Hydrodynamic function of ten prosthetic heart valves in the aortic position.

The hydrodynamic function of five mechanical, four pericardial and one porcine size 23 mm aortic prosthetic valves has been analysed by measuring pressure differences, regurgitation and energy losses in our pulsatile flow test rig. St Jude Medical, Hancock pericardial and Mitral Medical pericardial valves had the lowest pressure drop. Calculations of total energy loss showed that the Bjork-Shiley monostrut had similar overall function to the above valves, while the Ionescu-Shiley Standard, Ionescu-Shiley Low Profile, Omniscience and Duromedics valves had slightly greater total energy losses. The Bjork-Shiley spherical disc and Wessex Medical porcine valve had the greatest energy losses. The function of the newer designs of pericardial valves compared well with the mechanical valves currently available.