Cardiomyopathy classification separates the various cardiomyopathies into several subtypes. Cardiomyopathy is defined as a "disease of the myocardium with associated cardiac dysfunction".

It was initially classified according to the 1995 World Health Organizatiοn / International Society and Federation of Cardiology (WHO/ISFC) system as follows:

• dilated cardiomyopathy
• hypertrophic cardiomyopathy
• restrictive cardiomyopathy  
• arrhythmogenic right ventricular cardiomyopathy
• specific cardiomyopathy
• non-classified cardiomyopathies which include
  • fibroelastosis
  • mildly dilated cardiomyopathy
  • non-compacted myocardium
  • mitochondrial cardiomyopathy

This has since been revised in 2006 by the American Heart Association (AHA) as follows ²:

• primary cardiomyopathies predominantly involving the heart
  • genetic
    • hypertrophic cardiomyopathy
      • cardiomyopathy from primary cardiac glycogen storage diseases (PRKAG2 cardiac syndrome, Danon disease)
    • arrhythmogenic right ventricular cardiomyopathy
    • left ventricular non-compaction
    • cardiomyopathy from conduction defects
    • cardiomyopathies from ion channelopathies (e.g. long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome)
    • cardiomyopathies from mitochondrial myopathies
  • mixed
    • dilated cardiomyopathy
    • restrictive cardiomyopathy
  • acquired
    • inflammatory cardiomyopathy (i.e. myocarditis)
    • stress-induced cardiomyopathy (i.e. Takotsubo cardiomyopathy)
    • cardiomyopathy in peripartum and postpartum cardiomyopathy
    • tachycardia-induced cardiomyopathy
    • cardiomyopathy in infants of diabetic mothers
• secondary cardiomyopathies (these conditions can have multi-organ involvement)
  • infiltrative conditions - cardiomyopathy from 
    • cardiac amyloidosis
    • Gaucher disease
    • Hurler disease
    • Hunter disease
  • cardiomyopathy from storage conditions
    • cardiomyopathy in hemochromatosis
    • Fabry disease
    • systemic glycogen storage disease (e.g. Pompe disease)
    • Niemann-Pick disease
  • cardiomyopathy from toxic agents
    • drugs, heavy metals, chemicals which include

      • methamphetamine-induced cardiomyopathy (MACM) ³

  • cardiomyopathy from endomyocardial causes
    • endomyocardial fibrosis
    • Loeffler endocarditis
  • cardiomyopathy from systemic inflammatory conditions
    • cardiac sarcoidosis
  • cardiomyopathy from underlying systemic autoimmune conditions
    • systemic lupus erythematosus
    • scleroderma
    • dermatomyositis
    • polyarteritis nodosa
    • rheumatoid arthritis
  • cardiomyopathy from endocrine conditions
    • diabetes
    • hypothyroidism
    • hyperthyroidism
    • hyperparathyroidism
    • pheochromocytoma
    • acromegaly
  • cardiomyopathy from neuromuscular conditions
    • Friedreich ataxia
    • myotonic dystrophy
    • neurofibromatosis
    • tuberous sclerosis
  • cardiomyopathy from underlying nutritional conditions
    • beriberi
    • pellagra
    • scurvy
    • selenium deficiency
    • carnitine deficiency
  • cardiomyopathy from underlying electrolyte imbalances
    • potassium
    • magnesium
    • phosphate
  • cardiomyopathy related to cancer treatment
    • doxorubicin cardiotoxicity
    • cyclophosphamide cardiotoxicity
    • radiation cardiotoxicity