Tp-e间期的研究进展及其在冠心病中的临床应用

Tp-e间期和Tp-e/QT比值是新近提出的可以反映心室跨壁复极离散度(myocardial transmural dispersion of repolarization,TDR)的心电指标,其与恶性室性心律失常发生密切相关.冠心病是导致恶性室性心律失常甚至心源性猝死(sudden cardiac death,SCD)的最常见心脏结构异常,寻找冠心病患者恶性室性心律失常以及SCD的有效预测指标成为近些年临床上的研究重点.     

丹红注射液对兔离体左心室心电图及致心律失常作用

目的 观察丹红注射液(抗凝中药)对兔心脏电活动除极和复极过程的影响.方法 选用冠状动脉灌注兔左心室楔形组织块标本,对标本施加刺激周长(BCL)1000 ms基础刺激,1 h后进行实验;实验组给予丹红注射液;同时,分别以卡托普利和司帕沙星作为阴性对照组和阳性对照组,观察对跨壁心电图QRs复合波时程、QT间期、T波峰值至终点的时程(Tp-e)的影响,以及是否引早期后除极(EAD)和尖端扭转型室速(TdP).结果 丹红注射液对QRS波宽度无明显影响;当给予20、60 mL·L~(-1)时,较阴性对照组QT间期轻度延长(P<0.05),并与相关浓度的卡托普利作用一致;但对Tp-e间期及Tp-e/QT比值均无明显影响(P>0.05),且未诱发EAD或Tdp.结论 丹红注射液在本实验浓度范围内,仍无明显诱发尖端扭转型室速和其他室性心律失常的危险性.     

Tp—e／QT比值和QTd对急性ST段抬高性心肌梗死患者室性心律失常的预测价值

目的 探讨Tp-e/QT比值和QTd对急性ST段抬高性心肌梗死患者（STEMI）经皮冠状动脉介入治疗后的预测价值及对比分析.方法 自2011年1月至2012年3月我院12 h内行PCI者127例作为观察组,其中经急诊PCI实现IRA再通者71例（再通组）;未能实现血管再通治疗者56例（非再通组）.另选取106名健康者作为对照组.测量患者入院时及术后心电图的QT值、Tp-e值,计算QTd.患者室性心律失常采用Lown分级,其中Lown分级=3级者为MVA.分析Tp-e/QT比值和QTd与STEMI患者发生室性心律失常的相关性.结果 观察组患者入院时Tp-e/QT比值、QTd均高于正常组（P〈0.001）;室性心律失常患者的Tp-e/QT比值、QTd均延长,Tp-e/QT比值与室性心律失常的发生显著相关（r=0.3581,P〈0.001）;Tp-e/QT比值降幅与患者性别、年龄、糖尿病、Killip′s分级、LVEF、CK-MB、cTnI均无显著相关性（P〉0.05）,而与急性ST段下降程度呈正相关（r=0.3621,P=0.0001）.52例STEMI患者中MVA组24例,非MVA组28例,与QTd相比,只有Tp-e/QT比值与心率变异性呈负相关（P〈0.05）;再通组中,单支与多支病变患者Tp-e/QT比值、QTd变化均无显著差异（P〉0.05）.结论 STEMI患者与健康者相比,Tp-e/QT比值、QTd均延长,且Tp-e/QT比值更能准确有效地预测冠状动脉介入术后室性心律失常的发生.     

剖宫产时缩宫素对产妇Tp-e和QTc间期的影响

目的 观察和评价脊麻剖宫产时缩宫素对健康产妇Tp-e和QTc间期的影响.方法 ASA分级Ⅰ级择期剖宫产产妇40例,按随机数字表法分为缩宫素静脉推注组(静推组)和缩宫素静脉微泵组(微泵组),每组20例.在胎儿娩出后静推组55～60s静脉单次推注5%葡萄糖5ml+5 U缩宫素,微泵组10 min内静脉匀速泵注完5%葡萄糖20 ml+5 U缩宫素.记录并比较术前与脊麻后1、3、5 min,应用缩宫素后1、3、5、10min的QTc间期、Tp-e间期、平均动脉压(MAP)和心率.结果 静推组在应用缩宫素后1 min较术前心率明显增快[(89±13)次/min比(73±12)次/min],MAP显著降低[(69±12)mm Hg(1 mm Hg=0.133 kPa)比(82±13)mm Hg]和QTc间期明显延长[(426±21)ms比(405±18)ms](P＜0.01);而在应用缩宫素后1、3、5min时Tp-e间期均较术前延长(P＜0.01或＜0.05).结论 单次较大剂量(5 U)缩宫素静脉快速推注可延长健康产妇的QTc和Tp-e间期;而Tp-e间期的延长可能更准确预测室性心律失常的发生.在处理QT间期延长综合征产妇脊麻剖宫产时,缩宫素的使用方式应慎重考虑.

