Is a 5mm Atrial Septal Defect in Children Serious?

A 5mm atrial septal defect (ASD) in children is generally not considered serious. It is typically classified as a small ASD, especially when compared to larger defects. However, in newborns, whose hearts are smaller, the threshold for what is considered small may be adjusted to around 3mm. The most common type of ASD in children is the secundum type, which accounts for about 75% of all ASD cases. This condition is usually not life-threatening throughout childhood.

Understanding Symptoms and Development

During infancy, the resistance to blood flow in both the left and right ventricles is relatively equal, resulting in minimal shunting of blood. As a result, many infants do not exhibit noticeable symptoms. Clinical signs typically appear only when there is a significant left-to-right shunt, which can lead to increased blood flow to the lungs and other complications.

Long-Term Outlook and Quality of Life

Children with small ASDs, including those measuring less than 5mm, often enjoy a quality of life similar to that of children without heart defects. In many cases, symptoms do not appear until adulthood—often between the ages of 30 and 45. Most children with ASD are asymptomatic and often lead normal, active lives. The condition is usually detected during a routine physical examination when a heart murmur is heard, prompting further diagnostic evaluation at a hospital.

Spontaneous Closure and Monitoring

It's important to note that in children under the age of four, there is approximately a 15% chance that a small ASD (less than 5mm) will close on its own without medical intervention. Therefore, in many cases, no immediate treatment is necessary, and the child can grow up without significant health issues. Regular follow-ups with a pediatric cardiologist are recommended to monitor the defect's progression and ensure timely intervention if needed.