Introduction
It can lead to life-threatening complications, including heart failure and arrhythmias. There is currently no known cause of acute necrotizing eosinophilic myocarditis (ANEM). Still, it has been found to be more common in people with coexisting conditions such as autoimmune diseases, connective tissue disease, or immunosuppressive medications. There is no specific data on the prognosis of eosinophilic myocarditis. Approximately 10 percent of patients will die while in the hospital, and approximately 30 percent will live for less than three years.
What Is Acute Necrotizing Eosinophilic Myocarditis?
Acute necrotizing eosinophilic myocarditis is a rare but severe form of myocarditis, meaning inflammation of the heart muscle. It is characterized by the infiltration of eosinophils into the heart muscle tissue, causing damage that may lead to cardiac arrest.
What Is the Cause of Acute Necrotizing Eosinophilic Myocarditis?
Acute necrotizing eosinophilic myocarditis is caused by an allergic reaction to a trigger, such as a viral infection or certain medication. The triggers can set off the body's defense system, called an immune response. As a result, eosinophils, a type of white blood cell can accumulate in the heart muscle and cause it to become inflamed and scarred.
What Are the Symptoms of Acute Necrotizing Eosinophilic Myocarditis?
The symptoms of this condition may vary between people, but common signs and symptoms include:
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Abnormal heart rhythms (arrhythmias).
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Fluid retention can cause swelling in the ankles and legs.
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Shortness of breath is due to fluid build-up in the lungs and an increased risk of a blood clot in the leg or lungs.
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Chest pain can be mild or severe and usually worsens with exercise or when lying down.
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Decreased exercise tolerance is due to the ability of the heart to pump blood to the rest of the body. It may be reflected by a decrease in the person's usual exercise ability.
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Palpitations which is a sensation of a skipped or extra heartbeat.
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They also experience fatigue and fainting.
What Is the Diagnosis of Acute Necrotizing Eosinophilic Myocarditis?
A patient suspected of having ANEM should be hospitalized and monitored closely. Diagnosis is made by ruling out other causes for the symptoms and observing for eosinophilic infiltration of the heart muscle. Diagnostic tests may include:
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Echocardiography - To examine the structure and function of the heart and assess if the heart is enlarged or abnormally contracted.
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Electrocardiogram - To measure and record the electrical activity of the heart and detect arrhythmias.
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Blood Tests - To detect any underlying diseases or infections.
What Is the Treatment for ANEM?
The treatment for ANEM focuses on managing and monitoring the progression of the illness, with close attention to heart function, blood pressure, and blood flow through the body. Patients are typically treated with medications, such as beta-blockers, calcium channel blockers, and antiepileptics to control heart rhythm and blood pressure. They are also given antibiotics to treat any underlying infections. Some studies suggest that steroids, such as Dexamethasone may reduce eosinophilic infiltration. These treatments are not guaranteed to prevent complications, but they may help slow the progression of the disease. Some patients may have additional therapies, such as angioplasty, to manage blood flow through the body. This treatment may be necessary if blood flow is blocked. In some cases, surgery may be required.
What Is the Prognosis of ANEM?
Unfortunately, it is difficult to predict the prognosis for patients with ANEM, as it is a rare occurrence. ANEM may cause a full recovery in certain patients, while some may be left with permanent damage to the heart. The progression of the disease is unpredictable, making it difficult to estimate the outcome. But ANEM is treatable and reversible with prompt medical attention to manage the progression of the disease and prevent complications.
What Are the Common Triggers of Acute Necrotizing Eosinophilic Myocarditis?
The following triggers are associated with the development of acute necrotizing eosinophilic myocarditis:
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Heart Rhythm Disturbance: Abnormal heart rhythms (arrhythmias) are a common finding in up to 50 percent of patients with ANEM. These include atrial fibrillation, ventricular tachycardia, and complete heart block (a complete electrical disconnection of the heart).
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Cardiac Ischemia: Heart muscle injury that can result in the death of cardiomyocytes (heart muscle cells) and cause decreased blood flow to the heart.
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Pulmonary Hypertension: The blood pressure in the pulmonary artery is increased (carries blood from the right side of the heart to the lungs). This can cause shortness of breath and a bluish tinge in the fingertips.
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Heart Failure: Inability of the heart to pump blood to meet the body's requirements.
What Is the Differential Diagnosis of Acute Necrotizing Eosinophilic Myocarditis?
Patients with ANEM often present with an acute and severe presentation, which makes the differential diagnosis broad. Differential diagnosis of ANEM includes other types of myocarditis (inflammation of the heart muscle), viral cardiomyopathy, and neuromuscular disorders.
Acute Cardiomyopathy:
Acute cardiomyopathy is the most common cause of acute heart failure, occurring predominantly in older individuals. The clinical presentation of this condition is vague, with the diagnosis being made on the basis of abnormalities detected on an ECG (electrocardiogram) and imaging. Due to a large number of cases, clinicians must consider a broad differential diagnosis when making the diagnosis of ANEM.
Viral Cardiomyopathy:
Viral cardiomyopathy is a rare cause of acute heart failure that most commonly follows a viral infection such as the common cold or influenza. The clinical course of viral cardiomyopathy is similar to that of other forms of myocarditis but is often milder. Viral cardiomyopathy is often diagnosed based on a viral prodrome followed by an abnormal ECG and cardiac troponin rise.
Muscular Dystrophy-Adult and Juvenile Forms:
Although rare, ANEM may occasionally be caused by a neuromuscular disorder. The most common of these is myophosphorylase deficiency, an autosomal recessive disorder associated with abnormalities in the mitochondria. Patients with myophosphorylase deficiency have a high risk of developing ANEM.
Conclusion
Acute necrotizing eosinophilic myocarditis is a serious form of myocarditis. It is important to recognize the symptoms, seek treatment, and follow up with the doctor. Patients with ANEM should be treated aggressively with steroid therapy and be monitored closely for complications. Early detection and treatment are key to recovery and minimizing long-term complications.
