Case report: a case of masked subclavian artery stenosis in a haemodialysis patient.

Background: Subclavian artery stenosis is generally screened by a left-right brachial systolic blood pressure difference. However, subclavian artery stenoses are often underdiagnosed due to marginally identified symptoms. In dialysis patients, a relative or absolute contradiction of measuring blood pressure in shunt brachial artery may further limit the disease screening. Case summary: A 77-year-old female requiring dialysis presented with a suspected acute coronary syndrome complicated by cardiogenic shock. Five months before presentation, the patient was increasingly given inotropic drugs and had often chest discomfort during dialysis. An emergency coronary angiogram of the right coronary artery revealed 99% stenosis with hypoplasia. During catheterization, angiography of the aortic arch showed subtotal occlusion of the left subclavian artery. After revascularization, patients did not suffer from low blood pressure during haemodialysis. Discussion: Dialysis patients may have high perceived risk of subclavian artery stenosis. However, limitation of measuring blood pressure in shunt artery may enhance its underdiagnosis. Our case highlights the importance of screening for subclavian artery stenosis in patients undergoing dialysis.