Question

The nurse is examining the patient's cardiac rhythm strip in lead II and notices that all of the P waves are upright and look the same except one that has a different shape and is inverted. The nurse realizes that the P wave with the abnormal shape is probably:

a. from the SA node since all P waves come from the SA node.
b. from some area in the atria other than the SA node.
c. indicative of ventricular depolarization.
d. normal even though it is inverted in lead II.

Answer 1

The P wave with the abnormal shape is probably from some area in the atria other than the SA node.

Step-by-step explanation:

The nurse realizes that the P wave with the abnormal shape is probably from some area in the atria other than the SA node. The P wave represents the depolarization of the atria, and it should have the same upright shape and appear the same in lead II. However, if a P wave is inverted or has a different shape than the others, it suggests that it is coming from a different area in the atria. This abnormal P wave could be caused by an ectopic atrial pacemaker or a conduction abnormality in the atria.