Premature atrial contractions (PACs), also known as atrial premature complexes (APC) or atrial premature beats (APB), are a common cardiac dysrhythmia characterized by premature heartbeats originating in the atria. While the sinoatrial node typically regulates the heartbeat during normal sinus rhythm, PACs occur when another region of the atria depolarizes before the sinoatrial node and thus triggers a premature heartbeat.The exact cause of PACs is unclear; while several predisposing conditions exist, PACs commonly occur in healthy young and elderly people without heart disease, and by themselves are not considered an abnormal finding.^[1][2] PACs are often completely asymptomatic and may be noted only with Holter monitoring, but occasionally they cause a sensation of palpitations. In most cases, no treatment other than reassurance is needed for PACs, although medications such as beta blockers can reduce the frequency of symptomatic PACs.