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Viral myocarditis
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The myocardium is the heart muscle, the thick layer that contracts with every beat. Myocarditis is inflammation of that muscle. In the United States and other developed countries, the most common cause is viral infection.
The damage comes twice: first the virus, then the body's defenses. In the first hit the infectious agent invades the myocardium and replicates inside or around it, and that produces myonecrosis, the death of the muscle fibers. In the second hit the body's own immune system steps in: the cellular response switches on and attacks with its cytotoxic effects, meaning toxic to cells.
In North America and Europe the viruses found most often are parvovirus B-19 and human herpesvirus 6. And the puzzling thing about viral myocarditis is how much it varies: some people feel nothing more than fatigue, and others end up with heart failure, with arrhythmias, which are disordered heartbeats, or with cardiogenic shock, when the heart no longer pumps enough blood to the body.
In brief
Myocarditis is inflammation of the heart muscle; in the United States and other developed countries, viral infections are the most common cause.
It begins with direct invasion by the agent and its replication in the myocardium, with myonecrosis; the host immune response then adds its own cytotoxic effects.
The damage comes twice: first the virus, then the body's defenses.
In North America and Europe the viruses most often implicated are parvovirus B-19 and human herpesvirus 6; the picture ranges from fatigue to heart failure, arrhythmias and cardiogenic shock.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingViral Myocarditis, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated