Inherited cardiomyopathies

Cardiomyopathies are structural and functional disorders of the heart muscle.They are common, often 3 inherited, and an important cause of sudden cardiac death.Herein, we provide an overview of 4 diagnosis, genetic evaluation, and management of inherited cardiomyopathies for non-specialists.We 5 focus on the key role of the general practitioner in recognising symptoms and clues from the family 6 history.Further specialist evaluation is discussed alongside updated guidance from national and 7 international bodies.8 9 WHAT ARE THE CAUSES? 10 11 Cardiomyopathies are broadly divided into genetic and non-genetic causes, the former being inherited 12 cardiomyopathies.Non-genetic causes are classified as idiopathic or may be acquired, resulting from 13 metabolic, endocrinological, or inflammatory disorders, pregnancy, amyloidosis, infections, and toxic 14 agents including drugs and alcohol.Most inherited cardiomyopathies are single gene (monogenic) 15 disorders with an autosomal dominant pattern and a 50% risk of transmission to a child.The main 16 inherited cardiomyopathies are: Hypertrophic Cardiomyopathy (HCM), Dilated Cardiomyopathy (DCM), 17 and Arrhythmogenic Cardiomyopathy (ACM )(Figure 1).DCM may be considered genetic or acquired.18 19 HOW COMMON ARE THEY? 20 21 Inherited cardiomyopathies are found among all ethnicities and populations.HCM is the most common What you need to know  Inherited cardiomyopathies are common and a major cause of heart disease across all age groups. Asymptomatic individuals may still be at risk from sudden cardiac death. The ECG and echocardiogram will detect the majority of cardiomyopathies, but further evaluation may include additional ECG testing, specialist imaging, and genetic testing. Assessment of family members should be considered at an early stage with involvement of specialist centres.