In Reply We very much appreciate Dr Littmann’s close inspection and review of our Teachable Moment.¹ Although we do acknowledge that the right arm and right leg electrodes may have been reversed in Figure 2A, this does not detract from the main point of the article: the importance of evaluating the onset and termination of tachycardias in identifying their mechanism. Furthermore, such a reversal should not have affected the P wave vector in leads III and aVF, where we believe that the initial vector is indeed negative. It is also positive in lead aVL, consistent with the diagnosis of AV nodal reentrant tachycardia. In addition, a similar P wave morphology was seen on a number of other electrocardiograms performed during the patient’s hospitalization.

答复我们非常感谢Littmann博士对我们的教学时间的仔细检查和审查。¹尽管我们确实承认在图2A中右臂和右腿电极可能已经颠倒，但这并不减损本文的重点：评估心动过速的发作和终止对确定其机制的重要性。此外，这种逆转不应影响引线III和aVF中的P波矢量，我们认为初始矢量确实为负。它对aVL铅也呈阳性，与AV结折返性心动过速的诊断一致。此外，在患者住院期间进行的许多其他心电图检查中也观察到了类似的P波形态。