Background: In congenital heart surgery, in particular upon the radical correction of tetralogy of Fallot in children aged up to 1 year, hemodynamic indicators determined routinely often do not enable to assess in full the individual hemodynamic profile of the patient and to develop an individualized protocol for targeted hemodynamic therapy. This circumstance stipulates the use of advanced hemodynamic monitoring, and specifically the transpulmonary thermodilution (PiCCO) technique. However, the use of this technique is limited by the lack of reference values for patients with this nosological form and in this specific age group. Objective: The study was aimed at determining reference indicators of transpulmonary thermodilution in children aged up to 1 year after radical correction of Tetralogy of Fallot to develop protocols of targeted hemodynamic therapy. Methods: This prospective cohort study was based on the transpulmonary thermodilution data of 30 patients aged up to 1 year after radical correction of Tetralogy of Fallot performed at the Meshalkin National Medical Research Center of the Ministry of Health of Russia from 2019 to 2022. Results: Right ventricular failure developed in 11 patients (36.7%). A risk factor for right ventricular dysfunction was pulmonary regurgitation of grade 2 or higher, which developed in 14 patients (46.7%). The average regurgitation volume was 18.8 (12.1; 19.5) ml. According to the PiCCO data, no right ventricular failure was detected in children in the early postoperative period. Conclusion: Standard hemodynamic monitoring parameters using the PiCCO system, recommended for adult patients, cannot be applied to children, especially tender-age infants, after radical correction of tetralogy of Fallot. Transpulmonary thermodilution parameters do not enable to detect right ventricular failure after radical correction of tetralogy of Fallot in children aged up to 1 year.

Background: Cardiac surgery-associated acute kidney injury (CSA- AKI) in children with congenital heart defects (CHD) remains one of the key challenges in pediatric cardiac surgery. Most studies examining this complication focus on patients undergoing cardiopulmonary bypass for CHD correction. Cardiopulmonary bypass and its duration are the most significant factors in the development of CSA-AKI. Objective: The study aimed to assess the incidence of CSA-AKI using pRIFLE and KDIGO criteria in patients after coarctation repair without cardiopulmonary bypass, as well as to identify possible predictors of CSA-AKI and determine risk factors after surgery. Methods: One-single center, retrospective, propensity score matching analysis included 80 patients aged up to 1 year with coarctation of the aorta after cardiac surgery without cardiopulmonary bypass. Results: The incidence of acute kidney injury according to the pRIFLE and KDIGO criteria was 48.8 % and 35 %, respectively. Matched group of patients with CSA-AKI had longer duration of mechanical ventilation and day stay in intensive care unit after surgery (р < 0.001). With increasing patient age, the length of stay in the intensive care unit and the duration of mechanical ventilation went up. With an increase of RACHS-1 score from 1 to 2 and 3, the duration of stay in the intensive care unit augmented by 8.2 and 11 days, respectively (p = 0.004). Patients with prostaglandin infusions before surgery had a 1.6 ml/kg/hour more urine output in the first postoperative day. Conclusion: Despite significant progress in the investigation of acute kidney injury in pediatric patients after cardiac surgery, many unresolved issues remain requiring further study to fully unravel the complexities of AKI diagnosis and treatment in the pediatric population undergoing cardiac surgery.

