CORRELATION BETWEEN INVIVO TRANSMEMBRANE ACTION-POTENTIAL DURATIONS AND ACTIVATION-RECOVERY INTERVALS FROM ELECTROGRAMS - EFFECTS OF INTERVENTIONS THAT ALTER REPOLARIZATION TIME
CORRELATION BETWEEN INVIVO TRANSMEMBRANE ACTION-POTENTIAL DURATIONS AND ACTIVATION-RECOVERY INTERVALS FROM ELECTROGRAMS - EFFECTS OF INTERVENTIONS THAT ALTER REPOLARIZATION TIME
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DOI：
10.1161/01.cir.81.1.281
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发表时间：
1990-01-01
期刊：
影响因子：
37.8
通讯作者：
LUX, RL
中科院分区：
文献类型：
--
作者：
HAWS, CW;LUX, RL
采用经典的电缆理论分析了单极电图所测得的激动-恢复间期与跨膜动作电位时程之间的关系。理论分析表明，在均匀介质中，细胞外电位的时间导数与跨膜动作电位沿着传播的时间三阶导数的空间权重成正比。因此，被测量为QRS的最小导数（Vmin）的时间与T波的最大导数（Vmax）的时间之间的间隔的激活-恢复间隔应当与被测量为跨膜动作电位的上行的Vmax的时间与下行的Vmin的时间之间的间隔的动作电位持续时间相关。在12只麻醉犬中对这种关系进行了实验研究。在对照状态、心脏交感神经刺激、局部心外膜升温和心肌灌注分级降低期间，从彼此2 mm内的部位同时记录单极电描记图和跨膜动作电位。从几个部位起搏心脏。在心脏交感神经刺激和局部心外膜加温期间进行的激活-恢复间期和动作电位持续时间测量值之间存在密切相关性（对于心脏交感神经刺激和加温，分别为r = 0.96和0.99）。在5只冠状动脉灌注压逐渐降低的动物中，这些变量在62至212 msec的值范围内密切相关（r = 0.98）。然而，尽管总体相关性良好，激活-恢复间期和动作电位时程之间的平均差异较小，但在个别情况下，差异高达24 msec。该研究提供了与理论预测一致的新数据，该理论预测为T波的Vmax ≥的时间与局部动作电位的Vmin ≥的时间相关，并且激活-恢复间隔与动作电位持续时间直接相关。此外，结果提供证据表明，激活恢复间期是独立于T波形、驱动部位或存在局部陡峭复极梯度的动作电位时程的良好估计。
Classic cable theory was used to analyze the relation between the activation-recovery interval measured from unipolar electrograms and transmembrane action potential duration. Theoretic analysis demonstrated that the temporal derivative of the extracellular potential is proportional to a spatial weighting of the third temporal derivative of the transmembrane action potentials along a cable with uniform propagation in a homogeneous medium. Thus, the activation-recovery interval, measured as the interval between times of minimum derivative (.ovrhdot.Vmin) of the QRS and mximum derivative (.ovrhdot.Vmax) of the T wave, should be related to action potential duration, measured as the interval between times of .ovrhdot.Vmax of the upstroke and .ovrhdot.Vmin of the downstroke of the transmembrane action potential. This relation was examined experimentally in 12 anesthetized dogs. Unipolar electrograms and transmembrane action potentials were recorded simultaneously from sites within 2 mm of each other during control states, cardiac sympathetic nerve stimulation, localized epicardial warming, and graded reductions in myocardial perfusion. The heart was paced from several sites. There was close correlation between activation-recovery interval and action potential duration measurements taken during cardiac sympathetic nerve stimulation and local epicardial warming (r = 0.96 and 0.99 for cardiac sympathetic nerve stimulation and warming, respectively). In five animals in which coronary perfusion pressure was gradually lowered, the variables correlated closely over a range of values from 62 to 212 msec (r = 0.98). However, although the overall correlation was good and mean differences between activation-recovery interval and action potential duration were small, in individual cases there were differences up to 24 msec. This study provides new data that are consistent with the theoretic prediction that time of .ovrhdot.Vmax of the T wave is related to time of .ovrhdot.Vmin of the local action potential and that activation-recovery interval is directly related to action potential duration. In addition, the results provide evidence that the activation-recovery interval is a good estimate of the action potential duration independent of T waveform, drive site, or the presence of localized steep gradient of repolarization.