Shortness of breath, chest pains, tachycardia and palpitations

Hi Dr T,
I was just wondering about a recent 24 hour ecg I had. I walked up a hill whilst wearing one and I got chest pains which felt like pressure and breathlessness, but the ecg only came back with tachycardia at that time?
Now would the ecg if it was angina I was experiencing? Can that now be ruled out? Can pulmonary hypertension be revealed on a echocardiogram? I am being sent for one this week and they have mentioned this to me before but not sure if that would be the test to find that? The pains I experience come on when eg. Walking up stairs, climbing a hill or standing up in the mornings from lying, but say if I get them walking up the stairs by the time I’m at the top the pains have completely disappeared? Could this be tachycardia? The outline of my lips sometimes turn a blueish color too.. I do have a hole in my heart but have been told its too small to cause any major problems like what I have been experiencing. Sorry for all the questions my cardiologist doesn’t explain things very well to me and don’t have a lot of time in his office to discuss anything. Thanks for your time.