Video - Pulmonary shunts

A pulmonary shunt occurs when there is re-diversion of blood from its usual path through pulmonary circulation. This can occur when there is an abnormal flow of blood from the right side of the heart to the left side of the heart, bypassing the lungs. Examples include conditions like patent ductus arteriosus, ventricular septal defect, and atrial septal defect. Sometimes a pulmonary shunt may be said when the alveoli fill with fluid, causing parts of the lung to be unventilated although they are still perfused. This is because even though blood from the right ventricles passes through the lungs before reaching the left atria, it is still unoxygenated.