title: Clinical validity of measuring time difference between onset of mitral inflow and onset of early diastolic mitral annulus velocity in the evaluation of left ventricular diastolic function.
abstract: OBJECTIVE
  This study was performed to validate the clinical usefulness of measuring the time difference between onset of mitral inflow and onset of early diastolic mitral annulus velocity (T(E'-E)) for the evaluation of left ventricular (LV) diastolic function.
  
  
  BACKGROUND
  In recent studies, T(E'-E) correlated well with the time constant of LV pressure decay (tau), and the ratio of IVRT/T(E'-E), where IVRT is isovolumic relaxation time, was useful in the prediction of elevated LV filling pressure.
  
  
  METHODS
  Simultaneous left heart catheterization and Doppler echocardiography were performed in 40 patients.
  
  
  RESULTS
  The T(E'-E) was evaluated in the same cardiac cycle and in the same hemodynamic status in 31 patients. Despite the wide range of tau (31 to 70 ms), there was no delay in the onset of mitral annulus velocity compared with the onset of mitral inflow (T(E'-E) = 0) in 27 patients and, therefore, T(E'-E) did not correlate with tau. Only three patients showed prolongation in T(E'-E), and all three showed tau >or=50 ms and pre-A-wave pressure >or=18 mm Hg. In one patient, mitral annulus velocity began earlier than the onset of mitral inflow. Because T(E'-E) was 0 in the majority of patients, the LV filling pressure could not be predicted by the previously suggested index of IVRT/T(E'-E.)
  
  
  CONCLUSIONS
  In contrast to previous studies, T(E'-E) did not correlate with tau, and IVRT/ T(E'-E) could not be applied in the prediction of filling pressure, because of the limitation of a zero denominator. However, prolongation of T(E'-E) might suggest an elevated filling pressure in the setting of prolonged tau.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea. dwsohn@snu.ac.kr
authors.forename: Dae-Won
authors.initials: DW
authors.lastname: Sohn
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Young-Bae
authors.initials: YB
authors.lastname: Park
authors.forename: Yun-Shik
authors.initials: YS
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D003971:Diastole; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000502:physiology*; D015203:Reproducibility of Results; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*