A congenital cardiovascular shunt is any condition that causes the heart’s blood flow to deviate from its normal path. It's one of the most common birth defects. The most common shunts include a hole between the two upper chambers of the heart (the left and right atrium), and a hole between the two lower chambers of the heart (the right and left ventricles). A hole allows oxygenated blood and deoxygenated blood to directly mix, reducing the amount of oxygen that can be delivered to the rest of the body. Another common shunt condition is a lingering connection between the aorta (the major channel for delivering blood to the body) and the pulmonary artery (the vessel that delivers blood to the lungs). These arteries are normally attached during a baby’s development by a connection called the patent ductus arteriosus, which helps blood bypass the baby's developing lungs. The connection normally withers away after birth as the baby starts to breathe on its own. But if it lingers, it can cause blood pressure changes that can hurt lung and heart function, and potentially cause heart failure. Many congenital cardiovascular shunts, such as holes, are detected before birth during an ultrasound. Shunt symptoms after birth include difficulty breathing, bluish skin, slowed growth, and heart failure. An ultrasound can confirm if a shunt is present. Treating a shunt usually requires heart surgery that returns the blood flow to a normal path by removing or repairing the structures that are diverting the blood away it. Talk with your baby's doctors and specialist about the best course of treatment for your baby. Support groups are also good resources of support and information.