Acyanotic heart defect have normal levels of oxyhemoglobin saturation in systemic circulation. This tends to be left to right side heart shunts, whereas cyanotic heart disease is right to left shunts which lowers oxygen saturation level.
Left to right shunting heart defects include ventricular septal defect or VSD (30% of all congenital heart defects), patent ductus arteriosus or PDA, atrial septal defect or ASD, and atrioventricular septal defect or AVSD.
Acyanotic heart defects without shunting include pulmonary stenosis, a narrowing of the pulmonary valve, aortic stenosis and coarctation of the aorta.