NCIt definition : A type of heart disorder referring to the inability of the ventricles to fill with
blood because the myocardium (heart muscle) stiffens and looses its flexibility. Causes
include replacement of the myocardium with scar tissue, abnormal cellular infiltration
of the myocardium, or deposition of a substance (e.g., amyloid) in the myocardium.;
Alternative definition : CTCAE: A disorder characterized by an inability of the ventricles to fill with blood
because the myocardium (heart muscle) stiffens and loses its flexibility.;