Background: Aortic stenosis is the most common valvular heart disease among elderly patients. Transcatheter aortic valve replacement has become a revolutionary treatment practice, utilizing various access options, including transfemoral, transaortic, transapical, and other alternatives. The choice of access significantly impacts the safety and outcomes of the procedure. Objective: The study was aimed to analyze the immediate and long- term outcomes on adoption of transapical and transaortic accesses in aortic valve replacement using the domestic MedLab-KT prosthesis. Methods: From June 2018 to September 2025, 66 transcatheter aortic valve replacement surgeries were performed via transapical and transaortic approaches using the “MedLab-KT” prosthesis, including 4 repeat procedures for dysfunction of the biological aortic valve prosthesis by the valve-in-valve technique. A retrospective analysis of the results was conducted, assessing preoperative, intraoperative, and early and late postoperative data. Criteria for technical success, device success, and early safety were assessed. Patients were divided into groups according to time intervals, namely 2018–2021 and 2022–2025, to evaluate the impact of accumulated experience on immediate and long-term surgical outcomes. Results: Intraoperative mortality was recorded in a single case (1.6 %). The rate of 30-day mortality was 9 % (6 patients). The aortic valve implantation procedure was technically successful in 62 cases (93.9 %). Device success was recorded in 56 patients (84.9 %). The early safety rate was 83.3 %. The average follow-up period was 3.5 years. With the accumulation of experience, the early safety rate increased by 15 % but no significant difference was revealed. The rate of 5-year freedom from reoperations was 100 %; 5-year survival rate was 87.9 %. Moreover, 5-year freedom from valve dysfunction was 97.5 % (95 % CI 0.92; 1). Conclusion: The results of this study demonstrate the efficacy and safety of the transapical and transaortic approaches in transcatheter aortic valve replacement using the domestic prosthesis “MedLab-KT”, which demonstrates satisfactory hemodynamic characteristics for the mid-late postoperative period. Analysis of the immediate and long- term results allows us to recommend the transaortic and transapical approaches as alternatives when the transfemoral approach is not possible.

Background: Assessment of left ventricular (LV) contractile function along with blood supply has recently become an increasingly common “extension” in the analysis of perfusion scintigraphy and single-photon emission computed tomography data, isolated or combined with myocardial X-ray computed tomography. It enables to reveal additional, more sensitive markers of various pathologies, one of which is mechanical dyssynchrony. However, in case of largeperfusion defects, this approach may provide unreliable information. Objective: The study aimed at assessing the impact of extensive perfusion defects on the determination of mechanical dyssynchrony indices using ECG-synchronized perfusion single-photon emission computed tomography of myocardium. Methods: Sixty-five patients with ischemic cardiomyopathy were included in the study. All patients were examined using ECG-synchronized myocardial perfusion scintigraphy and radionuclide tomoventriculography, as well as cardiac magnetic resonance imaging. All examinations were carried out in the resting state. Patients were assigned to two groups according to ECG-synchronized myocardial perfusionscintigraphy data. Some formed a group with big perfusion defect relative to thearea of the LV in a state of functional rest (BDP; summed rest score ≥ 20%), while the others entered the group with minor defect of perfusion (MDP; summed rest score < 20%). The following parameters of LV contractile function were assessed using radionuclide modalities: ejection fraction (%), end-systolic (ml) and enddiastolic(ml) volumes, as well as parameters of mechanical dyssynchrony (phasehistogram standard deviation (deg) and phase histogram bandwidth (deg)).Magnetic resonance imaging as a reference method was used to assess ejection fraction, end-diastolic and end-systolic volumes of LV. The primary endpoint was summed rest score ≥ 20 %. Results: The MDP group comprised 21 patients (summed rest score 11.7 (5.8;16.1) %) and the BDP group amounted to 44 patients (summed rest score 30.8 (25; 41.1) %). In the MDP group, no differences in the estimated parameters between modalities were found. In the BDP group the parameters obtained by the ECGsynchronized myocardial perfusion scintigraphy differed significantly from those obtained by both radionuclide tomoventriculography and magnetic resonance imaging; whereas, no significant differences in the measured parameters were foundbetween radionuclide tomoventriculography and magnetic resonance imaging. The mechanical dyssynchrony indices in the BDP group were significantly higheraccording to the data of ECG-synchronized myocardial perfusion scintigraphy compared to radionuclide tomoventriculography. According to Bland – Altman analysis, allparameters did not show significant differences in the MDP group. Along with that, in the BDP group, volumes and mechanical dyssynchrony were significantly overestimated according toECG-synchronized myocardial perfusion scintigraphy data (mean differences end-diastolic volume 52.5 ml, end-systolic volume 35.9 ml, phase histogram standard deviation 7.9, phasehistogram bandwidth 67.2), while ejection fraction was underestimated (–3.4 %). Conclusion: In patients with large (≥ 20 % of the LV myocardium area) perfusion defects, monitoring indices by the ECG-synchronized myocardial perfusion scintigraphy may lead to overestimation of LV mechanical dyssynchrony indices.

