Usefulness of exercise stress echocardiography to identify masked pulmonary hypertension associated with hyperthyroidism.

Hyperthyroidism is recognized as a cause of pulmonary hypertension (PH). Exercise stress echocardiography (ESE) can assess changes in cardiovascular function during exercise and plays an important role in the noninvasive evaluation of patients with suspected PH. We herein report a case involving a 51-year-old woman with exertional dyspnea who was diagnosed with Graves' disease. Resting transthoracic echocardiography showed normal left ventricular systolic and diastolic function, no significant valvular disease, and a tricuspid regurgitation pressure gradient (TRPG) of 34 mmHg. ESE revealed an elevated maximum TRPG of 61 mmHg during exercise, associated with dyspnea. We presumed that the cause of exertional dyspnea was PH associated with hyperthyroidism. Following treatment with thiamazole, euthyroid status was achieved and her symptoms improved. Post-treatment ESE showed improvement, with a maximum TRPG of 38 mmHg during exercise. ESE has the potential to identify PH associated with hyperthyroidism and to serve as a noninvasive tool for monitoring the therapeutic course after treatment. Learning objective: Pulmonary hypertension (PH) should be suspected in patients with hyperthyroidism who present with unexplained exertional dyspnea. Exercise stress echocardiography (ESE) can noninvasively reveal masked PH and should be considered in patients with hyperthyroidism and exertional dyspnea when resting echocardiography does not identify a clear cause. ESE can also be used to monitor the therapeutic course of PH following treatment for hyperthyroidism.