Systemic-to-pulmonary shunt

A systemic-to-pulmonary shunt is a cardiac shunt which allows, or is designed to cause, blood to flow from the systemic circulation to the pulmonary circulation. This occurs when: A systemic-to-pulmonary shunt functions as follows:
 * 1) there is a passage between two or more of the great vessels; and,
 * 2) systemic pressure is higher than pulmonic pressure and/or the shunt has a one-way valvular opening.
 * 1) left-to-right in the absence of arterioventricular discordance.
 * 2) right-to-left if the great vessels are transposed.