title: Left ventricular isovolumic velocity and duration variables calculated from colour-coded myocardial velocity images in normal individuals.
abstract: OBJECTIVE
  To describe the normal myocardial velocity profile during the isovolumic contraction and relaxation period at four different locations within left ventricular base and to establish normal age and gender related isovolumic time and velocity values.
  
  
  RESULTS
  In 49 healthy individuals (26 women/23 men) in age groups 21-49 and 50-76 years, tissue velocity profiles and 2D-data were acquired at high temporal resolution (90-147 frames/s) for a subsequent off-line analysis using software enabling retrieval of myocardial Doppler velocity and 2D/anatomical M-mode information from different cardiac locations during the same cardiac cycle. The obtained velocity curves during the isovolumic contraction and relaxation period were usually biphasic and displayed clear regional differences in their respective positive and negative maximal velocities. Besides some gender related differences, mainly in the duration of the positive and negative velocity wave components during the isovolumic contraction period, a clear age-dependent increase in the duration of the isovolumic relaxation phase and its negative and positive velocity components was observed.
  
  
  CONCLUSIONS
  Modern tissue Doppler imaging supplemented by anatomical M-mode images of the mitral and aortic valve movements allows a proper analysis of the rapid isovolumic myocardial movements. The presented normal isovolumic time and velocity values may prove useful for studies of myocardial function.
authors.affiliation: Department of Clinical Physiology, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Stockholm, Sweden. britta.lind@hs.se
authors.forename: B
authors.initials: B
authors.lastname: Lind
authors.forename: J
authors.initials: J
authors.lastname: Nowak
authors.forename: P
authors.initials: P
authors.lastname: Cain
authors.forename: M
authors.initials: M
authors.lastname: Quintana
authors.forename: L-A
authors.initials: LA
authors.lastname: Brodin
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology; D018618:Echocardiography, Doppler, Color; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000502:physiology; D009200:Myocardial Contraction / Q000502:physiology*; D012016:Reference Values; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology*; D016276:Ventricular Function