CHF (with or without preexisting heart disease), often secondary to atrial fibrillation but also described in sinus tachycardia, has a recognized association with hyperthyroidism.1, 15 Studies of this association have found it to be an uncommon manifestation of hyperthyroidism generally.21 It also reduces LVEF in 3% of cases.22 Li et al. 23 suggested that for the Graves' disease patients with the higher thyroid hormone of FT4 > 70.5 pmol/L and at the same time with the heart rate above 90 times per minute, the risk of hepatic function injury would increase. Here, TG is linked to atrial fibrillation.