Subjects and methods: 258 Basedow' patients with thyrotoxicosis age 37, 0 (27, 0 - 52, 0), female: 213 (83, 6%); male 45 (17, 4%). Serum NT-proBNP levels were measured by electroluminescence immunoassay (ECLIA) and doppler echocardiography performed in EPIQ 5G to determine some cardiac morphofunctional parameters.