Heart attack - First Aid and Emergency Treatment Guide

My husband have acidity troubles, if he has late meals or it gram dal in dinner he feels burning sensation in chest. has pain in left cheast for long time, feels restless, full and difficult to breath. It doesn't respond to Gelucil, are they symptoms of heart trouble? Is it acidity only?

what should be the firstaid and safe medicines to be given in case of suspected case of heart attack?

I have a continuous pain in my chest on left side..the pain is very low but extends upto left shoulder and then to arm also...it continues for a couple of days with some times only feeling of sweating..is this a cause of concern..I have consulted doctors a few times but tests were negative...still they asked me to take medicine for cholesterol, BP and Asprin...besides keeping clonazepam mouth dissolving tablets at home....Is there a cause of concern...should I go for angiography...please suggest.
King C Bharati