The cardiovascular manifestations of influenza: a systematic review.

Influenza accounts for 3 to 5 million cases of severe illness and up to 300,000 deaths annually, presenting a considerable burden to healthcare services. A spectrum of cardiovascular complications has been reported in association with influenza infection. This can occur through direct effects of the virus on the myocardium or through exacerbation of existing cardiovascular disease. Direct myocardial involvement presenting as myocarditis is not uncommon during influenza infection. Clinical presentation may vary from asymptomatic to fulminant myocarditis resulting in cardiogenic shock and death. Cardiovascular mortality is also increased during influenza epidemics in patients with pre-existing coronary artery disease. Rates of myocardial infarction have been shown to increase following influenza outbreaks, whilst decreases in cardiovascular mortality have been demonstrated following influenza vaccination in high risk patients. The purpose of this review is to provide an overview of cardiovascular complications, their presentation, clinical course and the management options available following influenza infection.