Symptoms

Tetralogy of Fallot symptoms vary, depending on the amount of blood flow that's blocked. Signs and symptoms may include:

• A bluish coloration of the skin caused by low blood oxygen levels (cyanosis)
• Shortness of breath and rapid breathing, especially during feeding or exercise
• Poor weight gain
• Tiring easily during play or exercise
• Irritability
• Prolonged crying
• Heart murmur
• Fainting
• An abnormal, rounded shape of the nail bed in the fingers and toes (clubbing)

Tet spells

Sometimes, babies who have tetralogy of Fallot will suddenly develop deep blue skin, nails and lips after crying or feeding, or when agitated.

These episodes are called tet spells. Tet spells are caused by a rapid drop in the amount of oxygen in the blood. Tet spells are most common in young infants, around 2 to 4 months old. Toddlers or older children might instinctively squat when they're short of breath. Squatting increases blood flow to the lungs.

When to see a doctor

Seek medical help if you notice that your baby has the following signs or symptoms:

• Difficulty breathing
• Bluish discoloration of the skin
• Passing out or seizures
• Weakness
• Unusual irritability

If your baby becomes blue (cyanotic), place your baby on his or her side and pull your baby's knees up to his or her chest. This helps increase blood flow to the lungs. Call 911 or your local emergency number immediately.