muscular atrophy cardiac muscle atrophy acquired diminution of cardiac muscle tissue associated with wasting as from death and reabsorbtion of cells, diminished cellular proliferation, decreased cellular volume, pressure, ischemia, malnutrition, reduced function or malfunction, or hormonal changes; occurs with age, immobilization, weightlessness, malnutrition or denervation MP:0009418 MPheno.ontology abnormal cardiac muscle tissue morphology