• severe
  • Marked degeneration of the leaflet architecture leads to severe retraction and noncoaptation of the valve, which remains fixed in a semiopen position (2) . (onlinejacc.org)
  • blood
  • As a result, not enough blood flows through the valve. (nih.gov)
  • These valves may not have enough tissue flaps, they may be the wrong size or shape, or they may lack an opening through which blood can flow properly. (nih.gov)