I feel as though my heart gets stuck and my chest opens up. I am left with a swelling feeling in my chest that keeps it open until after a certain amount of time and it goes away. It gives me a slight rush, as though a lot of blood is being pumped out and does not really affect my breathing to much. It is not an intense pain, but it "feels weird" and is pretty discomforting. I have also had a few times when this occurs where my right arm get intense pain as a result of what is happening in my chest. It is a very sharp acute pain that spans on the inside of my arm from my armpit to the end of my bicep area.