A case of postcardiotomy cardiogenic shock after repair of a congenital ventricular septal defect in a 5-year-old boy is reported. Mechanical circulatory support, instituted with a centrifugal left ventricular assist device, adequately supported the patient for 50 hours until recovery of native left ventricular function occurred. Transesophageal echocardiography proved to be useful in assessment of left ventricular function, allowing for timely institution and withdrawal of mechanical circulatory support.