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Association of Cardiovascular Surgeons of Russia Russian Society of Cardiology (RSC)Association of Pediatric Cardiologists of RussiaRussian Scientific Society of Specialists in X-Ray Endovascular Diagnostics and TreatmentAll-Russian Public Organization for the Promotion of Radiation Diagnostics and Therapy "Russian Society of Radiologists and Radiologists".Task Force members declared no financial support/conflicts of interest. If conflicts of interest were reported, the member(s) of the working group was (were) excluded from the discussion of the sections related to the area of conflict of interest.

The study presents a bio-inspired chaos sensor model based on the perceptron neural network for the estimation of entropy of spike train in neurodynamic systems. After training, the sensor on perceptron, having 50 neurons in the hidden layer and 1 neuron at the output, approximates the fuzzy entropy of a short time series with high accuracy, with a determination coefficient of R2~0.9. The Hindmarsh–Rose spike model was used to generate time series of spike intervals, and datasets for training and testing the perceptron. The selection of the hyperparameters of the perceptron model and the estimation of the sensor accuracy were performed using the K-block cross-validation method. Even for a hidden layer with one neuron, the model approximates the fuzzy entropy with good results and the metric R2~0.5 ÷ 0.8. In a simplified model with one neuron and equal weights in the first layer, the principle of approximation is based on the linear transformation of the average value of the time series into the entropy value. An example of using the chaos sensor on spike train of action potential recordings from the L5 dorsal rootlet of rat is provided. The bio-inspired chaos sensor model based on an ensemble of neurons is able to dynamically track the chaotic behavior of a spike signal and transmit this information to other parts of the neurodynamic model for further processing. The study will be useful for specialists in the field of computational neuroscience, and also to create humanoid and animal robots, and bio-robots with limited resources.

We studied the effect of ethanol vapour on the parameters of the semiconductor-metal transition in a polycrystalline vanadium dioxide powder of the stable monoclinic phase a-VO2. It was synthesised by reducing vanadium pentoxide with oxalic acid while heated in air. The DC electrical resistance of the samples was studied between room temperature and 100оС in a tubular heater, in a microcompressor-generated air stream with saturated ethyl alcohol vapour. It was found that in the presence of ethanol vapour, the hysteresis loop shifted to higher temperatures by ten degrees and its cooling branch (corresponding to the transition of vanadium dioxide from the metallic phase to the semiconductor phase) became stepped.

The treatment of pulmonary valve disease is one of the urgent problems of modern cardiology and cardiac surgery. In most cases, pulmonary valve abnormalities are congenital. Synthetic conduits (homografts) and bioprosphetic valves are currently used in the surgical treatment of patients with the diseases mentioned above. Pulmonary valve surgical prosthetics allows one to normalize the circulatory dynamics and condition of the patient, however, time-dependent degradation results in conduit and valve dysfunction. The abnormal circulatory dynamics caused by valve and conduit dysfunction is linked to exercise intolerance, arrhythmia, right ventricular failure, and sudden death. Starting in childhood, affected patients undergo repeated openheart surgeries to restore valve function and potentially reduce morbidity and mortality. Percutaneous transcatheter treatment of the pulmonary valve stenosis with the Melody® valve (Medtronic Inc.) has been performed in a large number of patients worldwide. Despite minimal invasiveness, this procedure restores pulmonary valve function and reduces repeated open-heart interventions. Recent clinical trials have shown excellent and durable results in terms of both restoring valve function and decreasing right ventricular outflow tract obstruction. In this study, we want to reflect the relevance of the Melody transcatheter valve and present our first experience of its usage.

This article analyses experiments on the kinetics of the internal electrochromism of thin (micron) films of hydrated vanadium pentoxide xerogel with point contacts. It describes a cylindrical model of electrochromic colouration, which was used to evaluate the concentration of the colour centres in the initial film and after additional hydrogenation of this film by plasmaimmersion ion implantation. When we compared the calculated values of the concentration of colour centres with the equilibrium concentration of protons in the xerogel, we saw that the mobility of the protons migrating from the depth of the film to the cathode region, which are involved in the electrochemical reaction, was not a determinant of the electrochromism kinetics. The rate of electrochromic colouration could be increased by the formation of layered film structures based on hydrated vanadium pentoxide, which have increased overall electron conductivity and, as a consequence, low faradaic resistance of the electrochromic cathodic reaction.

This paper presents a model and experimental study of a chaotic spike oscillator based on a leaky integrate-and-fire (LIF) neuron, which has a switching element with an S-type current-voltage characteristic (S-switch). The oscillator generates spikes of the S-switch in the form of chaotic pulse position modulation driven by the feedback with rate coding instability of LIF neuron. The oscillator model with piecewise function of the S-switch has resistive feedback using a second order filter. The oscillator circuit is built on four operational amplifiers and two field-effect transistors (MOSFETs) that form an S-switch based on a Schmitt trigger, an active RC filter and a matching amplifier. We investigate the bifurcation diagrams of the model and the circuit and calculate the entropy of oscillations. For the analog circuit, the “regular oscillation-chaos” transition is analysed in a series of tests initiated by a step voltage in the matching amplifier. Entropy values are used to estimate the average time for the transition of oscillations to chaos and the degree of signal correlation of the transition mode of different tests. Study results can be applied in various reservoir computing applications, for example, in choosing and configuring the LogNNet network reservoir circuits.

In the present article we report a clinical case of successful two-stage treatment for juvenile aortic coarctation with aortic arch dysplasia in a newborn. We demonstrated possible application of balloon angioplasty, as a palliative procedure in children with severe health condition.

