Etiology
Mnemonic
“PLEASe Help!”: Causes of restrictive cardiomyopathy include Postradiation/Postsurgery fibrosis, Löffler endocarditis, Endocardial fibroelastosis, Amyloidosis, Sarcoidosis, and Hemochromatosis.
Infiltrative cardiomyopathy
- Amyloidosis: caused by an accumulation of abnormal proteins in the myocardium
- Most common cause of restrictive cardiomyopathy in high-income countries.
- See ATTRmt amyloidosis
- Sarcoidosis: secondary to deposition of granulomas in the myocardium
Pathophysiology
Infiltration (e.g., abnormal proteins, glycogen, eosinophils, granulomas, iron) or proliferation of connective or fibrotic tissue → ↓ elasticity of myocardium → ↓ ventricular compliance (severe diastolic dysfunction)
Clinical features
Diagnostics
Differ from Hypertrophic cardiomyopathy by EF = 25~50%, while restrictive cardiomyopathy > 60%