Dr. My wife is 33 and beta thalassemia minor, diabetic type 2, low b12, low vit D. She suffers shortness of breath with pain in centre of the chest (doesn't appear heart) sometime accompanied by numbness in the feet legs and lower face. Lasts for about 40 minutes then slowly improves. Done all possible tests but doctors unable to diagnose. They call it hyperventilation, anxiety, etc. Any recommendation for some test to get concrete answer so correct line of treatment can be started?