Parvovirus B19 myocarditis in children: a diagnostic and therapeutic approach.
Parvovirus B19 is one of the most frequent causes of pediatric myocarditis, associating high mortality rates or need for cardiac transplantation. The aim of this study is to describe the clinical course of Parvovirus B19 myocarditis in children with emphasis on the role of endomyocardial biopsy and cardiac magnetic resonance, and the use of an innovative therapeutic strategy. Eleven patients and 12 episodes of polymerase chain reaction (PCR)-confirmed Parvovirus B19 myocarditis were prospectively collected for 14 years. Diagnosis was confirmed either histopathologically or by magnetic resonance. A life-threatening clinical presentation is described, similar to previous series, but with 83.3% overall survival without transplantation. We also present a case of recurrent myocarditis, which is extraordinarily rare. Electrocardiographic patterns presented chiefly peaked p waves, low QRS voltages, and negative T waves on inferior or lateral leads. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance could be a useful diagnostic tool. A good concordance between myocardial and blood PCRs was observed. Seven patients received treatment with corticosteroids and beta interferon and all underwent a significant cardiac function improvement.


CONCLUSION
A severe clinical presentation is reported, similar to previous reports but with better outcomes. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance may be used. Both blood and myocardium PCR can be used in children to establish the microbiological etiology. Steroids with IFNß could be a useful therapeutic option, although further multicenter studies are needed to confirm these results.


WHAT IS KNOWN
• Parvovirus B19 is one of the most frequent causes of myocarditis in children. It is associated with a fulminant clinical presentation. • Endomyocardial biopsy is the gold standard diagnostic test but it is an invasive procedure.


WHAT IS NEW
• Myocarditis may recur in pediatrics, even it is extraordinarily rare. • IFNβ with steroids may be a useful therapeutic option to improve the outcomes.