**2. Patients and methods**

Twenty one patients were enrolled into this study. Their ages range from ten-month to 11 years: patient details are summarized in Table 1. The patients were divided into three groups; Seven patients of Kawasaki disease without coronary lesions over 6 months after healing (KD group), seven patients of ASD as a representative of RV volume overload (ASD group), *(ASD group),* seven patients of VSD or patent ductus arteriosus (PDA) as a representative of RV pressure overload in addition to LV volume overload (PH group). *(PH group). All the patients in the PH group were received diuretics.* 

*All patients were not fed for at least four hours.* Conbination of *ketamine-HCl and diazepan were used for general anesthesia with spontaneous respiration.* Heparin (100U/kg) was administered *after insertion of* arterial sheath. Intravenous infusion including 4.3% glucose and 20 mEq/l lactate maintained during the protocol. A coronary sinus catheter was inserted into the midto-anterior region of the coronary sinus via the inferior vena cava under fluoroscopy (Hamaoka et al., 1989). Blood sample collection was done at least 10 min after the end of all catheterization and angiography for the diagnosis because the influence of contrast medium to myocardial metabolism was reported to maintain 10-20 minutes by Wisneski et al (Wisneski et al., 1982). The verification of appropriate catheter position was determined by measuring oxygen saturation.

Oxygen saturation was measured by Oxygen Saturation Monitor system (Erma). Blood samples were obtained simultaneously from coronary sinus and femoral artery for the chemical analysis of concentrations of glucose, lactate and free fatty acids and oxygen concentration. Blood samples for glucose were mixed with titrate and, for lactate and pyruvate with 6% perchloric acid. This protocol was performed by the guideline of the Committee on Research of Kyoto Prefectural University of Medicine and informed consents were obtained from parents.

#### *Calculations on energy substrate metabolism:*

Pulmonary blood flow to systemic blood flow ratio (Qp/Qs) was calculated by means of Fick's method. Blood oxygen concentration was calculated as the product of Hb concentration, oxygen saturation, and an oxygen-binding capacity of 1.34 ml/g. The oxygen extraction rate (OER) for each substrate was calculated using the following formula:


The substrate factor for glucose or lactate is 0.75 and 5.7 for free fatty acids (FFA). FFA concentration of whole blood was calculated by multiplying plasma concentration with (100-hematocrit)/100.

Redox potential (Eh) = -204+30.7x log([pyruvate]/[lactate]) (Gudbjarnason & Bing, 1962). ΔEh = Ehcv – Ehao (Ehcv and Ehao represent Eh of coronary venous blood and of aortic blood, respectivelty)

#### *Statistical analysis*

320 Congenital Heart Disease – Selected Aspects

ratio of a given cell is regarded to reflect the cytosolic NADH/NAD+ ratio. The lactate and pyruvate are thought to provide for a redox coupling between organs through blood since plasma level of these metabolites equilibrate with cytosolic concentrations of cells. In view of "lactate shuttle theory" by Brooks (Brooks, 2002), lactate released into the coronary venous circulation and taken up by distal tissue that is to say myocardium via coronary

The energy substrates use in CHD had been focused on cyanotic disease (Scheuer et al.,1970, 1972, Rudolph et al.,1971, Fridli et al.,1977). As such, the studies of myocardial metabolism have long history but are very limited (Scheuer et al.,1970, 1972, Fridli et al.,1977, Åmark et al., 2007). In recent years, advancement of intensive care before and after surgical treatment, and carrying out of the long-term care of the circulation are getting to require precise

In this article, we focused on myocardial use of energy substrates, especially lactate, in young patients with RV volume overload (*represented in the atrial septal defect, ASD*) or with both RV pressrure load and LV volume load (represented in the ventricular septal defect, VSD). The author will also consider the myocardial redox state of non-cyanotic CHD in

Twenty one patients were enrolled into this study. Their ages range from ten-month to 11 years: patient details are summarized in Table 1. The patients were divided into three groups; Seven patients of Kawasaki disease without coronary lesions over 6 months after healing (KD group), seven patients of ASD as a representative of RV volume overload (ASD group), *(ASD group),* seven patients of VSD or patent ductus arteriosus (PDA) as a representative of RV pressure overload in addition to LV volume overload (PH group). *(PH* 

*All patients were not fed for at least four hours.* Conbination of *ketamine-HCl and diazepan were used for general anesthesia with spontaneous respiration.* Heparin (100U/kg) was administered *after insertion of* arterial sheath. Intravenous infusion including 4.3% glucose and 20 mEq/l lactate maintained during the protocol. A coronary sinus catheter was inserted into the midto-anterior region of the coronary sinus via the inferior vena cava under fluoroscopy (Hamaoka et al., 1989). Blood sample collection was done at least 10 min after the end of all catheterization and angiography for the diagnosis because the influence of contrast medium to myocardial metabolism was reported to maintain 10-20 minutes by Wisneski et al (Wisneski et al., 1982). The verification of appropriate catheter position was determined by

Oxygen saturation was measured by Oxygen Saturation Monitor system (Erma). Blood samples were obtained simultaneously from coronary sinus and femoral artery for the chemical analysis of concentrations of glucose, lactate and free fatty acids and oxygen concentration. Blood samples for glucose were mixed with titrate and, for lactate and pyruvate with 6% perchloric acid. This protocol was performed by the guideline of the Committee on Research of Kyoto Prefectural University of Medicine and informed consents

Pulmonary blood flow to systemic blood flow ratio (Qp/Qs) was calculated by means of Fick's method. Blood oxygen concentration was calculated as the product of Hb

artery circulation may affect redox state in the myocardial cells .

*understanding* of myocardial metabolism in CHD.

**2. Patients and methods** 

measuring oxygen saturation.

were obtained from parents.

*Calculations on energy substrate metabolism:* 

young patients with reviewing of myocardial substrate use.

*group). All the patients in the PH group were received diuretics.* 

Values are expressed as mean ± standard deviation. All statistical tests were performed using JMP (ver.6, SAS Institute Japan, Co). We used Kruskal-Wallis one way analysis of variance on ranks to compare overall differences among three groups. We compared median value of all groups using two tailed Mann-Whitney U tests. Because three pairwise planed comparisons were made we considered P<0.016 as significant. In case of comparison of paired samples, Wilcoxon signed-rank test was applied and P<0.05 was considered as significant.
