Background The advent of PCR testing for the presence of viral genomes has led to the identification of parvovirus B19 (PVB19) as a causative agent of myocarditis.

Methods The clinical presentation, course and outcome of children with PVB19 myocarditis was ascertained through a retrospective review. The PVB19 viral genome was detected by PCR from whole blood or endomyocardial biopsy specimens in patients presenting with new onset heart failure.

Results Seventeen patients presented at a median age of 1.3 years (range: 0.4–15.4 years) in cardiac failure with a mean fractional shortening of 15±3%. Eleven patients required mechanical ventilation and intravenous inotropes and seven required extra-corporeal mechanical oxygenation. Four of the five deaths occurred in patients who had a short prodromal illness of less than 48 hours. All patients with ST segment elevation died (n=4). All non-fulminant cases survived. Event-free survival occurred in 11/17 (65%) patients. Five (29%) patients died and one patient underwent heart transplantation. Complete recovery of cardiac function occurred within a median of 12 months (range: 1–48) in five patients. There was incomplete recovery in five patients and one patient had persistent dilated cardiomyopathy.

Conclusions PVB19 can cause a devastating myocarditis in children. Children with fulminant myocarditis, ST segment changes or a short prodrome have the worst outcome. Transplantation may be considered, but is rarely required in the acute period if mechanical circulatory support is utilised. If the initial presentation is survived, recovery of the myocardium can occur even in those who had fulminant myocarditis.