Premature atrial contraction
(Redirected from PACs)
Premature atrial contractions (PACs) are common and typically benign premature beats characterized by an abnormal early P wave within a cardiac cycle. Less commonly, they can precipitate atrial fibrillation, atrial flutter, or SVT.
- Shortness of breath
- Narrow-complex tachycardias
- Wide-complex tachycardias
- AV blocks
- Premature atrial contraction
- Premature junctional contraction
- Premature ventricular contraction
- Sick sinus syndrome
- Wandering atrial pacemaker
- Non-arrhythmic cardiac causes:
- Psychiatric causes:
- Drugs and Medications:
- Drugs of abuse (e.g. cocaine)
- Medications (e.g. digoxin, theophylline)
- Obtain EKG and look for:
- P waves that appear sooner than expected sinus beat
- Ectopic P waves that have different morphology
- Interval between normal P waves encompassing the PAC is less than twice the existing P-P cycle length (noncompensatory pause)
- Rule out underlying conditions:
- Chronic heart disease (increases prevalence of PACs)
- Chronic lung disease (increases prevalence of PACs)
- Drugs: cocaine, amphetamines, caffeine, nicotine, digoxin
- No specific treatment necessary
- If symptomatic, treat underlying disorder or discontinue offending agent.
- Discharge home, no specific follow-up (unless identifiable underlying etiology that needs to be treated).
- ↑ Specific dysryhthmias. In: Marx K, Rosen P, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier/Saunders, 2014.
- ↑ Brady W, Laughrey T, Ghaemmaghami C. Cardiac rhythm disturbances. In Tintinalli's Emergency Medicine: A Comprehensive Guide. Tintinalli J, et al. ed. 8th ed. McGraw Hill. New York, NY, 2016.