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Loeffler endocarditis

Updated : May 17, 2024





Background

Loeffler endocarditis, also known as eosinophilic endomyocardial disease or fibroblastic endocarditis, is a rare form of restrictive cardiomyopathy characterized by impaired heart relaxation and diastolic filling due to widespread infiltration of the heart by eosinophils. This condition was first described by W. Loeffler in 1936. It is typically associated with prolonged peripheral eosinophilia lasting around six months.

Loeffler endocarditis is considered one of the infrequent complications of the hyper-eosinophilic syndrome, a condition characterized by eosinophil infiltration of various body tissues without an apparent cause. Patients with Loeffler endocarditis may present with severe symptoms such as intracardiac thrombus formation, arrhythmias, and acute heart failure, that can be life-threatening if not promptly treated.

Epidemiology

Hypereosinophilic syndrome is an infrequent condition, with an annual occurrence of approximately 0.036 cases per 100,000 individuals. This disorder is uncommon in North America and is predominantly found in temperate and tropical regions of Asia, Africa, as well as specific areas of South America.

Typically, this condition is diagnosed in individuals between the ages of 20 and 50, although it can also manifest at both ends of the age spectrum. Cardiac involvement occurs in about 50% of cases, and it does not display a gender predisposition, except for primary hypereosinophilic syndrome, which is more prevalent in men compared to women.

Anatomy

Pathophysiology

The underlying mechanisms of hypereosinophilic syndrome (HES) remain incompletely understood. Some experts propose that if the eosinophil count remains consistently elevated, surpassing 1500 eosinophils per microliter of peripheral blood for a duration exceeding five months, the risk of end-organ damage rises.

This damage can affect various organs, including the lungs, heart, spleen, gastrointestinal tract, and central nervous system. When eosinophils infiltrate the heart, they release protein granules that can harm the endocardium and myocardium through the generation of direct toxins. These toxins subsequently trigger platelet activation.

The activated platelets then aggregate to form thrombi both within the heart chambers and within blood vessels, further exacerbating damage to the endocardium. Additional mechanisms may involve the activation of von Willebrand factor (VWF) and factor XII, potentially disrupting the endothelial lining thereby promoting procoagulant activity and the activation of fibrin production.

Etiology

Loeffler endocarditis is a rare manifestation of hypereosinophilic syndrome (HES), which can be classified into idiopathic, primary, and secondary types based on its underlying causes. Idiopathic hypereosinophilic syndrome is a rare condition characterized by elevated eosinophil counts, and it is the most common trigger of Loeffler endocarditis.

The primary type is often linked to underlying myeloproliferative and stem cell disorders, such as leukemia and lymphoma. In contrast, secondary hypereosinophilic syndrome is a reactive condition driven by non-neoplastic or paraneoplastic factors, leading to an increase in non-clonal eosinophils. These factors can include allergies, parasitic and fungal infections, as well as tumors.

Genetics

Prognostic Factors

Clinical History

Loeffler endocarditis is a rare condition characterized by the inflammation and thickening of the endocardium, which is the inner lining of the heart chambers. It is typically associated with hypereosinophilic syndrome (HES).

Cardiac Symptoms: Loeffler endocarditis primarily affects the heart, leading to symptoms such as:

  • Chest pain or discomfort
  • Shortness of breath
  • Fatigue
  • Palpitations
  • Signs of heart failure, such as edema, jugular venous distension, and hepatomegaly

The onset of Loeffler endocarditis is gradual, often occurring over months to years. It may start with nonspecific symptoms before progressing to more severe cardiac manifestations. The duration of Loeffler endocarditis can be chronic, with patients experiencing ongoing cardiac symptoms if left untreated. The course of the disease can be variable, and it may lead to complications if not managed appropriately.

Physical Examination

In addition to murmurs, abnormal heart sounds such as clicks or snaps may be heard, particularly when there is involvement of the mitral or tricuspid valves. In some cases, palpable vibrations can be felt over the chest wall. Vibrations are often associated with turbulent blood flow caused by valvular dysfunction.

In severe cases of Loeffler endocarditis with compromised heart function, patients may exhibit bluish discoloration of the skin and mucous membranes, known as cyanosis. This is a sign of inadequate oxygenation. In addition to cardiac findings, individuals with Loeffler endocarditis may also exhibit general signs of HES, which can include skin rashes, muscle weakness, and neurological symptoms (e.g., neuropathy).

