Fragmented heart muscle fibres following myocardial infarction: light micrograph of human heart muscle (myocardium) from the right ventricle following myocardial infarction, the death of a section of heart muscle resulting from an obstruction in a coronary artery. The fragmented fibres stain more deeply than normal muscle, but without evidence of nuclear staining. If the patient survives the heart attack, the process of repair begins, heralded by an invasion of polymorphs (white cells), macrophages & fibroblasts. Necrotic muscle is digested by macrophages & fibroblasts form a fibrous scar. Mag: x100 at 6x7cm size, x50 at 35mm size.