Christini David J, Riccio Mark L, Culianu Calin A, Fox Jeffrey J, Karma Alain, Gilmour Robert F
Division of Cardiology, Weill Medical College of Cornell University, New York, New York 10021, USA.
Phys Rev Lett. 2006 Mar 17;96(10):104101. doi: 10.1103/PhysRevLett.96.104101.
Alternation in the duration of consecutive cardiac action potentials (electrical alternans) may precipitate conduction block and the onset of arrhythmias. Consequently, suppression of alternans using properly timed premature stimuli may be antiarrhythmic. To determine the extent to which alternans control can be achieved in cardiac tissue, isolated canine Purkinje fibers were paced from one end using a feedback control method. Spatially uniform control of alternans was possible when alternans amplitude was small. However, control became attenuated spatially as alternans amplitude increased. The amplitude variation along the cable was well described by a theoretically expected standing wave profile that corresponds to the first quantized mode of the one-dimensional Helmholtz equation. These results confirm the wavelike nature of alternans and may have important implications for their control using electrical stimuli.
连续心脏动作电位持续时间的交替变化(电交替)可能会引发传导阻滞和心律失常的发作。因此,使用适时的过早刺激抑制交替变化可能具有抗心律失常作用。为了确定在心脏组织中实现交替变化控制的程度,采用反馈控制方法从一端对分离的犬浦肯野纤维进行起搏。当交替变化幅度较小时,可以实现对交替变化的空间均匀控制。然而,随着交替变化幅度的增加,控制在空间上会减弱。沿电缆的幅度变化可以很好地用理论预期的驻波轮廓来描述,该轮廓对应于一维亥姆霍兹方程的第一量子化模式。这些结果证实了交替变化的波状性质,并且可能对使用电刺激对其进行控制具有重要意义。