Optimal Pacing Research Articles

Autocorrelation maps for optimal setting in cardiac resynchronization therapy

Background and ObjectivePatients with chronic heart failure are treated with implanted devices artificially stimulating the ventricular myocardium to support the ventricular activation propagation dynamics. The criterion for stimulation/pacing timing is a shortening of the QRS duration in the ECG signal. The study suggests additional ECG parameters that could be helpful in cardiac resynchronization therapy (CRT) device pacing settings. MethodsThis issue was approached by computing and evaluating autocorrelation maps derived from body surface potential maps during the QRS complex. The autocorrelation maps were calculated from the body surface potential maps of seventeen patients, fourteen of whom were diagnosed with the left bundle branch block (LBBB) and three with the right bundle branch block (RBBB). Eleven of the LBBB patients were responders, and all three RBBB patients and three LBBB patient were non-responders. The body surface potential maps were measured during their spontaneous heart rhythm and optimal CRT setting. The patients’ autocorrelation maps were compared with the autocorrelation maps of a control group of 33 healthy persons using two-sample Kolmogorov-Smirnov and Wilcoxon rank-sum statistical tests. ResultsThe autocorrelation maps from spontaneous rhythm were significantly different (p < 0.00008) in healthy and LBBB groups, which was shown on 19 parameters extracted from the autocorrelation maps by both the statistical tests of equality. In the optimal CRT setting in the LBBB responders, four of the studied parameters (Shannon entropy of the histogram of the autocorrelation map's values, and mean, standard deviation, and geometrical mean of the autocorrelation map's positive values) were not significantly different from the parameters of the healthy subjects (p > 0.19). ConclusionsSelected parameters of autocorrelation maps can be used as additional parameters for optimal CRT pacing settings, leading to patients’ positive responses to the treatment.

USING GENAI TO TRANSFORM DIGITAL PRODUCT DEVELOPMENT AND DIGITAL SALES IN THE BANKING SECTOR

The article examines the problems and strategic applications of using Generative Artificial Intellegence (GenAI) in order to transform the development of digital products and digital sales in the banking sector. The intensive development of GenAI creates unprecedented opportunities for the transformation of this sector. The relevance of the research is due to the need to rethink traditional approaches in the context of digitalization. There are contradictions regarding the optimal pace of GenAI implementation: a number of researchers call for aggressive digital innovations, while others point to the need for a gradual transition based on financial institutions’ readiness and the maturity of the technologies themselves. The aim is to analyze the key areas of application of GenAI in the characterized area. The article systematizes the elements of the conceptual framework and the advantages of using generative artificial intelligence. The study proposes a novel strategic framework for assessing GenAI's impact and applications across key areas within the banking sector. Special attention is given to how GenAI affects the process of digital product development of financial products and its potential applications in digital sales, particularly through customer engagement, hyper-personalized communication, and chatbots. As a result of the study, it was found that the introduction of GenAI in the banking sector can significantly reduce the time to bring new products to market, enhance personalization in customer interactions, and drive revenue growth through innovative cross-selling strategies. The articles’ materials are of practical value for the heads of commercial and retail banks, specialists in digital transformation, and researchers in the field of financial technologies.

Accelerated atrial pacing reduces left-heart filling pressure: a combined clinical-computational study.

Accelerated atrial pacing offers potential benefits for patients with heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF), compared with standard lower-rate pacing. The study investigates the relationship between atrial pacing rate and left-heart filling pressure. Seventy-five consecutive patients undergoing catheter ablation for AF underwent assessment of mean left atrial pressure (mLAP) and atrioventricular (AV) conduction delay (PR interval) in sinus rhythm and accelerated atrial pacing with 10 bpm increments up to Wenckebach block. Computer simulations (CircAdapt) of a virtual HFpEF cohort complemented clinical observations and hypothesized the modulating effects of AV coupling and atrial (dys)function. In the study cohort, 49(65%) patients had a high HFpEF likelihood (H2FPEF ≥ 5.0), and 28(37%) an elevated mLAP ≥ 15 mmHg at sinus rhythm. Optimal pacing rates of 100 [70-110]bpm (median [IQR]) significantly reduced mLAP from 12.8 [10.0-17.4]mmHg in sinus rhythm (55 [52-61]bpm) to 10.4 [7.8-14.8]mmHg (P < .001). Conversely, higher pacing rates (130 [110-140]bpm) significantly increased mLAP to 14.7 [11.0-17.8]mmHg (P < .05). PR interval and, hence, AV conduction delay prolonged incrementally with increasing pacing rates. Simulations corroborated these clinical findings, showing mLAP reduction at a moderately increased pacing rate and a subsequent increase at higher rates. Moreover, simulations suggested that mLAP reduction is optimized when AV conduction delay shortens with increasing rate. Accelerated pacing acutely reduces left-heart filling pressure in patients undergoing AF catheter ablation and computer simulations with HFpEF features, suggesting it as a potential therapeutic strategy to alleviate congestion symptoms. Virtual HFpEF patient cohorts hypothesize that AV sequential pacing may further optimize this therapy's beneficial effects.

