Prevent heart palpitations with breathing--correct breathing, that is. Well, it's always a given to see a heart specialist for all heart ailments, including palpitations, but while you've not yet done so, try correct breathing.
You should breathe with your diaphragm, not by raising your chest but by expanding your belly to inhale and exhale by contracting it. Do this when you feel like your heart is about to palpitate. There are often telltale signs before it happens. You should know it if you sometimes suffer from palpitations.
Now, also avoid all softdrinks and spirited beverages. Shun all synthetic powdered or liquid juices or canned ones--even if they claim to be "fresh" fruit juices. They are acidic and create gas in your tummy which rises up to your chest and sometimes disrupts your heart beat if you're prone to palpitation.
Thus, you can prevent heart palpitations with breathing and a healthy lifestyle. It goes without saying, for instance, that staying up late at night can cause palpitations. So is an idle, dormant life. Start working out, again with your heart doctor's supervision.
In my case, mangosteen supplements and Q10 helped me a lot. I used to be unable to do any workout due to heart palpitations. Then I read about MX3-Plus which contains mangosteen extracts and Q10, said to be a good supplement for strengthening heart muscles, especially hearts that often suffer palpitations.
Today, by God's grace, I workout regularly and am athletic, fit and trim. Yes, you can prevent heart palpitations with breathing while you haven't seen your heart specialist yet. But you better see him or her soon!