A multicenter analysis of the choice of initial surgical procedure in tetralogy of Fallot.

A current debate on the surgical management of patients with tetralogy of Fallot (TOF) focuses largely on primary repair vs initial shunt in younger and/or smaller patients. To characterize practice patterns throughout the United States with respect to the choice of initial surgical procedure in patients with TOF, we analyzed data from a multicenter database. This retrospective study focused on 938 patients from 12 institutions who underwent their initial operation during the 10-year period 1986 through 1995. Overall, the percentage of shunts decreased from 35.1% (1986-1990) to 22.0% (1991-1995) (p < 0.0001). The percentage of primary repairs increased accordingly. However, there was marked interinstitutional variability. For the group of patients aged 3 months or less the overall in-hospital mortality was significantly higher than that for older patients for both shunts and repairs. Multiple logistic regression analysis indicated that age, weight, date of surgery, and the interactions between date of surgery and institutional volume and between age and institutional volume were significant predictors of the initial surgical management of TOF. With this model only part of the observed variance could be explained. Other unidentified variables, including "institutional preference," may be significant factors influencing the choice of initial surgical procedure.

Childhood acute rheumatic fever: a comparison of recent resurgence areas to cases in West Virginia.

A resurgence of acute rheumatic fever (ARF) was noted over the last 10 years in several areas of the United States. West Virginia was no exception with two reports appearing in the literature confirming an increased incidence in the 1980s among children and adults. The Pediatric Cardiology Division of West Virginia University Children's Hospital had 30 cases of ARF referred between 1980 and 1995, and surprisingly 27 of these cases had been diagnosed since 1986. This article describes our chart review of these 30 cases which studied epidemiological aspects, diagnostic criteria and regional differences by chi-square analysis. Other issues we present include "silent" mitral regurgitation and the unreliability of a history of a recent pharyngitis with or without appropriate antibiotic therapy while considering ARF in the differential diagnosis.

Plasma antioxidant depletion after cardiopulmonary bypass in operations for congenital heart disease.

We describe the use of two in vitro tests to characterize plasma antioxidant capacity at the time of cardiac bypass in operations for congenital heart disease in 30 patients aged 3 days to 16 years (average 4.4 +/- 0.9 years [standard error]). Bypass and crossclamp time, circuit volume, and type of operation were recorded for each patient. First, a test of plasma radical antioxidant power measured chain breaking (secondary) antioxidant capacity of plasma to prevent oxidation of linoleic acid in vitro. Second, overall ability of plasma to prevent lipid peroxidation was assessed by a classic test of plasma inhibition of malondialdehyde formation in a beef brain homogenate. Plasma total radical antioxidant power level at baseline was 0.74 +/- 0.03 mumol/ml plasma, which decreased to 0.15 +/- 0.05 mumol/ml plasma after bypass (p < 0.001) and 0.26 +/- 0.08 mumol/ml plasma with recovery (n = 18, p < 0.001). Analysis of variance of postbypass total radical antioxidant power value showed age (p = 0.0002, r = 0.63) and bypass time (p = 0.009, r = 0.4677) to be significant factors. Pump prime volume in milliliters per kilogram and preoperative hemoglobin value were not significant factors. Beef brain malondialdehyde formation in vitro was limited 92% +/- 3% by normal plasma before operation versus 53% +/- 5% after operation (p < 0.001) and 51% +/- 5% at recovery after arrival in the pediatric intensive care unit (p < 0.001). Analysis of variance of the changes from before to after operation showed age p = 0.0015, r = 0.55) and bypass time (p = 0.033, r = 0.39) to be significant factors. Thus antioxidant capacity of plasma is significantly diminished after cardiopulmonary bypass in children. Young patient age and long duration of cardiopulmonary bypass are identified as factors that correlate positively with depletion of antioxidant capacity with bypass.

Spectrophotometric measurement of plasma 2-thiobarbituric acid-reactive substances in the presence of hemoglobin and bilirubin interference.

The 2-thiobarbituric acid reaction with malondialdehyde has been used to assess lipid peroxidation in a variety of biologic systems. However, in an attempt to measure plasma thiobarbituric acid-reactive substances (TBARS) during extracorporeal membrane oxygenation, a form of sustained cardiopulmonary bypass, it became apparent that the absorbance signal at the 532-nm wavelength was composed not only of the peak absorbance of TBARS, but also of interfering substances from heme pigments and bilirubin. A method of subtracting interfering substances was developed and applied to normal human plasma. The method was tested by adding varying amounts of red blood cell hemolysate, bilirubin, and 1,1,3,3-tetramethoxypropane (TMP) standard to plasma and determining TBARS in the resulting mixture. In addition, varying the amount of added desferoxamine was investigated to determine the effects of iron chelation on the assay. This was important because the different samples would have varying amounts of free iron from hemoglobin to catalyze the reaction. It was found that the following equation could be used in this system to determine that amount of 532-nm absorption due to TBARS: MDA532 = 1.22[(A532) - (0.56)(A510) + (0.44)(A560)]. Regression analysis revealed an 86.6% recovery of the TMP spike. Analysis of variance showed that the variability in the model could be explained mainly by the additive increments of TMP spike (94.6%).