Reference values for pulsed Doppler signals from the blood flow velocity on both sides of the pulmonary valve

Age-related prolongation of phase I of V̇o2 on-kinetics in healthy humans

“…These data are in agreement with the modeling study by Barstow et al (6), who proposed that PhI duration would depend on "the rate of adjustment of blood flow" at exercise onset and the size of venous volume. Moreover, our finding of an age-induced reduction of the average pulmonary flow acceleration during phase I is in line with available data describing a decrease of resting pulmonary artery flow acceleration over age (56) in normal subjects, which finds its biological plausibility in the reduction of right ventricular systolic and diastolic function (33), increase of pulmonary arterial pressure and pulmonary vascular resistances (17,30), and augmentation of pulmonary artery stiffness (40) with increasing age. Also, the 60 -70 group showed a lean body mass significantly lower than that of the 20 -30 group; as a greater muscle mass has been shown to enhance venous emptying of the healthy subject's leg (31), a higher skeletal muscle pump-induced venous return during phase I may have played a contributing role in the youngest groups of our study population.…”

Concordance between M-mode, pulsed Tissue Doppler, and colour Tissue Doppler in the assessment of mitral annulus systolic excursion in normal subjects

“…4 Briefly, any pulsed Doppler signal is characterized by a definite spectral width that reflects the broadening of instantaneous velocities recorded within the sample volume. 10,11 The larger is the envelope thickness, the more dispersed are the velocities. Assuming normality of velocity distribution at any instant, 12 a rough adjustment for spectral dispersion can be obtained by estimating the mean between the maximal and minimal velocity identified by the signal in that instant.…”