Although credited, Katherine Heigl ("Izzie") and James Pickens Jr. ("the Chief") didn't appear in this episode.
The opening song is the Clash's Magnificent Seven off their 1980 Sandinista album. The Clash is Derek Shepherd's (Patrick Dempsey) favorite band.
Every episode of the show is named after a famous song. "Valentine's Day Massacre" is a song by Rustic Overtones featuring Imogen Heap.