A patient on GERD medication with hypertension and known cardiac disease develops 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. SUBSTERNAL pain RADIATING to the shoulder, arm, jaw, or neck in a patient with known cardiac disease and hypertension is ANGINA until proven otherwise. Radiation is the discriminating feature — reflux burns behind the sternum and rises toward the throat but does not classically radiate to the shoulder or arm. Stop treatment, place the patient in a comfortable position, administer oxygen, and give sublingual nitroglycerin. If pain persists after 3 doses at 5-minute intervals, activate EMS and treat as MI.
• B. Syncope involves loss of consciousness with bradycardia and pallor, not chest pain.
• C. Reflux is the tempting distractor given the GERD history, but the radiation pattern and cardiac history make angina the priority diagnosis. In an emergency you must assume the more dangerous diagnosis.
• D. Costochondritis produces sharply localized pain reproducible on chest wall palpation.

Note: Never rationalize chest pain into a benign diagnosis at the chair. Treat as cardiac and let the emergency department rule it out.