Vacuolar degeneration and myofibrillar loss of cardicac muscle is caused by:

Cardiomyopathy caused by anthracyclines (doxorubicin and daunorubicin) are characterised by histologic changes of vacuolar degeneration and myofibrillar loss. There are three different presentations of anthracycline-induced cardiomyopathy. Acute hea failure developing during administration of a single dose. Early onset doxorubicin cardiotoxicity develops in about 3% of patients during or sholy after a chronic course. The chronic presentation. Patients who received doxorubicin while still growing may have inadequate development of the hea. Adult exposure, patients may develop the gradual onset of symptoms or an acute onset precipitated by a reversible insult. Doxorubicin cardiotoxicity leads to a relatively nondilated ventricle, due to the accompanying fibrosis. Ref: Harrisons principles of internal medicine, 18th edition, Page: 1962.