A patient on GERD medication and antihypertensives presents with new substernal chest pain radiating to the shoulder. Vital signs are normal and no arrhythmia is detected. What is the most likely diagnosis?

Correct answer: A. Angina pectoris

• A. CORRECT — Despite being on GERD medication, substernal chest pain radiating to the shoulder (referred pain) in a patient with hypertension and cardiac history is classic angina pectoris. The radiation to the shoulder is a key cardiac referral pattern. Even with normal vital signs, angina should be the primary consideration.
• B. INCORRECT — While MI must be ruled out, the scenario of 'normal vital signs, no arrhythmia' and prior cardiac history points to stable or unstable angina as the primary working diagnosis.
• C. INCORRECT — Syncope (fainting) involves loss of consciousness due to reduced cerebral perfusion, not chest pain radiating to the shoulder.
• D. INCORRECT — GERD typically causes substernal burning after meals; radiation to the shoulder is not characteristic of GERD.