Pacing analysis and comparison of TOP-10 and NOT TOP-10 Ultra Trail Cape Town 100-km finishers.

Pacing strategies during endurance efforts vary depending on athlete experience, race length, and terrain. In ultramarathon trail running the specific race route profile can have a significant impact on optimal pacing strategy. The aim of this study was to determine the relationship between uphill, downhill and level running with overall performance and to compare the difference in pacing strategies between top 10 (TOP-10) and non-top 10 (NOT TOP-10) finishers of a 100-km ultra-trail marathon with +5000-m elevation gain. Fifty male finishers (TOP-10: N.=6, NOT TOP-10, N.=44) and forty-six individual segments (1.5±1.2 km) were analyzed based on 2021 100-km UTCT STRAVA data. Relative segment speed and CV% were used to identify pacing strategies. Spearman Rank and Mann Whitney-U tests were used to analyze the data. Significance was set at P<0.05. Uphill running had the strongest relationship with overall performance (r=0.826, P<0.01). Substantially weaker relationships between overall running performance and level (r=0.402, P<0.01) and downhill (r=-0.382, P<0.01) running performance were found. The CV% was significantly lower in TOP-10 (32.10±1.81) than NOT TOP-10 (35.39±4.43) (U=24, r=0.46, P<0.01). Uphill running performance remains a valuable measure of overall trail running performance as it represents a higher percentage of overall running demand. TOP-10 runners have diminished decay in initial running speed than NOT TOP-10 runners, despite a generally high variation in pace and net positive split in ultra-trail running.

Mitral regurgitation improvement following left bundle branch pacing versus right ventricular septum pacing: a dedication to postoperative amelioration of mitral regurgitation

Abstract Background Mitral regurgitation (MR) is correlated with left ventricular (LV) remodeling and LV function in patients. Left bundle branch pacing (LBBP) exhibits a significant decline in MR in left bundle branch block (LBBB) and cardiomyopathy patients. This research aims to evaluate the influence of LBBP on MR in comparison to right ventricular septal pacing (RVSP) in patients with atrioventricular block (AVB) or sick sinus syndrome (SSS). Methods Sixty consecutive patients with SSS or AVB were enrolled if they underwent pacemaker implantation via LBBP or RVSP. Patients with a history of mitral valve surgery were excluded. Echocardiogram parameters were assessed to measure MR and LV remodeling as well as LV function at baseline and follow-up. Results Thirty-six patients (60 %; mean age: 70.39 ± 14.80 years; 61.1 % male) underwent successful LBBP, and 24 patients (40 %; mean age: 71.58 ± 10.91 years; 66.7 % male) underwent RVSP. The average follow-up duration was relatively comparable between the two groups. In comparison to RVSP, LBBP demonstrated significant changes in MR area, and severity at baseline and follow-up (P&amp;lt;0.05). LBBP independently predicted MR amelioration in patients who underwent pacemaker implantation (HR=0.289, CI=0.087–0.9961; P=0.043). At follow-up, the LBBP subgroup with moderate/severe MR exhibited significantly shorter lead-TVA-dist, higher left atrium (LA) diameters, and mitral E/A ratio (P&amp;lt;0.05) compared to the none/mild MR subgroup. In LBBP with MR amelioration, LV remodeling (ΔLVEDD) was significantly enhanced compared to baseline (P=0.016). Additionally, a non-significant trend toward better improvement in LV function (ΔLVEF and ΔE/A) was observed in patients with MR amelioration. Conclusion LBBP, considered an optimal pacing technique for SSS or AVB patients, may substantially reduce MR and subsequently enhance LV remodeling and function compared to RVSP. This open, observational pilot study warrants confirmation through further investigations.Comparison between LBBP and RVSPKaplan-Meier curves for MR amelioration

Rationale and Design of OPT-RATE AF: A Randomized Clinical Trial of Increased Physiologic Pacing Rates in Heart Failure With Preserved Ejection Fraction

