程序电刺激时心室复极离散度的研究

了解程序电刺激 (PES)时心室复极离散度的变化 ,探讨PES诱发室性快速心律失常 (VTA)的可能机制。采用单相动作电位 (MAP)标测技术测定 10例无器质性心脏病的阵发性室上性心动过速患者接受PES时的心室复极离散度。结果 :S1 S1 刺激 ( 5 0 0ms)时的动作电位时程 (APD)的离散度 (APDd)与窦性心律时无明显差异 ( 34± 10msvs38± 9ms ,P >0 .0 5 )。随S1 S2 间期缩短 ,各标测点S2 的APD逐渐缩短 ,且与S1 S2 间期呈正相关 ,但激动时间 (AT)及其离散度 (ATd)、APDd、复极时间离散度 (RTd)逐渐延长 ;S1 S2 间期缩短至有效不应期 (ERP) +30ms后 ,S2 的APDd、RTd大于窦性心律及S1 S1 刺激时 (APDd :5 1± 8msvs 38± 9ms或 34± 10ms,P <0 .0 5 ;RTd :39± 10msvs2 4± 7ms,P<0 .0 5 ) ,但ATd无明显增大。心室内各点有效不应期离散度为 31± 14ms,ERP APD平均为 0 .89± 0 .0 8。认为在无器质性心脏病者PES可使心室复极离散度增大 ,但不增加传导差异 ,不易诱发VTA

The Dispersion of Ventricular Repolarization During Programmed Extra Stimulation in Patients Without Structural Heart Disease.

In order to study the mechanism of ventricular tachyarrhythmia (VTA) genesis during programmed extra stimulation(PES),monophasic action potentials(MAP) were recorded in 10 patients without structural heart disease.Dispersions of repolarization were calculated in condition of sinus rhythm,pacing and PES.Results:Dispersion of action potential duration(APDd) during S 1S 1 pacing(500 ms) was not different from that during sinus rhythm(34±10 ms vs 38±9 ms,P>0.05).Action potential duration (APD) decreased relatively along with S 1S 2 duration shortening and activation time (AT)、dispersion of AT (ATd)、APDd and repolarization time (dispersion RTd) increased gradually.After S 1S 2 duration was less than effective refractory period (ERP)+30 ms,APDd and RTd were larger than that during sinus rhythm or S 1S 1 pacing,but ATd was an exception.The average value of effective refractory period dispersion(ERPd)and ERP/APD were 31±14 ms and 0.89 ±0.08 respectively.We conclude that PES can make repolarization dispersion increase,but dispersion of AT is not increased by means of PES,VTA is not easily developed in normal subjects.Chinese Journal of Cardiac Pacing and Electrophysiology,2000,14(2):79～81] Programmed extra stimulation Ventricular repolarization dispersion Monophasic action potential