Question

Relate the physiologic clinical significance of atrial-septal defects on hemodynamics.

Answer 1

Atrial septal defect (ASD) is a heart defect in which blood flows between the atria (upper chambers) of the heart. Means there will be communication between the left and right atria. Oxygenated blood in the left atrium is under high pressure will pump into right atrium through this defect. This left to right shunting of blood places burden on right side of heart causing increased pulmonary blood flow.This atriovenous shunt normally does not cause cyanosis as shunting is from left to right means oxygenated blood is shunting to deoxygenated blood. But in some cases like pulmonary stenosis or pulmonary hypertension the right atrial pressure increases causing venous blood to flow into left atrium through the defect causing cyanosis.