Dear T1562,
I hear you - when you say your body does not want to do the 'taking it easy" thing. Many days, my body doesn’t want to cooperate with other parts of itself; my legs will get all fidgety and want to bust out in a really hard run - but my lungs will not want to - and my CNS starts shooting pains. And, I’m like going… 'Whatever!"
I am very curious how your root canal procedure went.
I just had 3 root canals ‘diagnosed’ this year. These are the first dental appointments I made since my Chiari surgery in 2012, so it has been awhile. I have accumulated 3 root canals over the years. 
Nuts again! Since this was my first dental work since the surgery, I didn’t know or anticipate any different.
But - WOW! Did I ever have a bad reaction to the Novocaine!!! With the dentist I went to, I had to go in for 3 different appointments and procedures - to the root canal specialist, to the cavity-filler, to the crown-fitter specialist. After each shot of Novocaine, I got really sick! I could barely drive home - and could barely move the rest of the day - like a mild paralysis took over.
The final appointment and shot of Novocaine was the worst and most violent reaction of all. Like you said - the tightening of the chest and couldn’t breath - I started passing out mere minutes after the shot! Everyone in the dental office was freaking out. They didn’t know whether to call 911 or not. They kept asking me if they should continue, or reschedule. I didn’t know either!!! All I knew is that I didn’t want to have to come back and do this all over again! I did my best to 'get tough!" I took another sliver of my Amitriptyline medicine - JUST IN CASE my reaction was nothing more than a panic attack. (I am prone to those as well. Very confusing - panic attacks sure feel like you are really dying! I honestly can’t tell them apart.)
In the end, I forced myself to sit through the procedure - and had two more near-passing-out spells. When I got home and recovered, I did some research.
I THINK the issue - for me - is the epinephrine in the novocaine. Epinephrine is ‘adreneline’ - and for some reason, since Chiaris, my CNS reacts in the extreme opposite from ‘normal’ whenever there is an increase in adreneline/epinephrine. My CNS wants to stop dead. (a month after my decompression surgery, I had to take a ‘tilt-table test’ in which they gave me a shot of epi. That’s the first time I nearly passed into eternity!!! My Blood pressure dived to 40 over 25 - and they almost had to revive me with those shocking paddles.)
In my research, I also learned that the only medication I’ve been on since surgery - 3 mg of Amitriptyline - does the job of BLOCKING epinephrine to the brain! Hmmm. That got me thinking. For some reason, my post-Chiari brain cannot handle adreneline/epinephrine. I don’t know if that’s ‘normal’ for Chiaris or not. Prior to Chiari’s, I had no issues with novocaine. NOW… I will either have to ask for ‘novocaine without epinephrine,’ for future dental procedures, or have the oral anesthesia. Unless I am going to react badly to gas anesthesia as well. I have no idea. In normal people, epi is supposed to give the CNS a boost! Not stop it dead. (In the ER shows, the docs are screaming, “Give me another milligram of Epi!” every time their patient’s heart is stopping. Epinephrine NORMALLY revs things up nicely. But, when is anything with Chiari’s ‘normal’???)
Let me know how you did with your procedures. Again, we all are different - and you may do just fine with epinephrine?!? I’m curious - and always learning about this CRAZY Chiari’s!
But - the caffeine DOES keep my blood pressure up through the entire workout - so it is rather… medicinal. By the grace of God - I’ve become quite good at the race walking!! I’m one of the fastest in the nation - on the Senior Olympics track meet circuit. It took a couple years, though. (My surgery was in 2012, but I started race walking in 2016.) My Central Nervous System didn’t always coordinate well at first. It is STILL slowly healing… and I am slowly slowly getting faster and faster times. Even with age. 