Symptoms, diet, time
Expect a comprehensive history (cardiac questions too), physical exam, rectal exam probably, check stool for blood, labs.
depending on duration, severity of symptoms, age, risk factors for ulcers, chronic esophageal changes.
Keep track symptoms, time of day, awakened at night? Triggers, relief, duration, other symptoms (sweats, short of breath, palps, chest discomfort etc), meds.