A 56-year-old man was admitted to the hospital with malaise, weakness, and fatigue, He was short off breath and had bilateral foot edema. Even though he had been very active a month earlier, Pre could no longer climb stairs. For the last two weeks, he had had a cough producing green sputum, a ''tight feeling'' in his chest, polyuria, and polydipsia, He had not had radiating chest pain, palpitations, leg pain or erythema, hemoptysis, diaphoresis, flushing, fever, chills, nausea, vomiting, diarrhea, or a loud snore.