• Q20 Congenital malformations of cardiac chambers and connections
  • Q21 Congenital malformations of cardiac septa
  • Q22 Congenital malformations of pulmonary and tricuspid valves
  • Q23 Congenital malformations of aortic and mitral valves
  • Q24 Other congenital malformations of heart
  • Q25 Congenital malformations of great arteries
  • Q26 Congenital malformations of great veins
  • Q27 Other congenital malformations of peripheral vascular system
  • Q28 Other congenital malformations of circulatory system