bluuebunny/crossref_metadata_2025 huggingface dataset:
A preliminary exploration of feminist translation strategies
Authors: Tan Ying
Published: October 2024

Interventionist feminist translation theory prompts translators to identify and rectify sexist notions in source
texts. It encourages critical awareness and reinterprets texts through a feminist lens. Based on interventionist feminist
translation theory, this research investigates how depictions of women’s physical charm, often unnecessary and rooted in
stereotypes, are handled in translations. Focusing on seven instances from Liu Cixin’s The Three-Body Trilogy — a
notable Chinese science fiction work debated for its sexism —, the study contrasts the source text with its English and Spanish
translations. By analysing the selected fragments of the Chinese novel and the unmissable alterations to the original in the
target texts, this paper demonstrates how the techniques of elision and adaptation can help translators iron out the sexist
implications. The findings contribute to our understanding of feminist translation strategies for addressing sexist elements in
literary works.
Cultural Fusion at Pizza 4P’s Vietnam
Authors: Lee Pham Phuong
Published: October 2024

Information

© The Author 2024
Fast unfolding of communities in large networks: 15 years later
Authors: Blondel Vincent , Guillaume Jean-Loup , Lambiotte Renaud
Published: October 2024

The Louvain method was proposed 15 years ago as a heuristic method for the fast detection of communities in large networks. During this period, it has emerged as one of the most popular methods for community detection: the task of partitioning vertices of a network into dense groups, usually called communities or clusters. Here, after a short introduction to the method, we give an overview of the different generalizations, modifications and improvements that have been proposed in the literature, and also survey the quality functions, beyond modularity, for which it has been implemented. Finally, we conclude with a discussion on the limitations of the method and perspectives for future research.
Therapeutic effects of LIPUS on the elasticity of injured tendons: animal experiment
Authors: Zheng Qian , Liu Mengyao , Jiang Lixin , Ta Dean
Published: October 2024

This paper aims to explore the efficacy and duration of low-intensity pulsed ultrasound (LIPUS) treatment in improving the elastic properties of injured tendons through animal experiments. 48 healthy 3-month-old New Zealand white rabbits (weight 2.5-3.0 kg) were randomly divided into the Control group (n = 9) and model group (n = 39). The rabbits in the model group were injected with 0.2ml PGE2 mixed solution (concentration: 500 ng/0.2ml) into the Achilles tendon 2cm above the calcaneus, once a week, for 4 weeks, to build the Achilles tendon injury model. The Control group was injected with the same volume of PBS solution. Three rabbits were randomly selected from the Control and model groups for model validation, the model group was randomly divided into the Model (n = 6) and LIPUS (n = 30) groups. Then the LIPUS was randomly divided into the LIPUS1 (n = 6), LIPUS4 (n = 6), LIPUS7 (n = 6), LIPUS14 (n = 6), and LIPUS28 (n = 6) subgroups. Following interventions on days 1, 4, 7, 14, and 28, tendon elasticity was assessed by shear wave elastography (SWE). The elastic modulus of the Model, LIPUS1, and LIPUS4 groups exhibited a significant decrease compared to the Control group during the early stages of treatment. With prolonged treatment duration, the elastic modulus of LIPUS groups gradually increased. By day 7, no statistically significant difference in elastic modulus existed between the LIPUS7 and Control groups, indicating that LIPUS treatment had successfully restored the Achilles tendon’s elasticity to a healthy state. In summary, LIPUS therapy demonstrates the potential to effectively ameliorate the elastic properties of injured Achilles tendons.
A numerical simulation method for ultrasonic transmission in cancellous bone based on a four-parameter random growth method
Authors: Chou Xingxing , Ren Wei , Han Yueqi , Wang Wei , Wang Jin
Published: October 2024

Quantitative ultrasound (QUS) has been widely used in non-destructive evaluation of bone health in research and clinical practice. To make a more accurate bone evaluation, the transmission characteristics of ultrasound in the bone need to be understood in detail. In the two-dimensional finite element model, cancellous bone is usually simulated by a non-porous structure solid or by approximating bone trabeculae as ellipses, which is different from real bone. However, although the error of the model constructed by bone CT images is small, it needs to be based on real bone samples, and the samples are limited. Therefore, a modeling method of cancellous bone based on four-parameter random growth method was proposed in this paper, and on this basis, numerical simulation of ultrasonic transmission was carried out. Firstly, based on the four-parameter random growth method, the aggregation algorithm is used to concentrate discrete pixels and smooth the edge of pores. Meanwhile, the built-in algorithm ensures the same porosity before and after processing to reduce the discrete pore structure. Secondly, based on COMSOL to establish the simulation model of ultrasonic propagation in cancellous bone, we analyzed the change of acoustic field distribution, discussed the correlation between the porosity of cancellous bone and backscattering coefficient (BSC) based on the ultrasonic backscattering method, and compared the experimental results of CT scan images of bone samples. The experimental results show that the cancellous bone modeling method in this paper has the same conclusion as the method based on CT images, which verifies the feasibility of this method. This method can generate a geometric model of the cancellous bone microstructure with specified porosity and different bone trabecular distribution, which is similar to the real bone structure, and can be directly imported into the finite element software to facilitate the study of bone microstructure related problems. It provides a more convenient method to study the mechanism of ultrasonic propagation in cancellous bone and has important significance in solving the inverse problem of recovering effective bone parameters from the received ultrasonic signals.
Electromagnetic compatibility study of acoustoelectric logging detector
Authors: Lu Junqiang , Qin Zhenyu , Men Baiyong , Chen Hongzhi
Published: October 2024

