Harmless (innocent) heart murmurs usually don't cause any other symptoms. Symptoms of worrisome heart murmurs depend on the cause. Heart murmur symptoms may include: 
Blue or gray fingernails or lips
Chest pain
Cough that doesn't go away
Dizziness
Swollen liver
Swollen neck veins
Fainting
Heavy sweating with little or no activity
In infants, poor appetite and lack of growth
Shortness of breath
Swelling or sudden weight gain
