老年人急性心肌梗死QT离散度变化的临床意义

目的 观察老年急性心肌梗死（ＡＭＩ）患者溶栓前后ＱＴ离散度（ＱＴｄ）的变化，分析其与室性心律失常的关系。方法 测量４０例老年ＡＭＩ患者的ＱＴ间期，计算其ＱＴｄ及校正后的ＱＴ离散度（ＱＴｄ）。结果 （１）ＡＭＩ组ＱＴｄ及ＱＴｄｃ大于１００ｍｓ患者中，室性心动过速（室速）、心室颤动（室颤）发生率明显高于ＱＴｄ、ＱＴｄｃ小于１００ｍｓ者（７３．０％及６．８％，Ｐ〈０．００１）。（２）溶栓再通组溶栓后ＱＴ     

急性心肌梗死患者校正QT离散度长期随访

自１９８５年Ｃｏｍｐｂｌｅ等发现ＱＴ离散度（ＱＴ ｄｉｓｐｅｒｓｉｏｎ，ＱＴｄ）以来，有关ＱＴｄ的研究大量出现，包括急性心肌梗死（ａｃｕｔｅ ｍｙｏｃａｒｄｉａｌ ｉｎｆａｒｃｔｉｏｎ，ＡＭＩ）急性期ＱＴｄ的研究。但ＡＭＩ后数月甚至数年后ＱＴｄ的演变则少有报道。本组追踪观察６４例ＡＭＩ患者急性期至发病后３年内ＱＴｄ的变化规律。 资料和方法 选取ＡＭ患者６４例，男性４７例，女性１７例，平均年龄（６３．７７±１１．１５岁）岁。再随机选取３０例其他类型冠心病患者作为对照组，男性２１例，女性９例，平均年龄（…     

老年人急性心肌梗死QT离散度变化的探讨

目的观察老年急性心肌梗死(AMI)病人溶栓前后QT离散度(QTd)的变化,分析其与室性心律失常的关系。方法测量40例老年AMI病人的QT间期,计算其QTd及校正后的QT离散度(QTdc)。结果QTd及QTdc>100ms病人中,室性心动过速、心室颤动发生率明显高于QTd、QTdc<100ms者(72.7%及6.9%,P<0.001)。溶栓再通组溶栓后QTd及QTdc分别为51.2ms±21.4ms及62.8ms±21.9ms,较溶栓前缩短(分别为77.4ms±21.1ms及90.0ms±30.6ms,P<0.05)。结论老年AMI病人QTd、QTdc延长者,室性心动过速及心室颤动发生率增高,溶栓后QTd及QTdc缩短提示溶栓后血管再通。     

急性心肌梗死恢复期介入治疗对QT离散度的影响

目的探讨急性心肌梗死(AMI)恢复期(2～4周)介入治疗对QT离散度(QTd)的影响。方法选定76例AMI恢复期患者,对照分析行经皮冠状动脉腔内成形术(PTCA)及冠状动脉内支架置入术术前1d和术后1h的标准12导联同步心电图,测量QTd及校正的QT离散度(QTcd),并与53例同期行冠状动脉造影结果正常者(对照组)进行比较。结果AMI组介入治疗术前最大QT间期(QTmax)、最大校正QT间期(QTcmax)、QTd及QTcd均较对照组明显增大,差异具有统计学意义(P<0.01);介入手术后QTmax、QTcmax、QTd及QTcd比术前明显降低,差异具有统计学意义(P<0.01)。而单独进行冠脉造影对QT离散度无明显影响。结论AMI患者QTd和QTcd明显高于正常人,而AMI恢复期介入治疗可使QTd和QTcd显著降低,从而降低急性心肌梗死后恶性心律失常和心源性猝死的发生率,改善AMI患者的预后。     

血管紧张素转换酶抑制剂对心肌梗塞后QT间期离散度的影响

QT间期离散度对急性心肌梗塞的预后具有重要价值 ,血管紧张素转换酶抑制剂 (ACEI)对缺血心肌具有保护作用 ,但ACEI是否影响QT间期离散度 ?本文将 12 0例患急性心肌梗塞的病人分为服用ACEI组和对照组 ,在服药前后分别测定QT间期离散度并统计在观察期间再次心梗的发生率。结果服用ACEI组QT间期离散度明显下降 (P <0 0 1) ,再次心梗的发生率也下降 (P <0 0 5)。急性心肌梗塞后服用ACEI可降低QT间期离散度和再次心梗的发生率。     

