**3. The clinical examination of infants with TGA**

All patients with TGA were broken down in 2 groups: the first group included patients with intact ventricular septum (IVS), while the second one incorporated those with ventricular septum defects (VSD). Two tasks were set; firstly, to study the clinical characteristics of patients depending on their age, for which purpose all of them were classified into 3 age groups: newborns aged 1 to 6 months and babies aged 6 to12 months. The second task was to compare the clinical characteristics of the deceased patients (subgroup I) and patients with favourable outcomes after surgical repair of the disease (subgroup II). Anthropometric measurements of patients with IVS depending on their age in the first and second group are given in Table 1.

Chemical Elements and Structural/Molecular

End-systolic

End-systolic

Shortening

End-diastolic dimension, сm

End-diastolic

End-systolic

End-systolic

Systolic output,

Shortening

Ejection

LV thickness,

End-diastolic

End-diastolic

patients with VSD are given in Table 4.

Properties of Myocardium in Infants with Transposition of Great Arteries 335

Subgroup I II I II II

dimension, cm 1.3±0.7 0.8±0.1 1.1±0.2 0.8±0.1 1.3±0.1

volume, ml 1.4±0.7 1.4±0.7 3.8±1.5 1.7±0.5 5.8±1.0 Systolic output, ml 6.0±2.1 4.6±1.0 20.4±13.6 7.3±1.9 16.9±1.7

fraction, % 44.1±4.9 51.2±2.1 40.7±6.6 47.2±2.2 48.0±5.1 Ejection fraction, % 79.1±4.4 82.4±1.7 77.8±6.8 83.0±1.5 75.6±4.1 LV thickness, сm 0.5±0.1 0.5±0.1 0.6±0.1 0.5±0.1 0.6± 0.1

volume, ml 8.6±3.0 5.6±1.8 19.1±8.7 6.5± 2.5\* 22.7±3.6

As the table shows, the age does not influence the following values of ECHO: RV endsystolic dimension, LV shortening fraction and LV ejection fraction. There was a slight agerelated increase in ASD, as well as a decrease in the unclosed ductus arteriosus size. As compared with the newborns, the following ECHO values tended to increase: RV size, endsystolic volume, systolic output, end-diastolic dimension, LV end-diastolic volume and LV thickness, thus indicating a reduction of myocardial contractility. ECHO data on TGA

Group Newborns 1 to 6 months old 6 to 12 months old Subgroup I II I II I II RV size, cm 1.2± 0.2 0.8± 0.1 1.0± 0.2 0.9± 0.2 1.5±0.4 1.4± 0.2

dimension, cm 1.1± 0.3 1.2± 0.1 1.5± 0.4 1.3± 0.2 1.4±0.3 1.4± 0.2

volume, cm 2.7±0.5 3.5± 0.9 9.4± 5.0 4.8±1.8 6.4± 2.3 6.4± 1.9

fraction,% 45.0±4.5 38.5±5.0 35.1±3.0 42.1±15.4 42.3±4.2 48.2±7.2

fraction, % 69.7±3.4 72.0±5.7 66.5±5.6 75.0±4.6 73.5±4.6 75.6±6.2

dimension, cm 1.3± 0.3 1.9± 0.2 4.6± 3.3 2.4± 0.2 2.5±0.3 2.5± 0.2

volume, cm 11.6±1.5 13.3±4.6 25.8±11.9 20.6±5.0 24.2±5.9 22.7±4.8

Table 4. Echocardiographic measurement data for TGA patients with VSD

Cm 0.51±0.1 0.3± 0.1 0.54±0.1 0.5± 0.1 0.6±0.1 0.7± 0.1

ml 10.1±3.5 9.3± 3.1 19.7±9.2 15.7±3.4 18.9±2.0 17.9±1.9

Table 3. Echocardiographic measurement data for TGA patients with IVS

1.6±0.2 1.5±0.1 2.0±0.3 1.7±01 2.5± 0.1

Group Newborns 1 to 6 months old 6 to 12 months old


*\* Р < 0.05* 

Table. 1. Anthropometric measurements of TGA patients with IVS

As can be seen from Table 1, the weight of patients in all groups was close to the norm. However, by the moment of surgery the delay in body weight gain as compared to the norm in newborns in both subgroups amounted to 1000 g, in infants – 200 g, while in those who survived in the third group it came to 1500 g. Dynamics of height measurements slightly exceeded the benchmark indicators. Similar anthropometric data were also obtained for the VSD group (Table 2).


