title: Myocardial velocity gradients detected by Doppler imaging.
abstract: Using a scanner whose colour Doppler mode has been adapted to display tissue motion (instead of blood flow), velocity gradients have been detected across the myocardium. A velocity gradient is a gradual spatial change in the value of velocity estimates. Velocity gradients have potential for assessing regional myocardial contractility. 28 M-mode scans were performed on nine normal volunteers at different locations in the left-ventricle posterior wall. In each case simultaneous Doppler M-mode and pulse-echo M-mode images were obtained. Doppler velocity gradient (DVG) was calculated from Doppler M-mode images and rate of change of wall thickness (RCWT) was calculated from pulse-echo M-mode images. In all Doppler M-mode images statistically significant velocity gradients were observed. In all but one scan, cyclically consistent peaks in DVG occur relative to the electrocardiogram waveform. 99% of systolic and 89% of early diastolic peaks in RCWT have a corresponding peak in DVG. Velocity gradients are consistent with wall thickness changes, suggesting that they have potential for assessment of myocardial contractility.
authors.affiliation: Department of Medical Physics, Royal Infirmary of Edinburgh, UK.
authors.forename: A D
authors.initials: AD
authors.lastname: Fleming
authors.forename: X
authors.initials: X
authors.lastname: Xia
authors.forename: W N
authors.initials: WN
authors.lastname: McDicken
authors.forename: G R
authors.initials: GR
authors.lastname: Sutherland
authors.forename: L
authors.initials: L
authors.lastname: Fenn
mesh_terms: D000328:Adult; D004452:Echocardiography; D015150:Echocardiography, Doppler; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D016276:Ventricular Function