Cardiac Sarcoidosis Review

Lisa Landis, RN

Cardiac Sarcoidosis

To understand what Cardiac Sarcoidosis (CS) is, let's first explain Sarcoidosis. Sarcoidosis is an autoimmune disease that causes a collection of immune cells (granulomas) to form in one or many organs which can possibly change the structure or function of the affected organ. Although Sarcoidosis most commonly affects the lungs and lymph glands, this article will focus interest on the heart.

As with Sarcoidosis, Cardiac Sarcoidosis (CS) does not have a definitive cause. It is thought that exposure to pesticides or other environmental chemicals, certain bacteria or viruses, and perhaps mold can be risk factors for acquiring CS. Of note, "Only 40-50% of patients with cardiac sarcoidosis diagnosed at autopsy have the diagnosis made during their lifetime.”^(PubMed) CS is often underdiagnosed partly because of the manifestations it presents. Heart conditions including complete heart block and ventricular tachycardia, cardiomyopathy, and heart failure are treated regardless of not knowing the specific underlying cause. Clinician awareness and newer technology are making CS easier to diagnose, yet still hard to differentiate from other heart diseases like heart failure because they share many of the same symptoms.

Who is Most at Risk for CS?

CS can affect all ethnicities and is not age-specific. As noted in an article featuring Dr. Nisha Gilotra, a Cardiac Sarcoidosis Expert at John Hopkins, CS is more common in those of African American and Northern European descent between ages 20-60 years of age.

What are the Signs & Symptoms of CS?

A patient with Cardiac Sarcoidosis may not have any symptoms but have an abnormal imaging scan. Others might report palpitations, chest pain, dizziness, fainting, shortness of breath, and/or leg swelling. Palpitations are often described as fluttering, racing, or skipping heartbeats and are caused by an arrhythmia in CS. Decreased blood flow through the heart vessels may cause chest pain. The lack of blood flow to the brain can induce dizziness or fainting (syncope). The heart's compromised ability to pump because of the presence of granulomas can increase fluid retention in the body causing shortness of breath and leg swelling in addition to arrhythmias.

How is CS Diagnosed?

Several diagnostic tests may be ordered by the Provider if CS is suspected. The endomyocardial biopsy is more specific in confirming the diagnosis; however, other imaging has been accepted as surrogate testing. The following is a list of testing that may be performed:

ECG to confirm arrhythmias like ventricular tachycardia or heart block
Event monitor to quantify the arrhythmic burden
Echocardiogram to assess the heart structure and function
MRI to provide a more accurate assessment of the heart structure and function
PET scan to confirm presence of abnormal tissues (granulomas/tumors)
Right Heart Cath is used as the pathway to obtain heart tissue (biopsy)
Biopsy sample is taken from the endo myocardium to confirm Sarcoidosis

Treatment Options

According to the Mayo Clinic, there is no cure for Sarcoidosis and most people are treated modestly or not at all. Sarcoidosis has been known to go away on its own; however, long-term effects of Sarcoidosis involving damage to the heart will need lifelong treatment. Early detection and treatment are imperative in yielding more favorable outcomes. The following treatments are most used:

Immunosuppressive medications (I.e., corticosteroids) which may reduce the production of granulomas
Pacemaker or ICD may be implanted to help manage the arrhythmia
Ablation can be performed by an Electrophysiologist to cauterize and create scar tissue areas of the heart in attempts to correct the arrhythmia
Heart Transplant may be performed in some cases

Conclusion

Sarcoidosis is a potentially life-threatening inflammatory disease of unknown etiology and affects multiple organs including the heart. Cardiac Sarcoidosis is organ-specific and often under-diagnosed as it is hard to differentiate from other heart diseases due to similar symptoms. Through early detection, advanced technology, and Provider awareness, patients have better outcomes.

References/Resources

Cardiac sarcoidosis: a comprehensive review - PubMed (nih.gov)

Cardiac Sarcoidosis | Johns Hopkins Medicine

Sarcoidosis - Symptoms and causes - Mayo Clinic

Infographic: Cardiac sarcoidosis: A heart under attack (mayoclinic.org)