#TetrologyOfFallot #BirthDefect #heart MEDICAL ANIMATION TRANSCRIPT: Tetralogy of Fallot is a birth defect that changes normal blood flow through a baby's heart. A healthy heart has four chambers, the right atrium and right ventricle, and the left atrium and left ventricle. After delivering oxygen to the body, oxygen-poor blood flows into the right atrium. When the right atrium contracts, it loads blood into the relaxed right ventricle. Then the right ventricle contracts, sending blood to the lungs through the pulmonary artery. The blood picks up oxygen in the lungs, then returns to the left atrium. The left atrium contracts, filling the relaxed left ventricle with blood. And the left ventricle contracts to pump and deliver oxygen-rich blood to the body through the aorta. Tetralogy of Fallot is a birth defect made up of four problems with the heart and its blood vessels. A Ventricular Septal Defect or VSD is a hole in the wall between the two ventricles. The hole allows oxygen-rich ...