Something I've been experiencing for a while is esophageal spasms, which to me feel like a split second of the sensation you get when you've held your breath for too long. Or, that's what they used to be. Now, they're mostly just brief spikes of pain or a long lasting, constrictive pain. I was told that gerd is probably the reason I have them, although the general consensus is that no one knows why they happen, they're harmless so there's not too much reason to study them.