[Treatment of acute low cardiac output syndrome after surgery of congenital heart defects: value of enoximone].

Children undergoing cardiac surgery are at additional risk for postoperative low cardiac output syndrome (LCOS). Anticipation of the syndrome from preoperative hemodynamic condition, surgical procedure, and adverse intraoperative events is a key to successful postoperative management. Inotropic support is primarily based on catecholamines. However, uncoupling of human cardiac beta-adrenoceptors during cardiopulmonary bypass with cardioplegic cardiac arrest may be the reason why many patients respond only weakly to beta-adrenoceptor agonists. Phosphodiesterase (PDE) inhibitors act by reducing intracellular breakdown of cAMP, which is elevated independently from beta-receptors. The use of PDE-inhibitors might be advantageous in patients with uncoupled beta-adrenoceptors, as occurs after cardiopulmonary bypass. In addition, PDE-inhibitors can prevent further downregulation of the adrenoceptors due to avoiding prolonged therapy by beta-agonists. In this context, the addition of enoximone, a PDE-inhibitor, to adrenergic agents has been found useful in increasing cardiac output in children with catecholamine-resistant LCO, as well as in children with compensated hemodynamics during catecholamine therapy.