Which statement best describes a typical PVC on ECG?

Which statement best describes a typical PVC on ECG?

• A. Narrow QRS
• B. Regular rhythm
• C. P waves preceding QRS
• D. Wide QRS

Answer: (D)

Premature ventricular contractions originate in ventricular tissue, not through the normal conduction system. That ventricular origin means the impulse spreads through the muscle rather than via the fast His-Purkinje pathways, so the depolarization takes longer and the QRS complex becomes wide and abnormal in shape—typically greater than 0.12 seconds. Because the beat is premature, the rhythm often looks irregular, and there is usually no clear P wave before the QRS (or the P wave may be dissociated). The T wave also tends to be in the opposite direction to the QRS, reflecting the ventricular origin. So the hallmark feature of a typical PVC on ECG is a wide QRS complex, which is why that option best describes it. The other statements describe supraventricular features (narrow QRS, regular rhythm, or P waves preceding the QRS), which don’t fit a PVC as well.

Premature ventricular contractions originate in ventricular tissue, not through the normal conduction system. That ventricular origin means the impulse spreads through the muscle rather than via the fast His-Purkinje pathways, so the depolarization takes longer and the QRS complex becomes wide and abnormal in shape—typically greater than 0.12 seconds. Because the beat is premature, the rhythm often looks irregular, and there is usually no clear P wave before the QRS (or the P wave may be dissociated). The T wave also tends to be in the opposite direction to the QRS, reflecting the ventricular origin.

So the hallmark feature of a typical PVC on ECG is a wide QRS complex, which is why that option best describes it. The other statements describe supraventricular features (narrow QRS, regular rhythm, or P waves preceding the QRS), which don’t fit a PVC as well.