Introduction: The frequency of myocarditis cases requiring intensive care has shown an increasing trend in recent years. Among the pathogens, Parvovirus B19 plays a prominent role. Patients require prolonged supportive therapy, sometimes mechanical circulatory support (MCS), or even heart transplantation (htx). The aim of our study is to review patients requiring intensive care due to myocarditis in the past 4 years and to describe the course of the disease.
Patients and methods: 25 patients were treated in our institute between January 1, 2020 and December 31, 2024.  Diagnosis was confirmed by cardiac MRI, biopsy, or both in 18 cases, viral etiology was based on the detection of viral DNA. Baseline echo data, renal and liver function impairment, proBNP were analyzed.  Need for mechanical ventilation and MCS, effectiveness of the pulmonary band in small children/infants and the frequency of htx were also documented.
Results: The median age of patients treated during the above period was 4.5 years (0.2-17.6), the average follow-up time was 1 year. The average proBNP value at admission was 20294 pg/ml, and the average shortening fraction was 22%. 40% of the patients required mechanical ventilation before or just after hospital admission. We detected reduced renal function (GFR≤60 ml/min/1.73 m2) in 5 patients. 3 patients required MCS therapy due to progressive decline on average 12 days after their admission to the hospital.  Chronic myocarditis (defined as no recovery within 6 months) was detected in 1 case. 3 patients required htx for progressive or inotropic dependent heart failure. Pulmonary banding as a bridge-to-recovery therapy was applied in 5 patients, de-banding was successful in 4 cases. 2 patients were lost during follow-up. One of them could be weaned from MCS, but due to a central nervous system embolism in the perioperative period brainstem death occurred. The other patient was lost due to perioperative infection.
Summary: Increasing incidence of myocarditis can be observed. Its course varies widely, but the need for organ replacement therapy is not uncommon. Pulmonary banding can be applied successfully as a bridge therapy in population under 2 years of age. Survival is over 90% even in severe cases.