Atrial Septal Defect

This condition involves a hole in the wall between the right and left atria of the heart, allowing blood to flow abnormally between them. It is a common congenital heart defect, accounting for about 5–10% of all cases, and occurs more frequent in females.

1. Secundum Atrial Septal Defect (ASD)

The most common type of ASD. It occurs in the middle part of the atrial septum

2. Primum ASD

This type occurs in the lower part of the atrial septum, near the atrioventricular (AV) valves. It is often associated with a broader defect known as an atrioventricular septal defect (AVSD) and may involve valve abnormalities.

3. Sinus Venosus ASD

A rare type of ASD that occurs near where the large veins (such as the superior vena cava) enter the right atrium. It is often associated with abnormal drainage of the pulmonary veins.

4. Unroofed Coronary Sinus

Defect where the wall separating the coronary sinus (a vein that collects blood from the heart muscle) and the left atrium is missing.

Many children with an ASD may not show any noticeable symptoms until their teenage years. However, if the defect is large and left untreated for a long time, it can lead to heart enlargement, arrhythmias, pulmonary hypertension, and sometimes mitral valve prolapse or regurgitation. In some cases, it may also cause complications during pregnancy and delivery, or increase the risk of a paradoxical embolism (a type of stroke caused by a blood clot passing through the heart defect).