title: Normalized left ventricular workload using phase-contrast magnetic resonance imaging in patients with aortic stenosis.
abstract: Aortic stenosis (AS) severity contributes to the left ventricle (LV) deterioration due to the aortic valve narrowing and the alteration of systemic hemodynamic load. This load increment may also increase the LV stroke work (SW) which represent the required energy to deliver the blood at ejection. In this study, SW was derived from in-vivo cardiovascular magnetic resonance (CMR) velocity measurements (n=57) using a lumped-parametric model. Furthermore, normalized SW (N-SW) was evaluated as AS severity parameter. SW differentiated from normal flow (>35 mL/m(2)) and low flow (<35 mL/m(2)) states (p<0.05). N-SW showed a good association with valve effective orifice area (EOA, r=-0.5, p<0.001) and valvulo-arterial impedance (ZVA, r=0.65, p<0.001). A severity threshold for N-SW (1.5 cJ/mL) was found using an EOA=1 cm(2) as AS severity marker. CMR-derived SW and N-SW may be useful to the assessment and grading of AS patients.
authors.forename: J
authors.initials: J
authors.lastname: Garcia
authors.forename: Z
authors.initials: Z
authors.lastname: Keshavarz-Motamed
authors.forename: R
authors.initials: R
authors.lastname: Capoulade
authors.forename: F
authors.initials: F
authors.lastname: Le Ven
authors.forename: L
authors.initials: L
authors.lastname: Kadem
authors.forename: E
authors.initials: E
authors.lastname: Larose
authors.forename: P
authors.initials: P
authors.lastname: Pibarot
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000473:pathology; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D012720:Severity of Illness Index; D016277:Ventricular Function, Left