title: Determinants of left ventricular vortex flow parameters assessed by contrast echocardiography in an in vivo animal model.
abstract: BACKGROUND
  Various left ventricular (LV) vortex parameters obtained during contrast echocardiography (CE) have been recently described. The aim of this study was to investigate their determinants and associations with conventional hemodynamic variables.
  
  
  METHODS
  CE was performed and LV pressure was simultaneously measured during pharmacologic inotropic modulation in 8 mongrel dogs. Customized software was used to assess both vortex geometric parameters (vortex depth [VD], length [VL], width [VW], transverse position, and sphericity index [SI]) and pulsatility parameters (relative strength [RS], vortex relative strength [VRS], and vortex pulsation correlation [VPC]). The associations between each of these parameters and conventional indices representing LV systolic and diastolic function were analyzed.
  
  
  RESULTS
  VD and VW did not change significantly during pharmacologic modulation, whereas VL (P = 0.0034) and SI (P = 0.001) showed significant and progressive linear decreases from baseline during dobutamine infusion. Significant linear changes during positive and negative inotropic modulation were observed in all pulsatiliy parameters (P < 0.01 each). Geometric parameters were critically dependent on LV volume, with pulsatility parameters showing significant positive correlations with heart rate, systolic and diastolic blood pressure (DBP), dp/dtmax , early and late mitral inflow velocities, and peak systolic and diastolic annular velocities. In multivariate analysis, LV end-diastolic volume was a main determinant for VL (r = 0.29, P < 0.001) and VW (r = 0.65, P < 0.001), whereas dp/dtmax for pulsatility parameters (RS [r = 0.61, P < 0.001], VRS [r = 0.46, P < 0.001] and VPC [r = 0.62, P < 0.001]).
  
  
  CONCLUSIONS
  Geometric and pulsatility parameters differed in their association with LV geometry and conventional physiologic indices representing LV function. These differences should be considered in interpreting these variables.
authors.affiliation: Cardiac Imaging Center, Asan Heart Institute Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Jeong-Sook
authors.initials: JS
authors.lastname: Seo
authors.forename: Yun-Sil
authors.initials: YS
authors.lastname: Choi
authors.forename: Hye-Ran
authors.initials: HR
authors.lastname: Kim
authors.forename: Youn-Ju
authors.initials: YJ
authors.lastname: Chung
authors.forename: Sung-Cheol
authors.initials: SC
authors.lastname: Yun
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Song
authors.forename: Duk-Hyun
authors.initials: DH
authors.lastname: Kang
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Song
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D004280:Dobutamine / Q000494:pharmacology*; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D023421:Models, Animal; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D015588:Observer Variation; D011673:Pulsatile Flow / Q000502:physiology; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology*
chemical_list: D004280:Dobutamine