Comparative study of the hydrodynamic function of six size 19 mm bileaflet heart valves.

The hydrodynamic function of six size 19 mm bileaflet mechanical heart valves was investigated in a pulsatile flow simulator. The St. Jude Standard, St. Jude Haemodynamic Plus, CarboMedics, Sorin Biomedica, Duromedics and ATS valves were studied. The mean pressure drop and effective orifice area during forward flow, regurgitant volumes and total energy loss were analysed. The St Jude Haemodynamic Plus and Sorin Biomedica valves had significantly lower forward flow pressure drops and total energy losses than the other four valves. Assuming that all six valves can be implanted in the equivalent size of aortic root, this should lead to improved in vivo performance.