title: Flow propagation velocity is not a simple index of diastolic function in early filling. A comparative study of early diastolic strain rate and strain rate propagation, flow and flow propagation in normal and reduced diastolic function.
abstract: BACKGROUND
  Strain Rate Imaging shows the filling phases of the left ventricle to consist of a wave of myocardial stretching, propagating from base to apex. The propagation velocity of the strain rate wave is reduced in delayed relaxation. This study examined the relation between the propagation velocity of strain rate in the myocardium and the propagation velocity of flow during early filling.
  
  
  METHODS
  12 normal subjects and 13 patients with treated hypertension and normal systolic function were studied. Patients and controls differed significantly in diastolic early mitral flow measurements, peak early diastolic tissue velocity and peak early diastolic strain rate, showing delayed relaxation in the patient group. There were no significant differences in EF or diastolic diameter.
  
  
  RESULTS
  Strain rate propagation velocity was reduced in the patient group while flow propagation velocity was increased. There was a negative correlation (R = -0.57) between strain rate propagation and deceleration time of the mitral flow E-wave (R = -0.51) and between strain rate propagation and flow propagation velocity and there was a positive correlation (R = 0.67) between the ratio between peak mitral flow velocity / strain rate propagation velocity and flow propagation velocity.
  
  
  CONCLUSIONS
  The present study shows strain rate propagation to be a measure of filling time, but flow propagation to be a function of both flow velocity and strain rate propagation. Thus flow propagation is not a simple index of diastolic function in delayed relaxation.
authors.affiliation: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. a-stoe@online.no
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Støylen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Skjelvan
authors.forename: Terje
authors.initials: T
authors.lastname: Skjaerpe
mesh_terms: D001783:Blood Flow Velocity; D003971:Diastole; D004548:Elasticity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013314:Stress, Mechanical; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*