Inversion of the heart is a birth defect of the heart in which the two main arteries that carry blood away from the heart - the pulmonary artery and the aorta - are displaced. This is a rare but serious heart defect that changes the way blood flows through the body, leading to severe hypoxia. Without early artery bypass surgery, the body is not supplied with an adequate supply of oxygen-rich blood, so it cannot function properly and the child can face serious complications, including death.