Mitochondrial phospholipids comprise a significant proportion of the entire phospholipid content of most eukaroytic cells.

In the heart, a tissue rich in mitochondria, the mitochondrial phospholipids provide for diverse roles in the regulation of various mitochondrial processes including apoptosis, electron transport, and mitochondrial lipid and protein import.

Pathology

 alteration in the content and fatty acid composition of phospholipids within the heart is linked to alterations in myocardial electrical activity.
 reduction in the specific mitochondrial phospholipid cardiolipin is an underlying biochemical cause of Barth syndrome, a rare and often fatal X-linked genetic disease that is associated with cardiomyopathy by mutations in the tafazzin (TAZ) gene.

References

 Hatch GM. Cell biology of cardiac mitochondrial phospholipids. Biochem Cell Biol. 2004 Feb;82(1):99-112. PMID: #15052331#