Prolonged left ventricular mechanical support in a seven-year-old patient following extensive myocardial infarction enabling myocardial recovery

Background: Mechanical circulatory assistance may help patients with acute failing ventricles enabling a recovery, bridge to heart transplantation or ultimately as a destination therapy. Myocardial infarction in children is a very rare etiology with extremely high early mortality.

Introduction: We report on a seven-year-old girl familial hypercholesterolemia with combined heterozygous LDL-receptor mutation who was transferred to our institution two weeks after acute severe myocardial infarction due to left main coronary dissection during coronary angiography. The patient was initially treated by surgical coronary revascularization and the implantation of an extracorporeal membrane oxygenation (ECMO) with two unsuccessful weaning attempts. Initial echocardiography showed massively dilated left ventricle with severely impaired inhomogeneous systolic function with septal disaggregation. ECMO treatment was continued for three weeks until no recovery seemed to be possible. We decided for the implantation of a left ventricular assist device (Berlin Heart Excor LVAD, Berlin, Germany) with the aim of bridge to a heart or combined heart liver transplantation. She was listed for heart transplantation because there was no objective recovery of the left ventricular function in serial transthoracic echocardiograms using pump flow reduction. Periodic treatment with lipid apheresis was performed due to extremely high blood lipid levels. After prolonged left ventricular support left ventricular function began to improve steadily and she could be weaned from the mechanical assistance following diagnostic cardiac catheterization after nine weeks of continuous support. The patient was discharged to a rehabilitation center 8 weeks after cessation of mehanical circulatory support.

Discussion: Myocardial infarction in the pediatric population has mostly a dismal prognosis leading to death within days. Mechanical unloading of the failing heart may enable recovery even after a prolonged period of mechanical circulatory support. Serial echocardiographic evaluations using reduction of mechanical assistance are necessary in decision making about the time point of possible weaning.