From a New York Times Magazine article:

It was all horribly familiar — a rerun of an episode 15 months earlier, when she was with her family in River Vale, N.J. Back then, the burning pressure sent her to the emergency department, and she was told the same thing: She was having a heart attack. Immediately the cardiologist looked for blockages in the coronary arteries, which feed blood and oxygen to the hardworking muscles of her heart. That was the cause of most heart attacks. But they found no blockage.

Since childhood, she had frequent terrible canker sores that lasted for weeks. Sometimes it was hard to eat or even talk. Her mother, a nurse, told her everybody got them and thought she was being dramatic when she complained. So she had never brought them up with her doctors. Now the woman saw that her answer somehow made sense to the rheumatologist.

Indeed, that was the clue that led the rheumatologist to a likely diagnosis: Behcet’s disease. It’s an unusual inflammatory disorder characterized by joint pains, muscle pains and recurrent ulcers in mucus membranes throughout the body. Almost any part of the body can be involved — the eyes, the nose and lungs, the brain, the blood vessels, even the heart. Behcet’s was named after a Turkish dermatologist who in 1937 described a triad of clinical findings including canker sores (medically known as aphthous ulcers), genital ulcers and an inflammatory condition of the eye.

To read more: https://www.nytimes.com/2019/11/20/magazine/heart-attack-diagnosis.html?te=1&nl=the-new%20york%20times%20magazine&emc=edit_ma_20191122?campaign_id=52&instance_id=14017&segment_id=19010&user_id=415092ec82728104b9ca7bbb44eeb7d3&regi_id=7441254120191122