Acyanotic congenital heart disease

Acyanotic congenital heart disease comprises numerous etiologies, which can be divided into those with increased pulmonary vascularity (pulmonary plethora) and those with normal vascularity:

• increased pulmonary vascularity
  • ventricular septal defect (VSD)
  • atrial septal defect (ASD)
  • atrioventricular septal defect (AVSD)
  • patent ductus arteriosus (PDA)
  • other less common
    • Gerbode defect
    • aortopulmonary window
    • ruptured aneurysm of Valsalva
    • coronary artery fistula
    • partial anomalous pulmonary venous return (PAPVR)
• normal pulmonary vascularity
  • small shunts (see above)
  • aortic valve stenosis
  • aortic coarctation
  • pulmonary stenosis

Note that certain congenital defects may initially cause acyanotic congenital heart disease and later cyanotic congenital heart disease. Conditions with a left-to-right shunt (e.g. VSD, ASD) may initially be acyanotic but over time can cause maladaptive changes in the right ventricle and pulmonary vasculature, leading to pulmonary hypertension and Eisenmenger syndrome. When this occurs, the shunt is reversed and deoxygenated blood enters the systemic circulation.