Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients

Abstract

BackgroundAtrial fibrillation (AF) is the most common arrhythmia in adults, and is encountered in 10-15% of the patients with hyperthyroidism. Unless euthyroidism is restored, pharmacological or electrical cardioversion is controversial in patients with AF who remain hyperthyroid.ObjectiveThe aim of this study was to assess the efficacy of electrical cardioversion and predictors of AF recurrence in hyperthyroid and euthyroid patients.MethodsThe study included 33 hyperthyroid (21 males) and 48 euthyroid (17 males) patients with persistent AF. The patients were sedated with intravenous midazolam before undergoing electrical cardioversion delivered by synchronized biphasic shocks. Rates of AF recurrence were recorded.ResultsMean follow-up was 23.63 ± 3.74 months in the hyperthyroid group and 22.78 ± 3.15 months in the euthyroid group (p = 0.51). AF recurred in 14 (43.8%) and 21 (44.7%) patients in each group, respectively (p = 0.93). Multivariate regression analysis in each group showed that AF duration was the only predictor of AF recurrence, with odds ratios of 1.38 (95% confidence interval [CI] = 1.05 - 1.82, p = 0.02) in the hyperthyroid group and 1.42 (95% CI = 1.05 - 1.91, p= 0.02) in the euthyroid group.ConclusionRates of long-term AF recurrence were similar in successfully cardioverted hyperthyroid and euthyroid patients. The only predictor of AF recurrence in both groups was AF duration.

The Real Role of β-Blockers in Daily Cardiovascular Therapy

“…Atrial fibrillation is a common finding in hyperthyroid states (encountered in 10–15% of the patients) [ 81 ]. In those with thyrotoxicosis, treatment with β-blockers not only significantly decreased heart rate and systolic blood pressure but also improved other hyperadrenergic symptoms such as muscle weakness, tremor, degree of irritability, emotional lability, and exercise intolerance [ 82 – 85 ].…”

Atrial fibrillation and hyperthyroidism: A literature review

“… 23 In a study performed by Gurdogan and colleagues, irrespective of thyroid status, prolonged duration of atrial fibrillation prior to cardioversion was a poor predictor for sustaining sinus rhythm. 24 Further studies are required to identify those who are good candidates for cardioversion when there is a history of hyperthyroidism.…”

Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients

“…I have read with great interest the article entitled "Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients" by Gürdogan et al, 1 recently published in Arquivos Brasileiros de Cardiologia. The investigators reported that rates of atrial fibrillation (AF) recurrence were similar in hyperthyroid and euthyroid patients and that the duration of AF was the only predictor of AF recurrence in both.…”

“…In the light of this knowledge, Gürdogan et al 1 should have reported the vitamin D levels of the patients in their study and discussed the association between the levels of this vitamin and AF recurrence.…”

“…We are pleased that Dr. Cerit showed great interest in our article entitled ''Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients'' published in Arquivos Brasileiros de Cardiologia. 1 …”