Enlarged right ventricle with thickened wall
Ventricular septal defect (abnormal opening between left and right ventricles)
Narrowing of the pulmonary artery causing blockage of bloodflow
Aorta is located more to the right than normal and takes in blood both ventricles
*Not part of Tetralogy of Fallot, but frequently occurs with it "Patent Ductus Arteriosus": a vessel that usually closes up shortly after birth, but in this case remained open, causing changes to bloodflow