Tachycardia can occur in infants. Supraventricular tachycardia (SVT) is the most common type of tachycardia observed, especially in infants and young children. Babies with this condition may exhibit symptoms such as rapid breathing and excessive drowsiness. Early diagnosis and treatment are of great importance if these symptoms are noticed. Tachycardia can sometimes be detected even in the womb and is not limited to infancy, also being observed in older children. When tachycardia is diagnosed in infants, appropriate treatment should be initiated immediately.