IPA: //ˌmaɪ.əʊ.kɑːrˈdaɪ.tɪs//
KK: /maɪəˈkɑrdɪtɪs/
A condition where the heart muscle becomes inflamed, often leading to chest pain, fatigue, and other symptoms.
The doctor diagnosed him with myocarditis after he complained of severe chest pain.
Myocarditis is formed from "myo-" (from Greek "musculus", meaning muscle) and "carditis" (from Greek "kardia", meaning heart, combined with "itis", meaning inflammation). The word refers to the inflammation of the heart muscle.
Think of 'muscle' ('myo-') and 'heart' ('kardia') being inflamed — that's what myocarditis means.