Vascular Hemodynamics Principles Flashcards
7 cards from real CCI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Vascular Hemodynamics Principles flashcards as text
Which of the following best describes the effect of arterial compliance on pulse wave velocity?
Answer: Lower compliance increases pulse wave velocity
Stiffer (less compliant) arteries transmit the pressure wave faster, resulting in higher pulse wave velocity.
The resistive index (RI) is calculated as:
Answer: (PSV − EDV) / PSV
RI = (peak systolic velocity − end diastolic velocity) / peak systolic velocity, ranging from 0 to 1.
In a patient with a large arteriovenous fistula, which hemodynamic change is expected in the feeding artery?
Answer: Decreased RI with high diastolic flow
An AV fistula creates a low-resistance pathway, producing low RI and elevated diastolic flow in the feeding artery.
Which hemodynamic phenomenon causes spectral broadening distal to a stenosis?
Answer: Post-stenotic turbulence
Post-stenotic turbulence produces a wide range of velocities that fill in the spectral window, causing spectral broadening.
A patient has an ABI of 0.6 at rest. According to standard classification, this corresponds to:
Answer: Moderate PAD
An ABI of 0.4–0.69 is classified as moderate peripheral arterial disease with significant flow limitation.
What is the primary reason collateral vessels have higher resistance than the native artery they replace?
Answer: Collaterals are smaller in diameter and longer in length
Poiseuille's law dictates that resistance is proportional to length and inversely proportional to radius to the fourth power, making small, long collaterals high-resistance.
On duplex ultrasonography, which finding is most specific for renal artery stenosis >60%?
Answer: RAR (renal-to-aortic ratio) > 3.5
A renal-to-aortic ratio greater than 3.5 is highly specific for hemodynamically significant renal artery stenosis.