What this basically means is that there is a form of heart disease that can mimick a heart attack but whose true cause may just be being over stressed leading to release of the fight or flight hormones ( adrenaline). Did you also know that research at Harvard university has shown that one of the ingredients required for one to live to 100yrs is to be optimistic about life. It also compared people who had suffered a heart attack and categorised them into optimistic guys and pessimistic guys based on a questionare they answered. The optimistic guys were doing much better 5 years down the line while a greater proportion of the pessimists had suffered a recurrent heart attack ( with all other things between the two groups held constant).
This gives me a whole new meaning to the verse " Guard your heart... proverbs 4:23)