Barth syndrome (BTHS) is associated with myocardial disease, frequently left ventricular noncompaction cardiomyopathy, which may necessitate cardiac transplantation or lead to death in some patients. We report a child with BTHS who had an “undulating cardiac phenotype” and ultimately developed decompensated heart failure requiring mechanical circulatory support with a ventricular assist device as a bridge to transplantation. His course was complicated by acute lung injury requiring placement of an in-line oxygenator to maintain end-organ function. Not only was his course complicated by cardiac and respiratory failure but his BTHS associated comorbidities complicated the management of his therapy using mechanical assist device support. He was successfully supported and subsequently was transplanted. Here we discuss the management of a child with BTHS using mechanical circulatory support and describe the use of an in-line oxygenator, Quadrox, with the Berlin Excor device.