Atrial Septal Defect: Common Symptoms and Physical Characteristics

Atrial Septal Defect (ASD) accounts for approximately 20% of all congenital heart disease cases. In infancy, ASD often presents no noticeable symptoms, and the condition is typically discovered during routine physical exams when a heart murmur is detected. During childhood, symptoms may begin to emerge, including fatigue, shortness of breath during physical activity, and an increased susceptibility to respiratory infections.

Impact on Growth and Development

Children with significant left-to-right shunting may experience delayed growth and development due to reduced systemic blood flow. This can lead to a smaller physical stature, weight loss, persistent tiredness, and breathlessness after mild exertion. Additionally, pulmonary vascular congestion increases the likelihood of developing bronchitis and other respiratory conditions.

Cyanosis and Associated Complications

In certain situations—such as crying, lung infections, or heart failure—the pressure in the right atrium may temporarily exceed that of the left atrium. This shift can cause a transient right-to-left shunt, resulting in cyanosis (a bluish tint to the skin due to low oxygen levels). If left untreated, some individuals may progress to chronic heart failure and persistent cyanosis by adulthood.

What to Expect During a Physical Examination

During a clinical evaluation, a healthcare provider will typically detect a grade II-III systolic ejection murmur. This type of heart sound is best heard at the left sternal border, specifically between the second and third intercostal spaces. The presence of this murmur is often the first clue in diagnosing an atrial septal defect and warrants further diagnostic testing.