Clinical assessment of diastolic retrograde flow in the descending aorta for high-flow systemic-to-pulmonary artery shunting.

OBJECTIVE: To investigate whether echocardiographic characteristics in the descending aorta of patients with cyanotic congenital heart disease who have received a systemic-to-pulmonary artery (SP) shunt can indicate shunt flow volume and predict postoperative adverse events related to high-flow shunting. METHODS: Among the 73 consecutive patients who received an SP shunt between 2010 and 2014, data for 53 patients who underwent postoperative Doppler echocardiographic assessment of diastolic retrograde flow in the descending aorta (dAo-RF) were reviewed retrospectively. RESULTS: The mean dAo-RF ratio was 0.50 ± 0.15 at intensive care unit admission and reached its peak level (0.56 ± 0.12) at 24 hours after surgery. All of the patients with a maximal dAo-RF ratio of ≥0.80 had experienced acute heart failure or cardiogenic shock due to postoperative high-flow shunting and required emergent surgical interventions to reduce pulmonary blood flow. Pulse oximetry-measured oxygen saturation and serum lactate level were significantly correlated with dAo-RF ratio, but they had some clinical dispersion to match the postoperative adverse events. CONCLUSIONS: The dAo-RF ratio is a simple, repeatable, and noninvasive index for postoperative assessment of SP shunt flow volume. A high dAo-RF ratio is a significant predictor of postoperative adverse events of high-flow shunting.