*\* Р < 0.05* 

Table 2. Anthropometric measurements of TGA patients with VSD

By the moment of surgery, the delay in body weight gain as compared with the norm in newborns was on average 400 g, in the 1 to 6 months old – 900 g, in 6 to 12 months old infants in the deceased subgroup this difference came to 3800 g, while in those who survived – 2400 g. Dynamics of height measurements slightly exceeded the benchmark indicators in both groups. Based on the data obtained, one might conclude that disruption of metabolic processes in TGA infants evidently manifests itself only by a decrease in body weight, with the height parameters remaining the same. Table 3 looks at echocardiographic (ECHO) measurement data in patients with IVS depending on their age.

II (n=5) 3.2±0.1 52.0±1.3 3.2±0.1\* 4.1±0.2 52.4±1.1

I (n=18) 3.2±0.6 51.2±0.2 4.7±0.1 4.9±0.2 57.3±0.4

II (n=5) 3.1±0.2 51.0±1.3 5.3±0.9 4.9±0.2 58.8±3.1

months old II (n=5) 3.1±0.1 50.0±0.8 7.4± 0.7 9.5±0.2 70.2±3.0 70.5±0.2

As can be seen from Table 1, the weight of patients in all groups was close to the norm. However, by the moment of surgery the delay in body weight gain as compared to the norm in newborns in both subgroups amounted to 1000 g, in infants – 200 g, while in those who survived in the third group it came to 1500 g. Dynamics of height measurements slightly exceeded the benchmark indicators. Similar anthropometric data were also obtained for the

> Height, cm

Newborns I 3,2±0,2 52,0±1,0 3,3±0,3 3,8±0,2 53,5±1,3 52,8±0,2 II 3,0±0,1 51,2±0,6 3,5±0,1 3,8±0,2 51,7±1,0

By the moment of surgery, the delay in body weight gain as compared with the norm in newborns was on average 400 g, in the 1 to 6 months old – 900 g, in 6 to 12 months old infants in the deceased subgroup this difference came to 3800 g, while in those who survived – 2400 g. Dynamics of height measurements slightly exceeded the benchmark indicators in both groups. Based on the data obtained, one might conclude that disruption of metabolic processes in TGA infants evidently manifests itself only by a decrease in body weight, with the height parameters remaining the same. Table 3 looks at echocardiographic

Height, cm

Newborns I (n=19) 3.2±0.6 50.4±3.2 3.1±0.1\* 4.1±0.2 53.5±0.5

At birth By the time of surgery

At birth By the moment of surgery

kg Norm Height,

cm

Weight,

I 2,8±0,5 51,1±0,8 4,1±0,6\* 5,0±0,2 58,1±2,5 55,8±0,2 II 3,2±0,1 50,8±0,2 4,0±0,1\* 5,0±0,2 56,8±0,7

I 3,4±0,4 50,6±1,2 6,0±0,8\* 9,8±0,2 63,3±3,0 70,5±0,2 II 3,0±0,1 50,6±0,3 7,0±0,5\* 9,4±0,2 70,5±2,1

kg Norm Height,

cm

Norm

52.8±0.2

55.8±0.2

Norm

Weight,

Group Sub

1-6 months old

6 to 12

VSD group (Table 2).

1 to 6 months old

6 to12 months old

*\* Р < 0.05* 

Group Sub

group

*\* Р < 0.05* 

group

Weight, kg

Table. 1. Anthropometric measurements of TGA patients with IVS

Weight, kg

Table 2. Anthropometric measurements of TGA patients with VSD

(ECHO) measurement data in patients with IVS depending on their age.


Table 3. Echocardiographic measurement data for TGA patients with IVS

As the table shows, the age does not influence the following values of ECHO: RV endsystolic dimension, LV shortening fraction and LV ejection fraction. There was a slight agerelated increase in ASD, as well as a decrease in the unclosed ductus arteriosus size. As compared with the newborns, the following ECHO values tended to increase: RV size, endsystolic volume, systolic output, end-diastolic dimension, LV end-diastolic volume and LV thickness, thus indicating a reduction of myocardial contractility. ECHO data on TGA patients with VSD are given in Table 4.


