**1. Introduction**

Cardiomyopathies can be defined as disorders of the myocardium which are associated with cardiac dysfunction and are aggravated by arrhythmias, heart failure and sudden death [Ricardson, 2006]. Genetics has played a very important role in the understanding of the different cardiomyopathies since, in 1957, Bridgen cited for the first time the word "cardio‐ myopathy" and in 1958, Teare, the British pathologist reported nine cases of septum hyper‐ trophy (Teare, 1958).

The American Heart Association (AHA) has classified cardiomyopathies as primary cardio‐ myopathies (the heart is the only organ affected) and secondary cardiomyopathies (the heart is affected as part of a systemic disease). The European Society of Cardiology (ESC) has classified them according to morphological and functional phenotypes involving their pathophysiology (Maron, 2006; Maron, 2008; Elliott, 2008)

Primary cardiomyopathies are those which and can be genetic, nongenetic or acquired. Secondary cardiomyopathies are those in which the cardiomyopathy is found in a systemic disease. Primary cardiomyopathies can then be classified according to their anatomical and functional impairment in hypertrophic cardiomyopathy, dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), arrhythmogenic right ventricular cardiomyopathy/ dysplasia (ARVC/D), ion channel disorders. Secondary cardiomyopathies are those found in muscular dystrophies, mitochondrial disorders among others. The unclassified cardiomyo‐ pathies are non-compaction cardiomyopathy and takotsubo cardiomyopathy (Elliott, 2008; )

The genetic diagnosis has a close involvement in the management of primary and secondary cardiomyopathies and its development will have a key role in the understanding of the different molecular mechanisms that lead to a cardiomyopathy.

© 2013 Vernengo et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
