1230 - Suspected Subclavian Steal Syndrome with Negative Imaging

Suspected Subclavian Steal Syndrome with Negative Imaging

Patient: Dale, 58-year-old male

PMH: Atrial fibrillation (ICD), hypertension, hyperlipidemia, hypothyroidism, CKD progressing to ESRD (PermCath for dialysis)

Case Description:

A 58-year-old male developed recurrent vertigo, diaphoresis, tinnitus, cervical discomfort, and transient syncope during physical therapy following placement of a tunneled dialysis catheter in the right internal jugular vein. He remained hemodynamically stable, with unremarkable cardiac and neurologic evaluations. Bilateral carotid Doppler studies demonstrated no significant stenosis. CT imaging confirmed appropriate catheter placement within the right internal jugular vein terminating in the superior vena cava, without impingement of the carotid sinus. Empiric treatment with meclizine and midodrine failed to resolve symptoms. Given the episodic nature and correlation with upper body exertion, dynamic or positional vascular compromise by the catheter was suspected despite negative static imaging. Since the symptoms were predominantly being reproduced on overhead movements, a physiatrist worked with the therapists to modify movements, thereby, limiting overhead reaching activities. Consequently, the patient had no further episodes after that restriction was added. 

Discussions:

Subclavian steal syndrome (SSS) is characterized by retrograde flow in the vertebral artery secondary to proximal subclavian artery stenosis or occlusion. While many individuals remain asymptomatic, some may present with vertebrobasilar insufficiency, manifesting as vertigo, diplopia, ataxia, dysarthria, or syncope as well as upper limb ischemic symptoms precipitated by exertion. Diagnosis is typically established via cerebrovascular duplex ultrasonography. 

Conclusions:

This case highlights the diagnostic complexity of SSS, particularly in patients with central venous catheters and absent confirmatory imaging findings. In patients presenting with new-onset exertional syncope and ipsilateral upper extremity symptoms following catheter placement, SSS should remain a differential consideration. Dynamic or positional factors not visible on static imaging may contribute to transient vertebrobasilar insufficiency, requiring further evaluation, such as catheter repositioning or adjustments to therapies, as implemented on our inpatient physiatry unit.