More than just a fall in blood pressure – a case report of bilateral subclavian artery stenosis

Abstract

Introduction: Chronic ischaemia of the upper extremities is rare, particularly when it is bilateral. Depending on the existence and location of collateral vessels, it may remain asymptomatic or it may present with symptomatic ischemia of the upper limbs and a high risk of coronary and cerebrovascular disease. Although the diagnosis is made by ultrasonography, the physical examination may reveal abnormalities, including differences in blood pressure values between both arms with unilateral occlusion. In this case report, blood pressure values were consistently low bilaterally, which led to an erroneous initial approach based on a presumed decrease in systemic blood pressure. Case description: The authors describe the case of a 77 year old female patient, with controlled hypertension and dyslipidaemia, who presented with brachial blood pressure (BP) measurements consistently lower than 90/60 mmHg, as well as complaints of fatigue with movements of the upper extremities. In the absence of other abnormalities, changes were made to the dose of her anti-hypertensive medication, without clinical improvement. After a few months without change in the clinical situation, the physical examination revealed a bilateral decrease in radial pulses and an increase in the ankle-brachial index, suggesting occlusive upper extremity arterial disease. This was confirmed by an arterial Doppler ultrasound, which revealed bilateral occlusion of the subclavian arteries. Comment: Blood pressure measurements were erroneously low because they were made at the brachial artery in a patient with a bilateral occlusion of the subclavian arteries. In these cases, the evaluation of BP based solely on brachial measurements may lead to an incorrect approach. It is important to integrate other signs and symptoms as well as a more complete physical examination when evaluating a possible diagnosis of this condition.