Acyanotic heart defects are heart problems that develop before or at birth but do not normally interfere with the amount of oxygen or blood that reaches the body's tissues. Acyanotic heart defects include ventricular septal defect (VSD), atrial septal defect (ASD), patent ductus arteriosus (PDA), pulmonary valve stenosis, aortic valve stenosis, and coarctation of the aorta.

Acyanotic heart defects do not usually cause cyanosis—a bluish tint to the skin, lips, and nail beds due to reduced oxygen flow. If cyanosis develops in a person with acyanotic heart defects, it is typically a result of increased activity (such as crying and feeding) during which more oxygen is needed.