[2][3] PACs are often completely asymptomatic and may be noted only with Holter monitoring, but occasionally they can be perceived as a skipped beat or a jolt in the chest.

[7] Hypertension, or abnormally high blood pressure, often signifies an elevated level of both psychological and physiological stress.

Since the premature beat initiates outside the sinoatrial node, the associated P wave appears different from those seen in normal sinus rhythm.

However, if the atrial beat is premature enough, it may reach the atrioventricular node during its refractory period, in which case it will not be conducted to the ventricle and there will be no QRS complex following the P wave.

Depending whether there are one, two, or three normal (sinus) beats between each PACs, the rhythm is called atrial bigeminy, trigeminy, or quadrigeminy.

[9] In otherwise healthy patients, occasional single premature atrial contractions are a common finding and most of times do not indicate any particular health risk.