Provided there is no evidence of gross myocardial lesion, the extrasystole itself is of no great significance.
1866, from myo- + Latinized form of Greek kardia "heart" (see heart). Related: Myocardial; myocarditis.
myocardium my·o·car·di·um (mī'ō-kär'dē-əm)n. pl. my·o·car·di·a (-dē-ə) The middle layer of the heart, consisting of cardiac muscle.