There are many things that could cause the heart to flutter or beat irregularly. There may be an imbalance in the body's chemistry, thyroid function, blood sugar, or it could be simply a matter of not drinking enough fluids. The standard recommendation for daily fluid intake is eight, 8 ounce glasses of noncaffeinated fluid daily. A person who commonly experiences irregular heart beats or arrhythmias should also avoid decongestants, chocolates and other caffeine products which could make the heart beat fast. If you continue to experience this problem, it is wise to have a thorough examination by your physician.