James S. Walker, DO

A 66-year-old woman presents tothe emergency department(ED) with exertional dyspnea, generalizedweakness, and orthostaticdizziness; the symptoms startedabout 1 week earlier and have progressedinsidiously. The patient alsoreports diaphoresis and nausea withoutvomiting. She has no chest pain,palpitations, cough, or hemoptysis;she has not had a recent respiratorytract infection. While she is waitingto be admitted, she has an episode ofsyncope.

A 74-year-old man with a history ofatrial fibrillation presents to hisprimary care physician with dyspneaof 4 days’ duration. The dyspnea developedwhile he was walking as partof his recovery from back surgery forspinal stenosis 1 month earlier. Hebecame progressively short of breathand was unable to carry out his exerciseprogram.