Trusted medical expertise in seconds.

Access 1,000+ clinical and preclinical articles. Find answers fast with the high-powered search feature and clinical tools.

Try free for 5 days
Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer.

Supraventricular premature beats

Last updated: February 23, 2021

Summarytoggle arrow icon

Supraventricular premature beats are atrial contractions triggered by ectopic foci rather than the sinoatrial node. They arise within the atria (atrial premature beats) or, through retrograde conduction, in the atrioventricular node (junctional premature beats). Premature beats may be found in healthy individuals as well as patients with underlying heart disease. Certain triggers, e.g., alcohol, smoking or electrolyte imbalances, may also contribute to the condition. Premature beats do not significantly impair cardiac output on their own; however, they may lead to more severe forms of arrhythmia such as atrial fibrillation. Unless patients exhibit severe symptoms (e.g., tachycardia), those experiencing premature beats do not require treatment.

  • Idiopathic
  • Potential triggers: smoking, alcohol, coffee
  • Cardiovascular disease or electrolyte imbalances (e.g., hypokalemia)

Atrial premature beats

  • Definition: extrasystole that originates in the atrial myocardium and occurs prior to the expected QRS complex
  • Typical findings on ECG
    • P-wave abnormalities or absent P waves
    • Altered PR interval in the premature beats (compared to the normal beats)
    • QRS complex may be normal, aberrant (widened), or absent
    • No full compensatory pause

Junctional premature beats

  • Treatment is not required in asymptomatic individuals without underlying structural heart defects.
  • Underlying conditions, e.g., electrolyte imbalances, should be treated.
  • Symptomatic patients
  1. Herold G. Internal Medicine. Herold G ; 2014
  2. Manolis AS. Supraventricular premature beats. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/supraventricular-premature-beats.Last updated: July 24, 2017. Accessed: December 8, 2017.