Background: Pulsed field ablation (PFA) is a widespread safe and effective approach to treat paroxysmal atrial fibrillation (AF). However, data regarding its use in persistent AF are limited, especially in comparison with thermal energy sources. Objective: The study aimed to assess the efficacy and safety of PFA for persistent AF treatment in comparison with radiofrequency (RFA) and cryoballoon ablations (CBA). The primary concern was to evaluate 1 year freedom from any atrial arrhythmias (AA) recurrence, including AF, atrial flutter or atrial tachycardia lasting 30 seconds or longer after the blanking period. Methods: We performed an extensive search using MEDLINE, EMBASE, and PubMed databases for studies providing outcome data on PFA in patient with persistent AF. Additionally, several studies on RFA and CBA involvement for persistent AF treatment were selected for comparative analysis. Results: Freedom from AA at 1 year after PFA, RFA and CBA was 68.95% [95 % CI 62.72%, 74.57%], 61.72% [95 % CI 51.74%, 70.79%], 68.23% [95 % CI 63.76%, 72.39%] respectively, with no significant differences between types of energy used. No significant differences were revealed in periprocedural and postprocedural complications between compared ablation types, as well. Conclusion: In patients with persistent AF, PFA required a shorter total procedural time than RFA but a longer one than CBA. Fluoroscopy time for PFA was significantly shorter than for thermal energy sources. No significant differences were found in safety or freedom from atrial arrhythmias at the 1-year follow-up between the compared ablation methods. Large randomized multicenter trials are needed to further assess the benefits of PFA compared to thermal energy sources in persistent AF treatment.

Background: Heart rhythm disturbances remain a serious problem in modern cardiology. Traditional pacemakers have certain limitations including invasiveness, risk of infection, mechanical complications, and a limited service life. Advances in bioengineering and optogenetics technologies offers new prospects for the production of minimally invasive, biocompatible, and controllable cardiac pacing systems. The combination of cell therapy and optogenetics enables to create a photo-controlled biological pacemaker, free from the key drawbacks of traditional devices. Objective: The aim of this study was to produce photosensitive cellular patches and to further investigate their functionality as an optogenetic tissue-engineered pacemaker in an ex vivo rat heart model. Methods: We engineered a cell-based construct using either human cardiomyocytes derived from induced pluripotent stem cells or neonatal rat cardiomyocytes expressing channelrhodopsin-2. These cells were seeded onto fibrous scaffolds made of poly-L-lactic acid and collagen, coated with fibronectin. The testing model was an isolated, temporarily maintained ex vivo rat heart. Optical mapping of calcium activity was used to record cardiac electrophysiology. Results: Functional coupling between the implanted patch and the host myocardium was observed 35 minutes after implantation. Photostimulation reliably increased the heart rate, which was confirmed by stochastic dominance analysis. The experiments in vitro on cell cultures demonstrated the operational capacity of channelrhodopsin-2 upon illumination with 470 nm light. Conclusion: This study successfully demonstrates a complete technology cycle, from the genetic modification of cells to the control of contractions in a whole organ. It represents a significant step towards developing targeted and safe methods for future temporary cardiac pacing. Our results confirm the fundamental feasibility of a hybrid optogenetic approach and lay the groundwork for further research into creating safe, controllable, and biocompatible next-generation pacemaker systems.

