54-Year-Old Man With Dyspnea, Cough, and Hypoxemia

摘要

A 54-year-old man has developed gradual onset ofndyspnea and nonproductive cough over the pastn6 months. He was an avid rock climber and long-ndistance runner; now, he is unable to perform eithernof these activities. He was first referred to a cardiol-nogist, who found the results of the following tests tonbe normal: ECG, exercise stress test, and cardiacncatheterization. His medical history is nonrevealing.nHe has not smoked for the past 10 years.