Atrial natriuretic peptide: could it be a marker for postoperative recurrent effusions after Fontan circulation in complex congenital heart defects?

Fontan operation and its modifications are used for the physiological correction of complex congenital heart malformations with functionally single ventricle. Atrial natriuretic peptide (ANP), a physiological diuretic and vasodilator that--together with the effects of cardiopulmonary bypass--plays an important role in the augmentation of capillary permeability in Fontan patients. The rise in right atrial pressure and wall stress is an important stimulus for the release of ANP. ANP levels were measured before and early after surgery in Fontan group (n = 20) and control group (n = 20, patients with simple cardiac defects) to study its influence on and association with mean right atrial pressure, pulmonary vascular resistance (PVR), systemic vascular resistance, amount of drainage during early and late postoperative period, duration of intensive care unit and hospital stay, and need for colloid supplement. Early postoperative ANP values showed a negative correlation with PVR (r = -0.55) and total drainage (r = -0.88). There was no significant change in ANP during surgery or in the postoperative period in control patients. Reduction of PVR and maintenance of efficient urine output are important in the management of Fontan circulation. We conclude that high levels of ANP measured early after Fontan operation can be used as a marker for the successful establishment of Fontan circulation in patients with complex congenital heart defects.