Dilated
Cardiomyopathy
(Congestive Cardiomyopathy)
Epidemiology and
Etiology:
- Causes:
- idiopathic
- drugs
/ toxins
- direct
toxic effect
- thiamine
deficiency (beriberi heart disease)
- genetic (25-35%)
- mostly
AD
- cytoskeletal gene defects mostly
- mitochondrial
gene defects:
- abnormal
oxidative phosphorylation
- beta-oxidation
of fatty acids
- alpha-cardiac
actin
- links
the sarcomere with dystrophin
- desmin
- lamin A and lamin C
- dystrophin (X-linked)
- Duchenne and Becker muscular
dystrophies
- peripartum (nutritional
deficiency or immunologic reaction)
- myocarditis
- hemochromatosis
- chronic
anemia
- sarcoidosis
- may
occur in any age
Common sites:
Gross features:
- heavy (often 2-3x normal)
- large,
flabby
- dilation
of all chambers
- myocardial
thickness variable (may be less or more thick than normal)
- mural
thrombi common
- no
primary valvular alterations
- may
have mitral or tricuspid regurgitation secondary to dilation
- coronary
artery disease is insufficient to explain the degree of cardiac
dysfunction
Histologic features:
- nonspecific,
do not suggest a specific etiologic agent
- muscle
cell changes:
- most
hypertrophied
- many
attenuated, stretched, and irregular
- variable
degree of interstitial and endocardial fibrosis
- may
see secondary subendocardial ischemic changes (fibrosis)
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- clinical
info:
- slowly
progressive CHF
- LVEF
<40%
- Systolic
heart failure
- Prognosis
poor:
- 50%
mortality in 2y
- 75%
mortality in 5y
References: