Tell your friend to try consuming more potassium. Potassium deficiency causes arrhythmia (palpitations), muscle cramps, etc. I had this same problem for a long time, I even wore a holter monitor for 48 hours to monitor my heartbeat. At the end of it, they told me nothing was wrong with me and that it was pretty common for young, tall, skinny people around my age to have heart palpitations. I wasn't very convinced.
Fast forward to a couple years later, and my research on foliar potassium in agriculture incidentally leads me to some info on potassium deficiency in humans. Turns out that one of the symptoms of a potassium deficiency in the blood is heart arrhythmia. Potassium also helps your muscles contract, helps your nerves function normally, and helps to maintain a normal blood pressure, all of which are contributing factors to your heart beat.
So, I changed my daily diet to include more potassium rich foods like spinach, bananas, oranges, mushrooms, pinto beans, etc. Some days I feel like a monkey because I'll eat a whole bushel of bananas, but I can get as stoned as I want without any heart discomfort. Now my heart palpitations are just a reminder that I'm getting low on potassium, so when I start to feel minor palpitations I just go munch on a big mouthful of spinach like Popeye and it goes away! After ten minutes or so I can smoke as much as I want, even hitting a huge bong with lots of drag with no issues, something that I couldn't handle when I was dealing with a potassium deficiency. Ever since I solved my problem, I've been pretty happy about it; because I was dealing with these issues for so long I had come to accept the palpitations as some sort of genetic predisposition. For a couple years I was drinking galangal root tea on a daily basis to alleviate my heart pains, and I had recommended it to a close friend of mine who was having the same issues as me. He didn't like it for some reason, and was reluctant to try it to see if it would help. Now that I've told him of my success with potassium, he's tried it and reported that it solved his heart issues too.
In addition to that, I've described this whole scenario to two other friends, who I was unaware had similar issues, and both told me they occasionally experienced the same thing and would try to eat more potassium (bananas seem to be everyone's go-to). Sure enough, both of them reported that they could toke as fat as they wanted to on days when they consumed adequate potassium. And for the people who think this could be an anxiety attack or something similar, the only anxiety I experienced due to this deficiency was when the doctors told me it was normal and I thought I just had a "weak heart", and would have to deal with it for the rest of my life. Thinking that I had this inherent physical weakness that I would have to compensate for was a little stressful. However, when you are in the middle of a smoke session with a bunch of buddies and you have to tap out because of palpitations, it's not because of anxiety, it's more like, "Huh, that last rip made my heart hurt a little bit every other beat or so. I guess I should stop smoking for now. Damn I wanted to get higher though, oh well." The pain that it causes is minor enough to where one could keep smoking if they were determined enough to get more baked. However, it is enough pain that most will stop their smoke break due to the discomfort or concern for their health. Now that I fully understand (I think) what causes my heart palpitations, they don't concern me at all when they happen, I just go eat some spinach like Popeye and then it's back to the grind
Hope this helps,
VK
