Which statement is true about PVCs?

• A. They Always Have A Preceding P Wave
• B. They Are Typically Wide QRS Complexes And Occur Prematurely
• C. They Originate From The Atria
• D. They Never Precede Another Beat

Answer: (B)

Premature ventricular contractions come from ventricular heart muscle itself, not the normal conduction path starting in the atria. Because the impulse starts in the ventricle, it depolarizes the ventricles in a slower, disrupted way, producing a wide and often bizarre-looking QRS complex on the ECG. This wide QRS occurs earlier than the next expected beat, hence it’s premature.

That’s why the statement about being wide and occurring prematurely is the best pick. You’ll typically not see a preceding P wave with a PVC, since the impulse isn’t coming through the atria and AV node first. The origin in the atria is incorrect. Also, a PVC is a beat itself, and after it there can be a compensatory pause or a normal beat; the idea that it never precedes another beat isn’t true.