Intravenous IgG: Supertherapy for Myocarditis and Acute Dilated Cardiomyopathy

To the Editor: We read with great interest the article by McNamara et al1 on intravenous immunoglobulin (IgG) therapy for myocarditis and acute dilated cardiomyopathy (DCM). There is as yet no general agreement of effective treatment of myocarditis and acute DCM. These workers are to be congratulated for conducting a well-designed clinical study of adult patients with NYHA class III to IV heart failure, based on previously published clinical2 and experimental3 experience. We would like to stress 3 points that we consider crucial in our understanding of the significance of this treatment.The first is related to the presence of preceding or associated infectious manifestations (ie, fever, pleurodynia, myalgia, and upper respiratory tract symptoms). This strongly suggests that myocarditis is …