Some Questions

Hi,
    So, I recently have been having more frequent palpitations as I have become more stressed out about other things. I have had infrequent palpitations throughout much of my young life, but this concerned me, so I had a few things done. I got the echocardiogram and found no structural problems. On the 24 hour Holter monitor they found some PVCs but I hadn’t felt any that day. (I also ran with it on and they said there were no PVCs while I was running). However, I do sometimes feel them and I do sometimes feel them when running, so I have a few questions:

1.) Is it more likely that the fluttering I sometimes feel is actually the more dangerous VT, while the one-time skipped beat sensations are the pvcs, or could the fluttering still just be pvcs or other arterial related palpitations even though each fluttering segment can last 5-10 seconds, instead of just the one perceived beat at other times?
2.) I have researched and found out that 90% of VT cases come paired with structural abnormalities, but that in the other 10% it could be a case of “idiopathic” or “vascicular” VT. Are either of these other two forms of VT any more or less dangerous than the VT associated with structural heart problems? Is VT in the absence of structural heart problems even dangerous, or is it just a begnine arrhythmia kind of like PVCs in the absence of structural damage would be?
3.) I am a little worried about my ejection faction result from the echo, because it was 52%, and although they listed 50-75% as the normal range, I worry that my PVC’s are actually starting the weaken the function of my left ventrical (as I have heard they could do), and that it is still just on the low end of normal since I am young (21, male), and that it will continue to decrease with time? Is this a valid concern?
4.) I am going to be wearing an event monitor so they can try to capture some of both these one-time “skipped” beats, as well as some of the occasional “fluttering” sensations I feel. Once they find them on there, will they be pretty well able to identify what type of arrhythmia(s) are causing them? Could it all possibly just be PVC’s?
5.) I am a runner an athlete, so is it dangerous for me to be running like 50-70 miles a week, with VO2 workouts every week, if it turns out I have VT? Would it be dangerous with just PVCs? What about if I have some other kind of arterial arrhythmia in addition to the PVCs?
6.) Is it somewhat normal for me to have noticed that when I was younger and not in good shape that I would have more of these palpitations, especially when trying to exercise, but now that I have been an athlete throughout high school and college, I only occasionally feel them? (at least before these past few weeks) Would this be normal in cases of VT as well? If so, how does that work, because I have heard it is dangerous for people with VT to exert their hearts, but if exercise actually seems to bring the VT down, how does this evolutionary catch-22 work?
7.) Once I am able to find out exactly what kind of arrhythmias I have, and if some of them are deemed a little more risky to live an active life with, or if later on in life I just can’t deal with the symptoms of a less dangerous one, would catheter ablation be particularly risky? I have heard that the complication rate of the procedure is like 1-2% and is basically less than minor things like getting a vasectomy or your tonsils removed, but is all this actually true? And if it is, how effective is it at removing the symptoms, and more importantly the danger indicated by such symptoms for certain arrhythmias, especially if it were a riskier one, such as VT?

[itdood]

If you haven't been diagnosed with VT, stop worrying about it.

From what I've read, PVCs don't start impacting the muscle until they are > 10-20% for total beats, depending on who you talk to.  That means > 10,000 to 20,000 PVCs per day.  Are you getting that many?  I've heard of people in full time bigeminy (50,000 PVCs per day) with no degrading effects to muscle.

Echos have a margin of error, I believe it's +/- 10%.  Also, you can't just make a blanket interpretation of the LVEF based on the number.    For all we know, I bet when you run your stroke volume goes much higher than someone who leads a sedentary lifestyle.  

Studies have shown that in hyper trained athletes, LVEF can become lower or higher.    A piece I've read that makes sense is that when you compare athletes to sedentary people, the at-rest *stroke volume* will usually measure the same as sedentary people when studied.  The only way an Athlete's heart can have the same stroke volume at rest as a sedentary person is by a lower LVEF.    This is because an athletic heart will have increased size of the LV.  If a large LV (athletic) is pumping the same amount of blood as a small LV, then that means the athletic LV isn't emptying as much, hence lower LVEF.  However, put those hearts under the stress and the stroke volume for the athletic heart can be 40% great than the sedentary heart.   This means the LV has adjusted to the work load by increasing its EF.    This is all a good thing for the athletic heart.  When at rest it's not working as hard as the sedentary heart.    there's more to this when you think about it.

So how many PVCs do you have per day?  What is the classification (are they isolate, frequent, infrequent, coupled, Unifocal, Multifocal....)?  What part of your heart are the PVCs originating in?

[michellepetkus]

I am with itdood, I think the chances of you having VT are slim especially after having a clean echo.  I know for me the flutter feelings I sometimes get are actually simple sinus tachycardia or sometimes bigeminy.  I can't say for certain what your flutters are and hopefully the event monitor will catch it so you can ease your mind.  But try not to worry.  The worry will actually make whatever you are feeling worse and more persistant.  Take care and hang in there.  Keep us posted on how you are doing.

[dave1726]

Thanks for both your answers. They are appreciated. You’re right, I really shouldn’t worry about the palpitations being anything more than PVCs, so I really don’t anymore. The EF% thing isn’t much of a worry to me either anymore, since the doctor explained to me that structurally my heart is fine and that if it really were a sign of systolic heart failure I would have these structural abnormalities. The idea that it might all be related to me having a larger athletic heart is a good one, although I’m not really sure if that’s it, because they actually said my diameter and mass measurements were in the lower half of normal for the general population, which is a little confusing since I am an athlete, but I guess as long as it is not diseased it really doesn’t matter, so it’s actually a good thing. Thanks again.