Understanding Myocarditis, Pericarditis, and Endocarditis

Doctor Tending To Woman

Myocarditis, pericarditis, and endocarditis might sound very similar, but even though all three are types of heart inflammation, they affect different areas of the heart. “They’re all very disparate things,” says Dr. Allan Klein, MD, Director of the Center for the Diagnosis and Treatment of Pericardial Diseases at Cleveland Clinic. “They work very differently.” Here, the Myocarditis Foundation explores the three types of heart inflammation and their key differences.

The Structure of the Heart

To understand the difference between these types of heart inflammation, you must first understand the heart’s structure. A human heart has three layers. Working from the outside inward, the layers are as follows:

  • Pericardium: The outermost layer of the heart, known as the pericardium, is a sac of connective tissue, serous membranes surrounding the heart. It cushions the heart and protects it from friction and enlargement. The pericardium is also where nerves and blood vessels lie that supply and support the heart.
  • Myocardium: According to Klein, this middle layer is “the muscle of the heart.” By expanding and contracting, the myocardium enables the heart to pump blood (systole) and relax and fill the heart (diastole).
  • Endocardium: The innermost layer of the heart is the endocardium. It is a layer of connective tissues and organ lining that coats the inner surfaces of the heart chambers, including several valves.

The main difference between pericarditis, myocarditis, and endocarditis is the layer affected. Pericarditis is inflammation in the pericardium, myocarditis inflames the myocardium, and endocarditis means inflammation in the endocardium.

Causes of Each Condition

The three types of inflammation don’t just differ in their location, as they often have different causes. “Pericarditis is most often caused by a viral illness,” explains Klein. “The same goes for myocarditis.” The virus can be something as simple as a common cold or the flu that migrates to the heart and infects it. An infected outer heart lining (pericardium) is incredibly painful especially with breathing and debilitating, while an infected heart muscle (myocardium) can even weaken the heart.

On the other hand, endocarditis, which affects the inner heart lining and valves, originates differently. Its most common cause is a systemic infection of bacteria, fungi, or other germs that spread through the body using the bloodstream. “The pathogen can seize onto the valves,” says Klein, “where it starts to deteriorate and destroy the tissues.” As valves deteriorate, they can start to leak.

Combating Pericarditis, Myocarditis, and Endocarditis

In cases of pericarditis or myocarditis, an antiviral medication Is not usually used since the viral cause is not known, Meanwhile, an anti-inflammatory medicine will reduce inflammation and pain. Treatment times may vary, as some patients can expect months to years of medication. In some cases, however, the heart is too weakened by myocarditis to fully recover, and the only remaining solution is a heart transplant.

Because endocarditis is caused by a systemic infection (bacteria) rather than a virus, it can be treated with antibiotics. Dentists and doctors use preventative antibiotics whenever there’s a risk that bacteria might enter the bloodstream. Antibiotics are also the most effective treatment available for patients diagnosed with endocarditis. If the infection damages the valves, however, symptoms might persist even after treatment is successful, and surgery might be necessary to repair or replace damaged tissues.

Learn More about Heart Inflammation

Knowing the difference between pericarditis, myocarditis, and endocarditis is vital for planning an effective treatment. That’s why the Myocarditis Foundation researches all types of heart inflammation to increase awareness and uncover new treatment options. To learn more, contact us today.