COVID-19 and the Heart: SARS-CoV-2-Associated Myocardial Infection

February 1, 2021
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Myocardial infection following COVID-19 illness has made headlines. Simon Lee, MD, tackles some commonly asked questions about MIS-C and isolated myocarditis after COVID-19 recovery.

Multisystem inflammatory syndrome in Children (MIS-C) is thought to be more of a post-infectious phenomenon that occurs several weeks after infection and recovery. The main theory being that it is related to an overwhelming inflammatory reaction causing the myocardial injury. There may also be some role of microthrombi, though all of this is being investigated currently.

Isolated myocarditis after COVID-19 is more likely to be related to an acute infection because the concern is that there is direct myocardial infection of the SARS-CoV-2 virus into the myocardium. Our current recommendation is that those who had COVID-19 symptom resolution more than 3 months ago have likely passed the “test of time.” Hypothetically speaking, if a child had been diagnosed with myocarditis at that time, our management would have been physical restriction for 3 months and an exercise stress test challenge to see if they develop symptoms of myocarditis. If the exercise stress test was normal, the child would have been cleared.

Informally speaking, we’ve performed about 40 to 50 cardiac magnetic resonance imaging (MRI) scans on our athlete population, the majority of which were asymptomatic or minimally asymptomatic. Only one athlete had myocarditis, and he presented with cardiac symptoms during his return to play. While this is certainly not a definitive sample size, it at least presents some data on which we can base our recommendations.

As the pandemic continues, we’ll learn more about MIS-C and isolated myocarditis after recovery from COVID-19.