Alveolar de recruitment is a common problem during general anesthesia and operations. Pediatric cardiac surgery with cardiopulmonary Bypass is associated with interruption of ventilation and might enhance loss of Ventilation compared to other surgical procedures. Electrical impedance tomography (EIT) allows for monitoring of ventilation distribution and can be helpful in detecting pulmonary de recruitment. This case series demonstrates for the first time that EIT is feasible during open heart surgery and in patients with open chest on the ICU using adapted belts in pediatric patients. It might be helpful to monitor changes in tidal volume distribution, to detect loss of Ventilation during surgery and to guide recruitment maneuvers.