[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Heart](https://durgical.com/en/general-pathology/areas/heart/) › Arrhythmogenic cardiomyopathy

# 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.

Updated Nov 12, 2026

## Key points

- Fibrofatty replacement of right ventricular myocardium; the wall can become paper-thin.
- Desmosome genes: PKP2 (plakophilin-2) is the commonest; JUP (plakoglobin) in Naxos syndrome with woolly hair and palmoplantar keratoderma.
- Exercise accelerates the disease; a cause of sudden death in young athletes.
- ECG: epsilon waves and T-wave inversion in right precordial leads; ventricular tachycardia with left bundle branch block morphology.
- Fat alone in the right ventricle of older or obese people is normal; the diagnosis needs fibrosis and myocyte loss.

## 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.

## Memory aid

Loose rivets (desmosomes) under strain (exercise): the right ventricle falls apart into fat and scar.

## 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.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/arrhythmogenic-cardiomyopathy/)

[More Pathology questions →](https://durgical.com/en/practice/?f=pathology)

## Elsewhere in DurgiPedia

- [Cardiac muscle: intercalated discs](https://durgical.com/en/histology/cardiac-muscle-intercalated-discs/)

## Connections

## Related 3

- [Cardiomyopathies: classification](https://durgical.com/en/general-pathology/cardiomyopathies-classification/)
- [Arrhythmias and sudden cardiac death](https://durgical.com/en/general-pathology/arrhythmias-and-sudden-cardiac-death/)
- [Fatty change (steatosis)](https://durgical.com/en/general-pathology/fatty-change/)

## Related conditions 3

- [Arrhythmogenic right ventricular cardiomyopathy](https://durgical.com/en/conditions/arrhythmogenic-right-ventricular-cardiomyopathy/)
- [Cardiac arrest (VF, pulseless VT, asystole, PEA)](https://durgical.com/en/conditions/cardiac-arrest/)
- [Ventricular tachycardia](https://durgical.com/en/conditions/ventricular-tachycardia/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

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](https://medlineplus.gov/genetics/condition/arrhythmogenic-right-ventricular-cardiomyopathy/) (MedlinePlus, US National Library of Medicine, 2025).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/general-pathology/arrhythmogenic-cardiomyopathy/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/arrhythmogenic-cardiomyopathy/