Perspective:

The following are 10 points to remember about the proposed phenotype–genotype-based (2013) classification of cardiomyopathy, endorsed by the World Heart Federation:

1. Cardiomyopathies are described by morphologically and functionally abnormal myocardium in the absence of any other disease that is sufficient by itself, to cause the observed phenotype.

2. The proposed MOGE(S) nomenclature is based on five attributes of cardiomyopathic disorders:

• Morphofunctional (M)

• Organ involvement (O)

• Genetic or familial inheritance pattern (G)

• Etiological annotation of details of the genetic disease or underlying cause (E)

• Functional status (S) using the American College of Cardiology/American Heart Association (A-D) stage and New York Heart Association (NYHA) (I-IV) class. *Note the addition of (S) is optional and left at the discretion of the physician.

3. The (M) provides a description of the diagnosis of the phenotype (M_D = dilated cardiomyopathy; M_H = hypertrophic cardiomyopathy; M_A = arrhythmogenic right ventricular cardiomyopathy; M_R = restrictive cardiomyopathy; M_LVNC = left ventricular noncompaction).

4. The (O) is documented as heart only (O_H) or involvement of other organs. Extracardiac involvement is described as skeletal muscle (O_H+M), auditory, kidney, nervous, liver, gastrointestinal, cutaneous, ocular, and mental retardation.

5. The (G) provides information about autosomal dominant (G_AD), autosomal recessive (G_XLR), X linked recessive, X-linked dominant, or matrilineal.

6. The (E) describes the description of the underlying cause, such as amyloid familial (E_{A-TTR [p.V1221]}). Etiological specification may also describe individual noncarrier, obligate carrier, or obligate noncarrier. Nongenetic etiology is also described by Viral (V); such as Epstein-Barr virus (E_V-EBV). Other etiologies include myocarditis, autoimmune, toxic cardiomyopathy, etc.

7. It is expected that the phenotype (M) would be routinely defined on morphological and morphofunctional traits, and that the second descriptor (O) would require the organs involved.

8. There are certain nomenclature that should be reviewed specific to hypertrophic cardiomyopathy, restrictive cardiomyopathy, amyloid heart disease, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and left ventricular noncompaction.

9. Although it may seem complex at first glance, this nomenclature does provide all the essential information for cardiomyopathy type, patient, and affected family members in reference to a genetic tree.

10. This nomenclature will allow for a universal approach to patients being diagnosed and managed with cardiomyopathies.