Sometimes, when teaching a class, it can actually be a challenge to find a good example of "normal" for your students. We all tend to collect the ECGs that are "interesting" or unusual. It is very important for students to fully recognize "normal" before they can appreciate "abnormal". Here is a nice example of a normal 12-Lead for you. It was obtained by a portable machine, like those used by EMS or on crash carts, so it does not include a fourth channel rhythm strip. Challenge your students to find the "normal" characteristics of this ECG: normal sinus rhythm; Lead II has the tallest QRS of the limb leads, indicating a normal axis; Lead V1 is primarily negative and the chest leads progress in an orderly fashion to a positive QRS in V6; no ST segment elevation or depression; no T wave inversions; no pathological Q waves; no abnormally tall or wide QRS complexes; and all intervals are normal. Challenge your students to pick out the normal features of this ECG.