Loffler's Eosinophilic Endocarditis

In 1936 Loffler described a very rare syndrome of eosinophilia, active carditis and multi-organ involvement.¹ There is 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.

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

• Causes of Loffler's endocarditis include hypereosinophilic syndrome, eosinophilic leukaemia, carcinoma, lymphoma, drug reactions, or parasites.
• Most cases are of idiopathic origin

• The usual presentation is with weight loss, fever, cough, a rash and possibly pruritis, and symptoms of congestive heart failure.
• Early cardiac involvement occurs in between 20 and 50% of cases.
• The physical findings are those of heart failure:
  • Peripheral oedema and elevated jugular venous pressure
  • Tachycardia
  • Cardiomegaly may precede signs of heart failure
  • There may be a murmur of mitral regurgitation as described in mitral valve disease
  • The gallop of a 3rd heart sound may be heard and possibly even a 4th heart sound
• 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.

• Other causes of restrictive cardiomyopathy include amyloidosis, sarcoidosis and myeloma.
• In children rhabdomyosarcoma may be found. It is commoner with tuberose sclerosis.

• Full blood count will show marked eosinophilia, being at least 0.44 x 10⁹/l.
• Electrocardiogram, echocardiogram and possibly CT scan and biopsy are useful to diagnose the cardiomyopathy. Loffler'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 A-V 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