For the past 3 days my wife has chest pain that extends until her left arm. she has also been often out of breath. what could it be? thanks in advance

Seek attention now: Someone with chest pain of recent onset associated with shortness of breath can have something serious and life-threatening. Please take her to the er or even call 911. One of the causes of what you describe is a heart attack. Don't delay. There may be other less serious causes, but one needs to make sure it isn't a heart attack. If she has pain at present, then call 911!

Depends: When does it occur? How old is your wife, what other medical problems does she have? It could be ischemic heart disease...Would see a doctor.