This is because myocarditis can lead to heart failure. When this happens, some people do not receive any warning, including chest discomfort, palpitations, shortness of breath, drowsiness, swelling, and fatigue. And the most serious outcome – sudden cardiac arrest – can occur without any symptoms. Before the pandemic, around 400,000 adults died of sudden cardiac arrest each year in the US. It is unclear how often myocarditis is the cause. Estimates range from a total of 1 percent to 20 percent in young adults.
Even if myocarditis turns out to be a common feature of Covid, we don't know how much it increases the total number of people affected by the condition. The final diagnosis can be made through a biopsy of the heart tissue. However, when people don't show symptoms, they usually don't get tested for myocarditis, which is usually caused by viruses, including influenza. Detecting heart defects leads to decreased cardiac function, according to Clyde Yancy, director of cardiology at Northwestern University's Feinberg School of Medicine and associate editor of JAMA Cardiology. When it comes to cases caused by Covid, he says, "The hope is that they will resolve spontaneously, which in many other circumstances does when a virus has struck the heart."
To find out if this is the case, researchers need to follow people diagnosed with myocarditis to see if they have complications. Baggish, Drezner, and others have formed a national registry to track Covid cases and cardiac effects in N.C.A.A. Athletes to collect this type of data; These efforts could lead to improvements in prevention and screening for myocarditis in college sports. (When the Big Ten announced on September 16 that their soccer teams were playing again, they found that players who tested positive for the virus would have to undergo a "comprehensive heart test".) And Eike Nagel, a senior one Author of July According to the JAMA study and director of the Institute for Experimental and Translational Cardiovascular Imaging at the University Hospital Frankfurt, the group will examine the study patients for several years. Even if the observed abnormalities only marginally increase a person's risk of heart failure, that result could predict a significant cumulative public health impact, according to Nagel: "At the population level, I would think we'd see an increased incidence of heart failure in a few years . But we don't have any data. "
It is also possible that the fear of getting Covid, moving around after recovery, is doing its own widespread harm. In July, Italian researchers, in a letter to the New England Journal of Medicine, reported a 60 percent increase in out-of-hospital cardiac deaths year over year in four provinces affected by coronavirus outbreaks. However, it is impossible to tell whether this change was due to Covid infection or whether people are not receiving medical care because they fear getting infected with the virus (or whether both – or other – factors played a role).