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

  • Churg-Strauss syndrome
  • Tropical endomyocardial fibrosis
  • Medication-induced hypersensitivity reaction
  • Giant cell myocarditis

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

The treatment paradigm for Loeffler endocarditis, often associated with hypereosinophilic syndrome (HES), is a comprehensive and multifaceted approach. It involves managing the underlying hypereosinophilic syndrome and addressing the specific cardiac complications that arise. Initial treatment for hypereosinophilic syndrome typically includes high-dose corticosteroids to control eosinophil levels, along with other immunosuppressive agents when necessary.

Cardiac management focuses on alleviating symptoms and improving heart function with medications such as diuretics, ACE inhibitors, beta-blockers, antiarrhythmics, and anticoagulants. In severe cases with significant valve damage, surgical interventions to repair or replace affected heart valves may be required.

Regular follow-up and monitoring are crucial to assess treatment response, and emotional support and patient education are essential components of care. The individualized approach to treatment aims to improve cardiac function, alleviate symptoms, and enhance the overall quality of life for individuals with Loeffler endocarditis.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Valve Repair or Replacement: In severe cases with significant valve damage, surgery may be required to repair or replace affected heart valves. This can improve cardiac function and reduce symptoms.

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Administration of pharmaceutical agent

Diuretics can be prescribed to manage fluid retention and symptoms of heart failure, such as edema and ascites. Furosemide, bumetanide, and spironolactone are commonly prescribed. Beta-blockers slow down the heart rate and reduce blood pressure, which can be beneficial in managing arrhythmias and heart failure.

Common beta-blockers include metoprolol, carvedilol, and bisoprolol. If arrhythmias are present, antiarrhythmic drugs may be prescribed to control heart rhythm. The choice of antiarrhythmic medication depends on the type of arrhythmia and its underlying cause. Examples include amiodarone, flecainide, and sotalol.

Anticoagulant medications, such as warfarin, are used to prevent blood clots and reduce the risk of thromboembolic events in individuals with heart valve involvement. In cases of severe heart failure, inotropic agents like dobutamine or milrinone may be used to strengthen the heart’s pumping function temporarily.

Some vasodilators, like nitroglycerin, may be used to relax blood vessels and reduce the workload on the heart, particularly in cases of acute heart failure. 

Medication

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References

Loeffler endocarditis

Updated : May 17, 2024




Loeffler endocarditis, also known as eosinophilic endomyocardial disease or fibroblastic endocarditis, is a rare form of restrictive cardiomyopathy characterized by impaired heart relaxation and diastolic filling due to widespread infiltration of the heart by eosinophils. This condition was first described by W. Loeffler in 1936. It is typically associated with prolonged peripheral eosinophilia lasting around six months.

Loeffler endocarditis is considered one of the infrequent complications of the hyper-eosinophilic syndrome, a condition characterized by eosinophil infiltration of various body tissues without an apparent cause. Patients with Loeffler endocarditis may present with severe symptoms such as intracardiac thrombus formation, arrhythmias, and acute heart failure, that can be life-threatening if not promptly treated.

Hypereosinophilic syndrome is an infrequent condition, with an annual occurrence of approximately 0.036 cases per 100,000 individuals. This disorder is uncommon in North America and is predominantly found in temperate and tropical regions of Asia, Africa, as well as specific areas of South America.

Typically, this condition is diagnosed in individuals between the ages of 20 and 50, although it can also manifest at both ends of the age spectrum. Cardiac involvement occurs in about 50% of cases, and it does not display a gender predisposition, except for primary hypereosinophilic syndrome, which is more prevalent in men compared to women.

The underlying mechanisms of hypereosinophilic syndrome (HES) remain incompletely understood. Some experts propose that if the eosinophil count remains consistently elevated, surpassing 1500 eosinophils per microliter of peripheral blood for a duration exceeding five months, the risk of end-organ damage rises.

This damage can affect various organs, including the lungs, heart, spleen, gastrointestinal tract, and central nervous system. When eosinophils infiltrate the heart, they release protein granules that can harm the endocardium and myocardium through the generation of direct toxins. These toxins subsequently trigger platelet activation.

The activated platelets then aggregate to form thrombi both within the heart chambers and within blood vessels, further exacerbating damage to the endocardium. Additional mechanisms may involve the activation of von Willebrand factor (VWF) and factor XII, potentially disrupting the endothelial lining thereby promoting procoagulant activity and the activation of fibrin production.

