Subclavian stenosis suspicion is indicated by which finding?

• A. Subclavian stenosis on the side with lower pressure
• B. Equal arm pressures
• C. Higher heart rate in one arm
• D. Lower systolic pressure in one arm by more than 20 mmHg

Answer: (A)

The main idea is that an asymmetric inter-arm blood pressure indicates unilateral subclavian artery disease. When the subclavian artery is narrowed on one side, the pressure distal to the narrowing drops, so the arm on that side has a lower systolic pressure than the other arm. This difference between arms is the clue that prompts further vascular evaluation for subclavian stenosis. If both arms show similar pressures, unilateral subclavian disease is unlikely, and a higher heart rate in one arm isn’t a reliable diagnostic sign.