Plasma ET-1 levels were significantly increased in both AF and hyperthyroid patients (mean±SEM: 1.96±0.164, 1.89±0.207, 1.31±0.101, 0.949±0.055, and 0.871±0.060 pg/ml for AF, Hyper+AF, Hyper, Hypo, and control; respectively, p<0.0001, Fig 2A). Here, EDN1 is linked to atrial fibrillation.