Rawling D A, Joyner R W
Circ Res. 1987 Apr;60(4):580-5. doi: 10.1161/01.res.60.4.580.
The normal cardiac activation sequence requires propagation of the action potential from the subendocardial Purkinje network into the underlying ventricular muscle cells. This process occurs at specific junctional sites distributed over the endocardial surface of both ventricles. At these junctional sites, action potentials can be recorded from cells that appear to be interposed between the Purkinje cells and the ventricular muscle cells. The action potential upstrokes recorded from these "transitional" cells have characteristic double phases produced by electrotonic interactions with the Purkinje cells and the ventricular muscle cells. We have shown that these junctional regions in the canine subendocardium appear to be fixed anatomic sites with locations independent of the activation sequence of the Purkinje network. In addition, the activation delay between the Purkinje cells and the ventricular muscle cells at a junctional site and the patterns of the action potential upstrokes of transitional cells at a junctional site are independent of the activation sequence of the Purkinje network. We have also demonstrated that at some locations there are multiple Purkinje activation signals recorded with a surface electrode and that these multiple activation signals represent discrete groups of Purkinje cells, some of which contribute to the junctional process while others appear to be substantially uncoupled from neighboring Purkinje cell groups and the underlying transitional cells.
正常的心脏激活序列需要动作电位从心内膜下浦肯野网络传播到下方的心室肌细胞。这个过程发生在分布于两个心室心内膜表面的特定连接部位。在这些连接部位，可以从似乎介于浦肯野细胞和心室肌细胞之间的细胞记录到动作电位。从这些“过渡”细胞记录到的动作电位上升支具有由与浦肯野细胞和心室肌细胞的电紧张相互作用产生的特征性双相。我们已经表明，犬心内膜下的这些连接区域似乎是固定的解剖部位，其位置与浦肯野网络的激活序列无关。此外，连接部位浦肯野细胞和心室肌细胞之间的激活延迟以及连接部位过渡细胞动作电位上升支的模式与浦肯野网络的激活序列无关。我们还证明，在某些位置，用表面电极记录到多个浦肯野激活信号，并且这些多个激活信号代表离散的浦肯野细胞群，其中一些参与连接过程，而另一些似乎与相邻的浦肯野细胞群和下方的过渡细胞基本解耦。
