1 asymptomatic patient (case 9) showed reproducibly positive LP. In a patient (case 9) with positive LP at baseline, LP transiently became negative during follow up. In RBBB-STE patients, reproducibly positive LP is at risk for malignant ventricular arrhythmias and sudden death. Repeated SAECG recording may be useful for screening high-risk patients who should receive electrophysiological study among asymptomatic RBBB-STE patients.     

Assessment of noninvasive markers in identifying patients at risk in the Brugada syndrome: insight into risk stratification

OBJECTIVES: The aim of this study was to compare the use of various noninvasive markers for detecting risk of life-threatening arrhythmic events in patients with Brugada syndrome. BACKGROUND: The role of conduction disturbance in arrhythmogenesis of the syndrome is controversial, whereas it is well established that repolarization abnormalities are responsible for arrhythmias. The value of noninvasive markers reflecting conduction or repolarization abnormalities in identifying patients at risk for significant arrhythmias has not been shown. METHODS: We assessed late potentials (LP) using signal-averaged electrocardiography (ECG), microvolt T-wave alternans (TWA), and corrected QT-interval dispersion (QTD) in 44 consecutive patients who had ECGs showing a pattern of right bundle branch block and ST-segment elevation in leads V1 to V3 but structurally normal hearts. The patients were compared with 30 normal individuals. RESULTS: Eleven patients were excluded from data analysis because of an absence of ECG manifestations of Brugada syndrome at the time of the tests. A history of life-threatening events defined as syncope and aborted sudden death was present in 19 of 33 patients (58%); in 15 of the 19 patients, stimulation induced ventricular fibrillation or polymorphic ventricular tachycardia. The LP were present in 24 of 33 patients (73%); TWA were present in 5 of 31 patients (16%); and a QTD >50 ms was present in 9 of 33 patients (27%). The incidence of LP in Brugada patients was significantly (p < 0.0001) higher than in the controls, whereas incidences of TWA and QTD were not significantly different. Multivariate logistic regression analysis revealed that the presence of LP had the most significant correlation to the occurrence of life-threatening events (p = 0.006). CONCLUSIONS: Late potentials are a noninvasive risk stratifier in patients with Brugada syndrome. These results may support the idea that conduction disturbance per se is arrhythmogenic.     

发热诱发Brugada综合征的临床及心电图特征

目的探究发热诱发Brugada综合征的临床及心电图特点。方法选择2000年1月—2019年1月武汉大学人民医院收治Brugada综合征患者112例,根据诱发因素将全部病例分为发热组(34例)和非发热组(78例),比较分析两组临床特点及药物激发试验结果。结果发热组在主要不良心血管事件发生率及家族史比例方面均显著大于非发热组(52.94%vs 29.49%,P=0.018;17.65%vs 3.85%,P=0.036);药物激发试验阳性的发热组患者表现出较发热时更长的QT间期和PR间期[(371.00±43.06)ms vs(327.00±36.89)ms,P=0.015;(187.88±27.41)ms vs(156.75±9.56)ms,P=0.022]。结论发热诱发Brugada综合征存在着相对较高的主要不良心血管事件风险和相关家族史比例,同一患者由发热与药物诱导的Brugada心电图也存在差异,表明发热诱发Brugada综合征具备相对独特的临床和心电图特点。     

Relationship between dominant prolongation of the filtered QRS duration in the right precordial leads and clinical characteristics in Brugada syndrome

Background: Electrical abnormalities in the RVOT may be involved in Brugada syndrome.
Objectives: We investigated the relationship between the signal-averaged ECG (SAECG) and electrophysiologic study (EPS), especially focusing on conduction delay in the outflow tract of the right ventricle (RVOT) and its contribution to clinical characteristics.
Methods: Twenty-four patients with Brugada syndrome (23 men and 1 woman; 61 ± 16 years old) were studied. We assessed the presence of late potential (LP) in SAECG and the filtered QRS duration in the right precordial leads (V₁ or V₂; RfQRS) and in the left precordial leads (V₅ or V₆; LfQRS) and the difference between them. In 18 patients, SAECG was evaluated for an LP on three separate occasions.
Results: SAECG was positive for LP in 15 patients at least once; and in 7 patients, SAECG was positive for an LP on multiple occasions, and 6 of 7 patients (86%) had a history of cardiac arrest. The difference between RfQRS and LfQRS was significantly greater in patients with cardiac arrest than in patients with syncope or in asymptomatic patients; 29 ± 10, 14 ± 11 (P < 0.01), and 7 ± 5 msec (P < 0.001), respectively. All patients were alive and one patient with cardiac arrest had an appropriate VF therapy delivered by the ICD.
Conclusions: The dominant prolongation of the filtered QRS duration in the right precordial leads may be related to the risk of arrhythmic event in Brugada syndrome.     

