u may have a soft psychiatric illness called as panic disroder a part of
anxiety disorder whichi is characterised by episodes of palpitations[ fast heartbeats] with sense of suffocations with the strong feeling of going to die which makes a person compulsory to attend physician and get evaluatee . that too repeatedly and not convinced even after repeated assuarance that u dont have any problem. but b4 that u shoud get evaluated by a cardiologist once and if nothing found, directly
consult a psychiatrist without loosing more time and money in inivstigations