Anesthetic Injection Makes Heart Beat Faster

Those who have been to the dental clinic and got the numbing or anesthetic injection must have experienced that whenever they get the numbing shot their heart beat faster as if it is about to come out of the chest though this feeling is there just for couple of seconds. You must be wondering that why it is so. Is it because of anxiety or nervousness that you have before getting the dental treatment? Anxiety and nervousness is one of the causes of this sort of feeling but the main cause is the epinephrine present in the dental anesthesia. When the person is nervous or anxious adrenalin or epinephrine releases in the body which makes the heart beats faster. Same epinephrine is also added in the dental anesthetic solution.

Why epinephrine is added to the dental anesthetic solution

Epinephrine is added to the local anesthetic solution as it is a vasoconstrictor means it constricts the blood vessels so the dental anesthetic can act locally for longer duration and at the same time less amount of anesthetic solution goes into the body. The dentist needs time to work on the tooth and for the anesthetic solution with the epinephrine is used. It is more affective in numbing also. In European countries instead of epinephrine Levonordefrin is used which is like epinephrine only.

How much Dosage of Epinephrine is recommended?

According to AHA the recommended dose of epinephrine for heart patients should not exceed 0.04mg. One cartridge of dental anesthesia contains around 0.018 mg of epinephrine. That means at one time not more than 2 cartridges of dental anesthesia can be given to the heart patient. In comparison a healthy person without any heart problem can receive around 11 cartridges of dental anesthetic solution.

Precaution that should be taken while injecting the dental anesthesia with epinephrine

There are certain precautions that the dentist can take while injecting the dental local anesthetic solution. While injecting they should “pull Back “ to ascertain that the solution is not being injected into the blood vessel because if it is directly injected into the blood vessels then the chances of palpitation and discomfort are more likely. Secondly the solution should be injected very slowly. The recommended rate of injection is 1ml/min. Even when all the precautions are taken like aspiration, slow delivery even then the sufficient amount of epinephrine can be absorbed in the body to cause the symptoms like palpitation, tachycardia, sweating etc. also known as “Epinephrine Reaction”.

Epinephrine free dental local anesthesia is also available like Carbicaine, but dentist don’t prefer using it unless they are indicated as the duration of numbness with these solutions is less and they are not very affective as they don’t have vasoconstrictor in them. So dentist prefer using local anesthesia with adrenalin or we can say epinephrine in it.


If your heart beats faster or you have the feeling that it is coming out of the chest while getting the anesthesia shot then it does not mean that you are nervous. The solution can also cause these symptoms. But you don’t have to worry as this affect wears off in couple of sec.


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