Read from the World of Warcraft client build files.
How Quivering Heart Girdle Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Quivering Heart Girdle suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Quivering Heart Girdle is part of the transmog set Swarmbreaker's Battleplate (Warrior, Paladin and Death Knight only). The other 16 pieces:
Built from the World of Warcraft client build files and recorded Auction House snapshots.
Where Quivering Heart Girdle Fits
Other Items Named Quivering Heart Girdle
2 other items in the current build are also called Quivering Heart Girdle. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 81087 (81082 to 81092) were usually added in the same batch as Quivering Heart Girdle: the same quest line, zone, vendor or reward set.