A 68-year-old man presents to the emergency department (ED) for dyspnea on exertion for the past 3 days. He denies chest pain, cough, orthopnea, or paroxysmal nocturnal dyspnea.

His history reveals he has hypercholesterolemia and a 10-year history of hypertension. He is maintained on lisinopril 20 mg/d, simvastatin 20 mg/d, and tadalafil 10 mg, as needed.

His physical examination reveals a blood pressure (BP) of 146/96 mm Hg, a respiratory rate of 18 breaths/min, and a room air oxygen saturation of 92%. He has no jugular venous distension and he has clear lungs in all fields. His heart examination reveals a regular rhythm, with no murmurs or extra sounds. He has normal peripheral pulses and no peripheral edema.