A 61-year-old woman was referred for evaluation of intermittent exertional breathlessness of 3 years duration at New York Heart Association functional class II. She had associated symptoms of chest tightness, palpitations, and dependent pedal edema for which she given metoprolol and furosemide as needed. On review of systems, she denied a history suggestive of angina, wheeze, orthopnea, paroxysmal nocturnal dyspnea, or syncope. Her other medical problems included hypothyroidism and hyperlipidemia. She was a remote 5-pack-year smoker and had no history of chronic pulmonary disease or thromboembolism. She lived on a farm and had been exposed to the usual farm animals.