A 67-year-old man presents with progressive shortness of breath over 8 months
A 67-year-old man presents with progressive shortness of breath over 8 months. He reports: • Increasing dyspnea with exertion • Dry, persistent cough • Fatigue • Decreased exercise tolerance • Unintentional 10-pound weight loss He denies wheezing, chest pain, fever, or recent respiratory infection. Past medical history includes hypertension and hyperlipidemia. He...