What was your pressure from your echo and then what was it from the RHC? I know they told me echos can underestimate or overestimate the pressure reading. My shortness of breath has been like you, walking uphill and/or going too fast. Have been bothered by that for years but has gotten worse the last few. Also climbing stairs sometimes. But I have weak knees also so never know if the problem is that or the breathing! I've been on a CPAP for 10 years due to mild sleep apnea. Now don't sleep well without it. You'll get used to it - I use a nasal pillow and not a full mask.