Well a healthy diet and exercise lack of stress is obvious, but, carrying some disperable aspirin (get used to the taste, it's OK) chewing 2 or more depending on dose and very very deep breathing - ensure diaphragm is coming right out, just a couple of times then rest or you get dizzy - also Flaxseed oil has helped me - there are many causes of heart disease, the main thing is not to worry about it and just be prepared to relaax, eat the aspirin, deep breathe and call help on your phone if you can, relaxation is the key as is asprin, as relaxing during an attack coupled with the deep breathing (scream or sing if u can but without panic- laugh if you can too!) the thing is to get oxygen to your extremeties and to thin the blood- learn the biology of the heart and you can figure out what to do calmly - hope this helps

the main thing is not to worry about it and just be prepared to relaax, eat the aspirin, deep breathe and call help on your phone if you can, relaxation is the key as is asprin, as relaxing during an attack coupled with the deep breathing (scream or sing if u can but without panic- laugh if you can too!)