Bram,
Yes. Go see your GP. If you can't get in to the GP, get in to an Urgent Care facility. This new symptom sounds very scary. You should keep getting it checked out each time it happens. KathyUK and Reluctant, this goes for you two too. Don't mess with your heart! You do matter. Good Golly!

I have spasms of my esophagus. Not hiccups. When it happens, the pain in my chest is very real, strange and scary. I do have Dystonia and severe spasticity. I have a baclofen pump and I take oral bac when I need extra. Until you know for sure that your new symptom is something like this, you don't want to mess with it. Get yourself back to the GP.

I hope it is something that passes.