FEATURES OF ATRIAL FIBRILLATION DEVELOPMENT IN PATIENTS WITH THYROTOXICOSIS

Abstract

The article presents a review of the literature on the development of atrial fibrillation in patients with thyrotoxicosis, which is one of the most common endocrine diseases, second only to diabetes mellitus.

The most common cause of thyrotoxicosis is Graves ' disease and functional autonomy of the thyroid node. The authors analyze the literature data on the cardiac effects of thyrotoxicosis, the features of cardiac remodeling in hyperthyroidism, the frequency of atrial fibrillation in thyrotoxicosis depending on age, as well as the possibilities of restoring sinus rhythm in a combination of these pathologies. Special attention is paid to the effect of subclinical thyrotoxicosis on the heart, which is understood as a violation of thyroid function, characterized by a low serum concentration of thyrotropin, normal values of free thyroxine and free triiodothyronine. Subclinical thyrotoxicosis can also cause cardiac remodeling and diastolic dysfunction. The prevalence of thyrotoxicosis in the elderly is higher in areas of iodine deficiency, which is relevant for our country due to the large area of iodine deficiency. In elderly patients, the cardiac effects of thyrotoxicosis predominate in the clinical picture, which makes it difficult to diagnose endocrine pathology, and correction of thyrotoxicosis is critical for successful heart rhythm control. The article also discusses the problem of thyrotoxic cardiomyopathy caused by the toxic effect of an excess of thyroid hormones: features of this heart lesion, factors affecting its formation, clinical significance and contribution to the development of rhythm disorders. The greatest significance is the development of atrial fibrillation against the background of thyrotoxicosis in patients of the older age group, which is already burdened with various cardiovascular diseases. Atrial fibrillation is the most common cardiac arrhythmia in thyrotoxicosis. The formation of arrhythmia in hyperthyroidism is based on the simultaneous existence of frequent focal impulses and circular movements of the excitation wave-the re-entry mechanism. Successful treatment of atrial fibrillation in patients with thyrotoxicosis is possible only when euthyroidismis achieved. In most cases, when thyrotoxicosis is stopped, spontaneous recovery of the sinus rhythm is noted. The chances of restoring sinus rhythm are lower in elderly patients with concomitant organic myocardial pathology or long-term atrial fibrillation. It should be remembered that even a radically cured thyrotoxicosis leads to a deterioration in the life prognosis.