Serious increase in palpitations over one day

[NBH613]

I'm a 21 year old male without any preexisting conditions that I know of.

I have felt what I believe are heart palpitations in the past (feeling a "thump" in the chest/throat), and experience maybe 1 or 2 a week. Today, however, I have experienced MUCH more than I am used to. I noticed it while walking to class this morning, I felt palpitations that didn't seem to go away for the rest of my walk to campus (several minutes), feeling palpitations for several seconds, then feeling okay again, then back to palpitations a few seconds or minutes later.

One I got to class and sat down, everything was back to normal. I felt no more palpitations for roughly 3 hours. When my class ended and I walked to the library, I once again felt a few more palpitations. This again stopped when I was back sitting.

This has repeated on and off all day, where I have felt normal when sitting (with a few palpitations all day), but with a very irregular number (at least one a minute) of what I'm assuming are palpitations when I am walking.

I'm concerned as I have never had a day where I felt palpitations anywhere near as frequently as I have today. As I indicated above, I have never been diagnosed with a heart condition, although I have spoken with my GP about feeling palpitations in the past, and once wore a 24-hour holter monitor during my teens, which raised no serious concerns. I have a fairly significant pectus excavatum, and I'm unsure if this might have anything to do with this.

I'm unsure what to do from here. I have not felt any lightheadedness or significant pain or pressure in my chest, which leads me to believe that this is not an emergency, although I will be more concerned the longer this goes on. Is this something that can wait until I can see my GP, or does this warrant a clinic/hospital visit?

[NBH613]

Thank you very much for your reply, this is very reassuring. Today I've felt a few palpitations, but already a significant improvement over yesterday.

I will likely check it out with my GP just to be sure, but you've help put my mind at ease!

[itdood]

I get PVCs like this too.  On and off.  Been going on since i was in my teens.  I'm 48 now and everything still works OK.

There are nerves that go from your brain stem to the heart to help control rate.  There are two types.  parasympathetic and sympathetic.  One speeds up the rate and can also make the muscle contract harder.  The other relaxes it and slows it down.

benign Ectopic beats, PACs or PVCs, are caused by cells that have something called 'enhanced automaticity' (EA).  Any cell in the heart can fire on its own which would cause the others near it contract (pump) too.  The SA has the fastest rate (100bpm) naturally so it usually paces the heart.  

most of the other cells are around 50bpm and usually never initiate a beat, but sometimes a group of them become over twitchy.  The interesting part about this aspect of the heart is that there is backup should the normal beat signal fail or fail to propagate, but I digress.  But when the cells have a higher propensity to fire, this is called EA like I spoke about above.  

One of the theories is that electrical signals come in from the para or sympathetic branch, that nerve signal can make a cell group with EA fire and boom, you've got a palp.  This explains why people often attribute palps to a move in position, eating, exercising, sitting, standing, etc...

When the signal changes on these nerves it's called "tone".  So the tone varies all the time.   When you stand up, when you sit down, when you eat, when you wake up, when you sleep, time of day.  you get the idea.

So the next you feel them, think to yourself that your heart nerve tone is changing, and it will eventually return to normal.

If you want, you can get more tests done.  I did this.  lots and lots of tests to be sure everything was OK.

My PVCs flared back in March then settled down all summer.

They flared again about 4 weeks ago.  they come and go.