MS can and does impact the heart, so you want to talk to your doctor(s) and ensure it's not that.
Has anyone ever felt this and how do you deal with the pain?
Yes, the pain from the MS hug is impressive, isn't it?! When my "hugs" started they're not just the inter-costal muscles in the rib area, but various pains and spasms and spasticity in much of my back and torso -- not fun. :(
My neurologist put me on an increased dose of baclofen and I've developed all sorts of tactics and gimmicks to deal with the issues.
For example, as silly as it sounds, I can get some dramatic relief from using an inversion table. That $120 spent was well worth it. I don't have back problems, but a short 30-second or 2 minutes upside down on the inversion table will "reset" the pain level -- sometimes for 10 minutes or sometimes for 10 hours.
Also doing opposites -- "pushing the envelope" ideas -- seem to help. If I was active before the pain started I'll spend time sitting or doing nothing. Or if I was inactive when the pain started, I'll get physical and find something to do.
Things like medical marijuana (depending on the particular strain) can help, but TBH that's not a whole lot of help.
mentioned stretching is a key!
Stretch multiple times a day if needed. And don't forget exercise during the periods when you don't have the intense pain. Yes, we all know the problems of exercise and MS, but the reality is "use it or lose it" -- or "use it or get stiff and 'harden'."
Here's hoping that this is a case of "this too shall pass" for you!