Inherited cardiomyopathiesBMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l1570 (Published 02 May 2019) Cite this as: BMJ 2019;365:l1570
- Chris Miles, British Heart Foundation clinical research fellow and honorary specialist registrar,
- Zephryn Fanton, cardiac physiologist,
- Maite Tome, consultant cardiologist and honorary senior lecturer,
- Elijah R Behr, professor of cardiovascular medicine and honorary consultant cardiologist
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Institute, St George’s University of London, London, UK
- Correspondence to E Behr
What you need to know
Inherited cardiomyopathies are an important cause of sudden cardiac death across all age groups
Patients with inherited cardiomyopathy are frequently asymptomatic and may be diagnosed incidentally or as a result of family screening
A 12 lead electrocardiogram (ECG) and echocardiogram will detect most cardiomyopathies. Further evaluation may include additional ECG testing, specialist imaging, and genetic testing
Refer patients with worrying cardiac symptoms such as exertional chest pain, syncope, sustained palpitations, and those with a family history of cardiomyopathy or premature cardiac death to secondary care for investigation
Cardiomyopathies are structural and functional disorders of the heart muscle. They are often inherited and represent an important cause of sudden cardiac death. General practitioners play a key role in early diagnosis by recognising symptoms and clues from the family history to initiate investigations. In this clinical update, we provide an overview of diagnosis, genetic evaluation, and management of inherited cardiomyopathies for non-specialists.
What are the causes?
Cardiomyopathies are broadly divided into genetic and non-genetic causes, the former being inherited cardiomyopathies. Most inherited cardiomyopathies are single gene disorders with an autosomal dominant inheritance pattern and a 50% risk of transmission to a child. The main inherited cardiomyopathies are hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and arrhythmogenic cardiomyopathy (ACM) (fig 1). DCM may be genetic or acquired.
Non-genetic causes may be acquired, resulting from metabolic, endocrinological, or inflammatory disorders, pregnancy, amyloidosis, infections, and toxic agents including drugs and alcohol, or classified as idiopathic when no cause is identified.
How common are they?
HCM is the commonest, affecting approximately 1 in 500 adults globally across racial groups.234 A US population based study estimated the prevalence of DCM at 1 in 2500 adults,5 but this is …