Electrophysiologic mechanism of atrial fibrillation in the dog with hypokalemia

低钾血症犬心房颤动的电生理机制

• 批准号: 06670728
• 负责人: YANO Katsusuke
• 金额: $ 1.34万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06670728/
• 关键词: atrial fibrillation; serum potassium; autonomic nerve; atrial extrastimulation

In the present study we investigated electrophysiologic mechanism of atrial fibrillation in the dog with hypokalemia, with special reference to whether triggered activity plays important role in the genesis of atrial fibrillation in the presence of hypokalemia. Furthermore, influence of autonomic nerve on the occurrence of atrial fibrillation was also investigated. <Materials and Methods> Thirty mongrel dogs weighing 10-13kg were anesthetized with intravenous sodium pentobarbital (30mg/kg) and put on artificial respiration using room air. The chest was opened by a median sternotomy and heart was suspended in a pericardial cradle. Bipolar epicardial electrodes were positloned at multiple sites of the atrium. Furthermore, electrode for monophasic action potential (MAP) was positioned on the atrial wall. To produce hypokalemia ion exchange resin (5.0g/kg of polystirene sulfonic acid calcium) was infused into the colon in the dog.To measure serum levels of potassium, sodium, chloride, calc … More ium, and magnesium, blood samples were taken before and sixty minutes after infusin of ion exchange resin. To stimulate autonomic nerves electrodes were positioned on the vagal nerve in the left neck and left stellate ganglion. Electrophysiologic study was performed before and 60 minutes after infusion of ion exchange resin and also performed under stimulation of autonomic nerves. <Results> Serum levels of potassium was signiflcantly reduced from 4.2+0.3mEq/L to 2.8+0.3mEq/L,but other electrolytes did not signiflcantly change. Incidence of electrically induced atrial fibrillation was increased in the presence of hypokalemia wit mild increase in intraatrial conduction delay and without signiflcant change in effective refractory period and these findings were increased by stimulations of both vagal nerve and stellate ganglion. Morphological changes of MAP suggesting existence of early after depolarization were observed after induction of hypokalemia and these changes were increased by stimulations of autonomic nerves. <Conclusion> In the presence of hypokalemia atrial fibrillation is readily induced and this inducibility is enhanced by increased tone of autonomic nerves. And triggered activity may play a rolein part in the occurrence of atrial fibrillation in this situation. Less

本研究探讨了低钾血症犬心房颤动的电生理机制，特别是触发活动是否在低钾血症心房颤动的发生中起重要作用。此外，还研究了自主神经对房颤发生的影响。<Materials and Methods>30只体重10- 13 kg的杂种犬用静脉注射戊巴比妥钠（30 mg/kg）麻醉，并使用室内空气进行人工呼吸。通过正中胸骨切开术打开胸部，将心脏悬挂在心包支架中。将双极心外膜电极定位在心房的多个部位。在心房壁上放置单相动作电位（MAP）电极。用离子交换树脂（5.0g/kg聚苯乙烯磺酸钙）灌胃狗结肠，造成低钾血症，测定血清钾、钠、氯、钙、镁、钙、镁、镁、 ...更多信息 在离子交换树脂注入前和注入后60分钟，采集血清中镁、铁和镁的含量。为了刺激自主神经，将电极定位在左颈部和左星状神经节中的迷走神经上。在离子交换树脂灌注前和灌注后60分钟进行电生理检查，并在自主神经刺激下进行。<Results>血钾由4.2 ± 0.3mEq/L降至2.8 ± 0.3mEq/L，其它电解质无明显变化。低钾血症时电诱发心房颤动的发生率增加，心房内传导延迟轻度增加，有效不应期无明显改变，刺激迷走神经和星状神经节均增加这些发现。低钾血症后MAP形态学改变提示早期后除极的存在，刺激自主神经可使MAP形态学改变增强。<Conclusion>在低钾血症的情况下，容易诱发心房颤动，并且这种诱发可通过增加自主神经张力而增强。在这种情况下，触发活动可能在房颤的发生中发挥作用。少

项目成果

Katsusuke Yano: "Effect of hypokalemia and disopyramide on electrical induction of ventricular tachyarrhythmia in nonischemic heart" International Journal of Angiology. (in press).

Katsusuke Yano：“低钾血症和丙吡胺对非缺血性心脏室性快速心律失常的电感应的影响”国际血管学杂志。

Katsusuke Yano: "Effect of hypokalemia and disopyramide on electrical induction of ventricular tachyarrhythmia in nonischemic heart" International Journal of Angiology. 5. 105-106 (1996)

Katsusuke Yano：“低钾血症和丙吡胺对非缺血性心脏室性快速心律失常的电感应的影响”国际血管学杂志。