Case Report: An Unusual Presentation of Bilateral Subclavian Stenosis in a Patient with Asymptomatic Hypotension

Abstract

BACKGROUND Subclavian stenosis is an uncommon clinical condition associated with severe cardiovascular complications, usually presenting with claudication and subclavian steal syndrome. Here we describe the rare case of bilateral subclavian artery stenosis in an asymptomatic patient. CASE REPORT Our patient was a 63-year-old chronic smoker with no prior medical history whose chief complaint was dyspnea from an exacerbation of his chronic obstructive pulmonary disease (COPD). He was hypotensive with blood pressure 74/56 mmHg at admission, which raised suspicion for sepsis, adrenal insufficiency but the workup (renal panel, full blood count and synacthen tests) were normal. He quickly recovered after we treated his COPD exacerbation, but his hypotension persisted despite repeated fluid challenges. To evaluate for structural causes of his hypotension, we performed a full cardiovascular examination with 4 limb blood pressure measurements and found upper limb hypotension and lower limb hypertension. Subsequent imaging with ultrasound and computed tomography confirmed the presence of bilateral subclavian artery stenosis. Our diagnosis was thus bilateral subclavian artery stenosis secondary to atherosclerosis from chronic smoking. The patient was subsequently referred to vascular surgery for consideration of surgical revascularization. CONCLUSIONS Bilateral subclavian stenosis is extremely rare and requires a high index of clinical suspicion. Early diagnosis is important in the primary prevention of associated cardiovascular diseases.

Figure 1.

Timeline of care showing the blood pressure trend with several episodes of hypotension despite multiple fluid challenges (represented as asterisk).

Figure 2.

Ultrasound duplex scan of (A) left vertebral artery showing retrograde flow pattern and (B) left subclavian artery showing increased flow velocity of 211 cm/s (arrow) suggesting subclavian artery steal syndrome. (C) Right vertebral artery showed slightly reduced flow velocity and late-systolic deceleration which might be a sign of mild subclavian steal phenomenon and (D) right subclavian artery showed normal triphasic waveform.

Figure 3.

(A) Computed tomography (CT) reconstructed and (B) CT coronal images showing left subclavian thrombosis and atherosclerosis (arrowheads), right subclavian artery stenosis (arrow). (C) CT axial image showing right subclavian thrombosis (arrow) and collaterals from the costocervical trunk (arrowhead).