I have to sleep with many pillows to elevate upper body to 45degree angle. Also sleep on right side. When lie with less pillows can't breathe deeply, feel heart tight in chest/chest pressure. Did echocardiogram and ecg all fine though trace valve regurgitation. Thought they would see enlarged heart but they did not. Also feel better when raise legs in bed, I thtink Cheney said that eases pressure off the heart. I know stress definateyl makes me feel more heart pressure, and the breathing issue got worse after panic attack in hyperbaric oxygen chamber, feels like strained heart muscle. But problem already started at onset cfs.