Aimee Gardner

Implantation of the HeartMate II and HeartWare left ventricular assist devices in patients with duchenne muscular dystrophy: lessons learned from the first applications.

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder affecting 1 in 3,500 males, characterized by progressive skeletal muscle weakness and death secondary to cardiac or respiratory failure in the 2nd or 3rd decade. Being a progressive disease, patients are rarely candidates for cardiac transplantation and death from dilated cardiomyopathy (DCM) is common. Implantation of left ventricular assist device (LVAD) offers the potential to alter clinical trajectory by alleviating heart failure symptoms. We report implantation of HeartMate II device in a 29-year-old male patient and HeartWare device in a 23-year-old female patient, each with DMD and end-stage DCM. By improving cardiac output, we were able to achieve resolution of the symptoms of heart failure and improve their quality of life. Preoperative planning and patient selection played a significant role in the postoperative course for these patients. These cases represent the first use for each device in this patient population and the first reported LVAD implantations in patients with DMD in North America.

Left Ventricular Noncompaction Cardiomyopathy in Barth Syndrome: An Example of an Undulating Cardiac Phenotype Necessitating Mechanical Circulatory Support as a Bridge to Transplantation

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.

Cardiopulmonary bypass in the immature fetus through novel use of a mini-centrifugal pump

The concept that the natural history of certain heart defects could be positively modified through in utero intervention has stimulated extensive research in fetal cardiac intervention and surgery since the early 1980s. Since the management of certain defects would require the use of cardiopulmonary support, extensive studies have been directed toward the application of a variety of perfusion circuits. The unique features of the fetal patient have directed the focus of many of these designs toward miniaturization of components and minimization of prime volume. Large extracorporeal surface contact areas and prime volumes have been identified as potential contributors to a frequently observed placental dysfunction following fetal cardiopulmonary bypass (CPB). We set out to develop means of CPB using a centrifugal micro-system that would not require supplemental prime volume. We describe the unique application of an adult right heart assist device, primarily used for ‘off-pump’ coronary revascularization for fetal cardiopulmonary support. Finally, while previous fetal experiments have used late-gestation mature fetuses, we studied more immature fetuses of mid-gestation, relevant to current clinical attempts in fetal therapy.