I was born with tachycardia , honestly not sure of the specifics, but I think it s supraventricular tachycardia. I m 17, and it has never caused any problems, but when it does occur, I always know to calm myself and just wait it out. Without consulting my doctor , I tried marijuana a while ago, and have done it 9 more times since. On my last time, I had the shakes , and a rapid heart rate . Luckily my mum was around, and was confident that I was fine, but I was, i guess, having a minor freak out considering my high. She still assures me that it wasn t life threatening or anything, but obviously opposed to me smoking illegal drugs. Since then I ve given up smoking, and that was about 3 months ago. Essentially, I just want to know if it is safe to smoke marijuana with tachycardia, as I never really knew the risks I may or may not have been running.