Case of the Month #8 - atrial fibrillation

Published 03/02/2022

What are the physiological triggers for AF during critical illness?

  • AF is the most frequently encountered arrhythmia in critical care. Precipitating factors are multiple and can relate to the patient, their illness, or their management. 
  • In the community, onset of AF is thought to be secondary to atrial remodelling via fibrosis as a result of hypertension, myocardial ischaemia, valve disease or inflammation. 
  • In critical illness atrial remodelling can be accelerated by persistent tachycardia and systemic inflammation. Acute imbalances in normal conduction due to electrolyte abnormalities, haemodynamic instability and sympathetic and parasympathetic activity can provide the trigger. 
  • Age, high BMI and disease severity factors all contribute to increased risk of developing AF in critical care.