Lesions not visible before 18-24 hours after onset. Earliest change is a poorly defined pale area, some with hemorrhagic changes. Area defined better with time, turning yellow with a pink margin of organizing tissue, and, finally, a discrete scar. Frank coagulative necrosis at 24-72 hours, loss of fiber nuclei, and heavy neutrophilic infiltrate. Complications include arrhythmias, shock, heart failure, cardiac rupture, and pulmonary emboli.
Late complications are mural thrombi and aneurysms.
Cotran RS etal. Robbins Pathologic Basis of Disease. Medline will open in a new window.