A 70-year-old man presents to the cardiology clinic complaining of progressively worsening shortness of breath over the past three months. He states, “I can barely walk to the mailbox without stopping to catch my breath.” His medical history is significant for an anterior myocardial infarction four years ago, leading to ischemic cardiomyopathy with a reduced ejection fraction. He is currently on a maximally tolerated guideline-directed medical therapy regimen, including sacubitril-valsartan, carvedilol, spironolactone, and dapagliflozin. He denies recent chest pain, fever, or palpitations. He is a retired teacher, a former smoker who quit five years ago, and drinks alcohol occasionally.

He appears comfortable at rest but slightly dyspneic when speaking in long sentences. He is afebrile. His blood pressure is 112/68 mmHg with a regular heart rate of 78 bpm, and his respiratory rate is 18 breaths per minute with an oxygen saturation of 95% on room air.