Heart Rhythm Community
12.2k Members
Avatar universal

Possible Inappropriate Sinus Tachycardia

Hi - I am a 36-year old female who has experienced a faster than normal pulse and some exercise intolerance for as long as I can remember.  For many years, I just brushed this off and none of my physicians flagged it as a cause for concern.  I even had a healthy, full-term pregnancy with no cardiac complications.  

A few weeks ago, I noticed my heart rate increasing to a level that made me very anxious.  I ended up in the ER, and an EKG indicated a pulse of 145 BPM.  I was admitted overnight, and received a chest CT scan, echocardiogram and complete blood panel.  Everything was normal, and my heart remained in sinus rhythm the entire time.

I've since been referred to a cardiologist, and I'm awaiting the results of a 24-hour holter monitor.  During my first and only appointment to date (EKG in the office read 112), my cardiologist told me that beta blockers would not do any good - and that I should drink liters of water and exercise for at least 30 minutes daily.  She thinks I am simply deconditioned. Inappropriate sinus tachycardia was not specifically mentioned, but my condition sounds much like the descriptions I've read of it online.


1.  With IST, would I have a heart rate of 75-85 while sitting relaxing at night - or are those numbers "too low"?  

2.  When I was in the ER, the doctors asked me to try a few vagal maneuvers to lower my heart rate.  If I had IST, would these vagal maneuvers actually be successful?

3.  If I do, in fact, have IST, what would be the risks in my having a second pregnancy?  I'm not so much worried about being uncomfortable - as I know that pulse naturally increases during this time.  I'm more worried about my symptoms worsening on a permanent basis or developing a cardiomyopathy.

Any insight or advice would be much appreciated!
1 Responses
1807132 tn?1318743597
The way I understand it IST is something that is usually caused by something outside the heart which makes it difficult to treat.  So the idea of drinking lots of water and working to condition your heart is a good first line of defense.  If it doesn't work then you may need to do further investigating.  Just to be clear did you have your thyroid levels checked?  If so what where they, were you borderline?  Hormone issues can definitely play into a fast heart rate.  I would say avoid caffeine if you can especially energy drinks and make sure you are getting enough water a day and see if things improve.  I would also tend to any stomach issues if you have them.  If there is anything going on with my stomach that sometimes causes my heart to speed up.  I would say you can try the vagal maneuvers and see if it helps but not sure if it will make in impact against IST.  Also try drinking lots of water when you notice the high rate and see if it helps it go down.  if so then dehydration may be part of the problem.  Finally you may want to check into dysautonomia since you say you have had issues most of your life.  Well hope you can get to the bottom of things and get your heart rate under control.  Take care.
Have an Answer?
Top Arrhythmias Answerers
1807132 tn?1318743597
Chicago, IL
1423357 tn?1511085442
Central, MA
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
Are there grounds to recommend coffee consumption? Recent studies perk interest.
Salt in food can hurt your heart.
Get answers to your top questions about this common — but scary — symptom
How to know when chest pain may be a sign of something else
For people with Obsessive-Compulsive Disorder (OCD), the COVID-19 pandemic can be particularly challenging.
A list of national and international resources and hotlines to help connect you to needed health and medical services.