Reversible Pulmonary Hypertension Related to Hyperthyroidism: A Case Report

A systematic assessment is crucial to confirm the diagnosis of pulmonary hypertension (PH) and classify it based on its etiological mechanism. This case report describes a young woman with a recent diagnosis of Graves' disease who presented with exertional dyspnea and fatigue. The initial ultrasound heart examination indicated moderate tricuspid regurgitation, an increased estimated systolic pulmonary artery pressure (sPAP), and suggestive alterations of atrial septal communication. For a more detailed characterization of this aspect, a transesophageal echocardiogram (TEE) was performed, which confirmed, through the agitated saline injection method, the presence of a patent foramen ovale (PFO). Further investigation for common causes of pulmonary hypertension yielded negative results. Treatment with methimazole and radioiodine ablation with glucocorticoid coverage was made. One year later, the patient reached a euthyroid state and reported an improvement in the symptoms. Follow-up transthoracic echocardiogram revealed resolution of pulmonary hypertension, with a normal sPAP and normal-sized right chambers. Right heart catheterization confirmed the normal findings. Hyperthyroidism is considered a potential cause of pulmonary hypertension through the effects of high cardiac output and autoimmune-induced pulmonary vascular endothelium injury. As such, it should be included in the etiological investigation of suspected pulmonary hypertension, as its cardiovascular manifestations may be completely reversible without the need for targeted therapy.