There are any number of conditions that can cause esophageal spasms. You can google lots of information, also use the search box at the top of this page. One reference: http://www.mayoclinic.com/health/esophageal-spasms/DS00763
One condition not often written about is food intolerances/allergies. Use the search box to look up many, many threads about keeping a food journal.
My particular triggers give me reflux feelings, also tachycardia. Do you have any other symptoms besides just the esophageal pain? Do have this symptom all the time or only sometimes?