Many congenital heart defects do not result in clear symptoms. However, serious or multiple congenital heart defects can cause symptoms such as: Blue skin, lips and fingernails Chest pain Fainting Heart murmur Palpitation (fast, strong or irregular heartbeats) Poor blood circulation Rapid breathing Tiredness Failure to thrive (grow) in newborns or infants These symptoms depend on the type and severity of CHD.