Abdominal Vasculature Flow Dynamics

Ch.16 CP

baseline

the zero doppler shift on a spectral display.

Flow towards the transducer is above; Flow away from the transducer is below

cardiac output

the amount of blood pumped by each ventricle in 1 minute.

diastole

relaxation of the heart muscles

doppler spectral waveform

provides information about bloodflow velocity, flow direction, presence of flow disturbance or turbulence, and vascular impedance. The waveform is displayed in a graph; the y-axis represents velocity or frequency and x-axis represents time

duplex sonography

real-time 2D imaging and pulsed doppler capabilities used either simultaneously or sequentially

hepatofugal

flow direction away from the liver

hepatopetal

flow direction toward the liver

high-resistance vessels

arteries with low or reversed flow in diastole that supply organs that do not demand constant blood perfusion

hydrostatic pressure

a form of potential energy. the pressure related to the weight of blood as compared to a reference point. the reference point in the human body is the right atrium. it is the effect that gravity has on the veins when the patient is erect

low-resistance vessels

arteries supplying organs that demand constant forward blood flow or perfusion

sample volume

obtains the doppler frequency information that is displayed. the sample volume or gate allows for selection of doppler-shifted echoes from specific depth according to arrival time

spectral broadening

an increase in returned echoes proportional to an increase in turbulence or flow disturbance

spectral doppler

a range of frequency shifts displayed as velocities; allows visualization of the doppler signal and provides quantitative data to evaluate the doppler shift

stroke volume

the amount of blood ejected by the ventricles with each contraction

systole

contraction of the heart muscles

systolic window

relatively signal-free area between the arterial doppler shift signal and the baseline during the systolic portion of a doppler spectral display

transmural pressure

determines the shape of the vein. transmural pressure equals the difference between the intravascular pressure and interstitial pressure

valsalva maneuver

a technique that significantly increases intrathoracic and intrabdominal pressure, halting all venous blood return to the heart