Children with heart diseases can present with various symptoms. Infants may exhibit signs such as rapid breathing, fatigue, excessive sweating while feeding, sudden paleness, restlessness, abdominal swelling, fainting, cyanosis (bluish discoloration), and swelling throughout the body. Older children may also show symptoms like rapid fatigue, difficulty breathing with exertion, chest pain, palpitations, fainting, cyanosis, and swelling in the eyelids, face, abdomen, and feet. Sometimes, fainting episodes due to heart disease can be mistaken for seizures or epilepsy. It is important to keep in mind that certain heart conditions can lead to sudden death.