title: Doppler indexes of left ventricular systolic and diastolic flow and central pulse pressure in relation to renal resistive index.
abstract: BACKGROUND
  The cardio-renal interaction occurs via hemodynamic and humoral factors. Noninvasive assessment of renal hemodynamics is currently possible by assessment of renal resistive index (RRI) derived from intrarenal Doppler arterial waveforms as ((peak systolic velocity - end-diastolic velocity)/peak systolic velocity). Limited information is available regarding the relationship between RRI and cardiac hemodynamics. We investigated these associations in randomly recruited subjects from a general population.
  
  
  METHODS
  In 171 participants (48.5% women; mean age, 52.2 years), using pulsed wave Doppler, we measured RRI (mean, 0.60) and left ventricular outflow tract (LVOT) and transmitral (E and A) blood flow peak velocities and its velocity time integrals (VTI). Using carotid applanation tonometry, we measured central pulse pressure and arterial stiffness indexes such as augmentation pressure and carotid-femoral pulse wave velocity.
  
  
  RESULTS
  In stepwise regression analysis, RRI independently and significantly increased with female sex, age, body weight, brachial pulse pressure, and use of β-blockers, whereas it decreased with body height and mean arterial pressure. In multivariable-adjusted models with central pulse pressure and arterial stiffness indexes as the explanatory variables, we observed a significant and positive correlation of RRI only with central pulse pressure (P < 0.0001). Among the Doppler indexes of left ventricular blood flow, RRI was significantly and positively associated with LVOT and E peak velocities (P ≤ 0.012) and VTIs (P ≤ 0.010).
  
  
  CONCLUSIONS
  We demonstrated that in unselected subjects RRI was significantly associated with central pulse pressure and left ventricular systolic and diastolic Doppler blood flow indexes. Our findings imply that in addition to the anthropometric characteristics, cardiac hemodynamic factors influence the intrarenal arterial Doppler waveform patterns.
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; tatiana.kouznetsova@med.kuleuven.be.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kuznetsova
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
authors.forename: Nicholas
authors.initials: N
authors.lastname: Cauwenberghs
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
authors.forename: Judita
authors.initials: J
authors.lastname: Knez
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Thijs
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Liu
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Gu
authors.affiliation: The Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium; Department of Epidemiology, University of Maastricht, Maastricht, The Netherlands.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Staessen
mesh_terms: D000328:Adult; D000368:Aged; D001530:Belgium; D001783:Blood Flow Velocity; D001794:Blood Pressure; D016009:Chi-Square Distribution; D003971:Diastole; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008365:Manometry; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D063177:Pulse Wave Analysis; D012079:Renal Circulation; D012307:Risk Factors; D013599:Systole; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance; D059289:Vascular Stiffness; D016277:Ventricular Function, Left
keywords: Doppler cardiac flow; artery stiffness; blood pressure; hypertension; population; pulse pressure; renal resistive index.