In infants diagnosed with ASD, the blood flow can be in which direction?

In infants diagnosed with an Atrial Septal Defect (ASD), blood flow can indeed occur in either direction. This is primarily due to the pressure differences between the left and right atria. Typically, the left atrial pressure is higher than that of the right atrium, which facilitates a left-to-right shunt. However, in certain conditions, such as increased right atrial pressure due to pulmonary hypertension, the flow can reverse, allowing for a right-to-left shunt.

The consideration of pressure dynamics in the heart is crucial in understanding how blood flows through an ASD. Infants with ASD may experience deficits in oxygenation as a result of the shunting, depending on the predominant direction of the flow at any given time. Thus, the ability for shunting to occur in either direction is a relevant concept in pediatric cardiology, particularly when evaluating the severity and implications of the defect in individual patients.