High magnification micrograph showing contraction band necrosis and karyolysis. H&E stain.

Contraction band necrosis is a type of uncontrolled cell death (necrosis) unique to cardiac myocytes and thought to arise in reperfusion from hypercontraction, which results in sarcolemmal rupture.^[1]

It is a characteristic histologic finding of a recent myocardial infarction (heart attack) that was partially reperfused.

The name of the histopathologic finding comes from the 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 extra thick striae, typical of cardiac muscle and striated muscle.

[edit] Pathophysiology

Contraction band necrosis is thought to arise by two mechanisms:^[1]

1. a calcium-dependent mechanism - activation of the contractile machinery of the cell via its usual mechanism, calcium, which is in excess due to ischemia.
2. a calcium-independent mechanism, as seen in rigor - activation of the contractile machinery in the setting of low ATP.

Reperfusion associated cell death has been modulated (reduced) in animal studies^[2] and is an area of active research, which holds the potential to significantly reduce the morbidity (disease burden) and mortality (death) of cardiovascular disease.^[1]

[edit] Additional images

Contraction band necrosis. H&E stain.

Contraction band necrosis. PTAH.

[edit] See also

• Myocardial infarction
• Timeline of myocardial infarction pathology
• Guanylyl cyclase

[edit] References

[edit] External links

• Contraction band necrosis - pathologypics.com