Anzawa R, Ishikawa S, Tanaka Y, Okazaki F, Mochizuki S
Division of Cardiology, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.
Europace. 2006 May;8(5):345-8. doi: 10.1093/europace/eul020.
We studied changes in atrial pacing threshold after termination of atrial fibrillation (AF) by acute administration of disopyramide phosphate (DP) to elucidate the suitable setting for atrial pacing output before AF termination.
Four patients with sick sinus syndrome implanted with AAI mode pacemakers were examined. Disopyramide phosphate (2 mg/kg body weight) was injected intravenously for termination of a total of eight AF episodes. The maximal pacing threshold after AF termination (5.2+/-0.8 V at 0.45 ms) was significantly higher than that at baseline (1.3+/-0.2 V at 0.45 ms; P<0.01) and the average increment was 433+/-68%. During a period free from AF, an acute administration of DP did not increase the atrial pacing threshold and serum disopyramide levels were not toxic.
The increased atrial pacing threshold observed after AF termination cannot be explained by the action of DP alone. However, our results suggest that atrial pacing output should be set at the maximum value before DP is administered to induce AF termination in patients with AAI pacemaker-dependent bradyarrhythmias.
我们通过急性给予磷酸丙吡胺（DP）来终止心房颤动（AF），研究AF终止后心房起搏阈值的变化，以阐明AF终止前心房起搏输出的合适设置。
对4例植入AAI模式起搏器的病态窦房结综合征患者进行了检查。静脉注射磷酸丙吡胺（2mg/kg体重）以终止总共8次AF发作。AF终止后的最大起搏阈值（在0.45ms时为5.2±0.8V）显著高于基线时（在0.45ms时为1.3±0.2V；P<0.01），平均增幅为433±68%。在无AF的期间，急性给予DP并未增加心房起搏阈值，且血清丙吡胺水平无毒性。
AF终止后观察到的心房起搏阈值升高不能仅用DP的作用来解释。然而，我们的结果表明，对于依赖AAI起搏器的缓慢性心律失常患者，在给予DP诱导AF终止之前，心房起搏输出应设置为最大值。
