Types of ASD

Types of ASD

The types of atrial septal defect are:

1. Primum ASD
2. Secundum ASD, also called fossa ovalis type of defect
3. Superior vena caval type of ASD near the orifice of the superior vena cava, usual sinus venosus ASD
4. Inferior vena caval type of ASD near the opening of the inferior vena cava without an IVC rim
5. Coronary sinus type of defect

Primum ASD is associated with cleft anterior mitral leaflet and mitral regurgitation. Superior vena caval defect is associated with partial anomalous pulmonary venous connection. Primum ASD is part of the endocardial cushion defect and atrioventricular septum is absent and the AV valves are at the same level.

In some individuals, more than one type of ASD may be seen. In secundum ASD, more than one defect may be seen sometimes. Occasionally a fenestrated type of atrial septum may be noted, with multiple small defects. Even though secundum ASD is the most eminently device closable defect, presence of fenestrations and multiple defects may make the procedure difficult.

Atrial septal aneurysm with a defect associated is also not uncommon. Such defects are prone for systemic embolism and stroke. Even otherwise paradoxical embolism can occur in ASD due to phasic right to left shunt during respiratory cycle and Valsalva maneuver.