Dilated cardiomyopathy following H1N1 infection

Acute myocarditis and dilated cardiomyopathy are known to be common manifestations of several viral infections, presenting with a wide spectrum of symptoms. The exact pathogenesis of influenza virus-induced myocarditis is still unclear. Management involves early detection using echocardiography and cardiac support to tide over acute phase. Following recovery, prognosis is known to be quite good; however, fulminant cases have poor prognosis. A 2-year-old female infant previously diagnosed to have H1N1 bronchopneumonia a year back, who was found to have compromised cardiac function suggestive of dilated cardiomyopathy on follow-up and was started on oral antifailure medications and kept on regular follow-up, presented to the emergency department with symptoms suggestive of severe form of dilated cardiomyopathy and succumbed to illness. The association between influenza viral infection and myocarditis is being linked with host immune response as well as direct cellular damage. Vaccination is being said to be the most cost-effective strategy to prevent this potentially fatal complication. Recent-onset cardiac symptomatology with a preceding history suggestive of influenza infection warrants a high index of suspicion for myocarditis and dilated cardiomyopathy. Early detection and prompt cardiac supportive care and management are paramount and help to reduce morbidity and mortality.