The pathological changes by HE stain in ADR group were part of myocardial fiber fracture and myocardial periacardial inflammatory infiltration.

A balloon is inflated at the level of the gastroesophageal junction to blindly rupture the muscle fibers while leaving the mucosa intact.

Myofibrillar fragmentation, swelling of the cardiac myocytes, absence of the Z line, increases of the mitochondria and collagen fibers were found in ouabain group by transmission electron microscopy.