Acute and chronic management in patients with Brugada syndrome associated with electrical storm of ventricular fibrillation.

BACKGROUND: Some patients with Brugada syndrome experience an electrical storm of ventricular fibrillation (VF). OBJECTIVE: The purpose of this study was to investigate the clinical, laboratory, electrocardiographic, and electrophysiologic characteristics, acute and subsequent chronic treatment, and follow-up data of patients with Brugada syndrome associated with electrical storm of VF. METHODS: Sixty-seven patients with Brugada syndrome (65 men and 2 women, age 46 +/- 14 years) were divided into three groups: 7 patients with a history of electrical storm of VF (group I), 39 symptomatic patients with documented VF and/or syncope (group II), and 21 asymptomatic patients (group III). Electrical storm was defined as three or more episodes of VF per day recorded by the memory of an implantable cardioverter-defibrillator. RESULTS: No significant differences were observed among the three groups with regard to clinical (age at diagnosis, familial history of sudden cardiac death), laboratory (SCN5A mutation and serum potassium level), electrocardiographic and electrophysiologic characteristics, and follow-up duration after diagnosis. However, arrhythmic events during follow-up after diagnosis and number of arrhythmic events per patient were significantly higher in group I compared with groups II and III. Isoproterenol infusion (0.003 +/- 0.003 microg/kg/min for 24 +/- 13 days) completely suppressed electrical storm of VF in all five patients treated and was successfully replaced with oral medications, including denopamine, quinidine, isoproterenol, cilostazol, and bepridil alone or in combination. CONCLUSION: No specifically clinical, laboratory, electrocardiographic, and electrophysiologic characteristics were recognized in patients with Brugada syndrome associated with electrical storm of VF. Isoproterenol infusion was effective as an acute treatment in suppressing electrical storm of VF and was successfully replaced with chronic oral medications.     

Prognostic value of electrophysiologic investigations in Brugada syndrome

INTRODUCTION: The prognostic value of electrophysiologic investigations in individuals with Brugada syndrome is unclear. Previous studies failed to determine its value because of a limited number of patients or lack of events during follow-up. We present data on the prognostic value of electrophysiologic studies in the largest cohort ever collected of patients with Brugada syndrome. METHODS AND RESULTS: Two hundred fifty-two individuals with an ECG diagnostic of Brugada syndrome were studied electrophysiologically. The diagnosis was made because of a classic ECG with a coved-type ST segment elevation in precordial leads V1 to V3. Of the 252 individuals, 116 had previously developed spontaneous symptoms (syncope or aborted sudden cardiac death) and 136 were asymptomatic at the time of diagnosis. A sustained ventricular arrhythmia was induced in 130 patients (51%). Symptomatic patients were more frequently inducible (73%) than asymptomatic individuals (33%) (P = 0.0001). Fifty-two individuals (21%) developed an arrhythmic event during a mean follow-up of 34 +/- 40 months. Inducibility was a powerful predictor of arrhythmic events during follow-up both in symptomatic and asymptomatic individuals. Overall accuracy of programmed ventricular stimulation to predict outcome was 67%. Overall accuracy in asymptomatic individuals was 70.5%, with a 99% negative predictive value. Overall accuracy in symptomatic patients was 62%, with only a 4.5% false-negative rate. No significant differences were found in the duration of the H-V interval during sinus rhythm between symptomatic or asymptomatic individuals. However, the H-V interval was significantly longer in the asymptomatic individuals who became symptomatic during follow-up compared with those who did not develop symptoms (59 +/- 8 msec vs 48 +/- 11 msec, respectively; P = 0.04). CONCLUSION: Inducibility of sustained ventricular arrhythmias is a good predictor of outcome in Brugada syndrome. In asymptomatic individuals, a prolonged H-V interval during sinus rhythm is associated with a higher risk of developing arrhythmic events during follow-up. Symptomatic patients require protective treatment even when they are not inducible. Asymptomatic patients can be reassured if they are noninducible.     

