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Possible arrhythmia, is this bad?

I am a 20 year old girl who has been experiencing severe palpitations for the past few months, and at one point I was admitted to the hospital for observation. I am underweight with a bmi of 17.2 due to chronic bowel problems, and I had  lower than normal potassium levels. The doctors took an ECG which showed a prolonged QT interval. The QTC was 536 ms (supposed to be below 460)  but the doctors said that its nothing to worry about an to continue with exercise. An echocardiogram showed trace mitral valve regurgitation but apparently thats also harmless.

However, now I still get a racing heart with any exertion (174 bmp walking up 3 flights of stairs, 120 bpm walking around the house). My resting heart rate is 65-69 bmp. The one thing I noticed is that when I walk up the 3 flights of stairs to get to my apartment my heart rate goes way up but comes down very quickly afterword. For example today I walked up the stairs and my heart rate climbed to only 156 bms (which is better than usual). I waited 60 seconds and my heart rate dropped to 78 bmp. After 2 minutes is was 68. I felt really weak and dizzy and had to lie down. Is is normal for your heart rate to fluctuate this much/nosedive after exercise?
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Avatar universal
At my first appointment w/ the cardiologist (electrophysiologist) I had a QTc of 460 ms which is borderline high and the doctor said this could potentially be caused by a low dose medication I was on.  The follow-up for that was a repeat EKG 1 month later to recheck the EKG.  In the meantime, we found out I had a QTc of 471 ms a few months earlier when I wasn't on any medications (at primary care physicians office before I wore a holter monitor and the QTc wasn't measured at that time).  My EKG appointment to reevaluate the QTc internal remained the next step but I was told to avoid medications that prolong the QTc interval.  When I had my follow-up EKG I was off the medication that could prolong the QTc interval and my value was still borderline high (I wasn't told what it was though).  My cardiologist then scheduled me for a exercise echo stress test the following week and an appointment w/ a genetic counselor the week after.  I met with the genetic counselor earlier this week and she recommended I get genetic testing to see if I have any of the genes associated w/ long QT syndrome.  The test is expensive and insurance companies do not always pay for them (the test is ~ 70% accurate) so she is looking into this for me and expects it will take about 2 weeks before she hears back.............Then.... a few hours after I met w/ the genetic counselor I received a call from the cardiologist to say the EKG portion of my stress test was abnormal and my QTc got above 500 ms (no actual numbers given).  I have been told to let the cardiologist know as soon as I hear back from the genetic counselor to determine the next steps - if I am ineligible for genetic testing I know the cardiologist wants to at least run a chemical stress test in which I will be infused w/ epinephrine and the QTc interval monitored.  Until we know what is going on, I have been instructed not to participate in any strenuous exercise.  Also, my situation is a little more complicated in that I have a benign heart block but it will very likely be exacerbated by use of B-blockers which is one of the treatments used to reduce the QTc interval.  So, my cardiologist has not started me on these yet - will see what happens in a few weeks.

I hope this helps and let me know if you have any questions.  As you can see though, my doctor is taking this very seriously and my baseline numbers are only borderline high.

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Avatar universal
  I left you a message with some advice about your situation. It should be in your message inbox. Hope all turns out well for you!
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Avatar universal
Hi spade.
I left you a note. I'm from Canada as well. I was brushed off by several cardiologists before I found an electro physiologist who diagnosed me.
Please send me a message and I will try to help you find a doctor in your area to help you. If you have a copy of any of your ECG many of these specialists will look at it through email.
Let me know. I have several long qt specialists email addresses.
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Avatar universal
Wow, you have sure been through a lot. I hope your doctors get to the bottom of it. They seem to be taking it very seriously which is good. Its always so stressful during this phase. Its interesting that the QT interval while you were exercising was even longer...from everything Ive read ( Im not a doctor), a faster heart rate usually shortens the QT interval. However, I also had the QTC of 536 while my heart rate was racing at about 150 bpm.

Its smart that your doctors are telling you to avoid strenuous exercise. Mine have told me to exercise at full speed but Im not doing that. It just doesnt seem wise. However, I read that being underweight prolongs the QT so Im trying super hard to eat more in hopes that this will resolve.

Thanks so much for your post, it was really helpful, and hopefully our QT issues get fixed ASAP!
Helpful - 0
Avatar universal
Yeah, Im seeing my GP on may 2nd and am definitely asking for a referral. I currently do not take ANY medications, and do not use over the counter cold medicines which rules out acquired long qt from drugs. The only electrolyte imbalance I had was the lower than normal potassium but sometimes I wonder if being so underweight has anything to do with it.

