The Collaborative International Dictionary of English v.0.48:
Carditis \Car*di"tis\ (k[aum]r*d[imac]"t[i^]s), n. [NL., fr. Gr. kardi`a heart + -itis: cf. F. cardite.] (Med) Inflammation of the fleshy or muscular substance of the heart. See Endocarditis and Pericarditis. --Dunglison. [1913 Webster]WordNet (r) 3.0 (2006):
carditis n 1: inflammation of the heart