My 5 1/2 yr old son has complained this last week that his heart is beating fast. He did have strep throat the week before and was on amoxicillin. When I take his pulse for 10 secs and multiply by 6. It's been anywhere from 85-120. He feels this rapid

Normal heart rate. this is a normal heart rate for a 5 and half years old child. Now a common reason for fast heart rate in children is fever, common colds and dehydration. Children tend to drink and eat less when they are not feeling well and eventually become dehydrated. Make sure that your child had adequate fluid intake, control fever if any with Tylenol (acetaminophen). if the problem persist, then consult with his doctor.
Normal 4 age. He seems to be a nervous young lad. The anesthesiologist will give him something to calm him down before his procedure. In the meantime, you can give him plenty of hugs and kisses and words of reassurance.