SVT or sinus tachycardia???

[NikkiD199930]

Hi...so last month I went for a physical for spring sports, as I am a 16 year old girl athlete.  My pulse was 150-160 and they made me go to the ER.  There, they did blood work, ekgs and a chest x-Ray and all the while my hr was 130-150 and it spiked to 190 twice.  They didn't give me any medicine or anything because I was a symptomatic.  So I was transferred to another hospital where they did more testing and an echo.  They didn't find anything significant except I had very mild mitral valve prolapse but no regurgitation or anything.  The blood work was borderline abnormal and they said to see an endocrinologist and an electrophysiologist.   Otherwise they didn't find/do anything and sent me home when it was between 100-130.  The electrophysiologist gave me a holter monitor for a week and said it was fine.  My average hr was 91, probably because it went in the 40s overnight.  It went to 180 on multiple occasions thing as well.  I'm still awaiting the results of the endocrinologist.  For now I am allowed to play sports and everything.  But like, what could be wrong?  They think a thyroid issue maybe, but I think the heart rate problem is significant.  Could it be like svt or something?  Because my heart just randomly does jump up.  And why can it be so variably/always changing so much?  My EKG rhythms looked 'normal' but could there still be a problem?  I'm sorry this is so long, and I know you can't diagnose me.  I was wanted someone news opinion on what's going on / do you have any thoughts or ideas.  Thanks.

[MichelleP_3811]

Like Tom said, svt is generally a sudden start and stop to the svt in what feels like one beat.  Considering they suggested an endocrinologist it suggest thyroid issues may be the culprit.  Hyperthyroidism can cause an elevated heart rate so get that taken care of and then see where you are at.  Until then make sure that you drink plenty of water and if you tend to low bp maybe add a few salty snacks to your diet though watch the sports drinks because they can contain high amounts of caffeine and sugar and sodium that you don't need unless you are sweating heavily.  Best of luck getting it sorted out.  If it does turn out to be thyroid related there is a section on this site that deals with thyroid issues you may want to check out.

[tom_h]

A couple of classic symptoms of SVT:

It starts and ends abruptly, within a beat.  It doesn't ramp up or ramp down slowly.  That said, when you drop out of SVT, either spontaneously or by Valsalva intervention, the NSR may come down slowly due to adrenaline in your system.  But there is an unmistakable drop from say 225 to half that speed.  There's a sudden quietness within.  Bjut if you palate your pulse, it's not uncommon to measure 100bpm as it slowly drops from there to normal resting rates.

Every person with SVT has their own personal speed. Typical rates can range from 160 to 240.  Rates can be higher or lower, but they usually don't vary by much unless you might be doing something at high respiration rates when SVT kicks in.  

If you don't have these symptoms, chances are you'll need to search for something other than SVT.