摘要
目的研究正常心室肌复极离散度，提供正常参考值，并探讨维持正常心室肌电稳定的机制。方法对19例无器质性心脏病者在左、右心室内膜多点单相动作电位（MAP）标测，测量各标测点窦性心律时的激动时间(AT)、动作电位时程(APD90)、复极时间(RT)、S1S1刺激时的APD（APDS1）、有效不应期(ERP)、ERP/APDS1及各指标的离散度。结果平均AT和APD90明显负相关，相关系数在左、右室分别为 -0.91和-0.94，窦律时的ATd、APDd、RTd分别为(28±8) ms、(40±12) ms、(27±6) ms，均无性别差异(P>0.05)，RTd明显小于APDd（P<0.01）。其中10例接受程序刺激，S1S1刺激（500 ms）时的APDS1d为（34±10） ms与窦律时的APDd（38±9） ms无明显差异（P>0.05），ERPd为（31±14） ms，ERP/APDS1为0.89±0.08，ERP/APDS1d为0.10±0.07。结论单相动作电位标测可较直接反映心室复极过程，正常心室肌存在复极离散度，同时也保持一定的电生理稳定性。
Abstract
Objective Values of the ventricular repolarization dispersion in people with normal heart structure were determined to provide a reference for further studies. The mechanisms of electrophysiological stability in normal ventricle were also discussed. Methods Multipoint endocardium monophasic action potentials (MAP) were recorded in 19 persons without structural heart disease. The activation time (AT), MAP duration at 90% repolarization (APD90) and repolarization time (RT) during sinus rhythm, APD during S1S1 stimulation (APDS1), effective refractory period (ERP) and ERP/APDS1 at every recorded site were measured and their dispersions, defined as the difference between the maximum and minimum of each parameter, were calculated. Results A close negative correlation between the average AT and APD90 was revealed in this normal group (LV:r=-0.91, RV:r=-0.94, P<0.01). Dispersions of AT(ATd), APD(APDd) and RT (RTd) during sinus rhythm were (28±8) ms, (40±12)ms and (27±6) ms, respectively, without any difference between males and females (P>0.05). RTd was significantly less than APDd(P<0.01). APDd during sinus rhythm was not distinctly different from that during S1S1 pacing (APDS1d) in 10 who received programmed stimulation ［(38±9) ms vs (34±10) ms, P>0.05］. Dispersion of ERP(ERPd), ERP/ APDS1 and dispersion of ERP/ APDS1 (ERP/ APDS1d) were (31±14) ms, 0.89±0.08 and 0.10±0.07, respectively. Conclusions MAP mapping is a relatively direct method to assess the myocardial repolarization course. Repolarization dispersion and electrophysiological stability exist in normal ventricular myocardia simultaneously.
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NSTL
维普
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