What is Loeffler Endocarditis?
Loeffler endocarditis is a condition that affects the heart and is closely linked to hypereosinophilic syndromes. These complex medical terms simply refer to a series of disorders marked by the presence of high numbers of eosinophils, a type of white blood cell, in the blood and tissues. These syndromes can result in extensive damage to several organs, including the heart, due to uncontrolled activity of these white blood cells.
This condition, first identified by W. Loeffler in 1936, is specifically associated with a high number of eosinophils in the blood and is a rare complication linked to hypereosinophilic syndromes. Loeffler endocarditis adversely affects the heart’s ability to relax and refill with blood.
The main issue in Loeffler endocarditis is the widespread presence of eosinophils in the heart muscle. Common symptoms include heart failure that can affect the left or right side of the heart, blood clots leading to events like stroke or blockages in the limbs or kidneys, or heart rhythm abnormalities. In severe cases, instant treatment is vital, and it often involves medications like steroids or therapies to suppress the immune system.
Loeffler endocarditis is sometimes also referred to as eosinophilic endomyocardial disease or fibroblastic endocarditis. There’s also a condition called endomyocardial fibrosis, which closely resembles the late stages of Loeffler endocarditis.
What Causes Loeffler Endocarditis?
Loeffler endocarditis is a rare heart condition that’s usually tied to having too many eosinophils, a type of white blood cell, due to different conditions known as hypereosinophilic syndromes. These syndromes can be grouped into three categories based on what causes them: idiopathic, primary, and secondary.
Idiopathic hypereosinophilic syndromes are cases where there’s no clear reason behind the elevated eosinophil count. These are the most common causes of Loeffler endocarditis.
Primary hypereosinophilic syndromes are typically related to disorders in bone marrow and stem cells, like leukemia and lymphoma.
Secondary hypereosinophilic syndromes are usually a reaction to a different underlying condition that isn’t a cancerous growth, or sometimes is connected to a tumor. These could include allergies, parasitic or fungal infections. In these cases, there’s an increase in non-clonal eosinophils – meaning the eosinophils aren’t all from identical cells.
Risk Factors and Frequency for Loeffler Endocarditis
Hypereosinophilic syndrome is a rare health condition affecting between 0.36 to 6.3 out of every 100,000 patients every year. It usually shows up in adults aged 20 to 50, but sometimes children, especially those with weakened immune systems, can also have it. About half of the people with this syndrome have heart-related issues. This is more common in men, though a similar condition, endomyocardial fibrosis, impacts men and women equally. Loeffler endocarditis, another related disease, is rare in North America and is mainly found in Asia, Africa, and parts of South America, particularly in temperate and tropical regions.
- Hypereosinophilic syndrome is a rare disorder, affecting 0.36 to 6.3 per 100,000 patients every year.
- This condition generally affects adults aged 20 to 50, but can also occur in children, especially those with weakened immune systems.
- Approximately 50% of patients show signs of heart disease, with men being more affected, however, endomyocardial fibrosis affects both men and women equally.
- Loeffler endocarditis, a similar condition, is rare in North America, but common in tropical and temperate regions of Asia, Africa, and parts of South America.
Signs and Symptoms of Loeffler Endocarditis
Loeffler endocarditis is a heart condition that may present itself through certain signs and symptoms. They can include shortness of breath, getting tired easily, difficulty sleeping when lying flat, and waking up at night unable to breathe. Other signs might include unintentional weight loss, fatigue, heart palpitations, chest pain or fainting. Some rare symptoms might even mimic those of heart valve disease, like problems with the mitral or aortic valves. The most common complaint, interestingly, is of shortness of breath, forming around 60% of total reported symptoms. Less common symptoms can also include problems like pericarditis, congestive heart failure and, in some cases, even changes to heart valves due to eosinophilic infiltration, which may lead to conditions like mitral valve insufficiency or aortic stenosis and regurgitation. Doctors conducting a physical examination will look for specific signs of this disease like high neck vein pressure, abnormal breath sounds, an enlarged liver, swollen limbs, abnormal heart sounds and other symptoms that suggest heart failure. They may also look for an irregular pulse. In advanced cases, patients may show symptoms of a condition called cachexia, which is severe weight loss, along with jaundice, a yellowing of the skin and eyes.
- Shortness of breath
- Getting tired easily
- Difficulty sleeping when lying flat
- Waking up at night unable to breathe
- Unintentional weight loss
- Fatigue
- Heart palpitations
- Chest pain
- Fainting
- Changes to heart valves leading to mitral valve insufficiency or aortic stenosis and regurgitation
- High neck vein pressure
- Abnormal breath sounds
- Enlarged liver
- Swollen limbs
- Abnormal heart sounds (suggesting heart failure)
- Irregular pulse
- Severe weight loss and jaundice (in advanced cases)
Testing for Loeffler Endocarditis
Noninvasive medical tools have become incredibly useful in diagnosing Loeffler endocarditis, a type of heart disease.
One of these tests is a Complete Blood Count (CBC), which can show an abnormally high number of eosinophils (a type of white blood cell). If these levels are high on more than one occasion, it could indicate endocarditis.
An electrocardiogram, which measures the electrical activity of the heart, may also reveal various issues such as irregular heartbeats or abnormalities in the size of the heart’s chambers. However, there isn’t a single electrocardiogram result that can confirm Loeffler endocarditis.
The physician might also order a 2D transthoracic echocardiogram, a type of ultrasound test that creates an image of the heart. The findings from this test can vary depending on the stage of the disease. As the disease progresses, it can show thickening of the heart’s inner lining or clots forming on the walls of the heart.
