Myocarditis, however, has shown to be more common in the male population than in the female. Multiple studies report a 1:1.3-1.7 female-male ratio of prevalence of myocarditis. In young adults, up to 20% of all cases of sudden death are due to myocarditis. Young males specifically have a higher incidence rate than any other population due to their testosterone levels creating a greater inflammatory response that increases the chance of cardiac pathologies. While males tend to have a higher risk of developing myocarditis, females tend to display more severe signs and symptoms, such as ventricular tachycardia and ventricular fibrillation, but do so at an older age. Among patients with HIV, myocarditis is the most common cardiac pathological finding at autopsy, with a prevalence of 50% or more.Myocarditis is the third most common cause of death among young adults with a cumulative incidence rate globally of 1.5 cases per 100,000 persons annually. Myocarditis accounts for approximately 20% of sudden cardiac death in a variety of populations, including adults under the age of 40, young athletes, United States Air Force recruits, and elite Swedish orienteers. With individuals who develop myocarditis, the first year is difficult as a collection of cases have shown there is a 20% mortality rate. Myocarditis in COVID-19
One notable instance of viral myocarditis is the involvement of the SARS-CoV-2 virus; myocarditis from SARS-CoV-2 is associated with a spectrum of severities from asymptomatic to fulminant, and is a complication in approximately 2-7% of COVID-19 cases.
A similar relationship was found between a left ventricular ejection fraction < 50%, increased mortality, and increased major adverse cardiovascular events.Myocarditis has been reported to be a major cause of sudden cardiac death (SCD) in infants, adolescents, and young adults, but the reported rates show wide variation (1 to 14 percent) among young people depending on differences in SCD definition and classification/ definition of myocarditis post-mortem as well as inhomogeneity in the study populations. And one has also to distinguish between studies about myocarditis in general and fulminant myocarditis. Epidemiology
The exact incidence of myocarditis is unknown since many cases are not associated with any symptoms. However, in series of routine autopsies, 1–9% of all patients had evidence of myocardial inflammation. The prevalence rate of myocarditis is estimated to be about 22 cases per 100,000 persons annually. Fulminant myocarditis, the most severe subtype, has been shown to occur in up to 2.5% of known myocarditis presentations. When looking at different causes of myocarditis, viral infection is the most prevalent, especially in children; however, the prevalence rate of myocarditis is often underestimated since the condition is easily overlooked. Viral myocarditis being an outcome of viral infection depends heavily on genetic host factors and the pathogenicity unique to the virus. If one tests positive for an acute viral infection, clinical developments have discovered that 1-5% of said population may show some form of myocarditis.In regard to the population affected, myocarditis is more common in pregnant women, children, and those who are immunocompromised.