one's heart stands still

(one's) heart stands still

One experiences a very strong emotions, especially excitement, nervousness, or fear, such that it feels as though one's heart stops beating for a moment. I swear, my heart stood still the moment my wife began walking down the aisle on our wedding day. My heart stands still whenever the principal calls me into her office, even if I know I haven't done anything wrong!
See also: heart, stand, still
Farlex Dictionary of Idioms.

one's heart stands still

Fig. one's heart (figuratively) stops beating because of strong emotions. When I first saw you, my heart stood still. My heart will stand still until you answer.
See also: heart, stand, still
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (one's) heart stands still
  • have (one's) heart stand still
  • have heart stand still
  • heart misses a beat
  • one's heart misses a beat
  • your heart misses a beat
  • (one's) heart misses a beat
  • (one's) heart skips a beat
  • heart skips a beat
  • have goose bumps