Inapropriate sinus tachycardia

[Mottec]

hi all
I am pretty sure I have IST even if Im not diagnosed that. I also have PAC. The tachycardia is bad enough that I take bystolic 1.25 mg daily. If I didnt I would have days were just sitting up in bed could make my heart beat faster. Going for a walk could make my heart race really fast. So Im glad bystolic works. Today however I have been lifing some moderately heavys stuff and I get palpitations so Im now considering a little more Bystolic.

I would like to hear from others with IST, to hear how they cope, and if they also get anxiety when the pulse is racing.

I also suffer from dizziness but I dont know if this is related.

[is_something_wrong]

Sick sinus syndrome involves both tachycardia and bradycardia, often at completely inappropriate times. You can have long pauses which may cause fainting, and runs of bradycardia (or a heart rate of 60 during exercise - just weird stuff), and often atrial fibrillation as well.

Postural tachycardia manifests with a normal heart rate except when standing up. It's probably caused by excess adrenaline levels causing dilated blood vessels, which will cause low blood pressure and tachycardia when standing.

IST involves a chronic rapid heart rate, as well as exaggerated heart rate response to stimuli such as exercise. I had IST (and PACs - I still have PACs) for a couple of months after a virus infection back in 2010. Even light exercise (such as walking) could get my heart rate into the 160s, and walking up hills could get the heart rate into the 200s. It probably didn't help that the heart rate made me panic. Propranolol (beta blocker) helped me tremendously.

[Mottec]

Yes. Its a thing to consider. How will I know that I have IST for sure though, and not sick sinus syndrome or postural tachcycardia.