急性心肌梗塞患者福辛普利干预前后校正QT间期离散度的变化

目的 :探讨急性心肌梗塞 (AMI)患者福辛普利 (fosinopril)干预前后校正 QT间期离散度 (QTcd)的变化。　　方法 :46例 AMI患者分基础治疗 福辛普利 10 mg/ d治疗组 (A组 ,2 3例 )和基础治疗组 (B组 ,2 3例 ) ,并对治疗前和治疗 7天后的 QTcd进行对比分析。另设正常人组 2 0例 (C组 )作对照。　　结果 :A组、B组患者 QTcd较 C组明显增加 (P<0 .0 1) ,在 46例 AMI患者中伴室性心律失常者 (n=30 )高于无室性心律失常者 (n=16 ,P<0 .0 1) ,前壁心肌梗塞 (n=31)与下后壁心肌梗塞 (n=15 )间 QTcd差异无显著性 (P>0 .0 5 )。治疗 7天后 A、B两组的 QTcd均较治疗前明显降低 (P均 <0 .0 1) ,但 A组较 B组下降更为显著 ,两组间有显著性差异 (P<0 .0 1)。　　结论 :AMI患者早期 QTcd增加 ,并且与室性心律失常的发生有关 ,福辛普利可降低 AMI早期 QTcd。本结果对改善 AMI近期预后有重要意义。     

急性心肌梗死患者QT离散度的临床意义

通过对健康人和急性心肌梗死 (AMI)患者 QT离散度(QTd)特点的研究 ,探讨该项指标对预测心肌缺血所致危险心律失常事件发生的临床应用价值。1　对象和方法　 1999～ 2 0 0 1年我院心内科收治的 5 2例首次患 AMI的患者。诊断符合 1979年世界卫生组织诊断标准并符合下列条件 :1无明显心脏扩大 ;2无电解质紊乱 ;3无束枝传导阻滞 ;4未应用潜在影响 QT间期的抗心律失常药物。正常对照组选用 5 0例性别、年龄相匹配的健康人 ,无心血管病症状与体征 ,无服用心血管药物史。入院后首次记录QT间期的常规 12导联同步心电图 ,同一医师首先测出每一…     

50例老年急性心肌梗死QT离散度改变的临床分析

急性心肌梗死（ＡＭＩ）是老年人的常见病，其早期死亡原因多为心室颤动（简称室颤）。新近的研究表明，室颤的发生与患者体表心电图ＱＴ离散度（ＱＴｃｄ）的增加有关。本文测定了５０例老年ＡＭＩ患者心电图ＱＴｃ、ＱＴｃｄ的变化，旨在探讨老年人ＡＭＩ后ＱＴｃｄ改变...     

急性心肌梗死QT离散度动态演变的临床意义

业已证实,QT离散度(QTd)对急性心肌梗死(AMI)严重并发症的发生有重要预测价值。但多数研究限于入院1次心电图(ECG)分析,对QTd的动态变化报道甚少。本研究分析了112例AMI不同时间的心电图498份,旨在探讨QTd的动态演变规律和临床意义。 1 资料与方法 AMI住院患者112例,男80人,女32人,平均年龄(68.08±11.03)岁。死亡25人,生存87人。按梗死部位分:前     

老年人急性心肌梗死再灌注前后QT离散度的改变

目的 :观察 QT间期离散度 （QTd）在老年急性心肌梗死 （AMI）再通前后的变化。方法 :测量和计算 16 5例老年 AMI患者及 40例正常老年人 QT间期、QTd和校正后 QTd（QTdc）。结果 :老年 AMI患者 QTdc显著长于对照组 （P<0 .0 1） ;AMI患者发生室性心律失常及死亡者的 QTdc明显长于未发生者 （P<0 .0 5 ） ;溶栓或 PTCA术后QTdc显著降低 （P<0 .0 1）。结论 :QTdc与心肌梗死严重性间存在一定相关性 ,QTdc可以作为观察早期溶栓和PTCA术是否成功的间接指标     

The D-allele of the ACE polymorphism is related to increased QT dispersion in 609 patients after myocardial infarction.

AIMS: Prolongation of QT dispersion can be observed in some patients with myocardial infarction and serves as a possible independent risk factor for sudden cardiac death. Angiotensin-converting enzyme (ACE) inhibition has been shown to reduce QT dispersion in myocardial infarction patients. We hypothesized that ACE gene I/D polymorphism, which is known to modulate ACE activity, may also affect QT dispersion after myocardial infarction. METHODS AND RESULTS: We studied 609 myocardial infarction patients (532 men, aged 56.1+/-0.3; mean 5.5 years after myocardial infarction) from a population-based myocardial infarction register by standardized questionnaire, anthropometry, ECG, echocardiography, and genotyping of ACE I/D polymorphism. In addition, 540 unaffected siblings (251 men, age 54.6+/-0.4 years) of these patients were studied by the same protocol. As compared with their healthy siblings, mean QT dispersion was prolonged in myocardial infarction patients (65.9+/-1.4 ms vs 91.2+/-2.3 ms, respectively, P<0.001). QT dispersion was negatively correlated to left ventricular ejection fraction (P<0.005). The ACE DD-genotype was associated with longer QT dispersion in myocardial infarction patients (103.0+/-4.6 ms vs 81.9+/-4.5 ms in the II group, P<0.001). This association was noted to be strong in multivariate analyses that included age, gender, ejection fraction, left ventricular end-diastolic diameter, medication, and heart rate. In contrast, no association between the ACE DD-genotype and QT dispersion was detected in healthy siblings of myocardial infarction patients. CONCLUSION: Thus, the ACE D-allele may be associated with increased QT dispersion in patients after myocardial infarction but not in healthy subjects. An interaction of myocardial damage and genetic predisposition that both enhance the activity of the renin angiotensin system may decrease the repolarization homogeneity of the heart.     

