Perfusion of hearts with nitro blue tetrazolium resulted in gross formazan staining of intact myocardium, while infarcted zones and scars were unstained or were poorly stained. Subsequent perfusion with 3.7% formaldehyde solution provided a rigid specimen with well-preserved anatomical structures and landmarks suitable for detailed correlation of three-dimensional infarct distribution with clinical data. Specimens are particularly amenable to further gross dissection of mapping of lesions from interval slices, or both.