Cardiac physiologic pacing (CPP) after atrioventricular node (AVN) ablation for persistent atrial fibrillation (AF) has improved outcomes in patients with heart failure with reduced and preserved ejection fraction (HFpEF). Emerging evidence suggests patients with HFpEF benefit from higher heart rates, yet the optimal pacing rate after AVN ablation remains unknown. OPT-RATE AF is a prospective, randomized crossover study of patients with HFpEF following AVN ablation for persistent AF (NCT06445439). Approximately 60 patients with AF and AVN ablation, CPP, and HF with left ventricular ejection fraction ≥50% will be enrolled. Participants will be randomly assigned 1:1 to a pacing lower rate limit of 60 beats-per-minute (bpm) for 3 months and then switched to a rate of 80 bpm for 3 months, and vice versa. The primary endpoint is change in exercise capacity assessed by the 6-minute walk test. Notable secondary outcomes will include change in Kansas City Quality of Life Questionnaire (KCCQ-12), creatinine and natriuretic peptide, and clinical events. Patient mortality and HF hospitalizations will be recorded at each phase. EKG, echocardiogram, pacemaker interrogation, and primary and secondary outcomes will be recorded at baseline, 3 months, and 6 months. Study enrollment is ongoing and estimated to be completed by 2026. OPT-RATE AF is a randomized clinical trial that will determine the effect of a higher pacing rate in patients with persistent AF and HFpEF following AVN ablation and/or CPP. Study findings will provide insight on the role of chronotropy in improving QoL and other important cardiovascular outcomes.

His Bundle Pacing and Left Bundle Branch Pacing in Patients with Heart Failure.

His bundle pacing (HBP) and left bundle branch pacing (LBBP) are emerging therapies for patients with heart failure and conduction disorders, offering potential advantages over traditional pacing methods. These approaches aim to restore physiological conduction and improve cardiac function more effectively. This study aims to evaluate the efficacy and safety of HBP and LBBP in patients with heart failure and conduction disturbances, comparing these techniques to conventional pacing. A comprehensive review of recent studies and clinical trials was conducted, focusing on the performance of HBP and LBBP in improving cardiac function, reducing QRS duration, and enhancing overall patient outcomes. The analysis includes data on clinical efficacy, procedural safety, and long-term benefits associated with these pacing modalities. Both HBP and LBBP have demonstrated significant improvements in cardiac function and clinical outcomes compared to conventional pacing. HBP effectively restores physiological conduction with improved synchronization and a reduction in QRS duration. LBBP has shown enhanced left ventricular activation, leading to better overall cardiac performance. Both techniques have been associated with a lower incidence of complications and a higher success rate in achieving optimal pacing thresholds. HBP and LBBP offer promising alternatives to traditional pacing for patients with heart failure and conduction disorders. These advanced pacing strategies provide superior clinical outcomes and improved cardiac function with reduced risk of complications. Further research and clinical trials are needed to fully establish the long-term benefits and safety profiles of these techniques in diverse patient populations.

BOATMAP: Bayesian Optimization Active Targeting for Monomorphic Arrhythmia Pace-mapping

Recent advances in machine learning and deep learning have presented new opportunities for learning to localize the origin of ventricular activation from 12-lead electrocardiograms (ECGs), an important step in guiding ablation therapies for ventricular tachycardia. Passively learning from population data is faced with challenges due to significant variations among subjects, and building a patient-specific model raises the open question of where to select pace-mapping data for training. This work introduces BOATMAP, a novel active learning approach designed to provide clinicians with interpretable guidance that progressively assists in locating the origin of ventricular activation from 12-lead ECGs. BOATMAP inverts the input–output relationship in traditional machine learning solutions to this problem and learns the similarity between a target ECG and a paced ECG as a function of the pacing site coordinates. Using Gaussian processes (GP) as a surrogate model, BOATMAP iteratively refines the estimated similarity landscape while providing suggestions to clinicians regarding the next optimal pacing site. Furthermore, it can incorporate constraints to avoid suggesting pacing in non-viable regions such as the core of the myocardial scar. Tested in a realistic simulation environment in various heart geometries and tissue properties, BOATMAP demonstrated the ability to accurately localize the origin of activation, achieving an average localization accuracy of 3.9±3.6mm with only 8.0±4.0 pacing sites. BOATMAP offers real-time interpretable guidance for accurate localization and enhancing clinical decision-making.

Evaluation of the Results of Left Bundle Branch Pacing after Atrioventricular Junction Ablation in Patients with Chronic Atrial Fibrillation

