The new coronavirus disease outbreak in 2019 (COVID-19) represents a dramatic challenge for healthcare systems worldwide. As to viral tropism, lungs are not the only COVID-19 target but also the heart may be involved in a not negligible percentage of the infected patients. Myocarditis-related cardiac dysfunction and potentially life-threatening arrhythmias are the main aftermaths. A few studies showed that myocardial injury in adult patients is often linked with a fatal outcome. Conversely, scientific evidence in children is sparse, although several reports were published with the description of a cardiac involvement in COVID-19 paediatric patients. In these young subjects, a background of surgically treated congenital heart disease seems to be a predisposing factor. Conclusion: This systematic review is aimed at summarizing all COVID-19 cases with a cardiac involvement published in paediatric age and trying to explain the underlying mechanisms responsible for COVID-19-related myocardial damage. What is Known: • Coronaviruses proved to be able to jump from animals to humans. • The outbreak of COVID-19 started from China (Dec 2019) and became pandemic. What is New: • Even in childhood, COVID-19 is not without the risk of cardiac involvement. • Myocarditis, heart failure, and arrhythmias are among the possible manifestations.

In preterm infants, failure or delay in spontaneous closure of Ductus Arteriosus (DA), resulting in the condition of Patent Ductus Arteriosus (PDA), represents a significant issue. A prolonged situation of PDA can be associated with several short- and long-term complications. Despite years of researches and clinical experience on PDA management, unresolved questions about the treatment and heterogeneity of clinical practices in different centers still remain, in particular regarding timing and modality of intervention. Nowadays, the most reasonable strategy seems to be reserving the treatment only to hemodynamically significant PDA. The first-line therapy is medical, and ibuprofen, related to several side effects especially in terms of nephrotoxicity, is the drug of choice. Administration of oral or intravenous paracetamol (acetaminophen) recently gained attention, appearing effective as traditional nonsteroidal anti-inflammatory drugs (NSAIDs) in PDA closure, with lower toxicity. The results of the studies analyzed in this review mostly support paracetamol efficacy in ductal closure, with inconstant low and transient elevation of liver enzymes as reported side effect. However, more studies are needed to confirm if this therapy shows a real safety profile and to evaluate its long-term outcomes, before considering paracetamol as first-choice drug in PDA treatment.

The alarming onset of some cases of myocarditis and pericarditis following the administration of Pfizer–BioNTech and Moderna COVID-19 mRNA-based vaccines in adolescent males has recently been highlighted. All occurred after the second dose of the vaccine. Fortunately, none of patients were critically ill and each was discharged home. Owing to the possible link between these cases and vaccine administration, the US and European health regulators decided to continue to investigate the potential causal relationship between COVID-19 mRNA vaccines and myocarditis. In any case, none of the patients fulfilled the criteria for multi-system inflammatory syndrome or Kawasaki-like disease and there was no evidence of acute SARS-CoV-2 infection.

Supraventricular tachycardia (SVT), being atrioventricular re-entry the underlying mechanism, is the most frequent tachyarrhythmia requiring a medical treatment in infants with no cardiac disease. The acute treatment of a single episode of SVT has generally an excellent prognosis. An antiarrhythmic prophylaxis of SVT recurrences is usually recommended during the first year of life. Although many efficient drugs are available for the SVT treatment, a careful risk-benefit analysis of each single case should suggest the correct drug choice.