Tpeak-Tend and Tpeak-Tend dispersion as risk factors for ventricular tachycardia/ventricular fibrillation in patients with the Brugada syndrome.

OBJECTIVES: Our objective in this study was to evaluate Tpeak-Tend interval (Tp-e) and other electrocardiographic parameters as risk factors for recurrence of life-threatening cardiac events in patients with the Brugada syndrome (BS). BACKGROUND: The Tp-e interval in the electrocardiogram (ECG) has been reported to predict life-threatening arrhythmias in the long QT syndrome. METHODS: Twenty-nine patients with the ECG pattern of BS and 29 healthy age- and gender-matched controls were studied. The follow-up period was 42.65 +/- 24.42 months (range 11 to 108 months). RESULTS: Upon presentation, five patients had suffered aborted sudden death, five syncope, and two presyncope. Eleven patients with the ECG pattern of BS had a prolonged (>460 ms) QTc in V2 but usually not in inferior or left leads. No patient had abnormally prolonged QT dispersion. Programmed electrical stimulation induced ventricular tachycardia/fibrillation in 5 out of 26 patients. Inducibility did not predict recurrence of events. Cardioverter-defibrillators were implanted in 14 patients (all symptomatic and two asymptomatic). During follow-up, nine symptomatic patients experienced recurrences. Previous cardiac events and a QTc >460 ms in V2 were significant risk factors (p = 0.00002 and p = 0.03, respectively). Tp-e and Tp-e dispersion were significantly prolonged in patients with recurrences versus patients without events (104.4 and 35.6 ms vs. 87.4 and 23.2 ms; p = 0.006 and p = 0.03, respectively) or controls (90.7 and 17.9 ms; p = 0.02 and p = 0.001, respectively). CONCLUSIONS: Our study demonstrates significant correlation between previous events, QTc >460 ms in V2, Tp-e, and Tp-e dispersion and occurrence of life-threatening arrhythmic events, suggesting that these parameters may be useful in risk stratification of patients with the Brugada syndrome.     

Combined assessment of T-wave alternans and late potentials used to predict arrhythmic events after myocardial infarction. A prospective study

OBJECTIVES: The aim of the present study was to determine whether the combination of two markers that reflect depolarization and repolarization abnormalities can predict future arrhythmic events after acute myocardial infarction (MI). BACKGROUND: Although various noninvasive markers have been used to predict arrhythmic events after MI, the positive predictive value of the markers remains low. METHODS: We prospectively assessed T-wave alternans (TWA) and late potentials (LP) by signal-averaged electrocardiogram (ECG) and ejection fraction (EF) in 102 patients with successful determination results after acute MI. The TWA was analyzed using the power-spectral method during supine bicycle exercise testing. No antiarrhythmic drugs were used during the follow-up period. The study end point was the documentation of ventricular arrhythmias. RESULTS: The TWA was present in 50 patients (49%), LP present in 21 patients (21%), and an EF <40% in 28 patients (27%). During a follow-up period of 13 +/- 6 months, symptomatic, sustained ventricular tachycardia or ventricular fibrillation occurred in 15 patients (15%). The event rates were significantly higher in patients with TWA, LP, or an abnormal EF. The sensitivity and the negative predictive value of TWA in predicting arrhythmic events were very high (93% and 98%, respectively), whereas its positive predictive value (28%) was lower than those for LP and EF. The highest positive predictive value (50%) was obtained when TWA and LP were combined. CONCLUSIONS: The combined assessment of TWA and LP was associated with a high positive predictive value for an arrhythmic event after acute MI. Therefore, it could be a useful index to identify patients at high risk of arrhythmic events.