The bidirectional relationship of thyroid disease and atrial fibrillation: Established knowledge and future...

Area of Science:

• Cardiology
• Endocrinology
• Internal Medicine

Background:

• Atrial fibrillation (AF) is common in thyroid disease, particularly hyperthyroidism, due to thyroid hormones affecting cardiac electrophysiology.
• Hypothyroidism poses a lower AF risk, often linked to overtreatment. New-onset AF can be the sole indicator of thyroid dysfunction, highlighting the need for screening.
• Managing comorbid thyroid disease and AF involves thyroid hormone control and standard AF therapies, but optimal approaches remain unclear.

Purpose of the Study:

• To review the current epidemiology, pathogenesis, pathophysiology, and management of the interaction between thyroid disease and atrial fibrillation.
• To highlight the clinical utility of screening for thyroid dysfunction in patients presenting with new-onset AF.
• To identify knowledge gaps and potential novel therapeutic avenues, such as immunogenetic overlaps in Graves' disease and AF.

Main Methods:

• Literature review and synthesis of existing research on thyroid disease and atrial fibrillation.
• Analysis of epidemiological data linking thyroid dysfunction and AF prevalence.
• Examination of the pathophysiological mechanisms underlying AF in hyperthyroid and hypothyroid states.

Main Results:

• Hyperthyroidism significantly increases AF risk through direct effects on cardiac electrophysiology.
• Hypothyroidism is associated with a lower AF risk, with overtreatment being a potential factor.
• Thyroid disease management is essential for controlling AF burden, but optimal strategies and benefits of treating subclinical disease are not well-defined.

Conclusions:

• Effective management of thyroid disease is critical for patients with comorbid AF.
• Further research is needed to clarify the optimal management of thyroid disease in AF patients and the benefits of screening asymptomatic individuals.
• Investigating the immunogenetic links between Graves' disease and AF may offer new therapeutic targets.