Abstract：

Objective To evaluate the effect of oxytocin on Tp-e and QTc interval during caesarean section under spinal anesthesia in healthy puerperas. Methods Forty ASA Ⅰ puerperas were selected and allocated to receive oxytocin intravenous bolus group (group-IB) or oxytocin continuous infusion group (group-CI) with 20 puerperas in each by random digits table. An intravenous bolus of 5% glucose 5 ml and 5 U oxytocin was administered after delivery a 55-60 s period. A continuous infusion of 5% glucose 5 ml and 5U oxytocin was administered after delivery a 10 min period. Measured the QTc interval,Tp-e interval,mean arterial pressure (MAP) and beart rate ( HR ) pre-operatively, then 1,3 and 5 ain after spinal anesthesia, and at least 1,3,5 and 10 min after oxytocin injection. Results In group-IB:HR was fast 1 min after oxytocin injection compared with pre-operatively [(89 ± 13) beats/min vs. (73 ± 12) beats/min] ,MAP was decreased [(69 ± 12 ) mm Hg ( 1 mm Hg= 0. 133 kPa ) vs. ( 82 ± 13 ) mm Hg] and QTc interval was prolonged [(426 ±21 ) ms vs. (405 ± 18 ) ms] (P ＜ 0.01 ); but Tp-e interval was prolonged 1,3,5 min after oxytocin injection compared with pre-operatively (P ＜ 0.01 or ＜ 0.05 ). Conclusions Single large dose of oxytocin intravenous bolus (5 U) can prolong QTc interval and Tp-e interval in healthy puerperas, and Tp-e interval can exact predict the occurrence of ventricular arrhythmias. The risk-benefit balance of oxytocin bolus during caesarean delivery should be discussed with women with a history of long QT syndrome.     

延迟PCI治疗STEMI患者Tp－ec、Tp－e／QT及心率震荡值的变化及预测价值

目的：探讨急性ST段抬高型心肌梗死（STEMI）患者延迟经皮冠状动脉介入（PCI）治疗前后Tp－ec、Tp－e／QT比值及心率震荡（ HRT）的变化及其对冠状动脉病变支数的预测价值。方法应用心电图及24 h动态心电图记录60例STEMI患者延迟PCI术前及术后心电信息,测算PCI前后Tp－ec、Tpe－／QT比值及HRT[震荡起始（ TO）和震荡斜率（TS）]值,进行对比分析。并通过冠脉造影结果,观察冠状动脉单支病变24例及多支病变36例上述各心电指标的差异。另选取同期56例健康者为对照组。观察入院时STEMI组与对照组上述各心电指标的差异。结果（1）与对照组比较,STEMI组患者Tp－ec、Tp－e／QT比值均明显延长,TO值明显升高,而TS值明显降低（ P ＜0．05）。（2）延迟PCI术后24 h内Tp－ec及Tp－e／QT比值及HRT较术前即可获得明显改善,术后Tp－ec及Tp－e／QT比值均显著下降, TO值明显降低,而TS值明显升高（ P ＜0．05）。（3）多支病变患者Tp－ec、Tp－e／QT比值均较单支病变者明显延长,TO值明显高于单支病变者,而TS值明显低于单支病变者（ P ＜0．05）。结论急性心肌梗死患者Tp－ec、Tp－eQ／T比值明显延长, HRT明显减弱,而延迟 PCI术能明显改善HRT 、缩短Tp－ec及Tp－e／QT比值,降低恶性心律失常及心源性猝死的发生。 Tp－ec、Tp－e／QT比值及HRT可能成为具有前景的预测STEMI患者冠状动脉病变范围、心肌缺血程度及评估PCI术预后的无创心电指标。     

Left ventricular hypertrophy amplifies the QT,and Tp-e intervals and the Tp-e/ QT ratio of left chest ECG

Objective

To evaluate the changes in Tp-e interval (an interval from the peak to the end of the T wave), QT interval and Tp-e/QT ratio of the body surface ECG in patients with left ventricular hypertrophy (LVH).

