Heygive me 10 markoncardiomyopathy

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Good sources found. Let me read the key cardiomyopathy sections from Robbins Pathology and Goldman-Cecil in parallel.

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Let me now read the detailed cardiomyopathy sections from Robbins Basic Pathology and Robbins & Cotran in parallel.

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Let me now read the actual cardiomyopathy section from Robbins Basic Pathology directly.

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Let me read the detailed cardiomyopathy section from Robbins Basic Pathology directly.

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Here are 10 marks on Cardiomyopathy, drawn from Robbins & Kumar Pathologic Basis of Disease and Goldman-Cecil Medicine:

Cardiomyopathy - 10 Mark Notes

1. Definition

Cardiomyopathies are intrinsic diseases of cardiac muscle that may be genetic or due to other well-defined causes. The term specifically refers to myocardial dysfunction NOT caused by coronary artery disease, hypertension, valvular disease, or congenital heart disease.

Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 515

2. Classification (3 Major Types)

There are three general pathophysiologic categories:

Dilated Cardiomyopathy (DCM) - most common (90% of cases) - systolic dysfunction
Hypertrophic Cardiomyopathy (HCM) - diastolic dysfunction
Restrictive Cardiomyopathy - least common - diastolic dysfunction
Robbins & Kumar Basic Pathology, p. 334

3. Dilated Cardiomyopathy (DCM) - Pathogenesis

DCM is characterized by progressive cardiac dilation and contractile (systolic) dysfunction. Causes include:

Genetic: 20-50% of cases; autosomal dominant loss-of-function mutations in cytoskeletal/sarcomeric proteins. Titin (TTN) truncating mutations account for ~20-25% of familial cases. X-linked forms involve dystrophin (Duchenne/Becker muscular dystrophy).
Viral myocarditis: Coxsackievirus B, parvovirus B19, HHV-6; viral injury can progress to end-stage DCM.
Toxic: Alcohol and acetaldehyde have direct myocardial toxicity.
Pregnancy: Peripartum cardiomyopathy.
Robbins & Kumar Basic Pathology, p. 334

4. DCM - Morphology

Heart is enlarged and heavy; all four chambers dilated
Ventricular wall may be normal, thickened, or thinned
Mural thrombi may form in dilated chambers (risk of embolism)
Microscopically: myocyte hypertrophy, interstitial fibrosis, occasional myocyte dropout - but these are non-specific end-stage changes
Robbins & Kumar Basic Pathology, p. 334

5. Hypertrophic Cardiomyopathy (HCM) - Pathogenesis

Virtually ALL cases are autosomal dominant gain-of-function mutations in sarcomere proteins (contractile apparatus)
Most common mutations: beta-myosin heavy chain and myosin-binding protein C
Results in diastolic dysfunction (impaired relaxation/filling), NOT systolic dysfunction
~60-70% have asymmetric septal hypertrophy causing left ventricular outflow tract (LVOT) obstruction
Goldman-Cecil Medicine, block 6

6. HCM - Morphology & Histology

Massive ventricular hypertrophy, especially the interventricular septum (asymmetric)
Small ventricular cavity
Histological hallmark: myocyte disarray (haphazard arrangement of myocytes), interstitial fibrosis, and thickened small intramural coronary arteries
LVOT obstruction leads to systolic anterior motion (SAM) of the mitral valve
Robbins & Kumar Basic Pathology, p. 336

7. HCM - Clinical Features & Complications

Often asymptomatic; may present with exertional dyspnea, angina, syncope
Most common cause of sudden cardiac death (SCD) in young athletes
Atrial fibrillation with risk of systemic thromboembolism
Risk stratification for ICD implantation is key in management
Goldman-Cecil Medicine

8. Restrictive Cardiomyopathy

Least common type; characterized by a stiff, non-compliant myocardium that restricts ventricular filling (diastolic dysfunction)
Ventricular systolic function is preserved early
Causes:
- Amyloidosis (most common in developed countries)
- Sarcoidosis
- Radiation-induced interstitial fibrosis
- Endomyocardial fibrosis (eosinophilia-associated)
- Loeffler endocarditis
Clinically mimics constrictive pericarditis
Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 521

9. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Progressive replacement of RV myocardium with fibrofatty tissue
Caused by mutations in desmosomal proteins (e.g., plakophilin-2, desmoplakin)
Autosomal dominant with variable penetrance
Clinical features: RV dysfunction, ventricular arrhythmias, sudden death in young adults/athletes
ECG may show epsilon waves; MRI demonstrates fibrofatty replacement
Robbins & Kumar Basic Pathology, p. 336

10. Myocarditis (Inflammatory Cardiomyopathy)

Myocardial damage due to inflammatory infiltrates secondary to infection or immune reactions
Most common cause in the US: viral infections (Coxsackievirus B, parvovirus B19)
Clinically: can be asymptomatic, cause acute heart failure, or evolve into DCM
Biopsy (Dallas Criteria): lymphocytic infiltrate with adjacent myocyte necrosis
Special form: Giant cell myocarditis - rare, rapidly fatal without transplantation; can be stabilized with early immunosuppression
Long-term mortality of biopsy-proven viral myocarditis: ~20% at 4.7 years
Robbins, Cotran & Kumar, p. 523; Goldman-Cecil Medicine

Summary Table:

Type	Primary Dysfunction	Key Genetics	Hallmark Feature
DCM	Systolic	Titin, dystrophin (loss of function)	Dilated 4-chamber heart
HCM	Diastolic	Beta-MHC, MyBPC (gain of function)	Myocyte disarray, SCD in athletes
Restrictive	Diastolic	Usually acquired	Stiff ventricle, amyloid deposits
ARVC	RV dysfunction	Desmosomal genes	Fibrofatty RV replacement
Myocarditis	Variable	N/A	Lymphocytic infiltrate + necrosis

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