Refractory Hypotension as an Initial Presentation of Bilateral Subclavian Artery Stenosis

Abstract

Bilateral subclavian stenosis is a rare clinical condition. An interbrachial pressure difference of 15 mm Hg can raise suspicion for unilateral subclavian artery stenosis, but the diagnosis of bilateral subclavian artery stenosis can be challenging. We present a case of a 75-year-old woman who presented with refractory hypotension after surgery. Initial vitals revealed blood pressure in the 60s/50s mm Hg in both arms. Cardiopulmonary examination was remarkable for diminished pulses in all 4 extremities and audible carotid bruits. She continued to be hypotensive despite aggressive fluid resuscitation. Troponin T peaked at 0.24 ng/mL (reference < 0.04), and an echocardiogram revealed a reduction in ejection fraction (37% from 50%). Left and right heart catheterization demonstrated normal filling pressures and cardiac output. During the procedure, however, it was noted that the patient's central blood pressure was 70–80 mm Hg higher than cuff pressures obtained in either arm. Selective angiography revealed 90% left subclavian ostial stenosis as well as 70% stenosis of the right subclavian artery.

Pseudo-hypotension with acute pulmonary oedema due to simultaneous bilateral subclavian artery stenosis in a patient with coronary artery bypass graft surgery using bilateral internal mammary arteries: a case report

“…Incidence of bilateral SAS, as in our case, is not well known and is considered very rare [1]. If bilateral SAS simultaneously progresses, as was the case in this study, it is difficult to identify SAS with an inter-arm BP difference [10]. The high ABI observed 1 year prior to admission, as in this study (represents the difference in BP of arms and legs), may be a key for accurately diagnosing bilateral SAS.…”

“…In addition, her BP gradually decreased 2–3 months prior to admission. Upon considering these findings, pseudo-hypotension due to bilateral SAS [10] was suspected. Finally, angiographic imaging aided by intravascular ultrasound and pressure measurements across the stenoses exhibited haemodynamically significant blockage in bilateral subclavian arteries (Figs 1A and 2B and D).…”

Pseudoshock: A Challenging Presentation of Bilateral Subclavian Artery Stenosis

“…The vertebral artery is the first vessel to branch off from the subclavian artery and supplies the upper spinal cord, brainstem, cerebellum and posterior part of the brain [4] . SAS is a form of upper extremity PAD which should be suspected when exam findings reveal a BP differential of 15 mmHg or more in the arms [5,6] , especially in patients with known lower PAD. Atherosclerosis has been identified as the most frequent cause, followed by fibromuscular dysplasia, compression syndrome and Takayasu arteritis [2,7] .…”

“…SAS is a form of upper extremity PAD which should be suspected when exam findings reveal a BP differential of 15 mmHg or more in the arms [ 5 , 6 ] , especially in patients with known lower PAD. Atherosclerosis has been identified as the most frequent cause, followed by fibromuscular dysplasia, compression syndrome and Takayasu arteritis [ 2 , 7 ] .…”

“…Common symptoms include upper extremity claudication, muscle weakness, and manifestations of vertebrobasilar insufficiency such as syncope, dizziness, diplopia, tinnitus and/or hearing loss [ 8 ] . Significant SAS is typically considered greater than 50% stenosis in the subclavian arteries [ 6 ] . Clinical exam findings include diminished upper extremity pulses, supraclavicular bruits, finger ulcerations and necrosis (particularly in those with longstanding disease) [ 3 ] .…”