Methods

The Tp-e interval and QT interval were measured on body surface ECGs in 42 patients without either hypertension or LVH (control group), 41 patients having hypertension but not LVH (non-LVH group), and 38 patients with both hypertension and LVH (LVH group).

Results

The mean corrected QT (QTc) interval, and mean corrected Tp-e[T(p-e)c] interval were significantly longer in the LVH group (0.430±0.021s vs. 0.409±0.019s, p < 0.01; 0.098±0.013s vs. 0.088±0.011s, respectively) than those in the control group. The Tp-e/QT ratio was also amplified in LVH group (0.232±0.028 vs.0.218±0.027) (p < 0.05).

Conclusion

LVH increased the QT interval, Tp-e interval and Tp-e/QT ratio of the body surface ECG.     

冠心病合并2型糖尿病患者Tp-e间期与Tp-e/QT比值的研究

目的探讨2型糖尿病合并冠心病患者QT间期、Tp-e间期和Tp-e/QT检测的临床价值。方法随机选取冠心病合并2型糖尿病50例,分别与年龄、性别与之匹配的体检组、2型糖尿病、冠心病患者各50例进行比较,分别测量四组V4导联QT间期、Tp-e间期、计算Tp-e/QT。结果 (1)冠心病合并2型糖尿病组与体检组对比QT间期、Tp-e间期和Tp-e/QT比值差异有统计学意义(P0.05)。(2)冠心病合并2型糖尿病组与2型糖尿病组、冠心病组对比,Tp-e间期和Tp-e/QT比值均显著高,差异有统计学意义(P0.05)。(3)冠心病合并2型糖尿病组与冠心病组、2型糖尿病组比较,QT间期差异无统计学意义(P0.05)。结论 Tp-e间期与Tp-e/QT比值比QT间期在预测室性心律失常更有价值;Tp-e间期和Tp-e/QT可作为冠心病合并2型糖尿病患者发生恶性心律失常的预测指标。     

Acute effects of electronic cigarette smoking on ventricular repolarization in adults

BackgroundElectronic cigarette (e-cigarette) use is constantly increasing. However, the association between e-cigarette use and ventricular arrhythmia is unknown. Thus, in this study, we aimed to evaluate the markers of ventricular repolarization such as QT interval, corrected QT (QTc), QT dispersion (QTd), peak-to-end interval of the T wave (Tp-e), corrected Tp-e and Tp-e/QT ratios in e-cigarette users.MethodsThe study population consisted 36 e-cigarette users and 40 healthy subjects. Ventricular repolarization parameters were obtained from 12-lead resting electrocardiogram. Ventricular repolarization parameters of the groups were compared.ResultsBasal demographic and laboratory data were similar in both groups. According to the electrocardiographic parameters, the Tp-e interval, corrected Tp-e, and Tp-e/QT ratio were significantly higher in individuals using e-cigarettes than in control subjects [74.9±6.4 milliseconds (ms) vs. 80.1±4.1ms, <0.001; 82.9±7.5 ms vs. 87.8±6.3 ms, p=0.003; 0.20±0.01 vs. 0.21±0.01, p=0.002; respectively].ConclusionThis is the first study to show the disruption of ventricular repolarization properties in e-cigarette users. E-cigarette use in terms of public health leads to augmentation of transmural dispersion of repolarization, which may be potential indicator of ventricular arrhythmogenesis.     

丹参酮注射液对急性冠脉综合征患者Tp-ec、QTd及心功能的疗效观察

目的探讨丹参酮注射液对急性冠脉综合征(ACS)患者Tp-ec、QTd及心功能的影响。方法将106例ACS患者随机分为试验组54例和对照组52例,对照组采取常规治疗方法,试验组在常规治疗基础上给予丹参酮注射液静脉滴注治疗。观察2组治疗前后Tp-ec、QTd及心功能的变化。结果 2组治疗后Tp-ec、QTd及心功能较治疗前有所改善,且试验组较对照组改善明显,差异均有统计学意义(P<0.05)。试验组恶性心律失常发生率显著低于对照组,差异有统计学意义(P<0.05)。结论丹参酮注射液可明显改善ACS患者的Tp-ec、QTd及心功能。