Atrial septal defects
Atrial septal defects (ASD) are a group of congenital heart diseases characterised by defect in the inter atrial septum allowing blood flow from one atrium to the other. They are among the most common congenital heart diseases. Recognised by Leonardo Da Vinci in 1531, atrial septal defect is the earliest recorded congenital malformation of the human heart. As the condition remains asymptomatic during the first few decades of life, it is usually diagnosed as an incidental finding on routine clinical examination.
Types of atrial septal defect
Atrial septal defects are classified according to the location of the interatrial communication. Echocardiography is the main imaging modality for diagnosis and functional assessment of ASDs.
Ostium secondum atrial septal defect
Ostium secondum ASD is the most common type and accounts for 70 - 80% of atrial septal defects. This type of defect occurs in the region of fossa ovalis. The size of the defect can be quite variable. Echocardiographic differentiation can be difficult between a small ASD and a patent foramen ovale (PFO). PFO is a valvular