Restrictive Cardiomyopathy

Decreased elasticity of myocardium leading to the impaired diastolic filling without significant systolic dysfunction (a normal or near-normal EF). Left ventricular volume is normal and wall thickness is either normal or symmetrically thickened (distinguishes from Hypertrophic Cardiomyopathy). It is less common than dilated cardiomyopathy and hypertrophic cardiomyopathy. It should not be confused with constrictive pericarditis, a disease which presents similarly but is very different in treatment and prognosis

Causes of Restrictive cardiomyopathy

  • Amyloidosis
  • Sarcoidosis
  • Hemochromatosis
  • Scleroderma
  • Loeffler eosinophilic endocarditis
  • Endomyocardial fibrosis or by scarring and fibrosis (2° to radiation).

History/PE of Restrictive Cardiomyopathy

  • Signs and symptoms of right-sided heart failure (JVD, peripheral edema, ascites, hepatomegaly) often predominate over left-sided failure, but dyspnea is the most common complaint.

Diagnosis of Restrictive Cardiomyopathy

  • Echocardiography is key for diagnosis,
    • Thickened myocardium and possible systolic ventricular dysfunction
    • Increased right atrium (RA) and LA size with normal LV and RV size
    • In amyloidosis, myocardium appears brighter or may have a speckled appearance
  • The cardiac biopsy may reveal fibrosis or evidence of infiltration.
  • ECG frequently shows LBBB; low voltages are seen in amyloidosis.
  • CXR, MRI, and cardiac catheterization are helpful for characterization (eg, sarcoid, amyloidosis).

Treatment

  • Treat the underlying cause.
    • Hemochromatosis: Phlebotomy or desferrioxamine
    • Sarcoidosis: Glucocorticoids for acute flares
    • Amyloidosis: Treat the underlying cause of amyloidosis, consider organ transplantation if severe end-organ disease (i.e., heart, kidney, liver if transthyretin amyloidosis)
    • Treat according to EF (HFrEF therapy or HFpEF therapy)
  • Therapeutic options are limited and are generally palliative only.
  • Medical treatment includes cautious use of diuretics for fluid overload and vasodilators to decrease filling pressure.
Restrictive cardiomyopathy USMLE

Reference:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1729880/

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