Excitable cells

Exciting simulations! :) And an excellent explanation.

From time to time I get episodes of sudden tachycardia¹. It's a very strange feeling: one second everything is fine, the next my heart jumps in my throat and starts beating at 230 bpm (not a typo). After a while, just as quickly as it came, the tachycardia goes away and I'm back at whatever HR I was before the trigger. If it doesn't go away by itself, breathing in deep and holding my breath typically does the trick. It's like a light switch! A bit scary, but also very fascinating.

Thanks for explaining so well what goes on "under the hood"!

¹ https://en.wikipedia.org/wiki/Paroxysmal_supraventricular_ta..., I believe.

I have a similar condition. Mine is:

https://www.mayoclinic.org/diseases-conditions/wolff-parkins...

I have the same bouts of tachycardia. They are very intermittent, no real cause. And the same breath holding technique works for me. Very interesting stuff!

I have the same condition. I was diagnosed at a very younger age with Wolff-Parkinson-White syndrome. It might be worth looking into.

https://www.mayoclinic.org/diseases-conditions/wolff-parkins...

A couple of years ago I woke with a minor headache that I ignored for various reasons all day, then skipped lunch as I had an important meeting later and lots to do ahead of it, and the headache got progressively worse. Just before the meeting I felt nauseous, threw up, and then started having the feeling of palpitations in my chest. I've always had them from time to time - that feeling that ones heart has skipped a beat or taken a couple of extra ones - but this time it wasn't going away after a couple of beats.

To cut a long story short, I went to hospital (instead of that meeting) and it turned out that it was atrial fibrillation and that while it feels medium terrifying it's not necessarily that big a deal.

It went away after a couple of days (if it had lasted longer they'd have done "electroconversion" to try to get it back into the proper ryhythm artificially). Apparently the real danger of this is that it might cause a blood clot which in turn could cause a stroke, but it's unlikely to be an issue in the short term.

They did put me on blood thinners and beta blockers between the occurrence and getting a full check up a month later, so I was very calm when we rescheduled that meeting.

Top tip: don't ignore a terrible headache; go to bed.

Edit: PS I think my heart rate was just above 100bpm at rest (possibly 120?), which was unnerving enough, so I can imagine how much more scary 230bpm must feel! You definitely win.

Do you drink a lot of caffeine? A family member had this occasionally with no family history of issues, and the cardiologist had them wear a portable EKG for a few days that synced with an Android phone, with not much results. Finally the family member cut down from 4 espresso shots a day to just 1 cup of brewed, and the issue hasn't returned.

With WPW you MUST NOT take beta blockers (AFAIR), it may kill you.

I had just plain vanilla Afib and got ablation 2 years ago - best thing ever, cured instantly.

Yeah, several cups of tea per day. I also recently had that test done, but nothing emerged as nothing occurred during the 24 hours I was monitored. Just like I expected, actually, as fortunately those episodes are very rare for me, not enough to warrant drastic lifestyle changes. (I can't give up my tea! :D )

Fortunately I don't think it's WPW in my case. Or at least, my cardiologist never mentioned it, so I assume it's some other condition that has similar symptoms.

I fainted when I was an exercise class. I'd had too much to eat before then, my digestion was pretty slow then, also it was a crazy hot day in a building with a pool (high humidity) and an old HVAC system. Didn't help that I had a crush on the instructor and was trying even harder because of that.

Woke up on the ground feeling very relaxed. Got a medical workup that checked a lot of things, they had me wear a Holter monitor for a month. In the last 30 minutes of the study period they caught five bad heartbeats of A-Fib when I was sleeping. Funny one of my evil twin's schemes went south around then and I (we?) were feeling really bad about it. My cardiologist told me that the threshold was one bad heartbeat so I have A-Fib and have a risk of strokes, he recommended that I take a baby aspirin as it has a mild blood thinning effect.

Around the beginning of the next year I developed a deep vein thrombosis which got cleared up with Eliquis, a blood thinner. The emergency room referred me to my primary care doc who ran all sorts of tests and couldn't find a reason for the DVT so he decided to keep me on Eliquis indefinitely, the cardiologist figured that covered the A-Fib so I dropped the aspirin because the combination could cause excessive bleeding.

I have one of those credit card Kardia EKGs and haven't seen an A-Fib episode yet. For the decade before I got that workup I did crazy amounts of cardio (helped me stay sane under incredible pressure) and around the time my evil twin was out I was getting up in the morning before sunrise, hiking 6 miles, going to the gym during the day, going out in the evening and hiking another 6 miles. My cardiologist says I have "Athlete's heart" with an abnormally low resting heart rate (drops below 50 at night when I get a good night's rest) and I shouldn't do more than an hour of cardio a day, so I don't.

Yeah, the first time it happened (about 15 years ago) I thought "that's it, I'm dead". Heart things are unnerving indeed! Best of luck with your AFib!

I have PSVT. I think it started for me around the age of 17 and was always pretty short-lived and infrequent, often with years between episodes. A couple years ago, chronic stress and lifestyle stuff began to catch up with me and the episodes started happening a few times a week, so I'm now prescribed Metoprolol as a pill in a pocket thing to deal with it. Generally speaking, as long as sleep, diet, and basic exercise are in order--and alcohol/caffeine consumption are kept low--it just doesn't happen. It also can almost always be remedied with some simple vagus nerve exercises. All of that can be tough to manage sometimes though, so I'm very seriously considering getting an ablation soon. The doctors have told me that it's not a particularly dangerous condition as long as you're an otherwise healthy individual, but it's definitely still terrifying and can't be good for you either.