急性心肌梗死患者QT离散度临床意义的探讨

目的：探讨急性心肌梗死患者QT间期离散度与恶性室性心律失常发生率的关系.方法：观察64例AMI患者发病24小时内的QT离散度,并观察其与两周内恶性心律失常发生率的关系.结果：急性心肌梗死组QT离散度较对照组增大;发生恶性心律失常的患者QT离散度与未发生者有显著统计学差异.结论：急性心肌梗死患者QT离散度增大对恶性心律失常的发生有预测性.     

体表心电标测测定急性心肌梗死患者QT离散度的探讨

目的 探讨有更大体表取样范围的体表心电标测(BSPM)中反映的QT间期离散度及分布.方法 (1)记录1998年3月至1999年12月间68例急性心肌梗死患者(平均年龄59岁)的96导联体表心电标测图及12导联心电图,分别测定QT间期及QT离散度,并与58名正常对照(平均年龄50岁)进行对比分析.结果 (1)正常人及急性心肌梗死患者BSPM法测得的QT离散度、QT最大值均大于12导心电图值,QT最小值小于12导心电图;(2)正常人BSPM法测得的QTd为(50.6±17.1)ms.最大值多位于左侧胸及偏后部、胸骨上部和右锁骨区,最小值位于胸部偏右下部.急性心肌梗死患者BSPM法测得的QTd为(83.3±28.7)ms,较正常对照组高.QT间期分布发生明显变化,QT间期最大值移至覆盖于心肌梗死部位的体表区域;(3)BSPM法测得QTd的变异系数低于12导心电图.BSPM法区分急性心肌梗死患者与正常人QTd的灵敏度高于12导心电图(分别为81%,58%);特异性分别为91%和90%.结论 12导心电图及BSPM方法均表明急性心肌梗死患者QT离散度增加,BSPM方法较12导心电图能更有效地发现体表QT间期最大、最小值及心室复极的离散,尤其可展示QT间期的空间分布.     

急性心肌梗死心功能与QTd离散度相关性的探讨

目的:探讨急性心肌梗死患者心功能与QT高散度(QTd)的相关性。方法:对于18例伴有不程度心功能不全的急性心肌梗死患者,采用同步12导心电图测量其入院时,入院后第1、2周的QTd,并分析其与心功能的关系。结果:研究对象入院时心功能(Killip)为Ⅱ~Ⅲ级,QTd为87±18.62ms,入院后第1周的QTd为60.76±12.23ms,入院后第2周心功能为Ⅰ级,QTd为42.26±12.31ms;与入院时QTd比较,入院后第1、2周的QTd显著改善(P分别<0.01、<0.001);心功能与QTd呈负相关关系。结论:急性心肌梗死患者心功能与QT离散度呈负相关关系,心功能越差,QTd值越大。     

QT dispersion as a predictor for arrhythmias in patients with acute ST elevation myocardial infarction

Aims and Objectives

To study the effect of Heart Rate Variability (HRV) and QT dispersion (QTd) in patients presenting with Acute ST elevation myocardial infarction (STEMI).

Methods

This is a retrospective study conducted on patients admitted with the diagnosis of acute ST elevation myocardial infarction. In all 100 patients with acute myocardial infarction in one year were subjected to a complete evaluation in terms of history and examination. Besides routine investigations standard 12 lead ECG was evaluated in all cases on admission, after 4 hrs, 24 hrs, 48 hrs and on discharge.

Results

The most common presenting symptoms were chest pain (88%) and dyspnea (50%). Tachycardia was seen in 56% while congestive heart failure was present in 29% patients. Patients who died had a higher QTd in comparison to patients who survived.

Conclusions

Markers of autonomic regulation of heart like QTd provides valuable information about the future course of events in a patient following acute STEMI which can be utilized to plan the future course of management in patients especially predisposed to adverse and catastrophic outcomes.     

