Could Pain Under The Sternum Be Oesophageal Spasm?

I think I may have gallbladder disease, although ultrasound and MRI scan show no stones, sludge, etc. I have had urq pain for over one year that goes away every so often. Lately it does not go away. I have tenderness over my entire right ribcage. Now I have developed what I call a spasm , a sensation in right under my sternum that makes me feel like I am going to lose consciousness. I have been to a cardiologist who noted nothing wrong but suggested a possible esophageal spasm.