You are in the hospital rounding on your patients. You notice one of your patient's ekg looks a little different from the prior day. What is odd about the EKG?

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This is a very interesting EKG. At a quick glance the ekg looks pretty normal with a regular rhythm and what seems to be normal p waves before each qrs. But when looking carefully at the atrial activity in leads v1, II, III and AvF something interesting is revealed. The p wave axis is totally the opposite than sinus. It is down in II, III, and AvF and up in AvR. This means this is an ectopic atrial pacemaker. Not only that but when looking at the rhythm strip and leads v1, II, and III you can see that this ectopic atrial pacemaker is going fast than the ventricle. Looking at lead II what looks like inverted t waves, is really the ectopic p wave marching through at a rate of 150 bpm. SO in actuality, the atrium is going at a rate of 150 bpm and capturing the ventricle only half the time with a regular 2 to 1 conduction. It is very subtle yet if looking carefully enough the rhythm is revealed to us.