Atrioventricular junction ablation (AVJA) together with the implantation of cardiac pacemaker has become a recognized and effective treatment strategy for patients with symptomatic tachysystolic atrial fibrillation that does not respond to heart rate control drug therapy. Left bundle branch pacing (LBBP) is a physiological alternative to right ventricular and biventricular pacing. The aim. To analyze the clinical results of the average duration with the use of LBBP and AVJA. Materials and methods. Over the period from January 2023 to July 2024, LBBP with subsequent AVJA was applied at the National Amosov Institute of Cardiovascular Surgery in 18 patients as a method of treatment of chronic tachysystolic atrial fibrillation to achieve heart rate control. Results. Mid-term results (at least 1 month) could be monitored in 15 out of 18 patients (84%); in the other three (16%) patients the time between pacemaker implantation and AVJA was too short. The mean period from pacemaker implantation to control examination was 5.07 ± 2.79 months (minimum period 1 month, maximum 12 months). During the period from implantation and ablation to the control observation in the study group, it was possible to observe an increase in left ventricular ejection fraction from 39.12 ± 10.56% to 46.38 ± 7.09%, p = 0.035; decrease in the values of end-diastolic volume from 184.22 ± 76.76 to 167.85 ± 36.93 ml, p = 0.074; decrease in the right ventricular pressure from 43.07 ± 8.29 to 34.38 ± 4.78 mm Hg, p = 0.013. It was also possible to observe a decrease in the left bundle branch capture thresholds from 1.27 ± 0.58 to 0.7 ± 0.39 V at 0.4 ms, p = 0.016; and a decrease in the average LBBP endocardial lead resistance from 638 ± 172.83 to 529.4 ± 120.15 Ohm, p = 0.012. Conclusions. Implantation of the LBBP pacemaker and AVJA was not associated with the occurrence of complications both in the intraoperative and postoperative periods, as well as in the remote period of the average duration in the studied group. The use of this approach in patients with chronic atrial fibrillation made it possible in a series of consecutive patients to improve the systolic function of the left ventricle, to reduce the values of the end-diastolic volume of the left ventricle and the right ventricular pressure at optimal pacing parameters.

Unveiling the relationship between the speed of internationalization and export resilience of MNCs in China: the moderating role of digital capability

ABSTRACT This paper presents a comprehensive analytical framework to examine the export resilience of multinational corporations (MNCs) in China, with a specific focus on the dual role of internationalization speed from both breadth and depth perspectives. Our findings unveil a nuanced impact: the speed of internationalization breadth (SIB) positively strengthens export resilience, while the speed of internationalization depth (SID) detrimentally impacts export resilience. Significantly, digital capability not only mitigates the adverse effects of SID but also amplifies the positive effects of SIB. Digitization acts as a catalyst, fortifying the advantages and alleviating the drawbacks in the relationship between internationalization speed and export resilience. These insights offer valuable practical guidance for MNCs in determining the optimal strategy and pace of internationalization to enhance export resilience.

Pacing strategies in marathons: A systematic review

BackgroundThe pacing strategy embodies the tactical behavior of athletes in distributing their energy across different segments of a race; therefore, a quantitative analysis of pacing strategies in marathon races could deepen the understanding of both pacing behavior and physical capacity in marathon athletics. ObjectiveThe objective of this systematic review was to synthesize and characterize pacing strategies in marathon road races by exploring the categories of pacing strategies and the factors that influence these strategies during marathon events. MethodsPreferred Reporting Items for Systematic Reviews guidelines were followed for systematic searches, appraisals, and syntheses of literature on this topic. Electronic databases such as Science Direct, SPORTDiscuss, PubMed, and Web of Science were searched up to July 2024. Records were eligible if they included pace performance measurements during competition, without experimental intervention that may influence their pace, in healthy, adult athletes at any level. ResultsA total of 39 studies were included in the review. Twenty-nine were observational studies, and 10 were experimental (randomized controlled trials). The assessment of article quality revealed an overall median NOS score of 8 (range 5–9). The included studies examined the pacing profiles of master athletes and finishers in half-marathon (n = 7, plus numbers compared to full marathon), full-marathon (n = 21), and ultramarathon (n = 11) road races. Considering that some studies refer to multiple pacing strategies, in general, 5 studies (∼13 %) reported even pacing, 3 (∼8 %) reported parabolic pacing, 7 (∼18 %) reported negative pacing, and 30 (∼77 %) reported positive pacing during marathon competitions. Gender, age, performance, pack, and physiological and psychological factors influence pacing strategies. ConclusionThis study synthesized pacing performance in marathons and highlighted the significance of examining pacing strategies in these events, offering valuable insights for coaches and athletes. Several key findings were highlighted: (1) pacing profiles and pacing ranges were identified as the primary indicators of pacing strategies; (2) the pacing strategy was found to be dynamic, with the most substantial effects attributed to gender and distance; and (3) three distinct types of pacing strategies for marathons were classified: positive, negative, and even pacing. These findings advance the understanding of marathon pacing strategies by shedding light on the factors that influence athletes’ pacing decisions and behaviors. Additionally, these findings offer practical benefits, aiding athletes in making well-informed tactical choices and developing effective pace plans to enhance marathon performance. However, due to the complex nature of marathon racing, further research is required to explore additional factors that might impact pacing strategies. A better grasp of optimal pacing strategies will foster progress in this area and serve as a basis for future research and advancements.

