Why did the numbing shot at the dentist make my heart race so fast it hurt?!
Question:
Why did the numbing shot at the dentist make my heart race so fast it hurt?
I've never had that happen before. We moved and I had to go to a new dentist. When they gave me the shot it seemed the same as always, but then my heart raced so fast it hurt. Now I'm afraid to go back to get the rest of my cavities filled because it freaked me out so bad when my heart hurt like that. I've always gotten the shots all my life and never had a problem. Please help!
Has anyone else had this problem?
Answers:
Classical reaction to epinephrine.. In each standard 1.8ml carpule of 2% Lidocaine that dentists use, there is also 1:100,000 (or .018mg) of epinephrine.
The epinephrine (also known as Adrenaline, the "fight or flight" hormone) does several things, such as constrict blood vessels and speed up heart rate. It's used with Lido because the blood vessel constriction will keep the lido in the area longer, prolonging its numbing effect.
You got the rapid heartbeat probably because some of the injection unintentionally ended up in your bloodstream. When we inject Lido/Epi, we try NOT to get the needle into a blood vessel. Sometimes it happens though, unfortunately.
When I give a Lido injection, I use an aspirating syringe which lets me know if I hit a blood vessel with the needle (the carpule becomes cloudy with a bit of blood when that happens). That's a sign that I should not inject-- I need to get a new carpule and reposition until I don't see blood in the syringe on aspiration before I inject.
Just remind your dentist to be real careful next time, so you won't get the same reaction. For good measure, you can ask your dentist to use 3% Mepivicaine with no Epinephrine instead of the standard Lido/Epi.
Don't be afraid, and good luck!