HCM or just IST?

Hi, my name is Nicole. 21 yr old female, recently diagnosed with inappropriate sinus tachycardia, panic attacks and mild mitral valve prolapse. I was in the ER today because of a HR of 170, which went down to 112 in the ambulance, back up to 170, then slowly went down to normal. Whew! :-/   I am currently taking Toprol 50 mg a day, but not all at once. Anyway, this might sound silly, but I was recently on a website about HCM (Hypertrophic Cardiomyopathy), and it said that people who have been diagnosed with mitral valve prolapse and panic attacks should be cautious as these conditions can mimic HCM. I have had an echocardiogram in December which determined the mild mitral valve prolapse, but can HCM be missed on an echo if you are not specifically looking for it? I do experience fatigue while (attempting) to exercise, but this could also be a side effect of the Toprol.
The one sudden death in my family was of my father from Wolff-Parkinson's-White, and the autopsy(in 1988) determined that his heart was structurally perfect except for the WPW. Also can an EKG determine HCM? I have had a holter monitor, which showed 250 PVC's, an event monitor which showed episodes of tachycardia at 145, and a run of skipped beats (4 in a row). I have been having some chest discomfort over the past few days and the doctor said that palpitations can irritate the chest wall. Is this true? My blood work was all normal .
I am just thinking of getting a second echo just to put my mind at ease about this for good.
So my question is about HCM and whether it will blatantly show up on an ECHO even if the technician is not specifically looking for it. Also, if people with IST can experience fatigue and breakthrough tachycardia despite medication. Your answer is greatly appreciated. Thanks!

[paanda2]

i have IST too. it can be really frustrating at times, and the medication also makes you feel bad too.

i think that they could have seen HCM on the echo; i think it would be a very obvious thing to see (although i'm not an echo-technician or a dr so i wouldn't know for sure). also, while IST can cause the heart to balloon out, because it overworks the heart, i don't think you would have it at age 21. i'm 20, and while i sometimes scare myself into thinking that i could have that bc of IST, i think the chances are slim. and besides, being on medicine controls IST.

IST can give a lot of symptoms that are often hard to explain, like SOB (which the beta blocker could also cause bc of the lowering of blood pressure) and chest pains as well.

also, the faster your heart beats, the more heart palpitations you can have, because the heart has less time to "restart itself" after each beat, so it can get ahead of itself and cause a skipped beat, PVC, etc. and i think MVP can cause heart palpitations too, but you would know better than me.

to you last question: IST can cause fatigue, because when a heart beats faster, it tires out (and tires you out too). that is why it is good to either fix it to get on meds, because long term that can cause damage. but then again, the medications can lower bp and cause more fatigue.

and yes to breakthrough tachycardia. i've had two episodes in the last 4-5 months where my heart "stops" and then i get the tachycardia of 140-150. i think its SVT but it hasn't been captured on a holter. i have been on a beta blocker for about 8 months too.

[Nicolina87]

thanks for responding! its at least good to know that im not the only one who has experienced breakthrough tachycardia even on beta blockers.:) do you mind me asking what you take? And how high was your heart rate before you took medication?
170 bpm was insanely scary, because my episodes used to only be around 145.i think you're right that the HCM would have been picked up on my previous echo, and i have a follow up appointment with my electrophysiologist tuesday. I'm sure you know the feeling where once one episode happens, you're afraid it will happen again. anxiety galore, which doesn't help matters.

[paanda2]

i take atenolol, 75 mg (broken up). before i was on the medication, my resting hr would be 84-88, and the average for my first holter (before the meds) was 96. i had one episode prior to this when my resting hr was 140; it was from stress i think (three days ago i had crashed my car into the side of my house that my was selling). so my hr was by no means high (like many IST suffers). in fact, i sometimes think that the diagnosis was premature (although granted the diagnosis was from a second dr who didn't have my files from before). i think anxiety was actually my real diagnosis; i had that one time where it was 140 and after that, all i could think about was my heart and there being something wrong. i think i worked myself into a nervous wreck, and that i might not really have anything wrong with me. no one ever said my hr was too high before this. the two episodes after i've been on the beta blocker also correlate with really stressful times too. so, yes i can definitely say that anxiety perpetuates everything!

[Nicolina87]

I just realized last night that the prescription I received as of April 1st was NOT generic Toprol XL (long acting beta blocker) but generic Lopressor (short acting beta blocker). It was switched by my general practitioner bc of a pill shortage, WITHOUT my knowledge. Neither the doctor nor pharmacist told me of any switch. So possibly this has to do with the breakthrough episodes. Instead of lasting 24 hrs, the generic Lopressor only last 10-12. Completely unbelievable! She wrote the original RX of Toprol XL and then the next one of Lopressor, and at what point did it occur to her NOT to at least inform me? So i could talk to my cardio and see if 1) He was aware of the shortage or 2) any further adjustments should be made? >:( sorry for ranting but im really mad that this might be whats making me feel so bad.

[Jerry_NJ]

I take the generic Metoprolol ER (Extended Release).  This is widely used, and lower cost than Toprolol.  I also break mine up, I get 100 mg tablets, that easily break in half.  I take 50 mg with Breakfast and 100 mg about 8 PM.  My need is "rate control" for AFib.  My dose level is enough to cause some dizziness, but I take the big "kick" when I'm just sitting and not long before bed time.

If I were on 50 mg, I'd break it in half and take half in the morning and half in the evening, SR, ER, or whatever notwithstanding.

[paanda2]

something tells me that they should not have been substituted/if so, you should have been asked first (and if you didn't know, they should have called your doctor). while everyone likes to think all beta blockers are the same, they aren't. your body was probably confused because it was used to one type but was getting another. long acting and short acting are different things.