Serial Doppler Assessment of Diastolic Function before and after the Fontan Operation

Serial Doppler echocardiography was used to evaluate the effects of the Fontan operation (FO) on diastolic ventricular function in 55 patients with univentricular heart. Examinations were performed before operation, before postoperative discharge, and 6 months to 6 years postoperatively. Preoperatively, early diastolic atrioventricular valve (E) flow was reduced and deceleration times prolonged relative to healthy children. All pulmonary vein diastolic flow variables, except diastolic velocity, were increased relative to control subjects. After FO, E/atrial velocity and E/atrial time velocity integral ratios were decreased whereas deceleration and isovolumic relaxation time remained constant. Diastolic pulmonary vein forward flow increased after FO. These data suggest inherently abnormal ventricular relaxation in the univentricular heart and that changes in flow patterns observed postoperatively were subtle and likely a result of reduced ventricular preload after FO. Overall, diastolic function most probably remained stable after FO. This information can be used as a benchmark for further diastolic function assessment in patients with surgically palliated univentricular heart.