car·di·ac 
(kärdē-ăk′)
(kärdē-ăk′)adj.
1. Of, near, or relating to the heart: cardiac arteries. See Usage Note at coronary.
2. Of or relating to the cardia.
n.
A person with a heart disorder.
[Middle English, from Latin cardiacus, from Greek kardiakos, from kardiā, heart; see kerd- in the Appendix of Indo-European roots.]