From the Guidelines
A left subclavian artery bruit is a significant finding that requires prompt evaluation for potential subclavian stenosis or occlusion, which can lead to subclavian steal syndrome and increased risk of posterior cerebral circulatory insufficiency, particularly in patients with symptoms aggravated by upper-limb exercise 1. The presence of a left subclavian bruit suggests turbulent blood flow, which can be caused by atherosclerotic disease, subclavian steal syndrome, arteritis, or fibromuscular dysplasia.
Key Considerations
- The diagnosis of subclavian steal syndrome should be considered in patients with symptoms of posterior cerebral circulatory insufficiency, such as lightheadedness, syncope, vertigo, ataxia, diplopia, motor deficits, or upper-limb claudication, which are typically aggravated by exercising the ipsilateral arm 1.
- Asymmetry between left and right arm blood pressure measurements can indicate subclavian artery stenosis or occlusion, with the side with the lower pressure being suspect for subclavian artery disease 1.
- Duplex ultrasonography may identify reversal of flow in a vertebral artery, and CT angiography or magnetic resonance angiography of the aortic arch may identify stenosis of the subclavian artery 1.
Management
- Asymptomatic patients with mild stenosis can be managed with medical therapy, including antiplatelet medication and statin therapy, as well as cardiovascular risk factor modification 1.
- Symptomatic patients or those with severe stenosis (>70%) should be considered for subclavian revascularization with endovascular or surgical techniques 1.
- Regular follow-up is essential to monitor disease progression and treatment effectiveness.
Important Points to Consider
- Subclavian steal syndrome can lead to posterior cerebral circulatory insufficiency, which can cause significant morbidity and mortality if left untreated 1.
- Prompt evaluation and management of a left subclavian bruit are crucial to prevent long-term complications and improve quality of life.
From the Research
Significance of a Left Subclavian Artery Bruit
A left subclavian artery bruit, or murmur heard over the subclavian artery, is a significant finding that may indicate underlying subclavian artery stenosis or occlusion. This condition can lead to various symptoms, including:
- Vertigo
- Unsteady gait
- Upper extremity pain and paresthesia
- Ischaemia of the left arm
- Subclavian steal syndrome
Clinical Implications
The presence of a left subclavian artery bruit warrants further investigation, as subclavian artery stenosis is associated with increased cardiovascular disease mortality 2, 3, 4. The condition can cause upper extremity, brain, and cardiac ischemia, making prompt recognition and treatment essential.
Treatment Options
Treatment options for subclavian artery stenosis include:
- Endovascular stenting and angioplasty as first-line management 3, 5, 4
- Open surgery, such as carotid-subclavian bypass or subclavian-axillary crossover bypass, for more challenging cases or when endovascular treatment is not successful 3, 5
- Drug-coated balloon angioplasty, a potential novel indication for subclavian artery stenosis 4
- Percutaneous transluminal angioplasty (PTA) and stenting, which has been shown to be effective in patients with left internal mammary-coronary bypass grafts 6
Diagnostic Considerations
Diagnosis of subclavian artery stenosis typically involves imaging studies, such as arteriography, CT-angiography, or ultrasound. The presence of a left subclavian artery bruit should prompt further evaluation to determine the underlying cause and guide treatment decisions 2, 3, 5, 4, 6.