The Cardiomyopathies

Abstract

Cardiomyopathies are a diverse group of conditions characterised by structural and functional abnormalities of the heart muscle that are unexplained by coronary artery disease, hypertension or valve disease. They are grouped into morphological and functional phenotypes, each of which can be caused by genetic and non-genetic mechanisms. Most genetic cardiomyopathies are monogenic disorders (i.e. the genetic mutation is sufficient to cause disease), but they can appear sporadic when a mutation has arisen de novo. Non-familial or non-genetic cardiomyopathies are subdivided into idiopathic (no identifiable cause) and acquired disorders in which ventricular dysfunction is a complication of a disorder unrelated to a primary disturbance of cardiomyocyte function. Examples of the latter include cardiac amyloidosis, haemochromatosis and myocarditis. By convention, left ventricular dysfunction caused by coronary artery disease, hypertension, valve disease and congenital heart disease is excluded from the term cardiomyopathy, although they can coexist.