Inappropriate Sinus Tachycardia Vs Pots

[blueskies1234]

I'm new around here, but have been learning a lot so far! It's exciting to talk to people who know what I'm talking about!

I am very confused about some things....What is the difference between inappropriate sinus tachycardia vs. POTS?

I have been sick since May '09 which they think started as a virus (perhaps mono, but it wasnt confirmed). I've had 2 tilt table tests-one was more autonomic (and less accurate according to my doc), and the other was cardiac (with the nitroglycerin). The 1st autonomic tilt test showed 'Mild Orthostatic Intolerance', but not as bad as typically seen for a POTS diagnosis. My heartrate did increase 35bpm and had a high of 147.

The 2nd tilt test (cardiac) gave me the diagnosis of 'Inappropriate Sinus Tachycardia' due to the increase in heartrate (165bpm) without the normal drop in BP.

The thing is, I have confirmed gastroparesis, unequal pupil size, extreme fatigue, fever, swollen lymph nodes, cold extremeties, I'm dizzy when I stand, brain fog etc.

I'm not sure where to go from here? Should I be seeing a cardiologist, or a neurologist?

Thanks in advance for any help you can provide :-)

[kayjay]

Your Bp does not have to drop for you to have POTS. My BP went up during my tilt table test. Sounds like you need a neuro and some docs that know what the test means.

With that said- was was never given anything during my test so if you got some kind of injection I guess it could mean something else. Good Luck

[Angelika_23]

I'm sure you will get better answers, but I have IST and POTS. My BP does not drop. With POTS, the 30 bpm increase in your heartrate when you come up from lying down is what qualifies the diagnosis. There is not necessarily a drop in BP.

I see a neurologist and a cardiologist.

Good luck

Angela

[Troy]

Hi,

I too have POTS but I am also confused with some of the terms used such as...

-Othastatic Hypertension (postural hypertension)

-Orthostatic Hypotension (postural hypotension)

-Orhastatic Intolerenace

-IST

how are these all different than just POTS ?

[firewatcher]

-Othastatic Hypertension (postural hypertension)

When you stand, your blood pressure increases beyond the normal increase that occurs, pushing you into the "hypertensive" category (above 120/80)

-Orthostatic Hypotension (postural hypotension)

When you stand your BP drops below the normal drop in BP (shouldn't drop more than around 10mm/hg systolic, if I remember correctly)

-Orthostatic Intolerance

either of the above, usually HYPO-tension

POTS

a sustained increase of 30 bpm or more from supine to upright regardless of what your BP does.

-IST (from Wikipedia)

is an uncommon type of cardiac arrhythmia, within the category of supraventricular tachycardia. The mechanism of the arrhythmia primarily involves the Sinus Node and peri-nodal tissue[1] and does not require the AV Node (Atrioventricular node) for maintenance. Treatments in the form of pharmacological therapy or Catheter ablation are available, although it is currently difficult to treat successfully.

USUALLY a high resting heart rate is present, with an average 24 hr HR of 95bpm or higher.

With POTS, the HR will decrease when supine, with IST, it looks like the HR is always high and activity pushes it even higher.

Edited January 8, 2010 by firewatcher

[blueskies1234]

Your Bp does not have to drop for you to have POTS. My BP went up during my tilt table test. Sounds like you need a neuro and some docs that know what the test means.

With that said- was was never given anything during my test so if you got some kind of injection I guess it could mean something else. Good Luck

Wow! Very interesting responses THANK YOU for the clarification! I am now convinced that I have POTS (not IST) afterall. I guess I need to find a doc that can interpret the results and get me a 'proper' diagnosis.

Thanks again!

[ramakentesh]

There is substantial crossover between IST and POTS - 50% of patients with IST have autoantibodies to beta 1 receptors overstimulating the heart but this occurs at all times. Blair Grubb thinks that some POTS patients also have beta 1 receptor antibodies causing POTS.