While I generally eat pretty well, the best thing I've done for my heart is to calm down my body and mind with yoga.
I maintained taking vitamins, minerals, or other supplements because i do believe that this will keep my health away from any other diseases. I do exercise also.
I cut gluten out of my diet. Since doing so eight months ago my heart palpitations went away. It has been linked to heart disease. They are finding out that many heart issues are auto-immune in nature. Check out Gluten Intolerance or Gluten Sensitivity on the web for a whole new world of information.
Best of luck! :)