difference between ST and SVT

[kyrela]

can anyone tell me what the difference is, if there is one?

[itdood]

I think trying to judge by rate alone isn't in anyone's best interest.  You can call out some generalities by rate, but I've had rates above 160 that were ST.  ST can be said to be < 160, but I've also read and heard that VT generally falls in this range too.  But then sometimes VT falls into higher ranges + 200.  You can also make some assumptions about how the tach starts and stops too, but there exceptions to every rule.

The best way to know what's going on is to catch it on a holter.

[donna80]

Just bumping for any other info on this.. How do you tell the difference? My episodes have never been caught on a monitor... My heart rate can go up to way over 100bpm something more closer to about 150bpm and flutters every odd beat lasting from minutes to hours!! But thats never been caught.. ? How do we know the difference?

[RNRita]

As I said, you don't need a holter to tell if it is SVT.  If you can count it and it is below 150, it is ST.  There is no doubt.  
That being said, you should ask your doctor (your ob is fine) what he/she thinks.  It could be your hormones.  A lot of women have problems like this during pregnancy and your doc should know about it.  No one can tell if it is anxiety until you see a doctor.  

[kyrela]

when I get mine, my HR doesnt usually go higher than 130ish, so that's why I was asking.  Can a holter monitor show if its ST or SVT? I'm pregnant so can't really go to an EP right now to get the works done from them. What happens to me is my HR races and comes out of know where, sometimes I can feel it coming, other times its like BAM there it goes and most of the time lasts less than a minute a few times has last about 20 minutes or so. How can you tell if its anxiety related or just caused by your heart?

[RNRita]

ST is sinus tachycardia and is a HR of between 100 and 149.  SVT is supraventricular tachycardia and is a HR of 150+. Supraventricular just means that it is originating above the ventricles. If it was in the ventricles, it would be Vtach and that is a lethal arrhythmia.  As for the second part of your question, if you are prone to getting SVT, you may get it from different triggers than someone else.  Sometimes it subsides on its own, but if it doesn't go back to normal or happens a few times, you should see a doctor.  
You actually should see a doc for any SVT when it first occurs.  ST is a more benign rhythm, sometimes brought on by exercise, stress, caffeine, or other things.

[kyrela]

also, does an to be considered and svt does it have to be brought on by something or last so long?