Premature atrial contraction

Premature atrial contraction, or PAC, is also called premature atrial beat.  This is a common cause of the feeling of a “skipped heart beat”.  They are frequent events for people with normal healthy heart function and people with heart disease.  They generally cause no symptoms, although a skipped heart beat or “fluttering” sensation is a common symptom.

The PAC is diagnosed when the p wave (atria contraction) occurs earlier than expected on an EKG recording.  The premature beat sensation occurs when the ventricles contract afterwards (the QRS complex).

The PAC is not related to other atrial rhythm abnormalities.  These others include atrial flutter, atrial fibrillation, atrial tachycardia, atrial escape beat, and ectopic atrial rhythm.