Fulminant Influenza B Myocarditis in a Pediatric Patient

The Utility of Troponin Dynamics in Influenza Myopericarditis: A Literature Review

Influenza, typically recognized as a respiratory ailment, can manifest severe cardiac complications, notably, myocarditis and pericarditis, with potential fatal outcomes. Interestingly, influenza B demonstrates a reduced occurrence of troponin I elevation despite the risk of cardiac issues, such as isolated pericarditis. Interpreting the absence of troponin elevation as an indication of no cardiac involvement in cases of influenza B-related pericarditis may be contributing to poorer clinical outcomes. This trend may stem from the cellular tropism and unique affinity of certain influenza strains for pericardial cells rather than myocardiocytes. A thorough grasp of troponin dynamics in influenza is pivotal for customizing approaches aimed at improving clinical outcomes in myopericarditis cases.

Influenza Myopericarditis and Pericarditis: A Literature Review

Myopericarditis is a rare complication of influenza infection. The presentation may range from mild and frequently unrecognized, to fulminant and potentially complicated by cardiogenic and/or obstructive shock (tamponade), which is associated with high mortality. We performed a review of literature on all influenza pericarditis and myopericarditis cases according to PRISMA guidelines using the PubMed search engine of the Medline database. Seventy-five cases of influenza myopericarditis and isolated pericarditis were identified from 1951 to 2021. Influenza A was reported twice as often as influenza B; however, influenza type did not correlate with outcome. Men and elderly patients were more likely to have isolated pericarditis, while women and younger patients were more likely to have myopericarditis. All included patients had pericardial effusion, while 36% had tamponade. Tamponade was more common in those with isolated pericarditis (41.2%) than myopericarditis (13.8%). Cardiogenic shock was more common in patients with myopericarditis (64%), with an overall mortality rate of 14.7%. Nearly 88% of the recovered patients remained without long-term complications reported. Conclusion: Influenza A appears a more common cause of pericarditis and myopericarditis. Isolated pericarditis was more commonly associated with tamponade but without reported deaths, whereas myopericarditis was more commonly associated with cardiogenic shock and death (19%).