My wife is 65 and has the following symptoms: shortness of breath, frequent (but not always) chest tightness, occasional swelling of ankles and feet, suddenly experiencing low level of energy. One hour naps daily and to bed by 8:00. Unusual for this high energy woman. No known health issues prior to this in the last few months. EKG and ECG, pulmonary CT scan looking for blood clots (negative), 24/7 heart monitoring, stress test all show no cardiolo issues. Never smoked, low blood pressure, low cholesterol. Any ideas?