Arrhythmogenic cardiomyopathy
- Lesion
In arrhythmogenic cardiomyopathy, heart muscle cells come apart and are replaced by fat and scar, mainly in the right ventricle, causing dangerous rhythms.
What it is
Arrhythmogenic (right ventricular) cardiomyopathy is an inherited disease, usually autosomal dominant with variable penetrance, caused by mutations in desmosomal proteins that hold myocytes together (plakophilin-2 most often, desmoplakin, plakoglobin, desmoglein, desmocollin). Myocytes detach and die, especially under the mechanical stress of exercise, and are replaced by fat and fibrous tissue. The right ventricle thins and dilates; the left ventricle can also be involved. It presents with ventricular tachycardia, syncope or sudden death in young people and athletes.
Structure
- Gross: dilated right ventricle with yellow fatty areas reaching through the wall; aneurysms in the ‘triangle of dysplasia’ (inflow, outflow, apex).
- Microscopy: islands of surviving myocytes trapped in fat and fibrosis; sometimes patchy inflammation.
Clinical notes
- Implantable defibrillators and avoidance of intense exercise reduce sudden death; relatives should be screened.
Test yourself
Think of the answer, then tap the question to see it.
What proteins are defective in arrhythmogenic cardiomyopathy?
Desmosomal proteins (plakophilin-2, desmoplakin, plakoglobin, desmoglein, desmocollin).
What replaces the myocardium of the right ventricle?
Fat and fibrous tissue (fibrofatty replacement).
Which syndrome combines arrhythmogenic cardiomyopathy with woolly hair and keratoderma?
Naxos syndrome, from plakoglobin (JUP) mutations.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Arrhythmogenic right ventricular cardiomyopathy: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2025).
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Representative model, for educational purposes only.