Risk Factors for New Onset Atrial Fibrillation during Thyroid Gland Surgery

OBJECTIVE: Thyroid dysfunction is a common cause of atrial fibrillation (AF). Incidence of AF is high in patients with both expressed and subclinical hyperthyroidism. The aim of our study was to determine the incidence and predictors of new onset atrial fibrillation (NOAF) in euthyroid patients undergoing thyroid surgery. SUBJECT AND METHODS: The study included 1,252 euthyroid patients with American Society of Anesthesiologists (ASA) physical status ASA 2 and ASA 3, who were 18 years and older and were in sinus rhythm. Patients without comorbidity and patients with persistent AF were excluded. We investigated the influence of the following preoperative characteristics on the occurrence of NOAF: age, sex, body mass index, ASA score, admission diagnoses, and comorbidity. We noted the influence of difficult intubation of trachea, type and duration of surgery, and time under general anaesthesia. Univariate and multivariate logistic regression were used to determine predictors of occurrence of NOAF. RESULTS: NOAF was noted in 0.72% of patients. Patients with NOAF were older (63.11 vs. 56.81 years) than patients without NOAF, but this was not statistically significant. Significantly more patients from the NOAF group had preoperative heart rhythm disturbance and a history of angina pectoris, in contrast to patients without registered NOAF (p = 0.001; p = 0.017). Multivariate analysis showed that a history of heart rhythm disturbance was an independent predictor of NOAF. CONCLUSIONS: Incidence of NOAF during thyroid surgery is similar to the other type of surgery, if the values of thyroid hormones are normal.