Extracorporeal membrane oxygenation (ECMO) is the primary mechanical circulatory support for pediatric patients with severe acute cardiac and/or pulmonary failure. However, in a failing heart, initiation of ECMO may increase OeÑ– ventricular volume, pressure and wall stress, and may even result in myocardial ischemia. Atrial decompression may therefore be eوٴectLve in reducing OeÑ– ventricular wall stress, reducing OeÑ– ventricular fiOOLnJ pressures and improving coronary perfusion. ÐLs may increase the probability of OeÑ– ventricular functional recovery. /eÑ– atrial decompression of patients on ECMO has been shown to be both an eوٴectLve and safe procedure. However, the pediatric experience reported in the literature consists mainly of postoperative congenital heart disease (CHD) patients and cardiomyopathies. Scarce reports exist about non-CHD neonates on ECMO. We present a neonate with acute fulminant enteroviral myocarditis with severe pulmonary edema upon ECMO initiation.