Coarctation is found in 8% of all congenital heart diseases. Clinical course of this defect varies from cardiogenic shock while closing an arterial duct in newborns to an asymptomatic hypertonia. Infants with this pathology are often in a critical condition requiring an urgent intervention. Sometimes atypical clinical course of this defect causes difficulties for a cardiologist to make an exact diagnosis. There is no doubt in indications for surgery in cases with this anomaly. From the beginning of an era of E1 prostaglandin patients with ductal-dependent blood circulation began referring to specialized clinic in a stable state that affected significant decrease in a hospital mortality. However in this problem there is a number of topical issues. They are surgical methods of correction, their longterm results, recurrence rates, methods of correction for the accompanying arch hypoplasia, correction though one or two accesses in a case with arch obstruction combined with other intracardiac anomalies. In what terms it is necessary to carry out re-interventions and a role of balloon dilatation at recoarctation. The review sets the task to generalize the accumulated knowledge and to present treatment results of the most succeeded researchers on this problem.

Background. History of conduits application in cardiovascular surgery extends back for more than 100 years. With their use it became possible to help newborns and infants with difficult congenital heart diseases. Various types of conduits are used and well-known and have advantages and shortcomings, but it is difficult to choose an “ideal” conduit. The main problem of all types is repeated operations, which sometimes are repeated throughout the patient’s life.Objective. Show immediate and medium term results with conduit application in pulmonary position in infants.Material and Methods. From January 2006 to June, 2016 in our Clinic we have operated on 48 patients and performed reconstructions of the right ventricular outflow tract applying many different conduits. Age range was from 14 days to 1 year (4,82 ± 4,09 months), mean weight was 4,7 ± 2,3 kg (2,9-10,2 kg).Results. In immediate postoperative period 7 patients died (overall mortality rate was 14,59%). In all discharged patients according to ECG data mean blood flow rate on the conduit was 2,42 ± 0,72 m/s (from 1,3 to 3,9 m/s), and a mean gradient was 22,22 ± 17,17 mm Hg (from 4 to 60 mm Hg). We performed 18 repeated operations. Early reoperation was necessary in 3 cases(8,82%) (during the 1 year after the primary surgery), in cases the reason was conduit stenosis, in 1 patient there was a right ventricle aneurysm. We avoid repeated surgery in cases with conduit Contegra application with mean follow-up period 16,3 ± 11 months (1-62 months).Conclusion. 1. Conduit selection for implantation in the pulmonary position has a tendency to be a serious challenge in infants and newborns treated for complicated congenital heart disorders.2. Repeated surgeries were not necessary when we applied conduits Contegra with mean follow-up 16,3 ± 11 months (1-62 months), but to make some authentic conclusions a more prolonged follow-up period is required.

Background. Aortic arch obstruction occurs in 5–9% cases with a combination of TGA and a ventricular septal defect (VSD), and with a double-outlet right ventricle (DORY) with a subpulmonary VSD (Taussig–Bing anomaly), the incidence of aortic arch obstruction is approximately 50%. In the past, surgical tactics with this combination consisted of a double-stage correction; this approach was accompanied by high hospital mortality – 31–64%. With the development of neonatal cardiac surgery, a one-step correction, first described by Pigot, was accepted as the preferred surgical tactic among centers with sufficient experience. This report presents our experience of one-stage arterial switching with aortic arch reconstruction over the last 10 years (2007–2017).Material and Methods. During the period from 2007 to August 2017, we performed 172 arterial switch operations; anomalies of the aortic arch occurred in 12 patients (6.97%), 7 patients with TGA with an ventricular septal defect (VSD), 5 with double outlet of the right ventricle (DORV) with an subpulmonary VSD (Taussig–Bing anomaly). Anomalies of the aortic arch included isolated coarctation of the aorta (n = 2, 17.8%), aortic coarctation with aortic arch hypoplasia (n = 5, 41.6%) and interruption aortic arch (n = 5, 41.6%). The mean age at the time of admission was 2.36 + 1.54 days (1–7 days). The average day in the specialized cardio-resistance unit before the operation was 2.05 + 1.1 days (1–4 days), the average weight was 3.32 + 0.45 kg (2.9–1.1 kg).Results. There were no cases with early and late mortality. In the long-term follow-up period, 5 repeated surgeries (41.6%) were performed in 3 patients. In all cases, the cause was neo-pulmonary artery stenosis, 3 patients underwent balloon angioplasty of the pulmonary artery (18, 24 and 28 months after the initial correction); later, 2 patients required open pulmonary artery plastics (3 and 6 years after endovascular interventions). Residual aortic arch obstruction did not develop in any of the patients, nor did coronary problems and dilatation of the neo-aorta root.Conclusion. In patients with TGA with an ventricular septal defect (VSD), and with a double-outlet right ventricle (DORV) with a subpulmonary VSD (Taussig–Bing anomaly), a one-stage correction in the neonatal period is preferred, which is accompanied by low mortality and morbidity. Features of surgical techniques allow to improve the results of surgical correction. The main problem in the long-term period is the frequent development of stenosis on the neo-pulmonary artery, which requires further improvement of surgical techniques and methods of plasticity of the neo-pulmonary artery.

Secondary dilation (arrhythmogenic) cardiomyopathy in children after artificial pacemaker implantation occurs rather rare. Criteria for implantation are typical: expressed disorders of systemic ventricle function (lowering EF < 35% in dynamics) and prolongation of QRS interval more 120 ms. Heart transplantation is the only alternative. We present 2 cases with successful application of cardioresynchronizer for critical lowering EF at a time of AP implantation. We consider this method will assist in overcoming critical decompensated heart insufficiency and it is a good alternative to the only reliable approach in these children-heart transplantation. The age of patients is not a constraint factor.