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Page 4 of 23 Rao. Vessel Plus 2022;6:24 https://dx.doi.org/10.20517/2574-1209.2021.91

Figure 1. M-mode recording of the echo, referred to in the text, is shown in this figure. Both ventricles are shown illustrating
measurements of LVIDd (left ventricular internal dimension in end-diastole) and RVEDD (right ventricular end-diastolic dimension).
Both measurements are made at the start of QRS complex of the electrocardiogram (at the top) recorded simultaneously. The LVIDs
(left-ventricular internal dimension in end-systole) is also shown. The measured numbers are compared with normal data and z scores
are secured. This information is also utilized for determining the left ventricular global systolic function by calculating the left-
ventricular shortening fraction. Reproduced from Ref. [19] .

Figure 2. This figure demonstrates two-dimensional echo. Parasternal long-axis view of the cardiac structures of a normal child
illustrating the left atrium (LA), left ventricle (LV), aorta (Ao), and right ventricle (RV). The mitral valve, aortic valve, and inter-
ventricular septum are also shown but not labeled. Reproduced from Ref. [19] .

and is unable to localize the site from which the abnormal flow velocity arises. Using both PW Doppler and
CW Doppler provides resolution of this problem [Figure 5]. Instead, HPRF Doppler may be used. Since the
HPRF Doppler is almost completely replaced by CW Doppler, it will not be discussed further. While
recording the CW Doppler velocities, the ultrasound beam needs to be either 0° or 180° along the path of
the blood flow to assess the actual flow velocity. An ultrasound beam angle less than 20° may be used. A 20°
angle reduces true velocity by 6% [15,16] . Any value more than 20° grossly underestimates the true velocity
magnitude [15,16] .