RVT Peripheral Arterial Physiologic Testing 4

Question 1

Photoplethysmography (PPG) is used to assess digital perfusion. What does a flattened, obstructive waveform on digital PPG indicate?

Accepted Answer

Significant arterial obstruction reducing pulsatile flow to the digit

Answer

Venous hypertension in the digit

Answer

Normal variant in elderly patients

Answer

Vasospasm that will resolve with warming

Question 2

Which condition can produce a falsely HIGH ABI, potentially masking severe peripheral arterial disease?

Accepted Answer

Medial arterial calcification (Mönckeberg sclerosis)

Answer

Severe anemia

Answer

Acute deep vein thrombosis

Answer

Cardiac tamponade

Question 3

During peripheral arterial physiologic testing, what is the significance of a 'pole test' (elevation test)?

Accepted Answer

It determines the critical closing pressure of limb arteries by elevating the limb until Doppler signal disappears

Answer

It assesses venous valve competence in the lower extremity

Answer

It measures the increase in cardiac output with limb elevation

Answer

It identifies deep vein thrombosis by elevation-induced pain

Question 4

A patient with Raynaud's phenomenon undergoes cold stimulation testing. Which finding would confirm vasospastic disease rather than fixed obstruction?

Accepted Answer

Complete recovery of digital waveform amplitude after rewarming to 37°C

Answer

Persistent absence of digital Doppler signal after rewarming

Answer

Bilateral ABI reduction during cold exposure

Answer

No change in digital PPG waveform with cold exposure

Question 5

What hemodynamic principle explains why a 50% diameter stenosis may not produce a resting pressure gradient but becomes hemodynamically significant during exercise?

Accepted Answer

Bernoulli's equation: pressure loss is proportional to flow velocity squared

Answer

Poiseuille's law: resistance increases with the square of radius reduction

Answer

Flow velocity remains constant regardless of stenosis severity

Answer

At rest, collateral resistance exceeds stenosis resistance

Question 6

Which clinical scenario would MOST warrant transcutaneous oxygen pressure (TcPO2) measurement as part of peripheral arterial physiologic testing?

Accepted Answer

Predicting wound healing potential in a patient with a non-healing foot ulcer

Answer

Screening for PAD in an asymptomatic patient with diabetes

Answer

Diagnosing proximal aortoiliac occlusion

Answer

Differentiating claudication from spinal stenosis

Question 7

In segmental limb pressure testing, what finding is characteristic of isolated popliteal artery disease?

Accepted Answer

Gradient between above-knee and below-knee segmental pressures with normal thigh pressures

Answer

Gradient between brachial and proximal thigh pressures

Answer

Gradient between ankle and metatarsal pressures

Answer

Symmetrically reduced pressures at all levels bilaterally