Can a healthy heart go into cardiac arrest or heart attack due too fear, anger, exercise, sexanxiety or any kind of stress such as: natural disaster?

Heart Disease at 28?: Not likely given your age. It is much more likely that any pains or other heart symptoms would be due to anxiety or stress and this is called a "panic attack'.

Kind of: Cardiac arrest of the temporary type can occur, it is called a vaso vagal reaction, usually leads to fainting, but can cause actual stoppage of the heart for a brief time, with subsequent recovery. Heart attack can occur in a healthy heart due to severe spasms of the arteries of the heart. Are you looking to explain someone's death?

No: This is the stuff of fiction. The one situation where it might happen is takotsubo which if it is ever fatal kills very seldom.