Downstream turbulence and high intensity transient signals (HITS) following aortic valve replacement with Medtronic Hall or St. Jude Medical valve substitutes

Abstract

Valve orientation has an important impact on microembolization to the brain. In the optimum orientation (large orifice facing the non-coronary leaflet) the Medtronic Hall valve showed negligible incidence of HITS. The St. Jude Medical bileaflet valve showed less variation but demonstrated significant HITS counts at any orientation. As the MH in the worst position shows significantly higher turbulent stresses than the SJM but no higher incidence of HITS, a strong correlation between turbulence and HITS was not demonstrated by this study.