Abnormal Flow Patterns & Unusual Waveforms/Situations

Question 1

Increased velocity of the ECA may suggest what? Explain

Answer 1

Presence of high grade stenosis of ICA (compensatory ECA flow) because ICA cannot accommodate the usual amount of blood, thus more VOLUME of blood flows through ECA creating a higher velocity

Question 2

T/F a higher volume of blood creates higher velocities

Answer 2

True

Question 3

What is the water hammer sign? What does it represent?

Answer 3

Normal/elevated PSV followed by precipitous decline
Diastole: reversed flow

Aortic regurgitation

Question 4

What happens if the CCA is occluded?

Answer 4

Reversed flow in the ECA to feed the ICA

Question 5

Occlusion ICA results in externalization/internalization of what (2) and retrograde flow in (2)

Answer 5

Externalization of CCA
Internalization of ECA
OA reversed flow
ECA reversed flow

Question 6

Externalization of CCA occurs when & why

Answer 6

When ICA is occluded, CCA becomes higher resistance because there’s the same volume of blood with less passage for it to go, causing higher resistance in CCA

Question 7

Temporal tap occurs only when (2)

Answer 7

The ECA is involved in collateral flow

The ICA is totally occluded

Question 8

**Signs of critical stenosis ICA (3)

Answer 8

Internalization ECA
Externalization CCA
Compensatory flow within ECA

Question 9

Increased velocity of the ECA may suggest what? Explain

Answer 9

Presence of high grade stenosis of ICA (compensatory ECA flow) because ICA cannot accommodate the usual amount of blood, thus more VOLUME of blood flows through ECA creating a higher velocity

Question 10

T/F a higher volume of blood creates higher velocities

Answer 10

True

Question 11

What is the water hammer sign? What does it represent?

Answer 11

Normal/elevated PSV followed by precipitous decline
Diastole: reversed flow

Aortic regurgitation

Question 12

What happens if the CCA is occluded?

Answer 12

Reversed flow in the ECA to feed the ICA

Question 13

Occlusion ICA results in externalization/internalization of what (2) and retrograde flow in (2)

Answer 13

Externalization of CCA
Internalization of ECA
OA reversed flow
ECA reversed flow

Question 14

Externalization of CCA occurs when & why

Answer 14

When ICA is occluded, CCA becomes higher resistance because there’s the same volume of blood with less passage for it to go, causing higher resistance in CCA

Question 15

Temporal tap occurs only when (2)

Answer 15

The ECA is involved in collateral flow

The ICA is totally occluded

Question 16

**Signs of critical stenosis ICA (3)

Answer 16

Internalization ECA
Externalization CCA
Compensatory flow within ECA

Question 17

If you increase angle correct, what happens to the velocity estimation?

Answer 17

Increased angle correct falsely elevates velocity

Question 18

IRREGULAR HR - when should you measure PSV?

Answer 18

After the most normal QRS interval-cursor

Question 19

ARRHYTHMIA - most common is

Answer 19

Atrial fibrillation

Question 20

Pulsus bisferans

What is it, who can be seen with it?

Answer 20

A component of reverse flow in aortic regurgitation

Can be seen in healthy individuals with compliant artery walls

Question 21

TACHYCARDIA elements (3)

Answer 21

> 100 BPM
PSV decreased
EDV increased

Question 22

BRADYCARDIA elements (3)

Answer 22

< 60 BPM
PSV increased
EDV decreased

Question 23

A high resistant ICA waveform indicates

Answer 23

Intracranial ICA stenosis