Bradycardia-dependent conduction block of the atrial tissue in a patient after double-chamber implantable cardioverter defibrillator implantation

Seldom are reports of phase 4 block or bradycardia-dependent conduction block in atrial tissue found in the literature. Here, we describe the case of a patient with sick sinus syndrome with Torsade de Pointes who, following the implantation of a double-chamber implantable cardioverter defibrillator, developed intra-atrial bradycardia-dependent conduction block. The patient's optimal pacing parameters were achieved by raising the rate.

Understanding the role of temporary epicardial pacemakers after heart transplantation in the cardiac intensive care unit

The International Society of Heart and Lung Transplantation (ISHLT) guidelines for the care of heart transplant recipients recommend the placement of temporary epicardial pacing wires at the time of surgery. However, there is little data regarding optimal postoperative pacing modality and its implication on ICU length of stay (LOS).We conducted a single-center retrospective cohort study of 187 patients who underwent heart transplantation from January 1, 2019 to February 28, 2023 and had postoperative epicardial pacemaker wires placed. The study's primary outcome was to observe the association between pacing modalities and prolonged ICU LOS (greater than 5 days). The secondary outcome was to observe the association between pacing modalities and prolonged hospital LOS (greater than 15 days), readmission within 30 days of discharge, days on inotropic and pressor support, death, high-grade rejection on biopsy, coronary artery vasculopathy at 1 year, primary graft dysfunction, mediastinitis, and development of a malignancy.22 patients (12%) had their pacing mode turned off at the time of arrival to the ICU, 36 patients (19%) had their pacing mode set to AAI, 101 patients (54%) had theirs set to DDD, and 28 (15%) had theirs set to VVI. No mode of epicardial pacing was associated with an increased ICU LOS, hospital LOS, increased readmission rates, increased short-term adverse effects (STAEs), increased long-term adverse effects (LTAEs), or increased duration of support with vasoactive medications.Our study demonstrated no significant association between the mode of temporary pacing and LOS or adverse effects after heart transplantation.

Optimizing electrical efficacy of leadless cardiac resynchronization therapy and leadless left ventricular septal pacing: Insights on left and right ventricular activation from electrocardiographic imaging

BackgroundLeadless cardiac resynchronization therapy (CRT) using the WiSE-CRT system is an emerging heart failure treatment. An implanted electrode delivers lateral or septal endocardial left ventricular pacing (LVP) upon detection of a right ventricular pacing (RVP) stimulus from a co-implanted device, thus generating biventricular pacing (BiVP). Electrical efficacy data regarding this therapy, particularly leadless LV septal pacing (LVSP) for potential conduction system capture, is limited. ObjectiveTo evaluate the acute performance of leadless CRT using electrocardiographic imaging (ECGi), and assess the optimal pacing modality (OPM) of LVSP based on RV and LV activation. MethodsTen WiSE-CRT recipients underwent an ECGi study testing: RVP; BiVP; LVP only; and LVP with an optimised atrioventricular delay (LV-OPT). BiV, LV and RV activation times (BIVAT-90, LVAT-95, RVAT-90), plus LV and BiV dyssynchrony index (LVDI, BIVDI) were calculated from reconstructed epicardial electrograms. The individual OPM yielding the greatest improvement from baseline was determined. ResultsBiVP generated a 23.7% improvement in BiVAT-90 (p=0.002). An improvement of 43.3% was observed at OPM (p=0.0001), primarily through reductions in RVAT-90. At OPM, BiVAT-90 improved in patients with lateral (43.3%, p=0.0001, n=5) and septal LV implants (42.4%, p=0.009, n=5). The OPM varied by individual. LVP or LV(OPT) were mostly superior in patients with LVSP, and for those in SR and LBBB (n=4). ConclusionLeadless CRT significantly improves acute ECGi-derived activation and dyssynchrony metrics. Using an individualised OPM improves efficacy in selected patients. Effective LVSP is feasible, with fusion pacing at LV(OPT) mitigating the potential deleterious effects on RV activation.

P-258 Not too big, not too small: euploid blastocysts that lead to live birth have an optimal surface area, diameter and optimal pace of development

