In 1995, the World Health Organization (WHO) defined cardiomyopathy as a “disease of the myocardium associated with cardiac dysfunction.” The WHO proposed a classification system based on pathophysiology (1). Each class may be caused by many disorders, and some disorders may overlap classes:

• Classification of cardiomyopathy:
  • Dilated (systolic):
    • Characterized by dilation and reduced systolic function of 1 or both ventricles
  • Hypertrophic (diastolic):
    • Left and/or right ventricular hypertrophy with normal to reduced end diastolic volumes
    • May include asymmetric septal hypertrophy
    • Cause of sudden cardiac death in young athletes
  • Restrictive (diastolic):
    • Restrictive filling and reduced diastolic volume of either or both ventricles
    • Systolic function may be near normal.
    • Etiology: Idiopathic, amyloidosis, etc.
  • Arrhythmogenic right ventricular (RV) dysplasia:
    • Fibrofatty replacement of the RV
    • May present with arrhythmia or sudden cardiac death in the young
  • Unclassified:
    • Cases that do not fit easily into 1 group (i.e., noncompacted myocardium)
  • Specific: Includes patients with cardiomyopathy in association with a known systemic disorder:
    • Ischemic
    • Valvular
    • Hypertensive
    • Inflammatory
    • Metabolic
    • Peripartum
• End-stage cardiomyopathy patients have stage D heart failure or severe symptoms at rest refractory to standard medical therapy.
• System(s) affected: Cardiovascular; Renal

ALERT
Pediatric Considerations
Etiology: Idiopathic, viral, congenital heart disease, and familial

Pregnancy Considerations
May occur in women postpartum