Contraction band necrosis

Background

Contraction band necrosis is a histopathologic finding named for its appearance under the microscope: contraction bands are thick, intensely eosinophilic staining bands, typically 4–5 micrometres wide, that span the short axis of the myocyte. They can be thought of as extra thick striae, typical of cardiac muscle and striated muscle. The condition is unique to cardiac myocytes and is thought to arise in reperfusion from hypercontraction, which results in sarcolemmal rupture.

The pathophysiology involves two proposed mechanisms. The first is a calcium-dependent mechanism: activation of the contractile machinery via its usual mechanism, calcium, which is in excess due to ischemia. The second is a calcium-independent mechanism, as seen in rigor mortis: activation of the contractile machinery in the setting of low ATP. Reperfusion-associated cell death has been modulated (reduced) in animal studies and is an area of active research, which holds the potential to significantly reduce the morbidity and mortality of cardiovascular disease.