Abstract Study question Does embryo diameter and surface area at tsB and tB as determined by AI predict live birth (LB) potential amongst euploid blastocysts? Summary answer Euploid blastocysts with optimal diameter (tsB:120-129; tB:136-140μm) and surface area (tsB:11771-13577; tB:15000-15643μm2) are more likely to lead to LB than larger or smaller blastocysts. What is known already Current embryology consensus favours larger blastocysts based on Gardner grading, associating expansion with higher quality. Human assessment of embryos is subjective, and it is unknown whether this dogma holds when assessing pre-expansion blastocyst stages. The impact of blastocyst surface area and diameter at tSB and tB; and pace of development on LB remains unclear. This may help clarify whether large blastocysts are associated with accelerated embryo growth and abnormal metabolic processes. The study’s objective was to use AI to quantitatively determine the optimal embryo surface area and diameter of euploid blastocysts that lead to live birth. Study design, size, duration Retrospective study including 97 time-lapse videos of euploid embryos with known live birth outcomes from January to December 2021 Participants/materials, setting, methods Embryo diameter and surface area were measured at start of blastulation (tSB) and at time of blastulation (tB) by an AI model (CHLOE-EQ, Fairtility Ltd). Live birth (LB) outcomes were manually annotated by embryologists. An Optimal embryo surface area and diameter were determined by the highest live birth rate and the suboptimal range was determine by a decreased Live birth rate. A comparison between the optimal and suboptimal live birth rate was measured using chi-square. Main results and the role of chance Moderately sized embryos were found to have higher LB outcomes. At tSB, optimal surface area was 11771-13577 um2, while optimal embryo diameter was 120-129μm. LB rate for optimal embryo surface area was higher than for suboptimal [Optimal 80% (20/25) vs Suboptimal 55% (40/72), p &amp;lt; 0.001]. In addition, optimal embryo diameter had higher LB rates than embryos with suboptimal diameter [80% (16/20) vs 52% (31/60), p &amp;lt; 0.05). At tB, optimal embryo area was 15000-15643μm2 and optimal embryo diameter 136-140μm. LB rate for optimal embryo surface area was higher than for suboptimal 82% (14/17) vs 49% (36/73), p &amp;lt; 0.05]. Optimal embryo diameter had higher LB rates than embryos with suboptimal diameter (77% 20/26 vs 47% 30/64, p &amp;lt; 0.05). Embryos with an optimal surface area and diameter were slower than bigger suboptimal embryos: t2 (26±2 vs 25±2), t8 (59±8 vs 53±6), t9 + (71±6 vs 67±6), tM (82±7 vs 77±8), tSB (99±6 vs 93±6), tB (107±7 vs 100±6), tEB (137±2 vs 122±12); t8-t5 (12±10 vs 6±5), t8-t2 (33±8 vs 28±5), tEB-tSB (34±2 vs 23±9), p &amp;lt; 0.05. Optimal vs small suboptimal embryos were faster in t9 + (71±6 vs 76±4), tEB (121±11 vs 137±2, tEB-tSB (20±10 vs 34±1). But were slower in t8-t5 (12±10 vs 5±6), t8-t2 (33±8 vs 28±5), p &amp;lt; 0.05. Limitations, reasons for caution This is the first time a quantitative embryo surface area and diameter has been studied in its correlation with live birth. Generalisation requires the replication across diverse centers with varying demographic profiles to validate findings and establish broader applicability within the context of assisted reproductive technologies. Wider implications of the findings This data-driven approach can support the embryo selection process, correlating quantitative parameters with live birth outcomes, thereby refining the precision of the decision-making in IVF. This level of quantitative data of embryo surface area and diameter is only accessible through AI tools. Trial registration number IRB-007CITY-FL21.08.2023

Complementary use of conduction system pacing techniques for the “pace and ablate” strategy in permanent atrial fibrillation - a case report

Abstract Introduction The feasibility of the conduction system pacing combined with atrioventricular node ablation was demonstrated in patients with atrial fibrillation in whom rate control can’t be achieved with medication and heart failure. Clinical case We present a case of an 82-year-old man with a personal history of permanent atrial fibrillation, admitted with symptoms of heart failure. The resting electrocardiogram showed a very fast ventricular response, and the echocardiography showed a depressed left ventricular function, raising the suspicion of a tachycardia-mediated cardiomyopathy. Since the patient was on maximum doses of atrioventricular nodal-blocking drugs, we opted for a physiological pacing and atrioventricular node ablation strategy. First, the His bundle capture was achieved at low pacing thresholds, and ablation of the atrioventricular node was attempted. Unfortunately, after several failed attempts, an acute increase in the His bundle capture threshold was noted, suggesting inadvertent tissue ablation beneath the pacing lead. In this scenario, we removed the lead from the His bundle area and achieved optimal left bundle branch area pacing. With the lead in this position, atrioventricular node ablation was performed during the first attempt. At the six-month follow-up, there was no recovery of atrioventricular node conduction. Device interrogation revealed stable pacing and sensing parameters, and there was a significant improvement in clinical status and left ventricular function. Conclusions Mastering both His bundle pacing and left bundle branch area pacing offers the potential to overcome intraprocedural challenges, giving alternative strategies to achieve physiological pacing. These approaches can be used interchangeably based on the evolving dynamics of the procedure and the patient’s specific needs.

