Introduction
Sarcoidosis is a disease where there is the growth of tiny collections of inflammatory cells in any part of the body and is mostly found in the lungs and lymph nodes and sometimes it can also affect the eyes, heart, skin, and other organs. The exact cause of sarcoidosis is not known but it could be due to the body's immune system that responds to an unknown substance. In genetically disposed individuals, the formation of granulomas could be due to chemicals, infectious agents, chemicals, and abnormal reactions to the body’s own protein. Sarcoidosis cannot be cured, but individuals do well with no treatment or only modest treatment. Sarcoidosis will go away on its own in some cases, but mostly, it may last forever and cause organ damage.
What Is Cardiac Sarcoidosis?
Sarcoidosis is an inflammatory condition where multiple organs are affected. In cardiac sarcoidosis, there can be interference with the normal functioning of the heart when tiny collections of immune cells form granulomas in the heart tissue. This, in turn, leads to heart rhythm abnormalities, also called arrhythmias, such as heart block or ventricular tachycardia, and can also lead to heart failure or cardiomyopathy.
How Common Is Cardiac Sarcoidosis?
Cardiac sarcoidosis is diagnosed in 2% to 5% of individuals with sarcoidosis elsewhere in their bodies. It is estimated that 20% to 30% of Americans with sarcoidosis might have the condition present in the heart. Cardiac sarcoidosis is more common in Japan as more than half of the individuals have their condition present in their heart. However, cardiac sarcoidosis is less common than sarcoidosis in other organs.
What Are the Symptoms of Cardiac Sarcoidosis?
The symptoms of cardiac sarcoidosis may be:
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Shortness of breath.
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Chest pain.
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Fainting.
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Coughing.
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Tiredness.
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Swelling in the legs.
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A tight feeling in the chest.
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Abnormal heartbeats that give heart palpitations.
How Is Cardiac Sarcoidosis Diagnosed?
The healthcare provider will examine the patient physically, discuss the medical history, and prescribe tests to check for abnormal heart rhythms. If sarcoidosis is present in other parts of the body, it is checked and confirmed if the signs of it are present in the heart. Tests to confirm the diagnosis of cardiac sarcoidosis are:
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Electrocardiogram: This will help identify the rhythm abnormalities, and when the patient presents only symptoms of palpitations, ambulatory rhythm monitoring will help identify the transient AV blocks and non-sustained VT.
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Echocardiogram or Echocardiography: Echocardiography will not show sensitive findings specific to coronary sarcoidosis. Basal septum thinning can be seen, regional wall abnormalities that are not often in coronary distribution, left ventricular dilation with or without aneurysm, and left ventricular systolic dysfunction.
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Holter monitor
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Positron Emission Tomography Scan: This test can add valuable information, such as evidence of active inflammation and extracardiac involvement, to diagnose coronary sarcoidosis.
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Cardiac Magnetic Resonance Imaging: To diagnose coronary sarcoidosis, it is a first-line imaging study with a high negative predictive value.
The healthcare provider uses biopsies to diagnose sarcoidosis in other parts of the body. Still, biopsies are not used in the heart as it is hard to get the sample tissue from where the problem occurs. The cardiac sarcoidosis stage can be properly diagnosed by the healthcare provider with the help of imaging. The severity of the disease can be normal to severe, starting early and progressing to progressive stages. There is a progressive myocardial impairment, followed by scarring in the active stage.
How Is Cardiac Sarcoidosis Treated?
There are several options to treat cardiac sarcoidosis, such as:
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Immunosuppression with corticosteroid medication is taken to reduce inflammation and fibrosis.
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Drugs to keep the immune system from overreacting.
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Medicines that will help to treat irregular heartbeats.
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Implantable cardioverter defibrillator (ICD).
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Catheter ablation to treat abnormal heart.
It can lead to heart failure if the situation is worse, and there might be a need for a heart transplant.
What Medications Are Used to Treat Cardiac Sarcoidosis?
The healthcare providers prescribe High doses of prednisone, which are taken for several months, and then they start taking smaller doses. Early treatment can help to make the symptoms better. Prednisone side-effects are infections, high blood pressure, osteoporosis, elevated blood sugar, mood swings and insomnia.
In 86% of the individuals, ventricular tachycardia can occur in those whose catheter ablation initially worked. After a heart transplant, individuals with cardiac sarcoidosis will have less than 10% chance of getting it.
What Is the Differential Diagnosis for Cardiac Sarcoidosis?
The differential diagnosis of cardiac sarcoidosis is:
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Myocarditis is difficult to distinguish from cardiac sarcoidosis as it has a similar clinical presentation that includes heart failure, ventricular arrhythmias, etc. An endomyocardial biopsy might be needed to distinguish these from sarcoidosis.
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Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) will also have conditions similar to cardiac sarcoidosis, including ventricular arrhythmias.
What Is the Prognosis of Cardiac Sarcoidosis?
There is a poor prognosis of cardiac sarcoidosis compared to other forms of sarcoidosis. It is unclear whether silent cardiac sarcoidosis without cardiac manifestation has a better prognosis than clinically manifest cardiac sarcoidosis.
Conclusion
There is a possibility to develop cardiac sarcoidosis in all ethnicities and ages, but there can be certain things that might put individuals at higher risk. Early diagnosis of cardiac sarcoidosis is challenging, even after the recent advances in imaging modalities. Early institution of corticosteroids can improve survival and is recommended whenever the diagnosis of cardiac sarcoidosis is considered.
