Myocarditis and Sports in the Young: Data from a Nationwide Registry on Myocarditis—MYKKE-Sport

Background: Myocarditis affects primarily young adults and children. It is the most common cause of sudden cardiac death (SCD) in this cohort. In animal models, myocardial involvement during viral infections has been shown to be higher with intensive exertion. The current recommendations for returning to sports after myocarditis are based on cohort and case studies. Often, the restrictions chosen by the medical community are arbitrary and not based on these recommendations and thus lead to poor compliance with serious consequences if not adhered to.

Method: This study is a subproject of the MYKKE registry, a German multicenter registry for children with suspected myocarditis. The observation period for this analysis was 84 months (June 2014 to June 2021). Every patient fulfilling the criteria of myocarditis (biopsy proven, positive cardiac biomarker or ECG abnormality) was sent a questionnaire regarding physical activity before, during and after the onset of myocarditis. Furthermore, the current recommendations for return to sport were included. History, cardiac MRI, echocardiography, biopsy, and laboratory records from every patient were retrieved from the MYKKE registry database.

Results: Fifty-eight patients (average age: 14.6 years) from nine centers participated (65.5% male). Most subjects (84.5%) participated in curricular physical activity, 36% in competitive sports prior to the onset of myocarditis. There was no difference of heart function between the physically active and inactive subjects. Most participants (60.3%) observed symptoms of an infectious disease in the two weeks leading to the myocarditis. Continuing with physical activity despite these symptoms did not lead to a worse outcome. The recommendations regarding the return to sports varied widely and followed current guidelines in merely 45%. Most patients (84.5%) did not receive the recommended exercise test before returning to sports.

Conclusion: Physical activity before and after the onset of myocarditis was not associated with a more severe outcome. There is still a discrepancy between current guidelines and the actual recommendations provided by health care providers. Especially the fact that only a minority of patients received the recommended exercise test before returning to sport is noteworthy, given the fact that malignant arrhythmias must be ruled out.

Publication History

Article published online:
28 January 2023