Aetiology

About 15-20% of cases of permanent atrial fibrillation and approximately 50% of cases of paroxysmal atrial fibrillation are idiopathic (1,2,3)

Most important triggers and associations seen in AF are

• cardiovascular disorders
  • hypertension
  • cardiac valve disease, especially mitral valve disease
  • coronary artery disease
  • left ventricular systolic dysfunction
• pulmonary disorders
  • infection
  • pulmonary embolism
  • OPD
• constitutional disorders
  • toxic insults e.g – chronic or acute alcohol intake
    • even modest habitual alcohol intake of 1.2 drinks/day was associated with an increased risk of AF (4)
    • data from the HOLIDAY study suggests that just one glass of an alcoholic drink was associated with a 2-fold greater odds and two or more alcoholic drinks were associated with a 3.5-fold greater odds of an AF episode occurring in the next four hours (5)
  • high caffeine intake
  • thyrotoxicosis
  • sepsis (especially chest and urine infections) (2)

In the context of secondary atrial fibrillation, the causes of atrial fibrillation may be considered in terms of common and rare causes.

Atrial fibrillation may result from any of the following changes in the atria (3):

• dilatation
• increased muscle mass
• inflammation, infiltration and fibrosis

Reference:

• (1) Pulse (2003), 63 (42), 96.
• (2) Money-Kyrle A, Thakkar R. Clinical review: Atrial fibrillation. GPonline 2017
• (3) Bajpai A, Savelieva I, Camm AJ. Treatment of atrial fibrillation. Br Med Bull. 2008;88(1):75-94.
• (4) Csengeri D et al. Alcohol consumption, cardiac biomarkers, and risk of atrial fibrillation and adverse outcomes.European Heart Journal, ehaa953 13 January 2021
• (5) Acute Alcohol Consumption And Discrete Atrial Fibrillation Events.Presented at ACC.21 by Prof. Gregory Marcus, M.D (San Fransico, CA, USA) (May 5th 2021)