 Fulminant ( sudden @-@ onset ) myocarditis has been linked to infection with H1N1 , with at least four cases of myocarditis confirmed in patients also infected with A / H1N1 . Three out of the four cases of H1N1 @-@ associated myocarditis were classified as fulminant , and one of the patients died . Also , there appears to be a link between severe A / H1N1 influenza infection and pulmonary embolism . In one report , five out of 14 patients admitted to the intensive care unit with severe A / H1N1 infection were found to have pulmonary emboli . 