Impact of left bundle branch area pacing on right cardiac chambers dimensions and function. a medium term single center echocardiographic study

Abstract Introduction Left bundle branch area pacing (LBBAP) has become, in the last years, the preferred method for physiological pacing due to a wider target area, optimal pacing and sensing thresholds, and stable parameters over time. LBBAP ensures rapid and synchronous left ventricular (LV) activation through the left-sided conduction system. On the other hand, there is little data on right ventricular (RV) activation in LBBAP. The purpose of this study was to evaluate the impact of LBBAP on the right heart anatomy and function over a mid-term follow-up period. Material and methods All consecutive patients with successful LBBAP for bradyarrhythmic indications between February 2021 and July 2022 at our institution were eligible for this study. Left bundle branch capture was defined as a paced QRS complex of right bundle branch block morphology, and proof of transition from non-selective to selective capture with differential pacing maneuvers. To avoid confounders, patients with LV ejection fraction below 40% and with severe valvular disease were excluded. In the end, 57 patients were prospectively evaluated. Patient and procedural characteristics were recorded at baseline and follow-up. Also, right atrial (RA) volume, RV basal diameter, tricuspid annulus peak systolic elevation (TAPSE), RV S` wave (RVS`W), and tricuspid regurgitation (TR) were evaluated before the procedure and at the end of the follow-up period. Results The mean age of the patients was 68.9± 10 years, and 70% were males. 29.8% had a baseline right bundle branch block, and 22.8% had a left bundle branch block morphology. The baseline LV ejection fraction was 54.3 ± 9.9 %. The paced QRS duration was similar to the baseline values (128.5 ± 16.3 vs. 134.4 ± 30.4 msec, p=0.119). The pacing and sensing thresholds were 0.7 ± 0.3 V at 0.4 ms pulse duration and 9.7 ± 4.2 mV, respectively. The mean LV activation time (measured as the R wave peak time in V6) was 80.9 ± 12 msec, and the mean RV activation time (measured as the difference between QRS duration and LV activation time) was 51.9 ± 24.2 msec. The patients were followed over a mean period of 591.2 ± 150.3 days. There were no complications over the follow-up period that led to pacing interruption. The follow-up pacing (0.6 ± 0.2 V, p=0.003) and sensing (11.7 ± 6 mV, p= 0.023) thresholds showed significant improvement compared to the procedural values. The right heart echocardiographic evaluation showed non-statistically significant changes between the follow-up and the baseline values for RA volumes (57.9 ± 33.7 vs. 51.5 ± 28.4 ml, p=0.122), RV basal diameter (32.8 ± 5.4 vs. 31.8 ± 6.4 mm, p=0.31), RVS`W (12.8 ± 3.2 vs. 12.85 ± 2.7 cm/sec, p=0.933), and TR (1.8±0.8 vs. 2±1, p=0.07). On the other hand, there was a significant improvement in the TAPSE (22.2±4.3 vs. 20.7±3.6 mm, p=0.021). Conclusions LBBAP was associated with preserved dimensions and function of the right cardiac chambers over a medium-term follow-up period.

Optimising electrical performance of leadless cardiac resynchronisation therapy and leadless LV septal pacing

Abstract Introduction Leadless left ventricular (LV) endocardial pacing with the WiSE-CRT System is an emerging form of cardiac resynchronisation therapy (CRT). The system was designed to provide lateral wall LV pacing (LVP) via an endocardial receiver electrode in response to detection of a right ventricular pacing (RVP) stimulus from a co-implanted device, thereby delivering near-simultaneous biventricular pacing (BiVP). However, it is unclear whether BiVP generates the optimal electrical performance in this system, particularly in the context of leadless LV septal pacing, a novel use for leadless CRT. Aim We aimed to characterise the acute performance of leadless CRT at different pacing modalities using electrocardiographic imaging (ECGi). Methods Patients with the leadless CRT underwent an acute ECGi study. The following pacing modalities were tested: RVP; BiVP; LVP; and LVP with an electrically optimised atrioventricular delay (LV-OPT) in patients with sinus rhythm (SR). Reconstructed epicardial electrograms (Figure 1) were used to calculate BiV activation time (BIVAT-90), LV activation time (LVAT-90), RV activation time (RVAT-90), LV dyssynchrony index (LVDI), and BiV dyssynchrony index (BIVDI). For each metric, the improvement compared to baseline rhythm was calculated, and the optimal pacing modality (OPM) in each patient was determined. Results Ten patients were studied, 5 receiving septal LVP, and 5 receiving lateral LVP. The underlying rhythm in 4 patients was SR with left bundle branch block (LBBB), and atrial fibrillation (AF) with complete heart block (CHB) in the remaining 6. BiVP generated a 23.7% improvement in BiVAT-90 compared to baseline (p=0.002). An individualised OPM resulted in a 43.3% BiVAT-90 improvement compared to baseline (p=0.0001), thus a 19.6% improvement compared to BiVP (p=0.02, Figure 2A). Using an OPM, BiVAT-90 was significantly improved in both patients with lateral (43.3%, p=0.0001) and septal LVP (42.4%, p=0.009). The BiVAT-90 OPM varied between patients (Figure 2B). BiVP was the OPM in 4/10 patients, all of whom had AF with CHB. BiVP was the OPM in 1/5 patients receiving LV septal pacing, with LVP or LV-OPT performing best in the remaining 4. In 3/4 patients in SR, LV-OPT was the OPM. Choosing the OPM increased performance primarily through significant improvements in RVAT-90 compared to BiVP (36.5% versus -8.2%, p =0.002). Conclusion Leadless CRT, both with lateral and septal LVP, significantly reduces electrical activation times and improves electrical dyssynchrony. Individualised selection of the OPM may be required with leadless CRT to accommodate for varying conduction disease phenotypes and implant locations.

