SERIAL EVALUATION OF CARDIAC FUNCTION IN CHILDREN UNDERGOING DIALYSIS

Abstract

Serial echocardiographic (echo) evaluation of cardiac performance in children undergoing chronic dialysis is currently not feasible due to significant dialysis induced changes of heart rate (HR), preload and afterload which alter selected echo indices in the absence of true dysfunction. To eliminate this problem the effect of the independent variables heart rate (HR), preload index (PI) (represented by left ventricular end diastolic dimension (LVED)/a matched control LVED) and afterload (represented by a simultaneously recorded aortic diastolic pressure (DP)) upon pre-ejection period (PEP), ejection time (ET), PEP/ET, shortening fraction (SF), mean circumferential fiber shortening (Vcf), isovolumic contraction time (ICT), maximum posterior wall velocity (PWV) and cardiac output (CO) was evaluated on 92 echograms obtained from four children undergoing chronic dialysis. Multiple linear regression analysis of the data was performed for each patient and for the entire group in order to express each echo index as a function of HR, DP, and PI. Few significant regressions were obtained for the group as a whole but were obtained (r>0.77,P<0.05) in all individuals for ET, CO, and SVR; in three for Vcf and PEP/ET; in one for ICT and SF but in none for PEP. For each echo index except CO, the independent variables differed among children. We conclude that these regressions should significantly improve the ability to interpret selected echo indices in some patients with frequent alterations of HR, preload, and afterload.