What Is A Heart Spasm Associated With Indigestion? Was Told

What is a heart spasm associated with indigestion? Was told by a cardiologist this was probably cause of chest pain that came on suddenly with a feeling of indigestion. The feeling of pressure/pain left after a few minutes, and did not involve arm or jaw pain. An EKG showed no problems. I'm a 76 y/o female of normal weight, who does 4 hours a week of cardio-pulmonary exercises every week. No diabetes. Only health issue is COPD, but I do not have to use oxygen.