Overview
Influenza infection can be associated with cardiac complications, including myocarditis and arrhythmias 36. These complications can range from temporary conduction disorders to more severe cardiac injury 36.Diagnosis
Cardiac troponin (cTn) elevation is a potential indicator of cardiac injury in influenza patients, though it is a relatively rare phenomenon (0-33% frequency) 6.
cTn elevation is more likely in elderly patients with comorbidities and in those with complicated influenza, acute respiratory distress syndrome, cardiac dysfunction, or higher risk of death 6.
cTn measurement is recommended for patients developing acute cardiovascular symptoms during influenza infection 6.Management
Baloxavir marboxil has been shown to reduce influenza virus transmission to household contacts 1.
Higher doses of oseltamivir (triple dose, 450 mg/day) did not significantly improve virological or clinical outcomes compared to double doses in severe influenza patients requiring mechanical ventilation 2.
Oseltamivir use has been associated with bradycardia and QT segment changes 3.Special Populations
Influenza-associated arrhythmias have been reported in adults, neonates, and fetuses of pregnant women 3.Key Recommendations
Influenza vaccination is associated with a lower risk of myocardial infarction, transient ischemic attack, cardiac arrest, stroke, and mortality 4. Influenza vaccination has also been found to be protective from cardiac arrhythmia 3. (Evidence: Strong)
Consider measuring cardiac troponins in all patients developing acute cardiovascular symptoms during influenza virus infection 6. (Evidence: Moderate)
Baloxavir treatment may reduce influenza virus transmission from index patients to household contacts 1. (Evidence: Moderate)References
1 Monto AS, Kuhlbusch K, Bernasconi C, Cao B, Cohen HA, Graham E et al.. Efficacy of Baloxavir Treatment in Preventing Transmission of Influenza. The New England journal of medicine 2025. link
2 Wong WT, Choi G, Wang X, Wu WKK, Lin G, Chan MCW et al.. Pharmacodynamic Effect of Different Dosage Regimes of Oseltamivir in Severe Influenza Patients Requiring Mechanical Ventilation: A Multicentre Randomised Controlled Trial. Influenza and other respiratory viruses 2025. link
3 Alam MM, Paul T, Aggarwal A, Zarich S. Influenza associated cardiac arrhythmia- a systematic review. The American journal of the medical sciences 2024. link
4 Ngwudike CJ, Villalobos A. Correlation Between Cardiovascular Protection and Influenza Vaccination. Current cardiology reports 2023. link
5 Behrouzi B, Bhatt DL, Cannon CP, Vardeny O, Lee DS, Solomon SD et al.. Association of Influenza Vaccination With Cardiovascular Risk: A Meta-analysis. JAMA network open 2022. link
6 Lippi G, Sanchis-Gomar F. Cardiac troponin elevation in patients with influenza virus infections. Biomedical journal 2021. link