The story
- Proto-Indo-European*ḱerd-
- Proto-Indo-European*ḱḗr
- Proto-Indo-European*ḱr̥díyeh₂
- Proto-Hellenic*kərdíyā
- Ancient Greekκαρδία (kardía)
- Englishcardio-
- Proto-Indo-European*gerbʰ-
- Proto-Hellenic*grə́pʰō
- Ancient Greekγράφω (gráphō)
- English todaycardiograph
Etymology from Wiktionary, CC BY-SA 4.0.