Hyperthyroidism presenting as isolated tricuspid regurgitation and right heart failure.

Although hyperthyroidism has many signs and symptoms, right heart failure can occasionally be the main presenting symptom. We describe the case of a previously healthy 42-year-old woman whose chief complaint was progressive bilateral lower extremity edema. The echocardiogram revealed right atrial dilatation and moderate-to-severe tricuspid regurgitation. Results of laboratory studies were consistent with hyperthyroidism. Thyroid ablation resulted in permanent resolution of symptoms and resolution of tricuspid incompetence on echocardiography. In a case of isolated, unexplained tricuspid regurgitation, it is important to consider indolent hyperthyroidism in the differential diagnosis.