title: Global diastolic strain rate for the assessment of left ventricular relaxation and filling pressures.
abstract: BACKGROUND
  Diastolic strain rate (SR) measurements that comprise all left ventricular (LV) segments are advantageous over myocardial velocity for assessment of diastolic function. Mitral early diastolic velocity (E)/SR ratio during the isovolumetric relaxation (IVR) period can be used to estimate LV filling pressures.
  
  
  RESULTS
  Simultaneous echocardiographic imaging and LV pressure measurements (7F catheters) were performed in 7 adult dogs. Loading conditions were altered by saline infusion and caval occlusion, and lusitropic state was changed by dobutamine and esmolol infusion. A curve depicting global SR was derived from each of the 3 apical views, and SR was measured during IVR (SR(IVR)) and early LV filling (SR(E)). SR(IVR) had a strong correlation with time constant of LV pressure decay during the IVR period (tau) (r=-0.83, P<0.001), whereas SR(E) was significantly related to LV end-diastolic pressure (r=0.52, P=0.005) in the experimental stages where tau was <40 ms. In 50 patients with simultaneous right heart catheterization and echocardiographic imaging, mitral E/SR(IVR) ratio had the best correlation with mean wedge pressure (r=0.79, P<0.001), as well as in 24 prospective patients (r=0.84, P=0.001). E/SR(IVR) was most useful in patients with ratio of E to mitral annulus early diastolic velocity (E/Ea ratio) 8 to 15 and was more accurate than E/Ea in patients with normal ejection fraction and regional dysfunction (both P<0.01).
  
  
  CONCLUSIONS
  Global SR(IVR) by 2-dimensional speckle tracking is strongly dependent on LV relaxation. E/SR(IVR) can predict LV filling pressures with reasonable accuracy, particularly in patients with normal ejection fraction and in those with regional dysfunction.
authors.affiliation: Department of Cardiology and Methodist DeBakey Heart Center, The Methodist Hospital, Houston, Tex 77030, USA.
authors.forename: Jianwen
authors.initials: J
authors.lastname: Wang
authors.forename: Dirar S
authors.initials: DS
authors.lastname: Khoury
authors.forename: Vinay
authors.initials: V
authors.lastname: Thohan
authors.forename: Guillermo
authors.initials: G
authors.lastname: Torre-Amione
authors.forename: Sherif F
authors.initials: SF
authors.lastname: Nagueh
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000617:Aminoglycosides; D000818:Animals; D006328:Cardiac Catheterization; D002316:Cardiotonic Agents / Q000494:pharmacology; D003971:Diastole / Q000187:drug effects / Q000502:physiology*; D004280:Dobutamine / Q000494:pharmacology; D004285:Dogs; D015150:Echocardiography, Doppler / Q000379:methods*; D053281:Enediynes; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000502:physiology; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D011412:Propanolamines / Q000494:pharmacology; D011669:Pulmonary Wedge Pressure; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology*; D017725:Ventricular Pressure / Q000187:drug effects / Q000502:physiology*
chemical_list: D000319:Adrenergic beta-Antagonists; D000617:Aminoglycosides; D002316:Cardiotonic Agents; D053281:Enediynes; D011412:Propanolamines; D004280:Dobutamine; C036604:esmolol; C047543:esperamicin A1