Table 4. Echocardiographic measurement data for TGA patients with VSD

Chemical Elements and Structural/Molecular

Left atrium (n=5)

myocardium.

Parts of the heart

Content of CE, µg/g

*\* P < 0.05* 

(Table 6).

Properties of Myocardium in Infants with Transposition of Great Arteries 337

It follows from Tables 5A and 5B that in 65 % of TGA patients, as compared to those with intact myocardium, the content of CE was reduced: K was lower, down to 78 %, concentration of Cl, Cr, Sr, Zn decreased to 50 % and the concentration of Br, Ni, Rb was also low. The content of Se equalled to just 25 % of the benchmark value. Three CE: S, Ca and Fe had an appropriate concentration. It was found out that only 2 CE had an increased concentration: Cu – 160 % and Mn – 170 to 200 %. According to the distribution of CE in the heart parts, the lowest concentrations of CE were found in LV and RA

Intact myocardium TGA patients' myocardium

S 2560±180 2575±370 2398±300 2505±260 Cl 504±83 615±158 348±43 290±42\* K 494±71 580±165 444±58 421±38 Ca 990±54 1112±96 1148±105 1109±86 Cr 0.8±0.11 1.1±0.44 0.6±0.25 0.7±0.18 Mn 2.0±0.2 2.0±0.2 3.1±1.1 4.2±1.4 Fe 404±101 340±23 338±53 375±38 Ni 0.3±0.06 0.4±0.09 0.2±0.04 0.2±0.04 Cu 9.0±0.49 8.9±1.14 13.0±2.18 14.3±2.70 Zn 344±38 298±57 183±21\* 192±27 Se 0.7±0.1 0.7±0.2 0.2±0.06\* 0.2±0.05\* Br 12±1.2 11±2.2 6±0.7\* 6±0.6\* Rb 1.2±0.17 1.1±0.24 0.5±0.10\* 0.5±0.07\* Sr 5.7±0.6 5.1±0.9 3.2±0.3\* 3.5±0.4

Left atrium (n=21)

Right atrium (n=20)

Right atrium (n=5)

Table 5B. Distribution of CE in infants' atrium with intact myocardium and TGA infants

Hence, irreversible hemodynamic disorders of the myocardial function and development of cardiac insufficiency might be connected with a low concentration of Cl, Cr, Sr, Zn, Br, Rb, Ni and specifically Se, which in this case drops to 25 % and even beyond the measurement limit. An increased content of Mn and Cu mostly in the right parts of the heart could be explained by an elevated functional load and plays a compensatory role. The content of S, Fe and Ca matches the benchmark values and does not affect the changes in the myocardium. On the basis of the results obtained it may be concluded that in order to maintain normal functional activity of the myocardium in TGA infants, the content of Cl, Zn, Sr, Cr, Ni, Rb, Br and especially Se that protects cardiomyocytes from lipid peroxidation should be optimal. The following relationships were revealed while comparing CE impoverishment in the myocardium of TGA infants in different heart parts

In the 1 to 6 and 6 to 12 months old groups, as compared with the newborn group, the following ECHO values were found to increase considerably: RV size, end-systolic volume, systolic output, end-systolic dimension, end-diastolic volume and end-systolic dimension. In addition, there was a trend toward an increase in the size of ASD, VSD and LV thickness. However, the size of unclosed ductus arteriosus tended to decrease. The shortening fraction (SF) and ejection fraction (EF) values matched the age-related indices. The pressure in the pulmonary artery was elevated in all groups, but it was particularly high in the 6 to 12 months old group.

Clinical/functional examination of TGA patients demonstrated that in terms of basic clinical indicators there were no statistically significant differences between the deceased and surviving infants with TGA. Moreover, average indicators of all 3 age subgroups (newborns, 1 to 6 months old and 6 to 12 months old) in both groups are identical within a time period. From this it follows that negative factors causing the death of infants with TGA are related to molecular disorders of metabolic processes in cardiomyocytes that, in turn, brought us to start studying the content of CE and structural/molecular characteristics of TGA infants' myocardium.
