가슴이 두근거리다 (ga-seu-mi doo-geun-geo-ri-da) – heart/chest is pounding/throbbing/beating very fast
Just like in English, this phrase can be used to describe anxiety, fear, infatuation, fatigue (from exercising), etc.
In short, it’s a very useful phrase to use, especially in daily life too!
두근거리다 means to beat very fast, throb or pound and is pretty much meaningless unless coupled with 가슴이 (chest/heart).
In speech, you could probably omit 가슴이 and it will still make perfect sense.
내일은 드디어 시험 결과를 알 수 있는데 지금 가슴이 두근거려 죽겠어.
I can finally know my exam results tomorrow but my heart is beating so fast I’m going to die.
공포 영화를 보면서 두 눈을 감아도 소리가 너무 커니 가슴이 두근거려.
Even when I close my eyes while watching horror movies, my heart pounds really fast because the loud sounds.
어제 내 좋아하는 여자 옆에 있다가 가슴이 두근거려 미쳤어.
Yesterday I was beside the girl whom I like and my heart was pounding so fast I went crazy.
마라톤을 끝마치고 나니 가슴이 두근거려서 바로 샤워 하면 좋겠어.
I finished the marathon and my heart was beating really fast so it will be great if I could go straight to shower.