Which statement best describes a typical PVC on ECG?

Which statement best describes a typical PVC on ECG?

• A. Narrow QRS with preceding P waves
• B. Wide QRS with preceding P waves
• C. Wide QRS without a preceding P wave
• D. Normal rhythm

Answer: (C)

PVCs are premature beats that originate in the ventricles. Because the impulse starts in the ventricular tissue rather than the atria, the depolarization spreads through the ventricles in a slower, abnormal way, producing a wide QRS complex (usually greater than 120 ms). There is typically no preceding P wave because the atria aren’t triggering this beat, so you don’t see a P wave just before the wide complex. This combination—an early beat with a wide, bizarre-looking QRS and no preceding P wave—is what characterizes a typical PVC. After a PVC, a compensatory pause often follows. The other patterns describe normal sinus rhythm or atrial-origin beats, which have different P–QRS relationships and QRS widths.

PVCs are premature beats that originate in the ventricles. Because the impulse starts in the ventricular tissue rather than the atria, the depolarization spreads through the ventricles in a slower, abnormal way, producing a wide QRS complex (usually greater than 120 ms). There is typically no preceding P wave because the atria aren’t triggering this beat, so you don’t see a P wave just before the wide complex. This combination—an early beat with a wide, bizarre-looking QRS and no preceding P wave—is what characterizes a typical PVC. After a PVC, a compensatory pause often follows. The other patterns describe normal sinus rhythm or atrial-origin beats, which have different P–QRS relationships and QRS widths.