Dun Wen, Boyden Penelope A
Department of Pharmacology, Center for Molecular Therapeutics, Columbia University, New York, NY, USA.
J Interv Card Electrophysiol. 2009 Jun;25(1):9-18. doi: 10.1007/s10840-008-9358-3. Epub 2009 Mar 12.
The incidence of atrial fibrillation (AF) increases with age. Alterations in structure and function of atrial ion channels associated with aging provide the substrate for AF. In this review we provide an overview of current knowledge regarding these age-related changes in atria, focusing on intrinsic ion channel function, impulse initiation and conduction. Studies on the action potentials (APs) of atria have shown that the AP contour is altered with age and the dispersion of AP parameters is increased with age. However, studies using human tissues are not completely consistent with experimental animal studies, since specimens from humans have been obtained from hearts with concomitant cardiovascular diseases and/or that are under the influence of pharmacologic agents. Ionic current studies show that while there are no age-related changes in sodium currents in atrial tissue, the calcium current is reduced and the transient outward and sustained potassium currents are increased in aged cells. While sinoatrial node firing is reduced with age, enhanced impulse initiation may occur in aged atrial cells, for example in the pulmonary veins and coronary sinus. Fibrous tissue is increased in aged atria, which is associated with an increased likelihood of abnormal electrical conduction. Thus, age-related AF involves alterations in the substrate as well as in the passive properties of aged atria.
心房颤动（AF）的发病率随年龄增长而增加。与衰老相关的心房离子通道结构和功能改变为房颤提供了基础。在本综述中，我们概述了目前有关心房这些与年龄相关变化的知识，重点关注内在离子通道功能、冲动起始和传导。对心房动作电位（AP）的研究表明，AP轮廓随年龄改变，AP参数的离散度随年龄增加。然而，使用人体组织的研究与实验动物研究并不完全一致，因为人类标本取自伴有心血管疾病和/或受药物影响的心脏。离子电流研究表明，虽然心房组织中的钠电流没有与年龄相关的变化，但老年细胞中的钙电流减少，瞬时外向钾电流和持续钾电流增加。虽然窦房结发放随年龄减少，但老年心房细胞中可能会出现冲动起始增强，例如在肺静脉和冠状窦中。老年心房中的纤维组织增加，这与异常电传导可能性增加有关。因此，与年龄相关的房颤涉及心房基质以及老年心房被动特性的改变。
