If you eat something that you are allergic too or have a food intolerance
too, your pulse will go up. The more you are allergic or intolerant, the more it will go up. There is a famous test that I use on a regular basis to test people for these reactions and it was developed by Dr. Cocas.
Another thing that can happen is that if you do not get enough sleep at night (more than 5 hours uninterrupted), your adrenal glands
will not recharge properly and you can feel a drop in blood pressure when you stand up quickly. You will feel a little dizzy and then your heart can race a little and give you that feeling. If you eat or drink things that have stimulants in them, like coffee, soft drinks, or eat things that have MSG in them, etc., this can make your heart race.
good luck to you