早期后去极与U波之间的关系

采用Ｆｒａｎｚ接触电极描记２２只闭胸犬右室心内膜单相动作电位（ＭＡＰ），观察氯化铯（ＣｓＣｌ）引起的Ｕ波与早期后去极（ＥＡＤ）的关系。静脉注射ＣｓＣｌ后，２２只犬中６只出现了显著可分析的Ｕ波。Ｕ波的联律间期（ＵＣＩ）与相应的ＥＡＤ联律间期（ＥＡＤＣＤ呈良好线性相关（ｒ＝０．９８，Ｐ＜０．０５），ＵＣＩ＝１６．００２＋１．０１０７ＥＡＤＣＩ。５只犬表现为Ｕ波幅度（ＵＡ）下降伴有ＥＡＤ幅度（ＥＡＤＡ）的下降，两者之间有良好相关性（ｒ＝０．７９，Ｐ＜０．０５），ＵＡ＝０．０７６＋１．０２ＥＡＤＡ。本结果支持Ｕ波产生机制的ＥＡＤ学说。

The Relationship Between Early Afterdepolarization and U Waves

The mechanism of the genesis of U wave in electrocardiogram is still unknown.This study was performed to observe the relationship between cesium chloride-induced U waves and early afterdepolarizations (EADs )by recording monophasic action potential(MAP) form right ventricular endocardium with Franz contact electrode in 22 chest-close dogs. There were prominently analysable U waves in 6 out of 22 dogs after administration of cesium chloride intravenously.The coupling intervals of U wave(UCI) and corresponding EADs(EADCI )were strongly related(r=0. 98,P<0.05,UCI=16.002 1.0107 EADCI).There were was a strong correlation between the amplitude of U waves(UA)and EADs (EADA)in five dogs as they decreased simultaneously(r=0.79,P<0.05,UA=0.076 1.02 EADA).The study provides the evidence in support of the hypothesis that afterdepolarization is the basis for U wave.