In our small study, postoperative cardiac index over time was similar in patients with prophylactically administered levosimendan and patients with prophylactically given milrinone. We observed an increase in cardiac output and cardiac index over time in the levosimendan group, whereas cardiac output and cardiac index remained stable in the milrinone group. This pilot study has primarily served to obtain experience using the new drug levosimendan in neonates and infants and to initiate further multicenter trials in pediatric patients.

Heparin-induced thrombocytopenia (HIT) represents a major challenge in patients following the fenestrated Fontan procedure. These patients are prone to thrombosis within the Fontan tunnel due to the low blood flow velocity. The communication between the Fontan tunnel and the common atrium may enable systemic embolization and can cause a stroke. Effective ongoing anticoagulation is necessary. Given the high risk of arterial and venous thrombosis with HIT, alternate anticoagulation management is essential as soon as HIT is suspected. We are reporting on two patients who developed HIT antibodies and thrombocytopenia after exposure to heparin during a Fontan procedure. Both the PF4 enzyme-linked immunosorbent assay (LIFECODES ® PF4 IgG assay) and the heparin-induced platelet aggregation test (HIPA, Institut für Immunologie und Transfusionsmedizin, Greifswald, Germany) were positive. The children were treated with argatroban (Argatra ® , Mitsubishi Pharma), a direct thrombin inhibitor. In only one patient was HIT associated with thrombosis within the Fontan tunnel.