The CHOIR study: acute hemodynamic effects of different pacing strategies in hypertrophic obstructive cardiomyopathy

Abstract Background The majority of patients with hypertrophic cardiomyopathy present with dynamic left ventricular (LV) outflow tract obstruction (LVOTO), referred to as hypertrophic obstructive cardiomyopathy (HOCM). Symptomatic treatment aims at reducing LVOTO with either medical therapy, invasive septal reducing therapies, or pacemaker therapy. There is conflicting evidence regarding the efficacy of pacemaker therapy. The effect of pacing strategies at physical exertion has not been investigated in HOCM. Purpose To identify the optimal pacing strategy for reducing LVOTO without compromising cardiac output at rest and exercise in HOCM. Methods In this ongoing project, we have so far included eight patients with symptomatic HOCM referred to our hospital for alcohol septal ablation (ASA). The day before ASA, we placed temporary pacing leads in the right atrium, the right ventricular (RV) apex and on the LV lateral wall. We also inserted a pulmonary artery catheter and performed per operative echocardiography. All patients had sinus rhythm. Intrinsic rhythm served as baseline and was followed by atrial sensed RV pacing, LV pacing and biventricular (BiV) pacing at rest and during supine cycling. We assessed LVOTO by echocardiography, and cardiac output by the thermodilution method under intrinsic rhythm and all pacing modalities. Results The mean age was 52±15 years, and two of eight patients were female. The mean maximal LV wall thickness was 16±1 mm. The resting LVOTO was 50±23 mmHg. Due to difficulties in placing the LV lead within a reasonable time frame, complete study protocol was not performed in all patients. All eight patients performed RV pace at rest, but only five patients (63 %) were LV and BiV paced at rest. Five patients performed supine cycling but only four patients completed with RV and BiV pacing. The graphs display LVOTO and CO in sinus rhythm and the different pacing maneuvers at rest and during supine cycling. At rest, 6 out of 8 patients (75%) had LVOTO reduction during RV pace, and CO was unchanged. Four of five patients (80%) had LVOTO reduction during BiV and LV pace compared to sinus rhythm, also with unchanged CO. During supine cycling four of five patients (80%) had a reduction of the LVOTO gradient during RV and BiV pacing, without significant CO change. No complications occurred during the interventions. Conclusion In this ongoing study on cardiac pacing in HOCM, RV, LV, and BiV pacing reduced LVOTO while CO remained unchanged at rest and during exercise.

PROBLEMS OF REGULATING ECO-POSITIVE CHANGES IN SMART CITY FORMATION PROCESSES

Architects, scientists of the Kharkiv National University of Urban Economy. O.M. Beketov conducts research focused on writing the terms of reference for the "Software package for modeling the city as a dynamic system". This development is devoted to the problem of improving SMART-oriented software and analytical tools based on working with large data arrays (BIG DATA) in architectural and urban planning management. The purpose of this toolkit is prognostics and monitoring of the architectural component of the city as a dynamic system. The relevance of its implementation lies in the optimization of the principles of functioning of the architectural component of the city with the calculation of its impact on the processes of functioning of other urban subsystems.&#x0D; As a development and improvement of this direction, a method for determining the optimal speed and acceleration of positive transformations of the architectural component of cities, based on the indicator "Ecological footprint of architecture", which is currently being developed, is proposed. It is a method of developing step-by-step strategies for the development of the architectural component of cities. The main problem is to determine the optimal pace of social, environmental and economic changes in the processes of achieving a sustainable state of the city. Too rapid changes will inevitably lead to an aggravation of the socio-economic crisis. Slow change has a negative impact on the sustainability and ecology of the region. For this reason, in this article, the authors have developed a concept for the formation of an indicator that determines the vector, speed and acceleration of modernization of the architectural component of the city. As a factor limiting the rate of change to a socially acceptable level, the indicator of "Sustainable accessibility of vital goods for the population" was chosen.