These are just as they sound, heart beats that are initiated in the atria at a premature time.
They can be caused by an irritated focus (trauma, ischemia, etc) or by aberrant atrial cells that overtake the natural pacemaker.
They may be influenced by the same endogenous as well as exogenous stimuli as atrial fibrillation, as detailed above.

Most PACs are benign and do not need to be worked up. The patient may feel a “skipped beat” or speak of a palpitation.
They typically are not associated with chest pain, fatigue, dyspnea, or syncope.
If the practitioner is unsure of the cause of the patient’s symptoms, he or she may want to put the patient on a holter monitor if it happens frequently or an event recorder, if the symptoms are more sporadic. (10)

Do you know that 90% of the stroke could have been prevented?
Smaller than a credit card, Kardia Mobile allows you to capture single-lead EKGs anywhere, anytime. In 30 seconds, it records a medical-grade EKG, which can be relayed to a doctor for analysis and diagnosis. Kardia Mobile easily attaches to most smartphones making it convenient to always have with you. Learn more about it.