摘要目的研究动物在体中层心肌细胞的电生理特性与体表心电图U波形成的关系.方法利用单相动作电位记录技术,同步记录16只兔子左心室心外膜下、中层、心内膜下心肌的单相动作电位,以下同剂量的Sotalol (1、 1.5、 2.0 mg/kg)作为工具药进行研究 .结果应用Sotalol前心电图上无U波,应用Sotalol 1.5 mg/kg后出现U波,随着Sotalol外膜相比有显著差异,心外膜下心肌的复极时程与体表心电图T波的顶点相一致,而中层心肌的复极时程与U波的终点相一致.结论 U波的产生可能是由于中层心肌复极延迟所致.

abstractsObjective To investigate the relationship between the U wave on electrocardiogram and the midmyocardium in rabbit left ventricle free wall in vivo. Methods The monophasic action potentials in the epicardium, midmyocardium, and endocardium of the left ventricle free wall were recorded simultaneously in 16 rabbits. The rabbits were then given an intravenous injection of Sotalol (1, 1.5 and 2.0mg/kg) in 30 minutes intervals, and measurements were taken.Results In the basic condition, there were no U wave on electrocardiogram. The U wave appeared after the intravenous Sotalol at 1.5mg/kg, and the U wave became greater with increased dosage of intravenous Sotalol (2mg/kg). The repolarization duration of the midmyocardium was prolonged longer than that of the epicardium and endocardium by Sotalol, and the repolarization duration of the epicardium coincided with the apex of the T wave, The repolarization duration of the midmyocardium coincided with the end point of the U wave.Conclusion The U wave may originate from the delayed repolarization of the midmyocardium.