Pii: S1010-7940(99)00101-3

Objectives: Modi®ed ultra®ltration increases blood pressure and cardiac index following open-heart surgery in children, but it is unclear if this is secondary to an improvement in global left ventricular function. A previous report has suggested that left ventricular systolic function as assessed in a single chord is improved by ultra®ltration (Davies MJ, Nguyen K, Gaynor JW, Elliott MJ. Modi®ed ultra®ltration improves left ventricular systolic function in infants after cardiopulmonary bypass. J Thorac Cardiovasc Surg 1998;115:361--370). The prominent vascular actions of modi®ed ultra®ltration necessitate left ventricular assessment using load-independent indices of systolic and diastolic function. Methods: In 22 consecutive infants and children undergoing open-heart surgery, left ventricular function was assessed following bypass and then 10 min later. Sixteen children (median weight 8.1 kg) underwent modi®ed ultra®ltration during this period, the remainder (median weight 7.3 kg) were controls for spontaneous recovery without ultra®ltration. Real-time pressure±volume loops, with transient inferior caval vein snaring were generated from conductance and microtip pressure catheters inserted through the LV apex. From these, loadindependent (slope of the end-systolic pressure±volume [Ees] and end-diastolic pressure±volume [Eed] relationships) and load-dependent (Pmax, maximum LV pressure; Ped, end-diastolic LV pressure; maximum [dP/dtmax] and minimum [dP/dtmin] time derivatives of LV pressure; t , time constant of isovolumic relaxation) indices of left ventricular function were measured. Results: Haemoconcentration was achieved in all modi®ed ultra®ltration patients, median increase in haematocrit 34% (interquartile range 21%, 42%), ®nal haematocrit 0.40 (0.35, 0.41). Ees increased 58% (9, 159, P ˆ 0:005). The changes in Eed, Pmax, Ped, dP/dtmax, dP/dtmin, and t were not signi®cantly different from the control group. Conclusion: Modi®ed ultra®ltration improves global left ventricular systolic function in infants and children following open-heart surgery. q 1999 Elsevier Science B.V. All rights reserved.