Heartstring is used in wands as a magical core substance (GF18)
Wands with a dragon heartstring as a core, are powerful and able of flamboyant spells. They learn quickly and will bond strongly with their current owner (PM).
In the series, wands with cores of Dragon Heartstrings belonged to:
- Viktor Krum (GF18)
- Lucius Malfoy (DH1)
- Bellatrix Lestrange (DH24)
- Peter Pettigrew (DH24)
- Minerva McGonagall (Pm)
- Gilderoy Lockhart (Pm)
- Hermione Granger (JKR)
- Dolores Umbridge (Pm)
- Garrick Ollivander himself (Pm)
Dragon heartstring was sparkling in the broken wand of Mr. Boot.
According to the Oxford Dictionary, it is derived from the late middle-English in the sense of 'cord-like structure attached to the heart'. Nowadays, it is used more often to in reference to one’s deepest feelings.