A patient on GERD medication with hypertension and a cardiac history develops substernal 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 chest pain RADIATING TO THE SHOULDER in a patient with known cardiac disease and hypertension must be treated as cardiac until proven otherwise. Normal vital signs and the absence of arrhythmia do NOT exclude angina — stable angina frequently presents with entirely normal vitals between and even during episodes.
• B. Musculoskeletal pain is reproducible on palpation and movement, and would be a diagnosis of exclusion in this patient.
• C. Syncope involves loss of consciousness and is not described here.
• D. GERD certainly causes substernal burning, and the patient does take medication for it, but radiation to the shoulder in a cardiac patient is the feature that must not be attributed to reflux.

Note: That reasoning is unsafe. Radiation to the shoulder, arm or jaw in a patient with cardiac history is a red flag regardless of vitals. Stop treatment, position the patient comfortably, give oxygen, administer nitroglycerin if prescribed, and if the pain is new, severe, or unrelieved by nitroglycerin, activate EMS and give aspirin 162–325 mg chewed.