Depolarization of the heart ventricles at an increasing heart rate was investigated in a rainbow trout Oncorhynchus mykiss (n = 14). It was shown that at an imposed supraventricular rhythm ranging from 30 to 60 bpm the depolarization wave initially propagates from the loci of earliest atrial excitation located near the atrioventricular orifice to the subendocardial trabecular layer of the noncompact myocardium and then travels towards the epicardium as well as along the wall. This indicates some preferential pathways of cardiac excitation conduction from the pacemaker zone to subendocardial myocytes. Regardless of the heart rate, the basic pattern of ventricular excitation in the rainbow trout heart consists in the propagation of the depolarization wave, which captures the entire thickness of the myocardial wall and activates the subendocardium faster than the subepicardium, from the dorsal regions of the cardiac base in basoapical and ventral directions. At a rhythm of 50–60 bpm, propagation of the depolarization wave in the basal ventricular areas is inverted from the dorsoventral to ventrodorsal direction.

中文翻译：

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心房电刺激是否影响虹鳟 Oncorhynchus mykiss 心脏心室去极化的顺序？

在虹鳟 Oncorhynchus mykiss (n = 14) 中研究了心率增加时心室的去极化。结果表明，在 30 到 60 bpm 范围内的强心室上性节律下，去极化波最初从位于房室口附近的最早心房兴奋位点传播到非致密心肌的心内膜下小梁层，然后向心外膜传播。沿着墙壁。这表明心脏兴奋传导从起搏区到心内膜下肌细胞的一些优先途径。不管心率如何，虹鳟心脏中心室兴奋的基本模式在于去极化波的传播，其捕获心肌壁的整个厚度并比心外膜下更快地从心脏基底的背侧区域在基底和腹侧方向激活心内膜。以 50-60 bpm 的节律，去极化波在基底脑室区域的传播从背腹向腹背方向反转。