PULMONARY VEIN AS AN ECTOPIC FOCUS IN DIGITALIS-INDUCED ARRHYTHMIA
PULMONARY VEIN AS AN ECTOPIC FOCUS IN DIGITALIS-INDUCED ARRHYTHMIA
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DOI：
10.1038/294582a0
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发表时间：
1981-01-01
期刊：
影响因子：
64.8
通讯作者：
CHEUNG, DW
中科院分区：
文献类型：
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作者：
CHEUNG, DW
包括人类在内的许多哺乳动物物种的肺静脉（PV）的图尼卡中膜由心肌组成1 -3。Brunton和Fayrer首先报道了猫和兔子的肺静脉独立搏动，甚至在心脏活动停止后也是如此。电生理学研究还表明，豚鼠的孤立肺静脉中存在自发性电活动，起搏区域位于与平滑肌相邻的静脉心脏部分的远端。肺静脉的固有频率较低，肺静脉的活动通常与窦性心律相关联5。因此，肺静脉作为辅助起搏器发挥作用。在洋地黄类药物的存在下，辅助起搏器（如浦肯野纤维）产生振荡后电位（OAP），其可能大到足以达到阈值6，7，并且已经表明浦肯野纤维处的OAP导致自发动作电位可能是洋地黄中毒期间室性心律失常的潜在机制6。相比之下，心房和心室肌对洋地黄的致心律失常作用不太敏感8。因此，我现在研究了PV是否可以发展OAP并作为洋地黄中毒的异位病灶。通过记录与细胞内微电极同时在PV和右心房，我证明了OAPs和重复活动的发展在PV哇巴因的存在。这些触发的动作电位在肺静脉传播到心房导致房性期外收缩。
The tunica media of the pulmonary vein (PV) in many mammalian species, including man, is made up of cardiac muscle1–3. Brunton and Fayrer first reported that independent pulsation of the PV occurred in cats and rabbits even after activity of the heart had ceased4. Electrophysiological studies have also shown spontaneous electrical activity in isolated PVs of the guinea pig and a pacemaking region has been located at the distal end of the cardiac portion of the vein adjoining the smooth muscle. The intrinsic frequency of the PV was low and activity at the PV was normally coupled to the sinus rhythm5. Thus, the PV behaves as a subsidiary pacemaker. In the presence of digitalis-type agents, subsidiary pacemakers such as Purkinje fibres develop oscillatory afterpotentials (OAPs) which may be large enough to reach threshold6,7, and it has been suggested that OAPs at Purkinje fibres leading to spontaneous action potentials may provide the underlying mechanism for ventricular arrhythmia during digitalis intoxication6. In contrast, atrial and ventricular muscles are not very sensitive to the arrhythmogenic action of digitalis8. I have therefore now investigated whether the PV can develop OAPs and act as an ectopic focus with digitalis intoxication. By recording with intracellular microelectrodes simultaneously at the PV and right atrium, I demonstrate that OAPs and repetitive activity develop at the PV in the presence of ouabain. Propagation of these triggered action potentials at the PV into the atrium results in atrial extrasystoles.