What procedure will increase right to left shunting in a patient with atrial septal defect?

A procedure that can increase right-to-left shunting in a patient with an atrial septal defect (ASD) is the creation of a right atrial to left atrial connection, such as through the use of a balloon septostomy. This procedure enlarges the existing ASD or creates a new one, allowing more deoxygenated blood from the right atrium to flow into the left atrium. This can be particularly useful in cases of severe pulmonary hypertension, where the pressure in the right atrium exceeds that of the left, facilitating right-to-left shunting. However, it's important to note that this procedure is generally considered a palliative measure rather than a definitive treatment for ASD.