title: Diastolic suction in heart failure: impact of left ventricular geometry, untwist, and flow mechanics.
abstract: OBJECTIVE
  Vector flow mapping (VFM) can be used to assess intraventricular hemodynamics quantitatively. This study assessed the magnitude of the suction flow kinetic energy with VFM and investigated the relation between left ventricular (LV) function and geometry in patients with an estimated elevated LV filling pressure.
  
  
  METHODS
  We studied 24 subjects with an elevated LV filling pressure (EFP group) and 36 normal subjects (normal group). Suction was defined as flow directed toward the apex during the period from soon after systolic ejection to before mitral inflow. The flow kinetic energy index was quantified as the sum of the product of the blood mass and velocity vector and its magnitude to the peak value was measured.
  
  
  RESULTS
  Suction flow was observed in 12 (50%) EFP-group patients and 36 (100%) normal-group subjects. The magnitude of the suction kinetic energy index was significantly smaller in EFP versus normal group (2.7 ± 3.8 vs. 5.7 ± 4.4 g/s/cm(2), P<0.01). The EFP-group patients with suction had a smaller LV end-systolic volume (ESV) (P<0.01), greater ellipsoidal geometry (P<0.05) and untwisting rate (P<0.01) than the EFP-group patients without suction. A regression analysis indicated a significant linear relation between the suction kinetic energy index and LVEF (r=0.43, P=0.04), ESV (r=-0.40, P=0.05), eccentricity index (r=0.44, P=0.04), and untwisting rate (r=0.51, P=0.04).
  
  
  CONCLUSIONS
  The magnitude of the suction flow kinetic energy index derived from VFM may allow the quantitative assessment of the suction flow, which correlates with LV systolic function, geometry, and untwisting mechanics.
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Nogami
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan. Electronic address: tomoco@md.tsukuba.ac.jp.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishizu
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Atsumi
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Division of Child Health, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nakamura
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Machino-Ohtsuka
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawamura
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Seo
authors.affiliation: Faculty of Medicine, Division of Clinical Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D003971:Diastole; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000473:pathology / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D014672:Vectorcardiography / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Failing heart; Geometry; Suction kinetic energy index; Untwisting