De or het hartchirurgie?

The correct Dutch article is:

de hartchirurgie

Meaning (Dutch) (medisch) heelkunde van het hart

How to use hartchirurgie

the hartchirurgiede hartchirurgie
this hartchirurgiedeze hartchirurgie
that hartchirurgiedie hartchirurgie
our hartchirurgieonze hartchirurgie
your hartchirurgiejouw hartchirurgie
every hartchirurgieelke hartchirurgie
which hartchirurgie?welke hartchirurgie?
a big hartchirurgie / the big hartchirurgieeen grote hartchirurgie, de grote hartchirurgie

Dutch words ending in hartchirurgie

openhartchirurgie

In compound words, the last part decides the article. See the rule

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).