I've had an echo, which the doctor said was disgustingly perfect. A 30 day holter monitor which didn't record anything, but I continue to have daily shortness of breath. It scares me because it does happen after exercise but also comes when I'm anxious. It doesn't fit the asthma frame because it's usually a feeling in my throat or chest that I'm just not getting enough air in. What could this be? Anxiety? Acid reflux? Something fatal? It's so scary. Any other tests to get done?