IST

[Hayleywayley]

Hey everyone, after 7months of tests and my body going haywire i finally have a diagnosis of inappropriate sinus tachycardia, I suffer from it daily unfortunately but oh well, does anybody else suffer from this condition? and if so I’d love to know how you manage with it and symptoms etc☺️

[JonathanPittsCrick]

HI Hayley, I'm afraid the diagnosis of "inappropriate sinus tachycardia" is really just a description – it doesn't say why it's happening or what you can do about it. In young people there are 3 main causes:

1) Low and/or unstable blood pressure: this is typically caused by not eating enough salt or drinking too much water. The simple solution is (obviously) to eat more salt and not drink more that 1 litre of water a day.

2) Disturbed cardiovascular control: this is usually caused by a virus affecting your nervous system (like "fatigue syndrome" or "ME"). The best solution is to re-train the system by undertaking a vigorous fitness program, but it can take several months before things get back to normal. Avoiding exercise (because it causes your heart to race) just makes it get worse.

3) Abnormal sinus node automaticity (this is pretty rare): for no known reason, groups of cells, unually at the edge of the sinus node, take over the heart rhythm at a higher rate, especially in response to adrenaline. It can be detected by abrupt stepwise changes in your heart rate seen on Holter recordings, where the rate increases by about 20 bpm from one beat to the next, and later drops back just as suddenly. It sometimes responds to anti-adrenaline (beta blocking) or antiarrhythmic drugs – like bisoprolol or flecainide – but often not. I have seen focal ablation of the abnormal cells work brilliantly but only tried in two or three cases. Sometimes the problem goes away by itself after a few years; more often people get used to it and notice it less and less.

I'm assuming that they have already checked that your heart and hormones are normal.

[Kerry40]

Hi , ive also been diagnosed with ist , I think in my case its a diagnosis where they don’t actually know what is causing my sinus tachycardia. I do have triggers for my episodes, eating small/big meal, drinking, soft or alcoholic drinks, being tired and sleeping will bring my tachycardia on ,otherwise my resting heart is 60bpm .Im on propranolol where i take one a day then i can take a further 3 if i need to in the day . Im due to see a consultant in 11 weeks so hopefully find out more then as I have had no information at all other than what ive searched myself. All the best with your IST

[Katiebobs]

Must be a relief to have a diagnosis. Hope things are managed to allow for a happy life where this condition does not dominate it

[Eliza2]

Hi Hayley yes I get the tachycardia often thankfully not for long. I have sick sinus after 3 ablations. It’s pretty distressing mainly because you don’t know if or when it will stop. If you care to chat you can pm me.

[FolkGirl123 in reply to Eliza2]

Hi Eliza - did your IST show up after a cardiac ablation? Was the ablation for IST or something else? I’m experiencing symptoms of IST 2-months post ablation for AVNRT.

[Lancastersvt in reply to FolkGirl123]

Hi

My adult son has been recommended to have an AVNRT ablation and no one mentioned the risk of IST. Apparently cardiologists consider the ablation a success even if the patient has IST.