Restrictive cardiomyopathy

Background

  • Muscle is stiff from fibrosis or infiltrating process (e.g. amyloidosis, hemochromatosis)
  • Form of diastolic dysfunction (difficulty filling); ventricular endocardial thickening or myocardial infiltration-->high filling pressures, impaired diastolic filling-->mitral and/or tricuspid regurgitation--> venous pulmonary hypertension
    • Ventricular EF typically normal, though systolic function may deteriorate in absence of compensatory hypertrophy
  • If nodal/conduction tissues affected by infiltrative/fibrotic process, may cause SA or AV block
  • Must distinguish from constrictive pericarditis

Clinical features

Differential Diagnosis

Cardiomyopathy

Restrictive cardiomyopathy etiology DDX

Evaluation

showing ST-segment and T-wave abnormalities

  • CXR- heart typically normally sized, though can be enlarged in advanced stages of some underlying disease processes
  • Echocardiography
    • Normal LVEF
    • Elevated LV filling pressures, impaired longitudinal contraction
    • +/- dilated atria, myocardial hypertrophy
  • Definitive diagnosis may require MRI, catheterization, biopsy

Management

  • Symptom-directed
    • Diuretics for edema or pulmonary vascular congestion
      • Caution as cardiac output preload dependant
    • Caution with afterload reduction as may cause profound hypotension
    • Treat arrhythmias
      • Avoid digoxin in amyloidosis as sensitivity to dig-induced arrhythmias common


See Also

References

https://www.merckmanuals.com/professional/cardiovascular-disorders/cardiomyopathies/restrictive-cardiomyopathy