title: Aortic valve hydrodynamics: considerations on the absence of sinuses of Valsalva.
abstract: OBJECTIVE
  The study aim was to compare the hydrodynamics of the Carpentier-Edwards Magna 21 (CEM) and St. Jude Medical Biocor-Epic-Supra 21 (SJME) valves at increasing stroke volume and pulse rate in two different aortic conduits, namely straight and with sinuses of Valsalva present.
  
  
  METHODS
  Both valve types were tested in the aortic chamber of the Sheffield pulse duplicator, at rates of 70, 80 and 90 beats/min, and stroke volumes of 50 and 60 ml. The systolic and diastolic performances were each recorded. The leaflet coaptation time, ventricle isovolumetric time and maximum instantaneous flow rate were also recorded.
  
  
  RESULTS
  Regardless of the aortic conduit, CEM valves showed a significantly lower gradient than SJME valves (p < 0.05), and a significantly larger effective orifice area (EOA) (p < 0.05); the latter parameter was unaffected for both valves, at an increasing pulse rate (p > 0.05). The maximum transvalvular flow velocity was significantly higher in the straight conduit for both valves (p < 0.05). With regards to diastole, the SJME valve showed the lowest regurgitant volume (p < 0.05). The leaflet coaptation time was significantly shorter for the SJME valve than for the CEM valve (p < 0.05), but when tested in a straight conduit it was shortened significantly for both valves (p < 0.05).
  
  
  CONCLUSIONS
  An absence of the sinuses of Valsalva may modify the diastolic and systolic behaviors of the tissue valve leaflets by reducing the time required for leaflet coaptation, and increasing the valve closing volume and maximum transvalvular flow velocity. It is speculated that these hydrodynamic changes may increase the working stress on the valve tissue, leading to possible premature structural valve deterioration.
authors: Cardiovascular Institute, University of Padova, Padova, Italy. tomaso.bottio@unipd.it
authors: Tomaso
authors: T
authors: Bottio
authors: Edward
authors: E
authors: Buratto
authors: Carlo
authors: C
authors: Dal Lin
authors: Alban
authors: A
authors: Lika
authors: Vincenzo
authors: V
authors: Tarzia
authors: Giulio
authors: G
authors: Rizzoli
authors: Gino
authors: G
authors: Gerosa
mesh_terms: D001021:Aortic Valve / Q000502:physiology*; D001705:Bioprosthesis; D001794:Blood Pressure; D001807:Blood Vessel Prosthesis; D003971:Diastole; D006339:Heart Rate; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008422:Materials Testing; D008955:Models, Cardiovascular; D011093:Polyethylene Terephthalates; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012850:Sinus of Valsalva / Q000502:physiology*; D013318:Stroke Volume; D013599:Systole; D014160:Transducers, Pressure
chemical_list: D011093:Polyethylene Terephthalates