Some common conditions can force your heart to beat faster, changing the rate and amount of blood moving through your heart and resulting in
heart murmurs. There are innocent murmurs and are common in
children and are quite harmless. "In any group of children, a large percentage is likely to have had one at some time. Innocent murmurs also may disappear and then reappear. Most innocent murmurs disappear when a child reaches adulthood, but some adults still have them.