I think u should see a neurologist
because your symptoms of flutter here and there for last so many years seems to be of some neurological origin. It is not easy to rule out heart disease
directly but i feel that it is last on the cards.
Chest pains that u have right now could be just because of anxiety
Marfans disease is seen in patients with who have long slender body and the arm span from side to side is more than their height. I agree that pneumothorax
is sen in such patients