GP1bM/VWF:Ag ratio over the perioperative course of infants with congenital heart disease. The intraoperative incidence of aVWS (defined as a ratio ≤0.83) ranged from 10% in the subgroup undergoing surgery without cardiopulmonary bypass to 50% in non-neonates undergoing biventricular corrective procedures. Professional illustration by Somersault18:24.