Abstract Background: Non-cardiac surgery is prevalent among individuals with a history of cyanotic congenital heart disease (CHD), including tetralogy of Fallot (ToF). Surgical and anesthetic procedures in such patients may lead to multiple complications. In the selected patient group, neuraxial block, a specific type of caudal anesthesia, can be a viable alternative for anesthetic management. Objective: The study aimed to assess the efficacy of caudal anesthesia as postoperative analgesia for an infant with uncorrected ToF who underwent anoplasty. Methods: The case was a 17-month-old female toddler with uncorrected ToF who underwent anoplasty to treat anorectal malformation. For the anoplasty performance, the patient received caudal anesthesia with sedation using bupivacaine. In addition, sedation was carried out using low-dose ketamine and midazolam combination following fluid rehydration. The entire surgical procedure was performed in the prone position and lasted approximately 60 minutes. Results: Based on intraoperative monitoring records, patient exhibited stable hemodynamics with no intraoperative or postoperative complications. Intraoperative systolic blood pressure ranged from 70 to 80 mmHg, diastolic blood pressure from 35 to 40 mmHg, and heart rate from 120 to 140 beats per minute, respectively. Conclusion: This study showed that caudal analgesia is an effective analgesic technique associated with few adverse effects and positive outcomes in pediatric patients with ToF

Background: Ventricular arrhythmias (VA) remain a leading cause of cardiovascular mortality. Existing ablation methods, including radiofrequency ablation (RFA), have limitations related to the depth and homogeneity of the lesion created. Objective: The objective of this study was to experimentally assess the efficacy of a new method on controlled chemical myocardial ablation using the VVF34 composition. Methods: The study was conducted on rats (n = 60) and minipigs (n = 6). The histological dynamics and dose-dependent fibrosis formation in response to intramuscular administration of VVF34 (0.1; 0.2 and 0.3 ml) were studied in rats. Intramyocardial injection under fluoroscopic guidance using a Myostar catheter was tested in minipigs, and the safety of the procedure was assessed using echocardiography and electrocardiography. Results: VVF34 has been shown to induce dose-dependent formation of a sharply marginated zone. A low dose (0.1 ml) proved to be optimal, resulting in the formation of dense fibrosis with minimal inflammation, while elevating the dose caused destructive necrosis. To create extended ablation lines, it was appropriate to use a series of injections spaced at least 3 mm. The intramyocardial injection procedure was safe, did not have a proarrhythmic effect, and did not impair cardiac contractility. Conclusion: Chemical ablation with VVF34 composition is a promising alternative to existing approaches and enables to create controlled homogeneous deep fibrotic lesions, opening up new possibilities for the treatment of resistant ventricular arrhythmias.

Background: The number of patients with aortic stenosis (AS) is increasing with the aging population. According to current guidelines, surgical treatment is recommended for severe AS in patients with symptoms of heart failure, a reduced ejection fraction (EF), and global left ventricular (LV) Strain. LVEF does not always reflect its contractility. Assessing right ventricular (RV) function is also important, as its dysfunction may persist even after aortic valve surgery. Objective: The study was aimed to assess RV global strain, strain of RV free wall and LV myocardial performance in patients with severe AS. Methods: This prospective non-randomized study included 72 patients with degenerative aortic valve disease and an effective orifice area of less than 1.0 cm2. The complex of examination methods included echocardiography and Speckle Tracking Imaging-2D Strain technology for assessing LV and RV deformation, LV myocardial function, 3D visualization of RV with subsequent construction of a 3D RV model and calculation of EF, fractional area change, linear dimensions, and tricuspid annulus displacement amplitude. Results: Decreased LV myocardial function was detected in 24 patients (33.3 %). Subclinical RV systolic dysfunction, namely decreased RV global strain, was detected in 40 (55.6 %) patients, while decreased RV free wall strain was observed in 11 (15.3 %) patients. Interplay was revealed between subclinical RV systolic dysfunction and LV myocardial performance in patients with severe AS. Conclusion: Subclinical LV and RV dysfunctions are observed in a significant number of patients with severe AS. Analysis and use of these data will enable to change the approach to the AS classification and the timing of surgical treatment in the future. Conclusion: Subclinical left and right ventricular dysfunction is observed in a significant number of patients with severe aortic stenosis based on echocardiography. Analysis and use of these data will likely lead to changes in the classification of AS and the timing of surgical treatment. Keywords: aortic stenosis, echocardiography, right ventricular systolic dysfunction, left ventricular myocardial function, right ventricular deformation.