心脏再同步治疗对心肌复极离散度的影响

目的观察心室不同位点起搏时心电图上心肌复极标志的变化，了解以双心室起搏技术为核心的心脏再同步治疗（CRT）对心肌复极离散的影响。方法 入选接受CRT植入的患者在起搏器植入后1周内记录12导联心电图，分别将起搏器程控为无起搏、右心室内膜下起搏（RV—EndoP）、左心室外膜起搏（LV—EpiP）及双心室同步起搏（BivP）四种不同状态并记录心电图。阅读不同起搏位点时的QRS时限、QT问期及TP-E时限。QTc用Bazett公式[QTc=实测QT／（RR）1／2]进行矫正。结果基线QYc为（489．2±51．2）ms，而RV—EndoP、LV—EpiP起搏导致QR明显延长[RV-EndoP（537．3±45．7）ms，P〈0．05；LV—EpiP（592．4±60．2）ms，P〈0．001]，而BivP起搏为（491．3±52．7）ms，P〉0．05；基线TP．F（113．8±15．7）ms，RV-EndoP、LV—EpiP均导致TP-E明显延长[RV．EndoP（124．8±24．7）ms，P〈0．05；LV．EpiP（133．3±37．8）ms，P〈0．005]，BivP时TP-E时限为（109．9±17．1）ms，有轻度缩短，但差异没有统计学意义（P〉0．05）。结论左心室外膜起搏可明显延长心肌复极离散指标；双心室同步起搏可减少由单纯左心室外膜起搏引起的复极离散度的增大。

Influence of cardiac resynchronization therapy on myocardial dispersion of repolarization

Objective To investigate the characteristic of electrocardiogram pacingin different sites and the effects of cardiac resynchronization therapy(CRT)on the dispersion of the repolarization.Methods Forty patients with biventricular pacemaker were included in this study.Standard surface ECGs were recorded continuously while the pacemaker was programmed to biventricular pacing,left ventricular(LV)pacing,right ventricular (RV)pacing and no pacing mode.ECG analysis was performed by electrophysiology specialists.The parameters of repelarization dispersion included QRS duration,QT interval and TP.E duration,and OTc interval were corrected for heart rate using Baser formula.Results When baseline QTc duration was(489.2±51.2)ms,RV-EndoP and LV-EpiP pacing induced QTc increase significantly[RV-EndoP(537.3±45.7)ms,P＜0.05;LV-EpiP (592.4±60.2)ms,P＜0.001];when BivP pacing intervals was(491.3±52.7)ms,P＞0.05;when baseline TP.E was(113.8±15.7)ms,RV-EndoP and LV-EpiP caused TP.E prolonging significantly,(RV-EndoP(124.8±24.7)ms,P＜0.05;LV-Epi P(133.3±37.8)ms,P＜0.005];the duration of TP.E was(109.9±17.1)ma for biventricular pacing(P＞0.05).Conclusions Epicardial pacing of left ventricle will increase the myocardial dispersion of repelarization,however,bi-ventricular pacing could avoid such kind increase of dispersion caused by epicardial pacing of left ventricle alone.CRT didn't change ventricular dispersion of reploarization in generally.