55-year-old Male with Exertional Dyspnea

Dyspnea is a common presenting complaint for many patients in the emergency department. A 55-year-old man with type I diabetes presented to the emergency department with one month of intermittent palpitations and dyspnea. His lungs were clear to auscultation, and his chest radiograph was normal. This case takes the reader through the differential diagnosis and systematic work-up of dyspnea with discussion of the diagnostic study, which ultimately led to this patient's diagnosis and successful treatment.