Biomedical Engineering Reference
In-Depth Information
7.5.2.1
Region of Interest for Cardiac Flow Analysis
Examination of the heart where the atria are positioned was performed to display
the optimal cross-sectional area of the right atrium. A slice section is taken perpen-
dicular to the axis joining the top of the heart to the apex through the septum (Fig
7.30 ). The velocity mapping on the right atrium of the heart is used since the scan
sections cut through the middle portion of atria.
Inflow from the inferior vena cava (IVC) and superior vena cava (SVC) result in re-
spective flow diversions that generate two vortices in opposite directions. During atrial
diastole, there is maximum suction of blood into the right atrium via the vena cava.
The chamber dilates due to the inflow of blood and the closure of the tricuspid valves
(TV). The maximum inlet flow at the superior and inferior vena cava is set to 155 and
128 cms −1 . At this instance, two strong vortices of opposite rotation are developed.
During the systolic phases, the atrium compresses and causes the outflow of blood into
the right ventricle which causes the valves to open. One of the vortices becomes sig-
nificantly weaker than the dominant vortex during their evolution over a cardiac cycle.
Fig. 7.30  Sectional view of blood flow in the right atrium
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