Table of Contents
Influenza Research and Treatment
Volume 2012 (2012), Article ID 351979, 8 pages
Review Article

Myocarditis Associated with Influenza A H1N1pdm2009

1Department of General Internal Medicine, Osaka Medical College, Takatsuki 569-8686, Japan
2Third Department of Internal Medicine, Osaka Medical College, Takatsuki 569-8686, Japan

Received 14 June 2012; Revised 28 October 2012; Accepted 15 November 2012

Academic Editor: Daniel R. Perez

Copyright © 2012 Akira Ukimura et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Acute myocarditis is a well-known complication of influenza infection. The frequency of myocardial involvement in influenza infection varies widely, with the clinical severity ranging from asymptomatic to fulminant varieties. The worst cases can result in death due to impaired cardiac function, although such fulminant myocarditis associated with influenza infection is rare, as shown by previous papers. Following the 2009 influenza pandemic, we reported on the clinical features of a cohort of 15 patients in Japan with H1N1pdm2009 myocarditis. In our subsequent survey of the literature for case reports or series of patients with myocarditis associated with H1N1pdm2009, we identified 58 detailed cases. We discuss here the high prevalence of fulminant myocarditis (36/58, 62%) among patients reported to have myocarditis associated with H1N1pdm2009. Mechanical circulatory support was required in 17 of the patients with fulminant myocarditis, 13 of whom recovered. We stress the need for increased awareness of influenza-associated myocarditis; such knowledge will facilitate earlier diagnosis and treatment of this fatal complication during future influenza pandemics.