急性心肌梗死患者T波電交替及竇性心率震蕩的特征及臨床意義

趙淑琴,黃曉青，朱莉,張煒,任莉娜，齊國(guó)先

(1.中國(guó)醫(yī)學(xué)科學(xué)院阜外醫(yī)院，北京 100037；2.中國(guó)醫(yī)科大學(xué)附屬第一醫(yī)院老年心內(nèi)科)

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·論著·

急性心肌梗死患者T波電交替及竇性心率震蕩的特征及臨床意義

趙淑琴1,黃曉青1，朱莉1,張煒1,任莉娜2，齊國(guó)先2

(1.中國(guó)醫(yī)學(xué)科學(xué)院阜外醫(yī)院，北京 100037；2.中國(guó)醫(yī)科大學(xué)附屬第一醫(yī)院老年心內(nèi)科)

[摘要]目的研究心肌梗死及心肌梗死合并糖尿病患者T波電交替(TWA)和竇性心率震蕩(HRT)的特征及其臨床意義。方法選取149例患者，其中心肌梗死 (MI) 57例，心肌梗死合并糖尿病(MI+DM)52例，對(duì)照組40例。給予動(dòng)態(tài)心電圖檢查,應(yīng)用時(shí)域分析法和漸量修正技術(shù)分析TWA值，以及HRT的兩個(gè)參數(shù)：震蕩初始(TO)、震蕩斜率(TS)。分析：①三組患者TWA、TO及TS均值的比較；TWA陽(yáng)性率的比較；②心肌梗死患者復(fù)合心臟事件(室速/室顫、心臟性死亡)的發(fā)生率。結(jié)果 ①M(fèi)I組和MI+DM組患者TWA均值及TWA的陽(yáng)性率明顯高于對(duì)照組 (P<0.01)，MI+DM組患者TWA的陽(yáng)性率高于MI組，但TWA均值差異無(wú)統(tǒng)計(jì)學(xué)意義；②MI+DM組室速/室顫發(fā)生率高于MI組(P<0.05)，MI+DM組心臟性死亡患者2例；③心肌梗死患者的震蕩初始(TO)較對(duì)照組增加(P<0.05)，而震蕩斜率(TS)則減低(P<0.01)。結(jié)論心肌梗死患者TWA值增加，HRT的兩個(gè)參數(shù)-TS減弱而TO增加。TWA和HRT可能為評(píng)價(jià)心肌梗死患者發(fā)生惡性心律失常及心臟性猝死的有用指標(biāo)。

[關(guān)鍵詞]心肌梗死；心律失常；心震蕩；猝死,心臟；心電描記術(shù)，便攜式

急性心肌梗死(AMI)是嚴(yán)重危害人類(lèi)健康的一種疾病，其發(fā)病率和死亡率較高，尤其是發(fā)生猝死的危險(xiǎn)性較高，預(yù)后較差，因此如何識(shí)別猝死的高危患者以給予相應(yīng)的預(yù)防和治療措施，是臨床工作者比較關(guān)注的熱點(diǎn)。人們一直在積極探索有效的評(píng)估心肌梗死預(yù)后的預(yù)測(cè)因子。目前T波電交替和心率震蕩的研究表明，T波電交替(TWA)和竇性心率震蕩(HRT)是預(yù)測(cè)惡性心律失常和心臟性猝死的有效指標(biāo)。我們團(tuán)隊(duì)?wèi)?yīng)用時(shí)域分析法和漸量修正技術(shù)分析動(dòng)態(tài)心電圖的TWA和HRT，探討AMI以及合并糖尿病患者的這兩項(xiàng)指標(biāo)的臨床特征及其意義。

1對(duì)象與方法

1.1研究對(duì)象急性心肌梗死組:選取2015年2月至8月在我院心血管內(nèi)科住院治療的心肌梗死患者57例；男35例,女22例；年齡36～75歲，平均(60±10)歲。心肌梗死伴糖尿病組共52例患者；男32例,女20例；年齡36～75歲，平均(60±10)歲。AMI的診斷標(biāo)準(zhǔn):典型的臨床表現(xiàn)；心電圖的動(dòng)態(tài)演變過(guò)程；心肌酶升高及肌鈣蛋白陽(yáng)性。2型糖尿病患者診斷標(biāo)準(zhǔn)：(1)糖化血紅蛋白≥6.5%，(2)空腹血糖FPG≥7.0 mmol/L。在心肌梗死后7～14 d進(jìn)行動(dòng)態(tài)心電圖檢查，非竇性心律；無(wú)室性期前收縮；房室傳導(dǎo)阻滯；嚴(yán)重肝腎功能不全；惡性腫瘤等合并其他嚴(yán)重疾病者被排除。對(duì)照組:同期在本院體檢的年齡、性別相匹配的身體健康者40例；男22例,女18例；年齡42～74歲，平均(63±9)歲。三組入選者在接受動(dòng)態(tài)心電圖1周內(nèi)，沒(méi)有服用(他受體阻滯劑等影響心律的藥物；在年齡、性別等基線資料方面差異無(wú)統(tǒng)計(jì)學(xué)意義，具有可比性。

