title: Echocardiographic vs Invasive Measurement of the Direct Flow Transcatheter Aortic Heart Valve Mean Gradient: Contradictory or Complementary?
abstract: In this case report, we explain the reason behind observed differences in echocardiographic and invasively measured mean aortic valve gradient after transcatheter aortic valve implantation. A 25-mm Direct Flow valve (Direct Flow Medical Inc, Santa Rosa, CA) was successfully implanted in a patient with severe aortic stenosis via the transfemoral route. The discrepancy between invasive and echocardiographic measurements could be explained by the combination of a non-flat velocity profile inside the tubular structure of the Direct Flow valve, which can cause local low pressure fields that result in true high gradients detected using Doppler, and pressure recovery.
authors.affiliation: Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy; Imperial College London, National Heart and Lung Institute, London, United Kingdom.
authors.forename: Vasileios F
authors.initials: VF
authors.lastname: Panoulas
authors.affiliation: Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy. Electronic address: alatib@gmail.com.
authors.forename: Azeem
authors.initials: A
authors.lastname: Latib
authors.affiliation: Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Eustachio
authors.initials: E
authors.lastname: Agricola
authors.affiliation: Division of Adult Congenital and Valvular Heart Disease, Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Baumgartner
authors.affiliation: Department of Cardiothoracic Surgery, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
authors.affiliation: Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Colombo
mesh_terms: D000369:Aged, 80 and over; D001021:Aortic Valve / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006350:Heart Valve Prosthesis / Q000592:standards*; D006801:Humans; D017063:Outcome Assessment, Health Care; D011184:Postoperative Period; D011474:Prosthesis Design; D012720:Severity of Illness Index; D065467:Transcatheter Aortic Valve Replacement / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome