Modified ultrafiltration improves global left ventricular systolic function after open-heart surgery in infants and children

Objectives: Modified ultrafiltration increases blood pressure and cardiac i ndex following open-heart surgery in children, but it is unclear if this is secondary to an improvement in global left ventricular function. A previou s report has suggested that left ventricular systolic function as assessed in a single chord is improved by ultrafiltration (Davies MJ, Nguyen K, Gayn or JW, Elliott MJ, Modified ultrafiltration improves left ventricular systo lic function in infants after cardiopulmonary bypass. J Thorac Cardiovasc S urg 1998;115:361-370). The prominent vascular actions of modified ultrafilt ration necessitate left ventricular assessment using load-independent indic es of systolic and diastolic function. Methods: In 22 consecutive infants a nd children undergoing open-heart surgery, left ventricular function was as sessed following bypass and then 10 min later. Sixteen children (median wei ght 8.1 kg) underwent modified ultrafiltration during this period, the rema inder (median weight 7.3 kg) were controls for spontaneous recovery without ultrafiltration. Real-time pressure-volume loops, with transient inferior caval vein snaring were generated from conductance and microtip pressure ca theters inserted through the LV apex. From these, load-independent (slope o f the end-systolic pressure-volume [E-es] and end-diastolic pressure-volume [E-ed] relationships) and load-dependent (P-max maximum LV pressure; P-ed, end-diastolic LV pressure; maximum [dP/dt(max)] and minimum [dP/dt(min)] t ime derivatives of LV pressure; tau, time constant of isovolumic relaxation ) indices of left ventricular function were measured. Results: Haemoconcent ration was achieved in all modified ultrafiltration patients, median increa se in haematocrit 34% (interquartile range 21%, 42%), final haematocrit 0.4 0 (0.35, 0.41). E-es increased 58% (9, 159, P = 0.005). The changes in E-ed , P-max, P-ed, dP/dt(max), dP/dt(min), and tau were not significantly diffe rent from the control group. Conclusion: Modified ultrafiltration improves global left ventricular systolic function in infants and children following open-heart surgery. (C) 1999 Elsevier Science B.V. All rights reserved.