Evaluation of cardiac autonomic neuropathy in graves' disease: relation to thyroid functional status, demographic and disease characteristics

• Grant number: 19/25573-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2020
• End date: September 30, 2021
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Denise Engelbrecht Zantut Wittmann
• Grantee: José Victor Roveroni Zuntini
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Graves disease is an autoimmune disease and is the main cause of hyperthyroidism. It occurs mainly in women aged 40-60 years. The pathogenesis of the disease involves the presence of anti-TSH receptor (TRAb) antibodies, which bind to TSH receptors on the surface of follicular cells, resulting in continuous and uncontrolled thyroid stimulation, which leads to over synthesis of thyroid hormones. T3 and T4 and thyroid hypertrophy. The clinical condition includes hyperthyroidism and specific extrathyroid manifestations that may affect several other systems such as cardiovascular. The most common signs are tachycardia, atrial fibrillation, angina pectoris or even acute myocardial infarction. Such manifestations occur mainly when the patient is in thyrotoxicosis state.This study aims to characterize a possible complication in patients with Graves' disease: Cardiac Autonomic Neuropathy by means of an evaluation performed at a tertiary care referral center in a university hospital.To this end, the NAC test will be performed on eighty patients diagnosed with Graves Disease in addition to the same number of people with no history of Graves' Disease corresponding to the control group. The test consists of cardiac monitoring of the patients during three stages: rest followed by deep breathing, Valsalva test and patient in an orthostatic position.Thus, we seek to trace a pattern of electrical activity of the heart correlating it to sociodemographic and disease characteristics.