Clinical Research Directory

Cardiac Symptoms in Patients With Treated Graves' Disease

Hyperthyroidism is a condition with increased production of thyroid hormone from the thyroid gland. Hyperthyroidism affects the heart's inotropy (contractile force) and chronotropy (rhythm). Therefore, patients often experience symptoms such as increased/irregular heart rate, pounding heartbeats, and shortness of breath. The cardiac symptoms often improve when hyperthyroidism is treated and biochemical euthyroidism is achieved. However, knowledge of the long-term effects on the heart is limited. Existing studies have generally shown that patients with hyperthyroidism have an increased morbidity and mortality. The investigators conducted a questionnaire survey which showed that about 38% of patients with Graves' disease continue to experience cardiac symptoms even months after normalization of thyroid hormone concentrations in the blood. This observation supports the presence of a persistent cardiovascular dysfunction, which may be due to a modulation of genomic or non-genomic factors with an effect on the cardiovascular system. These reflections are the focus of this clinical study. The aim of the study is to investigate the possible pathophysiology for this new "syndrome" in biochemically euthyroid patients. It is not a repetition of previous similar experiments.