1.2研究方法入選的病例接受動(dòng)態(tài)心電圖記錄,通過(guò)人機(jī)對(duì)話去除干擾、偽差，采用時(shí)域分析法和漸量修正技術(shù)計(jì)算TWA值(TWA≥47 μV為陽(yáng)性)[1-2],分析系統(tǒng)自動(dòng)篩選出符合條件的室性期前收縮，計(jì)算震蕩初始(TO)和震蕩斜率(TS)。TO≥0%為異常,TS≤2.5 ms/RR為異常。①比較三組患者TWA值；分析心肌梗死組和心肌梗死合并糖尿病組復(fù)合心臟事件[室性心律失常(包括室性心動(dòng)過(guò)速、心室顫動(dòng))及猝死]的發(fā)生率；②比較震蕩初始(TO)及震蕩斜率(TS)的均值差異無(wú)統(tǒng)計(jì)學(xué)意義。

1.3統(tǒng)計(jì)學(xué)處理采用SPSS17.0統(tǒng)計(jì)軟件進(jìn)行數(shù)據(jù)處理,計(jì)數(shù)資料采用χ2檢驗(yàn),組間比較用單因素方差分析,復(fù)合心臟事件比較采用Fisher檢驗(yàn)。P<0.05為差異有統(tǒng)計(jì)學(xué)意義。

2結(jié)果

2.1三組患者TWA值比較MI組[(57.82±17.80)μV]、MI+T2DM組[(60.19±17.09)μV]與對(duì)照組[(36.07±10.42)μV]比較，均差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。2.2三組患者TWA(≥47 μV)陽(yáng)性率的比較MI組[39例(68.4%)]、MI+T2DM組[36例(69.2%)]與對(duì)照組[2例(5%)]比較，均差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。

2.3心肌梗死和心肌梗死合并糖尿病患者復(fù)合心臟事件發(fā)生率的比較MI+T2DM組室性心律失常(VT/VF)發(fā)生率(15.4%)高于MI組(1.8%)，差異有統(tǒng)計(jì)學(xué)意義(P<0.05)；MI+T2DM組心臟性猝死(SCD)發(fā)生例數(shù)(2例)高于MI組(0例)，但差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。

2.4 三組患者心率震蕩參數(shù)-TO、TS均值比較 MI組、MI+T2DM組TS均值[(5.25±5.32)ms/RR、(5.05±4.97)ms/RR]與對(duì)照組[(12.52±5.16)ms/RR]比較，差異有統(tǒng)計(jì)學(xué)意義(P<0.05)；MI組、MI+T2DM組TO均值[(-0.71±2.22)%、(-0.97±3.25)%]與對(duì)照組[(-2.18±1.88)%]比較，差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。

3討論

TWA是指在心律規(guī)整時(shí)，體表心電圖上T波形態(tài)、極性和振幅的逐搏交替變化。TWA代表心室肌細(xì)胞復(fù)極化的不一致性，是產(chǎn)生折返的基礎(chǔ)[3-5]。T波電交替可由運(yùn)動(dòng)試驗(yàn)、心房起搏或除顫式心電描記術(shù)誘發(fā)，用于鑒別發(fā)生致死性心律失常或心臟性猝死(SCD)的高危人群[6-10]。近來(lái)TWA被推薦作為預(yù)測(cè)心律失常危險(xiǎn)分層的I級(jí)證據(jù)[11]。然而，傳統(tǒng)的TWA頻域分析方法結(jié)果不直觀、患者心率必須維持在一定范圍內(nèi)才能使用、需專(zhuān)用檢查設(shè)備及方法、價(jià)格昂貴等，因而頻域法TWA的無(wú)法廣發(fā)推廣應(yīng)用。近年來(lái)隨著漸量修正技術(shù)的產(chǎn)生和應(yīng)用，使時(shí)域法分析TWA應(yīng)用范圍得到擴(kuò)展。REFINE研究發(fā)現(xiàn)，動(dòng)態(tài)心電圖-TWA較運(yùn)動(dòng)試驗(yàn)-TWA預(yù)測(cè)心臟終點(diǎn)事件的作用更加顯著[12]。EPHESUS研究提示TWA≥47 μV時(shí)發(fā)生SCD的風(fēng)險(xiǎn)較小于47 μV時(shí)增加5.5倍，進(jìn)一步證實(shí)了動(dòng)態(tài)心電圖-TWA對(duì)心肌梗死后心力衰竭患者發(fā)生惡性心臟事件的預(yù)測(cè)價(jià)值[13]。本研究采用時(shí)域分析法和漸量修正技術(shù)分析動(dòng)態(tài)心電圖-TWA，結(jié)果提示急性心肌梗死患者以及心肌梗死合并糖尿病患者的TWA值明顯高于健康對(duì)照者。

