what is a dangerous heart rate for a 6 yo girl?

depends on what she's been doing for the last bit. sitting on the couch resting - i'd say about 140-160 is a little fast. running around playing, maybe 180 is fast. dangerously fast though, i would say over 200-220. if you're worried about something call your dr and check with them....

If she has a fever expect a high rate. 120-160. 180-200 then we are talking about maybe a treatable SVT. I have given adenocard to a 6 year old girl before. That is a med to slow a HR and break them into a normal rhythm. Do give that to a child though is pretty rare. Usually all rapid heart rates in kids are caused by fever, dehydration, or both.

By the rule at heart rate of 160 or above; some hearts will stop being efficient pumps. That is will not pump enough to keep you conscious.

But like all things biological wide variations do occur.

Yet if my 6 y.o. heart rate went 155, I'd take her to get checked out quickly.

My 6 year son had a resting BPM last night of 200! He has had a fever for 5-6 days but has been drinking no signs of dehydration ect but has had a mild cough, prior to leaving the house I gave him a dose of Advil as the tylenol just wasn't breaking his fever (102.9-upon leaving). We got to the ER and of course his BPM dropped drastically down to 98bpm. For fever your looking at an increase of heartrate of around 10bpm per degree in temp. A child with a normal resting bpm of 100 with a fever of 103.7 would have a resting bpm of around 137, couple that with possibly being dehydrated and overheated plus a cough and anxiety from waking up in the middle of the night my sons bpm shot up to 200. I brought him to the ER to get a chest x-ray just in case, if your child isn't dehydrated sick or running around take him to the ER asap, if he is sick or dehyrated try to cool him or her down, admit medicine to reduce the fever and reduce coughing and check again in 20-30 minutes and see if its gone down. My son's chest-xray was clear no pneumonia or pericarditis, so I was able to sleep at least, I still plan on getting a follow up as this has happened to him before, but I wonder if there is a point, especially since a lot of those nodule heart related diseases are rarely diagnosed at such a young age?

For resting - a rate of no more than 150 BPM, however, if the child is active or moving about, then a rate of 215 would be the highest it should go.