Is this really Inappropriate Sinus Tachycardia?

[livingwithspunk]

I am a 20 year-old female weighin 179 at 5'4.

In January I almost fainted at school while seated in the auditorium watching a comedy. I went to the emergency room where it was noted that I was tachy (about 120 seated) but there was no identifiable cause so I was sent home. About two days later I experienced the same issue, almost fainting twice in the shower. So, I went to the emergency room and the same was said, they couldn't find an explanation. I took a semester off from school to try and figure out what the cause of the symptoms was, and in March was diagnosed with Inappropriate Sinus Tachycardia. It is now June, and I am beginning to wonder if that is really what I have. I have low blood pressure (99/60-104/74 most days). My resting heart rate (according to my Fitbit) is 71-74 most days, and when I am awake it ranges from 79-100, 100-120 when I am up and walking around. If I feel tired at work after being on my feet continuously for a few hours it'll start to drift to 130-135, and after a quick break it regulates itself and drops back down. I have noticed when walking stairs or dancing around, or just moving faster than I typically do that it begins to race AFTER I do the activity and usually regulates itself around 118/120. Lately I've been noticing some cognitive symptoms. I have problems with processing and memory. I don't retain much of what I am told, read, or watch. I get blurred vision when I am tired. I have had a total of seven concussions, my most recent being in April of last year. Because of this I decided to see the concussion specialist that treated me previously about my cognitive symptoms. She isn't sure if they're related to previous head injury, or symptoms of brain fog that could somehow be related to my cardiac symptoms. Whichever, I'm beginning to wonder if everything is somehow connected and if my initial diagnosis is correct.

I called my cardiologist today and spoke to his nurse about it, but he's booked out through July and I go back to college in August. I just want answers that make sense.

I'm 20 years old and feel like I'm trapped in the body of a 50 year old.

[purple1234567]

I'm not overly familiar with Inappropriate Sinus Tachycardia, however, from what you describe the symptoms sound like what I know of Inappropriate Sinus Tachycardia.  

Did you go ahead and make an appointment with your cardiologist in July?  It wouldn't hurt just to do a check in before you go to collage in August, even just for peace of mind for you.