肺静脉起源的局灶性心房颤动模型:心房颤动触发机制与维持机制的分离Spontaneous focal atrial fibrillation arising from a peripheral atrial site:separation of AF triggers from AF maintenance
周菁,丁燕生,侯应龙,杨俊娟
摘要(Abstract):
目的建立非肺静脉起源的局灶性心房颤动(房颤)模型,观察该房颤的诱发和维持特点并探讨其可能的电生理机制。方法21只健康成年犬静脉麻醉后行右侧开胸手术,暴露靠近右上肺静脉的心脏脂肪垫(内含神经丛),将1根多电极导管固定贴靠于右上肺静脉,使其头端电极贴靠右上肺静脉与左心房交界处,另外将2根多电极导管分别固定于右心房中部和右心耳一侧。用一根细塑料管固定于右心耳与右心房交界处,将二者隔离开,隔离出的右心耳面积大约为240mm2。另将一根单向动作电位(MAP)导管经股静脉送至右心耳内以记录局部的单向动作电位。其中6只犬在右房中部用胶水固定一塑料的中空圆柱体,其内部面积大约为8mm2。分别以不同浓度(1、10、100mmol/L)的乙酰胆碱(Ach)浸润分离出的右心耳和圆柱体内部的心房表面。结果21只犬中有16只犬应用100mmol/L Ach浸润右心耳可重复发生自发持续性局灶性房颤(>10min)。右心耳处房颤的平均周长为30.6±4.6 ms,心房部位房颤的平均周长为105.2±32.0 ms(P<0.05)。房颤发生前均伴有MAP时程>90%的缩短。在房颤发作中,沿右心耳与右房交界处采用血管钳钳夹可导致全部16只犬右心耳处电活动的消失,但其中14只犬的房颤仍然在心房内持续存在,另2只犬的房颤在30 s内终止。6只犬在行右上肺静脉附近的神经丛内注射甲醛溶液后,再行100mmol/L Ach浸润右心耳仅造成MAP时程的明显缩短,不再能发生自发持续性房颤;全部6只犬Ach浸润圆柱体内部的心房表面不能发生自发持续性房颤。结论采用100mmol/L的Ach浸润足够面积的右心耳可建立右心耳起源的局灶性房颤模型。内源性自主神经系统在该房颤的触发和维持机制中起作用。
关键词(KeyWords): 心房颤动;自主神经通路;右心耳
基金项目(Foundation):
作者(Author): 周菁,丁燕生,侯应龙,杨俊娟
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