What characteristic distinguishes the P waves in PAT when viewed on an EKG?

What characteristic distinguishes the P waves in PAT when viewed on an EKG?

• A. They appear taller than normal
• B. They look the same as sinus generated P waves
• C. They look different from sinus generated P waves with normal cycles
• D. They are absent altogether

Answer: (C)

The characteristic that distinguishes the P waves in Paroxysmal Atrial Tachycardia (PAT) is their appearance. In PAT, the P waves often look different from sinus-generated P waves. This is because PAT arises from an ectopic focus in the atria, which results in a different electrical impulse and therefore alters the shape and configuration of the P wave compared to those initiated by the sinoatrial node.

In a normal sinus rhythm, P waves have a consistent morphology, reflecting the uniform electrical activity initiated by the SA node. However, during episodes of PAT, the ectopic origin of the impulses leads to variations in the P wave shape, which is a key distinguishing feature on an EKG. This difference can manifest as inverted or biphasic P waves or even P waves that are of different duration compared to sinus rhythms.

Recognizing these discrepancies is crucial for accurate diagnosis and distinguishing PAT from other arrhythmias.