Arterial Syndromes Flashcards
Define a syndrome?
the signs, symptoms or other manifestations to constitute the characteristics of a a morbid entity
Where does SSS begin?
with a stenosis near the origin of the subclavian artery or the innominate artery on the right side
Where does the pressure in the subclavian atery fall?
falls below that of the junction of the 2 vertebral arteries at the base of the brain
What is the downside is the retrograde flow of blood in the vertebral artery?
artery may cause a reduction in flow to the brain resulting in symptoms of vertebrobasilar insufficiency
What occuts in left sided SSS?
- ipsilateral
- contralateral
- the left vertebral has retrograde flow ,the contralateral vertebral and CCA will have increased flow
Right sided innominate artery stenosis?
- results have a far greater impact on cerebral hemodynamics because of the additional involvement of the right CCA
- The right CCA will have a lower perfusion pressure as a result of the proximal innominate artery stenosis
Accuracy of using doppler to diagnose SSS?
90-100% accurate
Whats the key to successfully diagnosing SSS?
- Reversal of flow in the vertebral artery
What is the final stage of SSS?
the reversal of flow in the vertebral artery
Define incomplete SSS?
Prior to constant flow reversal there is a deceleration of antegrade flow during systole with retrograde flow only in diastole
How is impending reversal of flow seen on doppler? (SSS)
Bunny sign
What is reactive hyperemia of the forearm?
- In cases where the vertebral artery is oscillatory rather than frankly retrograde, brachial artery compression with a blood pressure cuff should result in reduced retrograde and increased antegrade flow in the affected vertebral artery
- When the cuff is deflated,the pattern will show marked reversal of flow
Clinical symptoms of patients with SSS?
a loud supraclavicular bruit and always a reduced pulse and blood pressure in the affected arm
Blood pressure in SSS?
- A pressure difference greater than 20 mm Hg between the arms is a good indicator that a SSS may be present(impending steal)
- The ipsilateral arm will have decreased pressure
- The brachial artery pressures should be measured in order to complete the diagnosis
Where is blood shunted in a vertebral occlusion?
the thyrocervical and costocervical trunks of SCA
What occurs in the contralateral vertebral artery in a vertebral artery stenosis?
Compensatory enlargement of the opposite Vertebral artery occurs
Define thoracic outlet syndrome? (TOS)
- type of syndrome
- may contribute to
potential to effect
- entrapment syndrome that may contribute to various degrees of limb ischemia
- There is the potential effect of compressing the subclavian artery or vein and the brachial nerve plexus
TOS S/S?
- Patient presents with an upper extremity circulatory problem
- Such as cold, painful, or numb extremities
- It May vary with limb positioning
What is TOS bounded by? (3)
- Clavicle
- 1st rib
- scalene muscle
Define Paget-Schroetter syndrome?
- refers to effort-induced DVT of the upper extremity veins in young patients
- classifies as a thoracic outlet syndrome
How does TOS present?
- may injure? causing?
- typically in that arteries?
- Restriction at the thoracic outlet causes the vessels or nerves to be partially or completely compressed when the arm is in certain positions
- Repeated irritation may injure the intima causing thrombus formation
- Arterial emboli from thrombus can travel to distal parts of the arm usually from subclavian or axillary arteries
Uncomplicated TOS? (2)
No thrombus, plaque, or aneurysm formation
It May be caused by nerve compression
How is TOS diagnosed?
- Segmental BP’s and pulse volume waveforms are obtained with the limb in neutral position
How are BP’s obtained in TOS?
- proximal and distal brachial artery levels
- The test is repeated with patient’s arm in the position that causes the symptoms ie-just brushing the hair may cause discomfort
- The test is repeated with the head and arms in extreme positions
- A change in the BP’s or PVR’s should occur