Objective Nowdays,infants with low age,low weight and complicated symptoms are appropriate candidates for cardiac surgery of congenital heart disease.However,surgical strike and multiorgan immaturity have already increased the difficulty of postoperative care.With invasive assessments,we can just assess the real-time condition.But noninvasive assess ment has been proved the positive correlations between the assessment and postoperative outcomes.Therefore,surgeons and intensivists modify treatment in insidious onset,prevent the exacerbation and improve the long-term survival rate.