This reaction to tuna doesnt matter if its good or bad its called an allergic reaction, the heart speeds up the throat closes and the person breaks out in a rash and hives- which is what landed me in the ER for an epinepherine shot and so on. My advise and suggestion the heart speed for you like with me was a warning you might want to stay away from all tuna when I ignored it the other reactions came and not after the first time of eating tuna.