The Prevalence of Hyperthyroidism Amongst Atrial Fibrillation Patients in the National Guard Hospital, Riyadh, Saudi Arabia: A Cross-Sectional Retrospective Study

Introduction The thyroid gland is the largest pure endocrine gland. It is also responsible for the production of multiple important hormones that regulate heart function. Dysfunction of the thyroid gland could lead to hyperthyroidism, which in turn leads to many lipid and cardiovascular problems. One such cardiac condition that is highly associated with hyperthyroidism is atrial fibrillation. Atrial fibrillation is when abnormal electrical impulses suddenly start firing in the atria. With a prevalence of 16% to 60% of atrial fibrillation in hyperthyroid patients. To the best of our knowledge, no similar study was conducted in Saudi Arabia. Objectives Our study aims to investigate the percentage of people with atrial fibrillation that is caused by hyperthyroidism in the National Guard Hospital. Moreover, we hope that this study will improve the quality of life of these affected patients and add to their knowledge of medicine. Methods Since the population size has increased by approximately 4000 patients in the last five years, we estimated the sample size based on a confidence interval of 95% and a level of significance of 5%, which is 350 patients. We included all patients with atrial fibrillation due to hyperthyroidism in KAMC-R and patients’ records from 2015 to 2020. Also, we excluded all patients with atrial fibrillation due to other causes. In addition, the sampling method we used was convenient sampling. Result Out of 1100 patients with hyperthyroidism or subclinical hyperthyroidism, 40 or 3.6% of the patients had atrial fibrillation, while the rest were distributed among dilated cardiomyopathy, diabetes mellitus, heart failure, and other risk factors for atrial fibrillation. Conclusion We conclude that hyperthyroidism is a risk factor for atrial fibrillation; 3.6% of hyperthyroidism patients have atrial fibrillation. Most of the patients are elderly, and more than half (58%) are female.