Idioventricular Rhythm characteristics?

• A. Originates from atria with narrow QRS
• B. Originates from ventricles with wide QRS and no P waves
• C. Originates from SA node with normal PRI
• D. Originates from AV node with short PRI

Answer: (B)

Idioventricular rhythm is a ventricular escape rhythm, meaning the ventricles are driving the heartbeat because the normal pacemaker (SA node) or the AV node isn’t delivering impulses to the ventricles. Because the impulse starts in the ventricular tissue, conduction is slow and irregular through the ventricular myocardium, producing wide QRS complexes. P waves are not linked to each ventricular beat, so there are no clear P waves associated with the rhythm. The rate is typically very slow, around 20–40 beats per minute (with the term accelerated idioventricular rhythm describing a somewhat faster but still ventricular-origin rhythm).

This combination—ventricular origin, wide QRS, and absence of aligned P waves—best describes idioventricular rhythm.