Loeffler endocarditis is a rare manifestation of hypereosinophilic syndrome (HES), which can be classified into idiopathic, primary, and secondary types based on its underlying causes. Idiopathic hypereosinophilic syndrome is a rare condition characterized by elevated eosinophil counts, and it is the most common trigger of Loeffler endocarditis.

The primary type is often linked to underlying myeloproliferative and stem cell disorders, such as leukemia and lymphoma. In contrast, secondary hypereosinophilic syndrome is a reactive condition driven by non-neoplastic or paraneoplastic factors, leading to an increase in non-clonal eosinophils. These factors can include allergies, parasitic and fungal infections, as well as tumors.

Loeffler endocarditis is a rare condition characterized by the inflammation and thickening of the endocardium, which is the inner lining of the heart chambers. It is typically associated with hypereosinophilic syndrome (HES).

Cardiac Symptoms: Loeffler endocarditis primarily affects the heart, leading to symptoms such as:

  • Chest pain or discomfort
  • Shortness of breath
  • Fatigue
  • Palpitations
  • Signs of heart failure, such as edema, jugular venous distension, and hepatomegaly

The onset of Loeffler endocarditis is gradual, often occurring over months to years. It may start with nonspecific symptoms before progressing to more severe cardiac manifestations. The duration of Loeffler endocarditis can be chronic, with patients experiencing ongoing cardiac symptoms if left untreated. The course of the disease can be variable, and it may lead to complications if not managed appropriately.

In addition to murmurs, abnormal heart sounds such as clicks or snaps may be heard, particularly when there is involvement of the mitral or tricuspid valves. In some cases, palpable vibrations can be felt over the chest wall. Vibrations are often associated with turbulent blood flow caused by valvular dysfunction.

In severe cases of Loeffler endocarditis with compromised heart function, patients may exhibit bluish discoloration of the skin and mucous membranes, known as cyanosis. This is a sign of inadequate oxygenation. In addition to cardiac findings, individuals with Loeffler endocarditis may also exhibit general signs of HES, which can include skin rashes, muscle weakness, and neurological symptoms (e.g., neuropathy).

  • Churg-Strauss syndrome
  • Tropical endomyocardial fibrosis
  • Medication-induced hypersensitivity reaction
  • Giant cell myocarditis

The treatment paradigm for Loeffler endocarditis, often associated with hypereosinophilic syndrome (HES), is a comprehensive and multifaceted approach. It involves managing the underlying hypereosinophilic syndrome and addressing the specific cardiac complications that arise. Initial treatment for hypereosinophilic syndrome typically includes high-dose corticosteroids to control eosinophil levels, along with other immunosuppressive agents when necessary.

Cardiac management focuses on alleviating symptoms and improving heart function with medications such as diuretics, ACE inhibitors, beta-blockers, antiarrhythmics, and anticoagulants. In severe cases with significant valve damage, surgical interventions to repair or replace affected heart valves may be required.

Regular follow-up and monitoring are crucial to assess treatment response, and emotional support and patient education are essential components of care. The individualized approach to treatment aims to improve cardiac function, alleviate symptoms, and enhance the overall quality of life for individuals with Loeffler endocarditis.

Valve Repair or Replacement: In severe cases with significant valve damage, surgery may be required to repair or replace affected heart valves. This can improve cardiac function and reduce symptoms.

Diuretics can be prescribed to manage fluid retention and symptoms of heart failure, such as edema and ascites. Furosemide, bumetanide, and spironolactone are commonly prescribed. Beta-blockers slow down the heart rate and reduce blood pressure, which can be beneficial in managing arrhythmias and heart failure.

Common beta-blockers include metoprolol, carvedilol, and bisoprolol. If arrhythmias are present, antiarrhythmic drugs may be prescribed to control heart rhythm. The choice of antiarrhythmic medication depends on the type of arrhythmia and its underlying cause. Examples include amiodarone, flecainide, and sotalol.

Anticoagulant medications, such as warfarin, are used to prevent blood clots and reduce the risk of thromboembolic events in individuals with heart valve involvement. In cases of severe heart failure, inotropic agents like dobutamine or milrinone may be used to strengthen the heart’s pumping function temporarily.

Some vasodilators, like nitroglycerin, may be used to relax blood vessels and reduce the workload on the heart, particularly in cases of acute heart failure.