A newer version of this test, the 3D transthoracic echocardiogram, can provide more detailed images and show if the clots are blocking blood flow in the heart.
Another effective imaging tool is Cardiac Magnetic Resonance Imaging (Cardiac MRI). This test can help detect the disease earlier and differentiate between healthy and unhealthy tissues in the heart. It can provide a clear picture of the right side of the heart while also identifying smaller clots and early signs of endocarditis.
Doctors can also use a Cardiac MRI to understand the disease’s stage, monitor the response to treatment, and even predict the disease’s progression.
Although less frequently used, Cardiac Computerized Tomography (CCT), may be useful to visualize clots in specific cases where other tests may not be ideal.
Endomyocardial biopsy, a procedure where a small tissue sample is taken from the heart, is considered the gold standard for diagnosing eosinophilic endocarditis. However, due to its invasive nature, doctors usually reserve this procedure for situations when other tests don’t provide a clear diagnosis. During the biopsy, the tissue sample is examined for signs of heart damage resulting from eosinophils.
The doctor may also recommend molecular testing to further evaluate the condition or to examine bone marrow. These tests are crucial for diagnosing hypereosinophilic syndromes, a group of disorders that can also cause high eosinophil counts.
Treatment Options for Loeffler Endocarditis
Loeffler endocarditis is a medical condition that affects the heart and there is not a lot of information regarding the best treatment strategies. However, there are some recommended measures to help manage the symptoms:
1. Simple treatments such as diuretics, digoxin, and medications for heart failure can be used. These heart-failure medications can include ACE inhibitors and angiotensin II receptor blockers, which lower blood pressure, along with beta blockers and aldosterone antagonists that help reduce heart strain and decrease fluid build-up.
2. Atrial fibrillation, a heart rhythm disorder, and excess fluid can be managed using medicines that control heart rate and diuretics. These are the primary treatments.
3. If necessary, procedures to remove fluid from the pleura (the area around the lungs) or the abdominal cavity (ascites) can also be carried out.
While there’s no specific requirement for preventative blood-thinning treatment in Loeffler endocarditis, if a clot in the heart’s chamber (ventricular thrombus) is detected through heart imaging tests, then blood thinners such as warfarin or low molecular weight heparin should be started. The same applies if a mechanical heart valve is implanted.
It’s important to also treat the underlying cause, known as hypereosinophilic syndromes. As soon as these are diagnosed, steroids, which reduce inflammation, are typically the first choice of treatment. Depending on the cause, a drug called hydroxyurea may also be used. It is also recommended that all patients with hypereosinophilic syndromes, whether or not their heart is affected, be tested for a specific genetic mutation (FIP1L1-PDGFRA), because it can change management of the disease. If the test is positive, a medication called imatinib, which blocks certain proteins that cause cells to grow, may be given, and it has been reported to work well.
Surgery options can include removing part of the heart lining (endomyocardium) and replacing or repairing heart valves. People with Loeffler endocarditis may need replacement of the mitral valve, one of the heart’s four valves, due to its inability to function properly (mitral regurgitation). It’s important to know that the data on these surgeries is limited. Tricuspid valve surgery, which involves another heart valve, has been linked to higher death rates after surgery. A mechanical or bioprosthetic valve can replace the mitral valve, however a biological valve is better to reduce the risk of blood clots.
What else can Loeffler Endocarditis be?
When your doctor is trying to diagnose a heart condition, there are a number of other health problems they might need to consider and rule out. These can include:
- Restrictive cardiomyopathy (a type of heart disease that could be caused by various conditions like amyloidosis or sarcoidosis)
- Diastolic dysfunction due to heart problems as a result of high blood pressure
- Churg-Strauss syndrome (an illness that can cause inflammation of your blood vessels)
- Giant cell myocarditis (an uncommon disorder that causes inflammation of heart muscle tissue)
- Reactions to certain medications that may produce hypersensitivity
- Tropical endomyocardial fibrosis (a rare form of heart disease, typically found in tropical regions).
What to expect with Loeffler Endocarditis
Patients who respond to steroids tend to have a better outlook than those who do not. However, because this disease is very rare, there isn’t enough clear information about the long-term health hazards and the risk of death associated with it.
Possible Complications When Diagnosed with Loeffler Endocarditis
Possible complications may involve:
- Restrictive cardiomyopathy: A type of heart disease where the heart chambers are unable to properly expand and fill with blood.
- Congestive heart failure: A condition where your heart can’t pump enough blood to meet your body’s needs.
- Ventricular apical mural thrombosis: A blood clot in the lower chambers of the heart.
- Systemic and coronary embolism: An obstruction in a blood vessel causing issues like stroke, heart attack, or kidney damage.
- Splenic infarction: A condition where blood flow to the spleen is blocked.
- Mitral valve regurgitation: A condition where the heart’s mitral valve doesn’t close tightly, allowing blood to flow backward in your heart.
- Aortic valve regurgitation or stenosis: Conditions affecting the aortic valve in the heart, making it leaky or constricted.
- Tricuspid valve disease: Dysfunction of the tricuspid heart valve.
Preventing Loeffler Endocarditis
There isn’t enough solid proof on how to best treat this illness. We also need more information about how patients suffering from this illness fare over time and how long they live. As this is a pretty rare disease, it sometimes takes a while before it’s correctly identified. This is because not many doctors have experience diagnosing it. Careful monitoring and adjustments to medication are usually necessary.
Furthermore, the best way for a patient to recover fully is by having a team of different health professionals working together. This team-based approach can give the patient the best chance to improve their health and quality of life.