I live in Canada, so I hope the wait times for a cardiologist aren't horribly long.(I know someone who waited 8 months to see a specialist). I guess my GP can give me some sort of beta blocker if the wait is super long...By the way, what type of workup is your cardiologist suggesting for the long qt symptom? Is there anything specific I should ask for?

thanks again for your advice!
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Avatar universal
This is why I was wondering what doctor told you your qtc was nothing to worry about - a cardiologist is a heart specialist, a resident does not have the formal training in this area.  Since a non specialist told you this, you certainly need to be seen by a cardiologist (which looks like your next move).

Having a prolonged qtc can be the result of a genetic mutation (long qt syndrome), can be acquired, or, in about 2% of cases be caused by unknown factors.  The acquired form can be brought on by certain medications or electrolyte imbalances.  The website qtdrugs.org provides a list of medications known to prolong the qt interval.  I completely agree with is-somethin-wrong about the dangers of having a qtc at the values you mention.  Your values are much higher than mine and I am getting an extensive work up even though I am essentially asymptomatic.  

I would suggest you see your dr and ask for a referral asap.  Also, look at the link I provided to see if there are any medications you are taking that are on the list.  These should be avoided by someone with a prolonged qtc and can cause the acquired prolonged qtc.  Please do not stop taking any medications without talking to your dr though.  That said, there are many OTC (nasal decongestants, some cold medicines etc) that you should avoid  at this time until you have been evaluated by a cardiologist.
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Avatar universal
Really? I guess I should ask my GP for a referral ASAP then. I cant believe the resident in the hospital said the QT of 536 was harmless. Im trying super hard to gain weight and eat potassium rich foods like baked potatoes and apricots etc...hope it corrects the QT interval.

My potassium level was 3.4 (normal being >3.5 I think?) They said it was lower than normal and to start eating better. Also, weirdly enough, the 4 days I was in the hospital they measured my blood pressure 3 times per day and alot of the time it was high. It was only low once, the rest of the time it was elevated (150/104, 137/93...in that ball park). The hospital wasnt worried about the high blood pressure, they just said to eat better. Thanks for your input, you seem pretty knowledgable! I will definitely seek a second opinion.
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Avatar universal
It was the QTC interval that was over 500. Thanks for your input, I will definitely try to find a cardiologist!
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1124887 tn?1313754891
If your QTc at times is above 530 msec, it can be dangerous. It's an extremely good reason for bringing your potassium within normal limits, as low potassium will prolong QT, and if you already have a prolonged QT, low potassium can further prolong it. QTc above 500 msec puts you in risk for a dangerous arrhythmia and you should get a second opinion from a doctor specialized in cardiology or at least internal medicine.

How low was the K+ ?

Regarding the other symptoms, as you know I'm not a doctor, but it all reminds me of low blood pressure (which fits with the head rushes when you stand up). The heart compensates by racing, to increase minute volume and blood pressure. I have this "problem" too. It's funny that the heart rate lowers so rapid after climbing some stairs. I think the cause is that after exercise, your blood pressure increases a bit, so the heart doesn't need to race in order to keep up the blood pressure. If you did, say 30 minutes of aerobic exercise, I guess the heart rate would drop far slower.. (please don't try that until you've got a diagnosis for your condition..)

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Avatar universal
Head rushes might be orthostatic hypotension - I get this also.

I had a qtc of 460 ms when I saw a cardiologist (for  palpations that turned out to be a heart block) and that value was worrisome enough that I went from "never needing to see her again" to "I need to come back in a month for a follow up EKG".  My number was about the same and I am now having follow up tests.

Do you know if your qtc was 550 or was it the qt interval?  There is a big difference.  In any case, your symptoms warrant a referral to a cardiologist.  Hopefully your gp will get you a referral (if it isn't suggested, you might ask about it).
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Avatar universal
I never actually saw a cardiologist in the hospital. I only saw a resident in general medicine who was being supervised by a physician in general medicine. I had 2 ECGs in the hospital. On one of them the QTC interval was normal at 450 ms and was done when I woke up from a nap. The one with the prolonged QTC interval was done when I was feeling unwell( experiencing the palpitations) and was done the day before I was discharged.

I have never fainted before but I get a lot of head rushes when I stand up. None of my family members faint either. I made a follow up with my GP to address the ECG reading.
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Avatar universal
What doctor told you that a Prolonged qtc interval was nothing to worry about? The ER doctor or a cardiologist?

It is my opinion (and I am not a doctor), that you need to be seen by a cardiologist, if you already have been then you need a second opinion. Your qtc interval could have been caused by your low potassium but, it may be a sign of long qt syndrome.  Did your qtc return to a "normal" range before you left the hospital? Have you been scheduled for a follow up EKG? Any p fainting spells by you or other family members?

Heart rate fluctuating significantly after exercise could be due to a number of things.  A stress test would help determine whether anything is going on that requires treatment.
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