What you are refering to is cross shunting of blood between heart chambers. Usually the shunt is from left side to the right side. The reason this happens is because the pressure is higher on the left side normally and blood lows through the septum (wall separating chambers). This not as serious as right to left side because the blood that goes to the right side is oxygenated blood and will be recirculated through the lungs.uase the
When there is cross shunting (right side to left side) the pressure on the right side is abnormally high. This condition can cause hypoxia because the right side blood has not been oxygenated by the lungs, and that blood mixes with good oxygenated blood and contaminates the blood that goes into circulation.
Hope that provides some insight, and only your doctor can tell what treatment is appropriate and apparently there is just minor left to right flow. Often that doesn't cause a problem nor advance. Take care and thanks for the question.