PAC vs PVC on ECG

By behereaxum

Summary

On the monitor, two early beats interrupt the rhythm. Are they atrial, or ventricular?

Chapters

  1. On the monitor, two early beats (0s)
  2. Start with normal sinus rhythm: each (6s)
  3. A premature atrial contraction fires early (13s)
  4. A premature ventricular contraction fires from (23s)
  5. Side by side, the difference is (34s)
  6. So ask yourself two quick questions. (47s)
  7. Answer those, and you can call (58s)

Transcript

On the monitor, two early beats interrupt the rhythm. Are they atrial, or ventricular? Start with normal sinus rhythm: each beat begins with a P wave, followed by a narrow QRS complex. A premature atrial contraction fires early from the atria. Look for an early, oddly-shaped P wave before a normal, narrow QRS. A premature ventricular contraction fires from the ventricles. There's no P wave, and the QRS is wide and bizarre, often followed by a full compensatory pause. Side by side, the difference is clear. The PAC keeps its narrow QRS, with an early, abnormally-shaped P wave. The PVC is wide and bizarre, with no preceding P wave at all. So ask yourself two quick questions. First: is there an early P wave present? And second: is the QRS narrow, or is it wide? That's all it takes. Answer those, and you can call PAC versus PVC at a glance.