epicardium /ep′ikär″dē·əm/ [Gk, epi + kardia, heart] , the outermost of the three layers of tissue that form the heart wall. It is composed of a single sheet of squamous epithelial cells overlying delicate connective tissue. The epicardium is the visceral portion of the serous pericardium and folds back on itself to form the parietal portion of the serous pericardium. Compare myocardium. See also pericardium. −epicardial, adj.
