Inappropriate Sinus Tachycardia... or is it?

[Stubborn Coyote]

Hello, I am new here. I am 25 years old and I recently went through cardiology testing to determine why I am having spells of tachycardia and dizziness upon standing up.  I'm wondering if I am seeing the wrong doctors. My GP and Internist ordered blood work and it all came back squeaky clean, so I was referred to a Cardiologist team. They did an ECG and tested my blood pressure, and revealed that my blood pressure was dipping slightly, which they said indicated a problem and ordered a tilt table test, echocardiogram, stress test, and 30 day event monitor. I thought we were definitely getting somewhere!

Echo and stress test showed my heart is healthy and functioning well. TTT was complicated. I was fine the first few minutes on the table, but nausea hit me out of nowhere and it quickly felt like my whole body was on fire. My blood pressure had dropped. I then had a panic attack (I have agoraphobia and panic disorder) and my blood pressure went back up. They gave me nitroglycerin, which caused pooling and pain in my arms and legs. I was very weak and woozy but didn't faint. They were only testing for syncope, so test was negative. 

My event monitor apparently showed that every time I recorded, my heart rate increased considerably. All events were recorded after getting out of bed, picking things up, bending over and standing back up. During my last appointment, I saw a doctor I had never seen before, and she insisted I take a beta blocker, but couldn't provide a diagnosis or even a discussion about my test results. She said I am just dehydrated and didn't believe me when I said I drink at least 80oz a day and am allergic to caffeine, so never drink coffee or tea. She said I *may* have Inappropriate Sinus Tachycardia. She didn't sound confident and I don't believe it, as my heart rate returns to normal if I sit or lay down. 

I experience fatigue, dizziness, gray-outs, tachycardia, a HR increase of 20-50bpm when I stand, and sometimes there are days my heart rate doesn't drop below 120, reaching the 150s with minimal exertion. I also have many other issues I am reading may be associated with dysautonomia, such as decreased sweating abilities (I don't sweat despite living in Florida), unexplained itching and hives, exaggerated allergic responses, headaches, asthma, brain fog, exercise intolerance, irritable bowel, and severe anxiety and panic attacks. I feel like my doctors are acknowledging that I have a problem, but don't know what to do with me. I feel like they have put me on the back burner because my cardiologist has not even seen my event monitor results yet, but had a team member throw me a tentative diagnosis anyway to get me on meds. I refused any prescription until I get to the bottom of it, so now I'm waiting for them to release my test results so I can get a second opinion. My problem is, I am not sure where to go next. 

Has anyone had a similar experience and know what my next move should be?

Thank you!

[StayAtHomeMom]

You can try a second opinion with another cardiologist. Or search for a POTS specialist. Mine is a neurologist, so be mindful they are not always cardiologists. I would definitely see about getting a copy of all of your test results. Your tilt table sounded interesting and if they recorded the data correctly it may be unnecessary to repeat for a while. If I remember right there is a database on here to search for a specialist. You may have to travel. I travel 3 hours for mine. But it is worth it. 

IST is only subtly different. When I brought the possibility of POTS to my PCP she thought is could be IST ( I think it may be more common).

I learned the hard way about taking meds before a diagnosis. Sometimes when it is not what is wrong the meds can make you feel worse. 

I would try upping your salt. It sounds like you are drinking enough water. Urine color and output are good indicators of hydration levels. Electrolytes may be helpful as well. 

The unknown can be scary but believe you will find your answer. Whatever it may be. And keep your spirits up. Good Luck!!

[Pistol]

Hi - I am so sorry you have to go through this. It makes me sooo mad that there still is so much misunderstanding of dysautonomia out there!! If a cardiologist says a TTT is negative because you did not pass out then the cardiologist needs to take a seminar on how to interpret TTT's. If you are symptomatic and your BP changes or your HR increases and stays up ( you did not mention what your HR did ) then you have a positive TTT. It is wrong to only look for syncope. I had 2 TTT's, one I had syncope after Nitroglycerin and one I had tachycardia. The second one was positive for POTS based on the HR increase ( this is per my specialist ) but the cardio that did the test said it was negative because I did not pass out. And he was a EP! --- I saw 5 cardiologists and 1 neurologist but did not get diagnosed until I saw my autonomic specialist ( 7 hours away ). I would really request a doc with knowledge of POTS, you can call major hospitals in your area and ask who treats dysautonomia before making an appt. If the docs say they treat it then at least they acknowledge it's existence!!! --- Cudos to not taking meds just because someone tells you to. Beta blockers probably could be a start and they do prescribe them for IST but it sounds like you do not have that if your HR goes down with laying down. --- Have you checked the physician list on this forum?? Best of luck - do not give up - eventually you will find help!!!