Factors associated with the symptom severity of thyrotoxic atrial fibrillation

Aim: to identify factors associated with the symptom severity of thyrotoxic atrial fibrillation (TAF). Patients and Methods: this retrospective study included 70 patients with overt hyperthyroidism and TAF. The following parameters were used to assess TAF severity: the type of atrial fibrillation (AF); functional class (f.c.) of the heart failure (HF) and the ejection fraction (EF) coexisting with AF; evaluation of AF-related symptoms using the European Heart Rhythm Association score (EHRA); and the ventricular contraction rate (VCR) during AF. Clinical features, medical history and echocardiographic parameters were compared in patients with different TAF severity to determine factors, associated with severe clinical course of TAF, meeting the following criteria: persistent type of AF; III-IV f.c. of the heart failure; EF<50%; EHRA 3–4; and VCR ≥90 per minute. Results: as regards the clinical features and medical history, only male gender was considered as a predictor of the severe course of TAF defined as follows: the persistent type of AF, a decrease in EF<50%, the development of heart failure III-IV f.c., and the severe AF symptoms (EHRA 3–4). The echocardiographic parameters: the left atrium diameter was associated with the type of AF, and the left ventricle mass index was associated with EHRA symptom severity class. Both parameters were associated with the heart failure f.c. and the EF during TAF. Conclusion: factors associated with the symptom severity of TAF, were identified in the study. These findings could be used for predicting the clinical course of TAF and, in the future, for optimizing the guidelines for the management of patients with TAF. KEYWORDS: thyrotoxicosis, hyperthyroidism, atrial fibrillation, thyrotoxic atrial fibrillation, Graves’ disease. FOR CITATION: Ponomartseva D.A., Babenko A.Yu. Factors associated with the symptom severity of thyrotoxic atrial fibrillation. Russian Medical Inquiry. 2022;6(9):494–500 (in Russ.). DOI: 10.32364/2587-6821-2022-6-9-494-500.