[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/) › Dilated cardiomyopathy

# Dilated cardiomyopathy

- Lesion

In dilated cardiomyopathy the heart becomes large, baggy and weak. Genes, alcohol, infections, pregnancy and some drugs can cause it.

Updated Nov 12, 2026

## Key points

- Morphology: enlarged, heavy, flabby heart with dilation of all chambers; mural thrombi; valves normal.
- Histology is non-specific: hypertrophied and stretched myocytes with interstitial and endocardial fibrosis.
- Genetic DCM: autosomal dominant most often (TTN); X-linked with dystrophin mutations; LMNA also causes conduction block.
- Alcohol and its metabolite acetaldehyde are directly toxic; thiamine deficiency (wet beriberi) can add high-output failure.
- Peripartum cardiomyopathy: late pregnancy to months after delivery; angiogenic imbalance (a cleaved prolactin fragment); many recover.
- Takotsubo: postmenopausal women after emotional stress; apical ballooning; contraction-band necrosis; usually recovers.

## What it is

Dilated cardiomyopathy (DCM) is progressive dilation and systolic dysfunction of the ventricles, usually with some hypertrophy. A sizeable minority is genetic, most often truncating mutations in the giant sarcomere protein titin (TTN), and also lamin A/C (with conduction disease) and dystrophin (Duchenne and Becker). Acquired causes include alcohol, myocarditis, anthracyclines and other drugs, iron overload, peripartum cardiomyopathy and tachycardia. Takotsubo (stress) cardiomyopathy is a reversible ventricular dysfunction triggered by catecholamines.

## Structure

- Gross: large globular heart, thin or normal-thickness walls, dilated cavities, often mural thrombi in the apex.
- Microscopy: myocyte hypertrophy with irregular nuclei, some stretched attenuated fibres, interstitial fibrosis; little inflammation.

## Clinical notes

- Presents with slowly progressive heart failure, arrhythmias and embolism; transplant is an option at end stage.
- In Latin America, Chagas cardiomyopathy is an important cause of a dilated phenotype.

## Memory aid

Titin, toxins (alcohol, anthracyclines), viruses and the puerperium: the big, weak, baggy heart.

## Test yourself

Think of the answer, then tap the question to see it.

## Which gene is most often mutated in familial dilated cardiomyopathy?

TTN, encoding titin (truncating mutations).

## What is the typical shape of the left ventricle in Takotsubo cardiomyopathy?

Apical ballooning with a narrow neck, like the octopus trap that gives it its name.

## When does peripartum cardiomyopathy appear?

In late pregnancy or the months after delivery.

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## Elsewhere in DurgiPedia

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

## Connections

## Related 6

- [Cardiomyopathies: classification](https://durgical.com/en/general-pathology/cardiomyopathies-classification/)
- [Myocarditis](https://durgical.com/en/general-pathology/myocarditis/)
- [Toxic and radiation injury of the myocardium](https://durgical.com/en/general-pathology/toxic-and-radiation-injury-of-the-myocardium/)
- [Alcohol: how it injures the liver, brain, heart and fetus](https://durgical.com/en/general-pathology/alcohol-how-it-injures-the-liver-brain-heart-and-fetus/)
- [Heart failure: hypertrophy and remodelling](https://durgical.com/en/general-pathology/heart-failure-hypertrophy-and-remodelling/)
- [Hemochromatosis: hepcidin, HFE and where iron settles](https://durgical.com/en/general-pathology/hemochromatosis-hepcidin-hfe-and-where-iron-settles/)

## Related conditions 7

- [Dilated cardiomyopathy](https://durgical.com/en/conditions/dilated-cardiomyopathy/)
- [Peripartum cardiomyopathy](https://durgical.com/en/conditions/peripartum-cardiomyopathy/)
- [Takotsubo (stress) cardiomyopathy](https://durgical.com/en/conditions/takotsubo-cardiomyopathy/)
- [Alcohol use disorder](https://durgical.com/en/conditions/alcohol-use-disorder/)
- [Heart failure](https://durgical.com/en/conditions/heart-failure/)
- [Myocarditis](https://durgical.com/en/conditions/myocarditis/)
- [Chagas cardiomyopathy](https://durgical.com/en/conditions/chagas-cardiomyopathy/)

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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: [Dilated cardiomyopathy: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000168.htm) (MedlinePlus, US National Library of Medicine, 2025); [Peripartum cardiomyopathy: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000188.htm) (MedlinePlus, US National Library of Medicine, 2025).

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Representative model, for educational purposes only.

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