Measurement of Left Ventricular Myocardial Velocities by Pulsed Wave Tissue Doppler in Healthy Dogs
V.M.C. Oliveira; D.G. Prada; A.P. Vaz-Curado; F.L. Yamato; M.H.M.A. Larsson
Pulsed wave Tissue Doppler Image (TDI) enables the assessment of The objective of this study was to determine radial and longitudinal regional myocardial velocities, through a single sample volume placed myocardial tissue velocities of healthy dogs via pulsed wave TDI mode, within the myocardial wall. The major advantage of this technique is to and to investigate their correlations with weight, left ventricular end quickly enable segmental analysis of myocardial function on real time, diastole diameter (LVEDD), shortening fraction (SF) and heart rate (HR). Thirty healthy awake adult dogs of different breeds and crossbreeds were studied. The longitudinal velocities were recorded in four segments: basal and middle of the left ventricular free wall (LVFW) and interventricular septum (IS). The radial velocities were obtained in two segments: next to endocardium and next to epicardium of LVFW. Systolic (Sm), early diastole (Em) and late diastole (Am) motion peak velocities were determined in all studied points, as well as Em/Am ratio. Early diastole peak velocity of mitral blood flow (Ef) was measured and the ratio between and Em (at base of LVFW) calculated (Ef/Em). Significant differences (p < 0.05) between females and males were not observed. On longitudinal fibers, Sm was higher in the basal segment than in the middle segment of the IS and LVFW. Em and Am waves did not significantly differ between segments of the same wall. Sm and Em were higher in the LVFW than in the IS. On radial fibers, Sm and Am of endocardium did not significantly differ from those of epicardium. Em was higher at endocardium. Ef/Em ratio was 6.666 ± 2.517. Myocardial velocities and heart rate did not correlate. Only positive weak correlations were found between velocities (radial or longitudinal) and weight or LVEDD. SF had weak positive correlation with Am at base of LVFW, and weak negative correlation with Sm of the base of LVFW (longitudinal motion), and Em of endocardium (radial motion). Pulsed wave TDI provides images of good quality and reliable measurements of longitudinal velocities at the basal and the middle segments of LVFW and IS and of radial velocities of LVFW. Sm velocities decreased from the basal to the middle segments of LVFW and IS. On radial fibers, a gradient between endocardial and epicardial velocities was observed only for Em. Further research on older dogs would aid to evaluate physiological aged related changes.