title: Rest and exercise Doppler hemodynamics of the Medtronic Intact aortic bioprosthesis.
abstract: OBJECTIVE
  Exercise treadmill testing was used to evaluate the functional rest and stress hemodynamic profile of the Medtronic Intact aortic bioprosthesis.
  
  
  METHODS
  A group of 93 patients (mean age at operation 72.9 years; range: 61-79 years) was studied. Mean time to follow up was 20.8 months. The preoperative diagnosis was aortic stenosis (AS; n = 66), aortic regurgitation (AR; n = 19) or AS/AR (n = 8). Left ventricular function was assessed as normal (n = 78), moderate (n = 14) or poor (n = 1). Patients received a range of valve sizes: 21 mm (n = 7); 23 mm (n = 41); 25 mm (n = 32); 27 mm (n = 7); and 29 mm (n = 6).
  
  
  RESULTS
  For all valve sizes, Doppler-derived hemodynamics at rest and peak exercise, respectively were: mean aortic valve gradient (AVG) 13.2 +/- 5.2 mmHg and 22.2 +/- 8.9 mmHg; peak aortic valve gradient (AVG) 24.3 +/- 9.6 mmHg and 39.1 +/- 13.5 mmHg; effective orifice area (EOA) 1.39 +/- 0.49 cm2 and 1.38 +/- 0.5 cm2; and effective orifice area index (EOAI) 0.76 +/- 0.26 cm2/m2 and 0.75 +/- 0.26 cm2/m2. Mean and peak AVG decreased as valve sizes increased, while both EOA and EOAI increased as valve sizes increased.
  
  
  CONCLUSIONS
  The Medtronic Intact aortic bioprosthesis provides good hemodynamics both at rest and exercise, across the range of implanted valve sizes.
authors.affiliation: Wessex Cardiothoracic Centre, Southampton University Hospitals, UK.
authors.forename: P C
authors.initials: PC
authors.lastname: Strike
authors.forename: S A
authors.initials: SA
authors.lastname: Balanescu
authors.forename: D
authors.initials: D
authors.lastname: Gardiner
authors.forename: S A
authors.initials: SA
authors.lastname: Livesey
authors.forename: I A
authors.initials: IA
authors.lastname: Simpson
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D001705:Bioprosthesis; D001783:Blood Flow Velocity; D015150:Echocardiography, Doppler; D005080:Exercise Test; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D012146:Rest; D016277:Ventricular Function, Left