Decreases by magnesium of QT dispersion and ventricular arrhythmias in patients with acute myocardial infarction.

AIMS: Magnesium treatment suppresses ventricular arrhythmias in acute myocardial infarction and possibly mortality after infarction, but the underlying mechanisms are inadequately understood. We tested whether the effect of magnesium could be attributed to an influence on the autonomic control of the heart, changes in disturbed repolarization, relief of ischaemia or limitation of myocardial injury. METHODS AND RESULTS: Fifty-nine consecutive patients with acute myocardial infarction were randomized to receive 70 mmol of magnesium (n = 31) infused over 24 h or placebo (n = 26). Occurrence of ventricular arrhythmias and heart rate variability (SD of 5-min mean sinus beat intervals over a 24 h period, SDANN; low frequency/high frequency amplitude ratio, LF/HF ratio), and the number of ischaemic episodes on vectorcardiography were measured from the first day of treatment. QT dispersion corrected for heart rate was measured from the 12-lead ECG. Magnesium decreased the number of hourly ventricular premature beats (P < 0.001) and the number of ventricular tachycardias (P < 0.05). QT dispersion corrected for heart rate was decreased in both measurements at 24 h and 1 week (P < 0.001). SDANN and LF/HF ratio were unchanged. The number of ischaemic episodes on vectorcardiography were equal, and peak creatine kinase MB release did not differ between the groups. In testing the pathophysiological mechanisms, serum magnesium levels after infusion correlated with hourly ventricular premature beats (rs = -0.47; P < 0.01), ventricular tachycardias (rs = -0.26; P < 0.05), and QT dispersion corrected for heart rate (rs = -0.75; P < 0.001), but not with SDANN, LF/HF ratio or peak creatine kinase MB. QT dispersion corrected for heart rate correlated with hourly ventricular premature beats (rs = 0.48; P < 0.001) and ventricular tachycardias (rs = 0.27; P < 0.05). CONCLUSIONS: Magnesium suppresses early ventricular arrhythmias in acute myocardial infarction. The decreased arrhythmicity is related to enhancement of homogeneity in repolarization, but not to attenuation of prevailing ischaemia, improvement of autonomic nervous derangements or myocardial salvage.     

老年急性心肌梗塞QT及JT离散度与室性心律失常的关系

目的观察急性心肌梗塞（AMI）患者早期心电图QT离散度（QTd）及JT离散度（JTd）的变化，以探讨老年AMI患者QTd、JTd与室性心律失常的关系。方法测量老年组AMI患者109例和非老年组AMI患者34例心电图的QT、JT间期，计算其QTd及JTd。结果（1）QTd及JTd在老年组分别为64．77±21．67ms、60．00±22．38ms，非老年组为55．59±11．33ms、49．41±14．99ms，两组比较差异极为显著（P＜0．01）。（2）QTd、JTd在老年组发生室性心律失常分别为78．89±24．24ms、76．00±24．81ms，在非老年组发生室性心律失常分别为60．76±14．41ms、61．54±14．63ms，两组比较差异显著（P＜0．05）。（3）老年组QTd、JTd≥100ms者全部发生恶性室性心律失常，显著高于QTD、JTd＜100ms者（P＜0．01）。结论老年AMI患者QTd、JTd值越大，室性心律失常的发生率越高，QTd、JTd可作为预测室性心律失常发生的一项重要指标。     

急性心肌梗塞早期QT间期离散度、JT间期离散度增加与近期预后的关系

测定１０７例急性心肌梗塞（ＡＭＩ）患者第三心肌梗塞日的ＱＴ间期离散度（ＱＴｄ）和ＪＴ间期离散度（ＪＴｄ）．并以１００例正常人作对照。结果显示：ＡＭＩ组ＱＴｄ、ＪＴｄ较对照组显著增大（均Ｐ＜０．００１）。住院期间死亡组（３Ｏ例）ＱＴｄ与ＪＴｄ较存活组（７７例）明显增大（均Ｐ＜０．００１）。提示以ＱＴｄ、ＪＴｄ增大来评价ＡＭＩ患者的近期预后有一定意义。     

急性心肌梗死患者QT、JT离散度与室性心律失常的关系

目的:探讨急性心肌梗死(AMI)患者QT间期离散度(QTd)、JT间期离散度(JTd)与室性心律失常的关系.方法:测量63例AMI患者首次心电图的QTd及JTd,比较有室性心律失常组与无心律失常组的QTd、JTd.结果:AMI有室性心律失常组QTd及JTd显著高于无室性心律失常组,QTd(112.86±33.84)ms对(54.48±24.43)ms,JTd(101.43±36.34)ms对(41.38±19.22)ms,P<0.01.结论:QTd或JTd增大时发生室性心律失常的可能性增大.