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This condition involves eosinophilic myocarditis, endomyocardial fibrosis, thromboembolism, and acute heart failure.

The heart failure is due to restrictive cardiomyopathy. It is associated with various eosinophilic states. Eosinophilic arteritis and myocarditis is rapidly progressive so that the diagnosis is usually made post mortem. It was first described in 1936 when Löffler reported a very rare syndrome of eosinophilia, active carditis and multi-organ involvement.[1]

NB: Löffler's syndrome is different. It is a transient respiratory illness with eosinophilia and shadowing on chest X-ray, usually due to parasitic infestation.

Most cases are of idiopathic origin.

However other causes include:

  • The usual presentation is with weight loss, fever, cough, a rash (possibly pruritic) and symptoms of congestive heart failure.
  • Early cardiac involvement occurs in 20 to 50% of cases.
  • The physical findings are those of heart failure:
  • Systemic emboli may cause renal or neurological problems.
  • Signs of a restrictive cardiomyopathy may be very similar to those of constrictive pericarditis but the presence of a palpable apex beat and mitral regurgitation suggest cardiomyopathy.
  • Full blood count will show marked eosinophilia - at least 0.44 x 109/l
  • Electrocardiogram, echocardiogram and possibly CT scan and biopsy - useful to diagnose cardiomyopathy (Löffler's cardiomyopathy is characterised by restrictive filling but quite good left ventricular systolic function)
  • Cardiac catheterisation
  • Congestive failure is treated in the usual way with diuretics, digoxin, ACE inhibitors and other drugs to reduce afterload.
  • In early disease, immune suppression and cytotoxic drugs have had variable success.[2]
  • Steroids appear of benefit in acute myocarditis.
  • Prednisolone and hydroxycarbamide have been used to suppress eosinophilia.
  • Once fibrosis has occurred, surgery may be of benefit:
    • Removing fibrosed endocardium may improve elasticity.
    • Mitral and even tricuspid valves may need replacement.
    • Operative mortality is 15-30% and complete atrioventricular (AV) block is a common complication.
  • Prognosis is poor and depends upon the degree of involvement of the heart. Onset is usually slow but with accelerating right and left heart failure.
  • Syncope and sudden death are less common than with other constrictive cardiomyopathies.
  • The mean survival time is 18 months.[3]

Further reading and references

  • Hasan SA; Loeffler eosinophilic endocarditis. eMedicine. October 2008.

  1. Loffler W: Endocarditis parietalis fibroplastica mit Blut-eosinophilie, ein eigenartiges Krankheitsbild. Schweiz Med Wochenschr; 1936 66: 817-820.

  2. Solley GO, Maldonado JE, Gleich GJ, et al; Endomyocardiopathy with eosinophilia. Mayo Clin Proc. 1976 Nov51(11):697-708.

  3. Adler CP; Obstructive-restrictive cardiomyopathy. On the clinical aspects and pathology of Loffler endocarditis. Versicherungsmedizin. 1989 Sep 141(5):151-4.