Affordable Access

Publisher Website

The mechanisms of atrial fibrillation in hyperthyroidism

Thyroid Research
Springer (Biomed Central Ltd.)
Publication Date
DOI: 10.1186/1756-6614-2-4
  • Review


Atrial fibrillation (AF) is a complex condition with several possible contributing factors. The rapid and irregular heartbeat produced by AF increases the risk of blood clot formation inside the heart. These clots may eventually become dislodged, causing embolism, stroke and other disorders. AF occurs in up to 15% of patients with hyperthyroidism compared to 4% of people in the general population and is more common in men and in patients with triiodothyronine (T3) toxicosis. The incidence of AF increases with advancing age. Also, subclinical hyperthyroidism is a risk factor associated with a 3-fold increase in development of AF. Thyrotoxicosis exerts marked influences on electrical impulse generation (chronotropic effect) and conduction (dromotropic effect). Several potential mechanisms could be invoked for the effect of thyroid hormones on AF risk, including elevation of left atrial pressure secondary to increased left ventricular mass and impaired ventricular relaxation, ischemia resulting from increased resting heart rate, and increased atrial eopic activity. Reentry has been postulated as one of the main mechanisms leading to AF. AF is more likely if effective refractory periods are short and conduction is slow. Hyperthyroidism is associated with shortening of action potential duration which may also contribute to AF.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times

More articles like this

Atrial fibrillation and hyperthyroidism.

on Indian Pacing and Electrophysi... 2005

[Hyperthyroidism and atrial fibrillation].

on Revista clínica española July 1999

Atrial Fibrillation and Hyperthyroidism*

on Indian Pacing and Electrophysi... Jan 01, 2005

[Occult hyperthyroidism and atrial fibrillation].

on La Clinica terapeutica Nov 30, 1985
More articles like this..