NCIt definition : A heart disorder in which the pericardial sac becomes thickened and fibrotic, tightening
the myocardium and impeding the normal myocardial function.;
Alternative definition : CTCAE: A disorder characterized by a thickened and fibrotic pericardial sac; these
fibrotic changes impede normal myocardial function by restricting myocardial muscle
action.;