目前大部分的研究表明，室性早搏后心臟無(wú)效收縮引起的血流動(dòng)力學(xué)變化是導(dǎo)致HRT產(chǎn)生的機(jī)制。HRT有兩個(gè)時(shí)項(xiàng):TO、TS，分別代表了竇性周期早期加速過(guò)程和相繼的后期減速過(guò)程。根據(jù)Schmidt等[14]給出的公式：

TO=100×[(RR1+RR2)-(RR-2+RR-1)]/(RR-2+RR-1),心率震蕩用于心肌梗死危險(xiǎn)分層的評(píng)估[15]。本研究表明心肌梗死患者與對(duì)照組比較，HRT變鈍、TS減弱而TO增加。迷走神經(jīng)具有抗心律失常作用，本研究結(jié)果表明這種保護(hù)性作用被破壞。糖尿病是臨床上的常見(jiàn)病和多發(fā)病，是心血管系統(tǒng)疾病的危險(xiǎn)因素，冠心病所致的死亡約占糖尿病患者死亡的75%。有研究表明糖尿病能夠增加SCD的發(fā)生風(fēng)險(xiǎn)[16]。我們推測(cè)心肌缺血后，心肌細(xì)胞結(jié)構(gòu)、功能均受到不同程度損傷，心肌細(xì)胞復(fù)極化不協(xié)調(diào)，心室肌電活動(dòng)更加不穩(wěn)定，容易發(fā)生惡性室性心律失常，病死率增加。

綜上所述，TWA與心率變異性、心室晚電位等一些心電學(xué)指標(biāo)一樣，在臨床上的應(yīng)用越來(lái)越普遍。尤其對(duì)于缺血性心臟病、心肌病等患者發(fā)生惡性心律失常以及心臟性猝死的預(yù)測(cè)作用越來(lái)越引起大家的重視。但TWA的應(yīng)用也有一定的局限性，且與相關(guān)疾病的預(yù)警價(jià)值以及確切的作用機(jī)制等，還需要進(jìn)一步的研究和探討。

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作者簡(jiǎn)介：趙淑琴，助理研究員,Email:junqin8731@163.com

中圖分類(lèi)號(hào):R542.22

文獻(xiàn)標(biāo)識(shí)碼:A

DOI:10.3969/J.issn.1672-6790.2016.03.016

(收稿日期：2016-04-10)

The clinical manifestation and characteristic of ambulatory ecg-based t-wave alternans and heart rate turbulence in patients with acute myocardial infarction

ZhaoShuqin*,HuangXiaoqing,ZhuLi,ZhangWei,RenLi'na,QiGuoxian

(*FuwaiHospital,CAMS&PUMC，Beijing100037,China)

[Abstract]ObjectiveTo explored the characteristic and clinical manifestation in patients with ischemic heart diseases according to T-wave alternans (TWA) using modified moving average (MMA) method and heart rate turbulence (HRT).MethodsA analysis of 149 patients who underwent MMA-based TWA and HRT divided into 3 groups: group-C of 40 controls,group-MI of 57 patients with myocardial infarction,52 patients with MI with diabetes(group-MI+DM).The TWA was calculated automatically using time-domain modified moving average method.Group-MI was divided into two subgroups: HRT abnormal subgroup and HRT normal subgroup and the accidence of cardiac events of inhospitalization was observed in the two subgroups.ResultThe TWA value was differ significantly between MI and controls (P<0.001).Among MI with diabetes,the accidence of ventricular tachyarrhythmia is higher than MI.Impaired HRT were observed most frequently in group- MI (P<0.05),especially the decrease of the HRT onset slope (TS) (P<0.05).ConclusionT-wave alternans is elevated in patients following myocardial infarction.Weaken HRT,increased To and decreased TS were observed in myocardial infarction patients.TWA and HRT may be independent predictors of cardiac and arrhythmic death in myocardial infarction patients.

[Key words]Myocardial infarction；Arrhythmia；Commotio cordis；Death,sudden,cardiac;Electrocardiography,ambulatory