普鲁卡因胺对绵羊心室跨壁复极时间的影响

Effects of procainamide on transmural ventricular repolarisation

目的研究普鲁卡因胺对心室跨壁复极时间的影响。方法对6只绵羊用苯巴比妥麻醉后,开胸,用4个针状(p lunge need les)电极分别插入到左心室的基底部和心尖部,测量室壁激动-恢复间期(AR I)。静脉注射普鲁卡因胺20mg.m in-1后观察AR I的变化。结果窦性心律时,心外膜、中层心肌和心内膜的AR I差异无显著性,[分别为(266.0±30.5)m s、(265.0±28.9)m s和(265.7±28.1)m s,P>0.05]。普鲁卡因胺对各层心肌的AR I均有延长作用,心外膜、中层心肌和心内膜的AR I分别延长了(66.8±18.3)m s、(70.3±14.7)m s和(65.3±15.7)m s(P>0.05)。结论钠通道阻滞剂普鲁卡因胺对左室的心外膜、中层心肌和心内膜复极的延长程度相似。

Aim To investigate the pharmacological effect of procainamide on transmural ventricular repolarization. Methods The transmural activation-recovery intervals （ARI） and their responses to procainamide （20 mg · min^-1 iv for 20 min） were studied in 6 open-chest, pentobarbitone-anaesthetised sheep. ARI was measured from unipolar ECGs acquired with 4 plunge needles inserted into the basal and apical parts of the left ventricular wall. Results During sinus rhythm, there was no significant difference in the pooled ARI between the epicardium （266.0 ms ± 30.5 ms） , midmyocardium （265.0 ms ± 28.9 ms） and endocardium （265.7 ms ＋ 28. 1 ms,P 〉 0.05 ）. Procainanide prolonged ARI in all myocardial layers. The pooled ARI prolongation of the epicardium, midmyocardium and endocardium of the 6 animals was 66. 8ms ＋ 18.3 ms ,70. 3 ms ＋ 14. 7 ms and 65.3ms ＋ 15.7 ms （ P 〉 0. 05 ）, respectively. Conclusions Sodium channel blocker procainamide results in a similar repolarisation prolongation in the epicardium, midmyocardium and endocardium of the left ventricle.