title: Energy dynamics of the intraventricular vortex after mitral valve surgery.
abstract: Mitral valve morphology after mitral valve surgery affects postoperative intraventricular flow patterns and long-term cardiac performance. We visualized ventricular flow by echocardiography vector flow mapping (VFM) to reveal the impact of different mitral valve procedures. Eleven cases of mechanical mitral valve replacement (nine in the anti-anatomical and two in the anatomical position), three bioprosthetic mitral valve replacements, and four mitral valve repairs were evaluated. The mean age at the procedure was 57.4 ± 17.8 year, and the echocardiography VFM in the apical long-axis view was performed 119.9 ± 126.7 months later. Flow energy loss (EL), kinetic pressure (KP), and the flow energy efficiency ratio (EL/KP) were measured. The cases with MVR in the anatomical position and with valve repair had normal vortex directionality ("Clockwise"; N = 6), whereas those with MVR in the anti-anatomical position and with a bioprosthetic mitral valve had the vortex in the opposite direction ("Counterclockwise"; N = 12). During diastole, vortex direction had no effect on EL ("Clockwise": 0.080 ± 0.025 W/m; "Counterclockwise": 0.083 ± 0.048 W/m; P = 0.31) or KP ("Clockwise": 0.117 ± 0.021 N; "Counterclockwise": 0.099 ± 0.057 N; P = 0.023). However, during systole, the EL/KP ratio was significantly higher in the "Counterclockwise" vortex than that in the "Clockwise" vortex (1.056 ± 0.463 vs. 0.617 ± 0.158; P = 0.009). MVP and MVR with a mechanical valve in the anatomical position preserve the physiological vortex, whereas MVR with a mechanical valve in the anti-anatomical position and a bioprosthetic mitral valve generate inefficient vortex flow patterns, resulting in a potential increase in excessive cardiac workload.
authors.affiliation: Department of Cardiovascular Surgery, Ebina General Hospital, 1320, Kawaraguchi, Ebina, 243-1311, Kanagawa, Japan.|Department of Hemodynamic Analysis, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.|Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Kouki
authors.initials: K
authors.lastname: Nakashima
authors.affiliation: Department of Cardiovascular Surgery, Kyoto Prefectual University of Medicine, 465 Kajii-cho, Hirokoji Agaru, Kawaramachi-dori, Kamigyo-ku, Kyoto, 602-0841, Japan. keiichiitatani@yahoo.co.jp.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Itatani
authors.affiliation: Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Oka
authors.affiliation: Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Horai
authors.affiliation: Department of Hemodynamic Analysis, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Miyazaki
authors.affiliation: Department of Cardiovascular Surgery, Ebina General Hospital, 1320, Kawaraguchi, Ebina, 243-1311, Kanagawa, Japan.|Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nie
authors.affiliation: Department of Hemodynamic Analysis, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.|Department of Cardiovascular Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato Minami-ku, Sagamihara, 252-0375, Kanagawa, Japan.
authors.forename: Kagami
authors.initials: K
authors.lastname: Miyaji
mesh_terms: D001705:Bioprosthesis; D001783:Blood Flow Velocity / Q000502:physiology*; D003971:Diastole; D004452:Echocardiography; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000175:diagnosis* / Q000503:physiopathology; D013599:Systole
keywords: Flow energy loss; Mitral valve surgery; Vector flow mapping (VFM)