Indirect Testing Flashcards
Define an ABI test:
Comparison of the systolic pressure at the ankle to the systolic pressure of the brachial artery
When an arterial lumen is narrowed to a critical level, the distal arterial flow and pressure do what?
Decrease
Retrograde vertebral flow on the same side as the lower brachial pressure indicates what?
Subclavian steal syndrome
What is the average ABI in a supine, resting patient?
1.1
Falsely high ABI’s (5-10% too high) will occur in a patient with what?
Medial calcification
Medial calcification occurs in what kind of patients?
Diabetics and patients on steroid therapy for renal disease
What is normal toe/brachial pressure?
> 0.75
Toe pressure is also used to detect what below the ankle and when should they be done?
Arterial disease
Should be done when ABI > than 1.3
Describe the ABI classification of >1.0:
Normal
Describe the ABI classification of 0.9-1.0:
Minimal disease, usually asymptomatic
Describe the ABI classification of 0.5-0.9:
Claudication, usually single level obstruction
Describe the ABI classification of <0.5:
Rest pain, severe, multilevel disease
Describe the ABI classification of <0.3:
Severely ischemic leading to gangrene
Significant lesions with developed collateral circulation results in what?
Normal distal pressures and waveforms at rest
What is a normal result of a exercise stress test? (3)
- Little to no drop in ankle pressure after 5 mins of exercise
- Decrease in post-exercise systolic pressure should be <20% of the resting pressure
- Systolic pressure should return to normal within 3 mins