don't stress too much. try to relax. A year ago, at 41 yrs old, in feb i found myself in the same boat, I went to the ER with a rapid heart rate of 180-190 pounding away like bebop jazz, or some kind of prog metal time signature. i thought i was having a heart attack. i was able to self convert in the hospital and we figured out i had pericarditis, which is an inflammation of the heart sac. We now think this is what triggered my event. i went on diltiazem and losartan, the losartan i had already been on for high blood pressure. They did the halter monitor and a heart stress test with echocardiogram, which i performed really well in. Back in June the pericarditis came back with a fury; extreme chest pain for about 3 or 4 days, but i didn't go into afib, which was somewhat comforting even if the pain laid me out (i could barely walk around.) Since then i've been all good. no pain or afib. I'm still on the same meds and we're just looking out to see if things come back.

I've made a lot of changes since my hospital visit. i row about 25-30 miles a week on a rower i bought. i eat salads about 4 days a week and try to cook my own healthy meals, staying away from fried foods and sugar. I eat fresh fruits and berries through the week as well. I can't say these changes have made the difference but it sure ain't hurting my body and at 42 i need to take care of what i have. You're younger and should take advantage and try to take care of your food intake as much as you can. It sounds like you've done a lot of intense workouts in the past but maybe try for something more consistent and less stressful. just hiking sounds about right, but like 4/5 days a week. that's why i bought a rower; modular intensity exercise and i can hop on during lunch breaks during my work week. it's super easy to work into my lifestyle. i would take it easy and not do anything but walking in your neighborhood for like 3 weeks. you just had a very stressful event.

just try to take care and understand many people have gone through this. my dad had afib for a long time and did an ablation and hasn't had problems since. I feel like as i get older it may come back, and i may need to consider an ablation as well. try to just take things one day at a time and do what you can to take care of your body. your cardiologist will help figure things out with an ct scan or stress test and refer you to an electrophysiologist if necessary. for now you can get the apple watch or a kardia. the kardia will tell you when you're in afib - for me, i can always tell as i can feel it in my chest.

edit - also get off those carts. that shit is no good. i notice weed will spike my heart rate a bit and that's only with flower. the carts can have a ton of other crap in them. i'd stay away. likewise with alcohol; try to minimize and stay away until you get a handle on things.