We thank Dr Das for his interest in our case series published in CHEST (May 2010).1 In his letter, Dr Das emphasizes some of the key clinical data presented in Table 1 of our report on six patients with both pandemic 2009 influenza A(H1N1) (A[H1N1]) and cardiac dysfunction. We agree that other conditions, including but not limited to sepsis, multiple organ dysfunction syndrome, and peripartum cardiomyopathy, may have contributed to the cardiac dysfunction observed in our case series. Limited by the nature of a small case series, we were careful not to assign a causal relationship to the observed association between A(H1N1) and cardiac dysfunction. Regarding Dr Das’s proposal of right-sided heart dysfunction contributing to left-sided heart dysfunction, transthoracic echocardiographic assessment of right-sided heart function was normal in all of our cases except the patient in case 6, who had moderate right ventricular dysfunction. We agree that in hospitalized patients it is difficult to distinguish whether cardiac dysfunction is attributable to direct virally mediated myocarditis, systemic inflammatory response, or other comorbidities. However, we believe it prudent for clinicians to be aware of a high prevalence of cardiomyopathy associated with A(H1N1) in hospitalized patients.