Pacing-induced chronic atrial fibrillation impairs sinus node function in dogs - Electrophysiological remodeling
Pacing-induced chronic atrial fibrillation impairs sinus node function in dogs - Electrophysiological remodeling
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DOI：
10.1161/01.cir.94.11.2953
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发表时间：
1996-12-01
期刊：
影响因子：
37.8
通讯作者：
Zipes, DP
中科院分区：
文献类型：
--
作者：
Elvan, A;Wylie, K;Zipes, DP
背景我们评估了起搏诱导的慢性心房颤动（AF）对窦房结功能、心房内传导和心房不应性的影响。（20至30 kg），通过射频导管消融产生房室结阻滞，并植入心室抑制（VVI）起搏器（Minix 8330，Medtronic）植入并程控为以每分钟80次脉冲起搏。其中11只犬的右心房内膜起搏电极与脉冲发生器相连校正窦房结恢复时间、P波持续时间、评估AF持续时间的24小时霍尔特ECG、对异丙肾上腺素反应的最大心率（10 μ g/min），阿托品给药后的固有心率（0.04 mg/kg）和普萘洛尔（0.1毫克/千克），在基线（EPS-1）和单独VVI起搏2 - 6周后（EPS-2）获得心房有效不应期（ERP）（n=4）或VVI起搏和快速心房起搏（n=11）。与EPS-1组相比，EPS-2组校正窦房结恢复时间和P波时限延长，最大心率和固有心率降低，心房ERPS缩短，AF持续时间延长。转为窦性心律后1周，这些变化部分逆转至基线水平。结论起搏诱发的慢性房颤可引起窦房结功能障碍，缩短心房内传导时间，缩短心房不应期，使房颤持续，房颤终止后逐渐逆转。
Background We assessed the effects of pacing-induced chronic atrial fibrillation (AF) on sinus node function, intra-atrial conduction, and atrial refractoriness.Methods and Results In 15 mongrel dogs (20 to 30 kg), AV nodal block was produced by radiofrequency catheter ablation, and a ventricular-inhibited (VVI) pacemaker (Minix 8330, Medtronic) was implanted and programmed to pace at 80 pulses per minute. In 11 of these dogs, right atrial endocardial pacing leads were connected to a pulse generator (Itrel 7432, Medtronic) and set at a rate of 20 Hz to induce AF. Corrected sinus node recovery time, P-wave duration, 24-hour Holter ECG to assess AF duration, maximal heart rate in response to isoproterenol (10 mu g/min), intrinsic heart rate after administration of atropine (0.04 mg/kg) and propranolol (0.1 mg/kg), and atrial effective refractory periods (ERPs) were obtained at baseline (EPS-1) and after 2 to 6 weeks (EPS-2) of VVI pacing alone (n=4) or VVI pacing and rapid atrial pacing (n=11). At EPS-2, corrected sinus node recovery time and P-wave duration were prolonged, maximal heart rate and intrinsic heart rate were decreased, atrial ERPSs were shortened, and the duration of AF was increased significantly compared with EPS-1. These changes partially reversed toward baseline 1 week after conversion to sinus rhythm. Sinus node function and AF inducibility observed in the control dogs that underwent ventricular pacing alone (n=4) did not change.Conclusions Pacing-induced chronic AF induces sinus node dysfunction, prolongs intra-atrial conduction time, shortens atrial refractoriness, and perpetuates AF, changes that reverse gradually after termination of AF.