Furukawa Toshiyuki, Hirao Kenzo, Horikawa-Tanami Tomoe, Hachiya Hitoshi, Isobe Mitsuaki
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Circ J. 2009 Mar;73(3):468-75. doi: 10.1253/circj.cj-08-0869. Epub 2009 Jan 16.
The role of autonomic effects in the occurrence and maintenance of atrial fibrillation (AF) has undergone little investigation in the remodeling heart.
In the present study, 2 groups were studied: those with complete atrioventricular block (AVB) produced by radiofrequency current application (AVB dogs, n=17) and those not undergoing AVB (sham dogs, n=5). Eight weeks after creation of AVB, electrophysiologic study, including pulmonary vein (PV) pacing for AF induction, was performed under vagal nerve stimulation (VNS) and sympathetic stimulation (SS) in both groups. After 8 weeks, atrial dimensions and the percentage of fibrosis in the atria were significantly greater in the AVB dogs. In AVB dogs, atrial and PV effective refractory periods were shorter (P<0.01), and atrial conduction velocity increased (P=0.01) during SS, but not during VNS. Inducibility of AF increased only during SS in the AVB dogs (sustained AF: control 7%, SS 60%; P=0.005), whereas it increased only during VNS in the sham dogs.
In the remodeled atria, sympathetic stimulation was crucial for the genesis of AF, which is completely different from the condition in normal atria.
自主神经效应在心房颤动（AF）发生及维持中的作用在心脏重构方面鲜有研究。
在本研究中，对两组进行了研究：通过射频电流应用产生完全房室传导阻滞（AVB）的犬（AVB犬，n = 17）和未进行AVB的犬（假手术犬，n = 5）。在AVB形成8周后，两组均在迷走神经刺激（VNS）和交感神经刺激（SS）下进行电生理研究，包括用于诱发AF的肺静脉（PV）起搏。8周后，AVB犬的心房大小和心房纤维化百分比显著更大。在AVB犬中，心房和PV有效不应期较短（P<0.01），且在SS期间心房传导速度增加（P = 0.01），但在VNS期间未增加。AVB犬仅在SS期间AF诱发率增加（持续性AF：对照组7%，SS组60%；P = 0.005），而假手术犬仅在VNS期间AF诱发率增加。
在重构心房中，交感神经刺激对AF的发生至关重要，这与正常心房的情况完全不同。
