Ventricular septal defect (VSD) is a birth defect in babies that causes a hole in the wall (or septum) between a baby’s lower heart chambers. Heart chambers are also called right and left ventricles.

When a doctor listens to the heart of a person with a heart murmur, they may hear a whooshing, swishing, humming, or rasping sound. This is due to rapid, turbulent blood flow through the heart.