Congenital Heart Defects: Recognizing the Common Symptoms

Left-to-Right Shunt (Cyanosis May Develop)

This is the most common type of congenital heart defect. Examples include ventricular septal defect (VSD), atrial septal defect (ASD), and patent ductus arteriosus (PDA). These conditions often lead to increased blood flow to the lungs, which can cause a range of symptoms depending on the severity of the defect.

Ventricular Septal Defect (VSD)

Small VSDs often cause no noticeable symptoms, and children typically develop normally. However, moderate to large VSDs may lead to symptoms such as difficulty feeding, rapid breathing, excessive sweating, poor weight gain, and frequent respiratory infections during infancy. In severe cases, congestive heart failure may develop within the first six months of life. If significant pulmonary hypertension occurs, cyanosis may appear, physical activity can become limited, and right heart failure may eventually develop.

Atrial Septal Defect (ASD)

Many infants with ASD show no symptoms early in life. However, as children grow older, they may experience shortness of breath during physical activity, reduced stamina, delayed growth, and frequent lung infections. In cases with large shunts, heart failure can occur, leading to fluid retention and fatigue.

Patent Ductus Arteriosus (PDA)

If the ductus arteriosus is small, symptoms may be absent. However, when the opening is large, children may suffer from frequent respiratory infections, difficulty breathing, feeding problems, and poor growth. In severe cases, heart failure can develop. As pulmonary hypertension worsens, blood may flow in the reverse direction from the pulmonary artery to the aorta, causing differential cyanosis—bluish skin discoloration in the lower body and left arm, while the right arm remains unaffected.

Right-to-Left Shunt (Cyanotic Heart Disease)

This type of defect results in reduced oxygen levels in the blood, causing cyanosis—bluish discoloration of the skin and mucous membranes. Common conditions include Tetralogy of Fallot and transposition of the great arteries.

Tetralogy of Fallot

Cyanosis typically appears between 6 months and 1 year of age and progressively worsens over time. Children may have low exercise tolerance and often squat to relieve shortness of breath. Infants may experience episodes of sudden breathing difficulty during crying or feeding, sometimes leading to fainting, seizures, or loss of consciousness lasting several minutes. This is known as a hypoxic spell, caused by spasms in the right ventricular outflow tract that temporarily block blood flow to the lungs. Older children may complain of headaches and dizziness due to chronic oxygen deprivation. Clubbing of the fingers and toes is also common. A loud, harsh heart murmur can usually be heard along the left sternal border, often accompanied by a vibration. In extreme cases with complete pulmonary obstruction or atresia, no murmur may be present. The second heart sound of the pulmonary valve may be diminished or sound singular.

No Shunt (Non-Cyanotic Heart Defects)

These defects do not involve abnormal blood flow between the heart chambers but can still cause serious symptoms. Two common examples are pulmonary stenosis and coarctation of the aorta.

Pulmonary Stenosis

Mild cases may not produce any symptoms initially. However, as the severity increases, symptoms such as cyanosis, shortness of breath during exertion, fatigue, and palpitations may appear. In severe cases, patients may experience fainting spells and swelling due to fluid buildup in the body.