MYKKE is a prospective multi-center registry for children and adolescents with myocarditis. The aim is to generate prospective multi-center data on epidemiology, diagnostics, and therapy of pediatric patients with myocarditis in order to enable evidence-based diagnostic and therapeutic approaches for this myocardial disease.

MYKKE is a long-term prospective registry providing a core platform for clinical research studies, which can be attached in a modular fashion. After a six-month pilot phase including 8 centers, the basic registry was opened in June 2014 to all hospitals in Germany treating patients with paediatric heart disease. While the scientific lead is with two study coordinators and a study group consisting of principal investigators from the collaborating centres ("MYKKE Investigators"), MYKKE is hosted and technically administered by the Competence Network for Congenital Heart Defects, which was initiated in 2003 by the Federal Ministry of Education and Research of the German government and is now part of the German Center for Cardiovascular Research (DZHK). Ethical approval was first obtained at the initiating centre (Deutsches Herzzentrum Berlin) and subsequently confirmed by local authorities of all collaborating centres.

The treating physicians enter basic data from patients enrolled at the study site via an online web interface to a central study database. For each patient, a specific patient identification number (PID) is generated based on name, first name and date of birth in order to store data in a pseudonymized fashion. As the PIDs are generated by a specific algorithm, data from the same patient are always linked to the same dataset even when data from different visits are entered by different institutions.

The web interface provides two different forms for each patient. The first form ("general sheet") is filled-in only at first presentation and consists of 12 items regarding disease and patient history, and initial symptoms of the disease. The second type of sheet ("current visit") can be generated once for each new patient visit and includes 52 items on characteristics of the current visit, current symptoms, diagnostic tests performed, confidence of the treating physician in the diagnosis on a subjective scale, left-ventricular function, therapy, complications, and follow-up care provider after discharge. Items primarily require yes/no responses via ticking respective boxes, allowing for completing each data sheet in <5 minutes when all data are available.

Inclusion Criteria:

• Admission or referral diagnosis of myocarditis
• Age <18 years
• Written informed consent of the parents or legal guardians

Exclusion Criteria:

• Unwillingness to give consent

Patients admitted to pediatric heart centers or pediatric cardiology departments