Ultrastructure of mitochondrial reticulum of human cardiomyocytes in alcohol cardiomyopathy.

Endomyocardial left ventricular biopsy material from patients with chronic alcoholism exhibits structural alterations of the mitochondrial reticulum in alcohol cardiomyopathy. The progress of gradually developing structural changes depends on the stage of the disease. The early stage of the disease is characterized by spatial reorganization of the mitochondrial reticulum: intermitochondrial junctions disappear and mitochondria form separate clusters uniformly distributed within a muscle cell. Subsequently, in the second and third stages of chronic disease, destructive irreversible changes in the ultrastructural organization of mitochondria develop. Megamitochondria and septate mitochondria appear. A third additional compartment containing granules forms in mitochondria. Many lipofuscin granules appear due to the accumulation of lipids in mitochondria. Structural changes of the mitochondrial reticulum are considered as a compensatory adaptive reaction of the cardiomyocyte mitochondrial system in response to altered myocardial function in alcohol cardiomyopathy, including abnormalities in the cardiac rhythm and ventricular conductance.