AF Association

Is Af similar is IST?

Been ill since August, saw electro physiologist last week who says I either have AF or IST....inappropriate Sinus Tachycardia. So my heart beats all the time at 110 plus at resting, shooting much higher with exhersion. So have been house bound and unable to go to work. Can anyone tell me if there is a test/procedure to see which condition I have? Either one it is my heart beating too fast. Been given Bisoprol which has lowered heart beat but also lowered BP so still constantly exhausted.

8 Replies


In my ignorance I thought that they could tell from the ECG.

I take Metoprolol when I need to control my rate, which is also a beta blocker but it seems to not have such a pronounced effect on my blood pressure and tiredness (though I am always glad when heart resets and I can stop). I'm not sure why more people don't take it and Bisoprolol is drug of choice (I can't take that).

Sorry you're feeling unwell and in a quandry about what best to do, I think that is one of the worse things watching and waiting to see what way it's going to go and trying to judge when you need help and intervention and when you can stick it out.



I too am puzzled Cassie as AF is so easy to see on a 12 lead ECG due to the chaotic bottom line with complete absence of P wave. One would hope since you have seen an EP that they have done at least a 24 hour Holter test or even a 7 day event monitor or are these things you will soon be having? If so then they will know pretty quickly what it is.



Do you have a picture of a ECG of someone with AF and what is a P wave?


The p wave is the little blip just before the T wave which is the big spike. In AF there isn't one and also the gaps between are all over the place and sometimes there is no discernable wave form at all.just a chaotic wiggly line. With ectopics. the T wave is often upside down and referred to as flipped Ts. I am sure that there are website which will show this but frankly find that even after ten years of this mongrel I do not feel qualified to read ECGs and many GPs get it wrong plus some cardiologists as well. There was a link long ago to such a medical discussion where an expert explained why several ECGs had been wrongly diagnosed.


Thank you x


When my G.P. read my e.c.g. he sent me to hospital! He thought it showed long Q.T. syndrome. My E.P. said that all was fine and I didn't have it. I have A.F. , first degree heart block and bundle branch block non of which are life threatening but apparently to an non expert, can look that way on an e.c.g.! I decided never to buy a heart monitor with e.c.g. reader ,after that! X


I'm exactly the same 110 plus all the time and I am also taking bisoprolol which to be honest hasn't lowered my heart rate much. I am tired, out of breath and feel exhausted too...I only 52 and feel about 92. I have had 2 cardioversions and have now been referred to an EP who I am seeing on Christmas Eve.....fingers crossed for both of us. xxxx


Thank you for your replies. I have had a 24 hr heart monitor whilst in hospital which showed my heart beat sometimes goes at a different rate than my that AF?? Sorry for my ignorance. He also said it showed I had ectopic beats. I also had 7 day monitor whilst admitted another time, was never told what it showed.....other than heart shooting up to 155 on slight exhertion.

On Bisoprol now but seem to have gone the other way.....heart rate down to 74 but BP now only 90/60 so feel very tired. Can't seem to win. Any advice please??


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