The acoustoelectric effect logging detector can achieve downhole acoustoelectric effect measurement, but the excitation of the acoustic transducer can generate significant electromagnetic interference (EMI) signals, it is difficult to effectively measure weak converted signals of acoustoelectric effect underground. The EMI problem of acoustoelectric effect logging detectors can be solved by studying EMI characteristics. Based on the analysis of the structure, measurement function, and measured interference signals of the receiving electrodes of the detector, the EMI sources, coupling paths, and sensitive components in the detector were studied. The basic process of EMI generated by high-voltage pulse excitation source of acoustic transducer is analysed, and two electromagnetic coupling interference analysis models for detectors, namely conductive coupling and borehole electromagnetic coupling, are established. This study can provide a fundamental method and reference for electromagnetic compatibility analysis of acoustoelectric effect logging detectors.
An application and discussion of wide-band signal processing technology in the primary calibration for hydrophones
Authors: Jia Guanghui , Chen Yi , Wang Shiquan , Zhang Dong
Published: October 2024

Wide-band signals are potentially available in the measurement of transducers, which can obtain wide-band responses of electroacoustic parameters of them directly. The hydrophone of B&K 8103 is calibrated in a Φ 1.2 m×1.8 m small water vessel by wide-band signal processing technology in the frequency range of 3.15 kHz to 100 kHz. A thin pellicle co-vibrates with acoustic particle in the free-field, and its oscillation can be detected by a laser Doppler vibrometer, which can estimate the acoustic pressure distribution. The transfer function model is established in a small water vessel, and the wide-band frequency responses of the transfer impedance of transducer and hydrophone as well as the transfer impedance of transducer and pellicle in the small water vessel are calculated respectively. The wide-band signal processing technology of frequency domain filter process are used, which can isolate the reflecting acoustic wave from the boundaries and the surface of the water vessel. To verify the accuracy of the wide-band calibration measurements, the calibration results are compared with that using tone-burst signals in the water vessel and using free-field reciprocity method in the large water tank. The comparisons show that their calibration results are in a good agreement with each other, and the maximum deviation is 0.7 dB. All these demonstrate that the wide-band signal processing technology described is accurate and stable.
Defect modes in imperfect periodic structures
Authors: Li Yilun , Cottereau Régis , Tie Bing
Published: October 2024

Lack of periodicity in engineering structures can arise because of imperfections in the production process or a particular purpose to produce desirable physical effects. This contribution presents a series of numerical simulations that quantitatively characterize the influence of defects on the dispersion relation and associated eigenmodes of imperfect periodic structures. Local defects are introduced periodically on a scale larger than the size of the unit cell of the non-disturbed periodic structure. The observations reveal that these defects can give rise to non-propagating modes at frequencies situated within the bandgaps of the periodic structure. The eigenfrequency of such a defect mode varies monotonically with the amplitude of the defects, and its deformations are located in and around the disturbed cell. Additionally, a finite element analysis is conducted to study the existence of the observed defect modes when the imperfect periodic media are bounded.
A New Method for Temperature Dependent COM Parameters Extraction and Its Application to Simulation of SAW Devices
Authors: Li Lingqi , Zhang Qiaozhen , Li Baichuan , Yang Yang , Tian Yahui , Li Honglang
Published: October 2024

Surface Acoustic Wave (SAW) filters are widely used in mobile communication systems due to their superior performance. Yet, application scenarios for these SAW devices can be limited by temperature stability. The coupling of modes (COM) model is proved to be an efficient modeling approach to design SAW devices at present. However, temperature dependent COM parameter extraction is still absent. This work proposed a new method combining COM model with quasi-3D periodic finite element method (FEM) model coupled with thermal field, which can accurately and rapidly simulate and optimize the temperature stability of SAW devices. The COM parameters extraction method used in this study mainly depends on harmonic admittance. For a given temperature (T), the thermal effect can be computed by incorporating the linear thermal expansion coefficients and temperature coefficients of elasticity into the model. For validation, the admittance responses of a finite-length SAW resonator and the S-parameter of a double-mode SAW (DMS) for 42º YX-LiTaO3 piezoelectric substrate are calculated by using P-Matrix with the extracted COM parameters. For validation, the admittance responses of a SAW resonator on 42º YX-LiTaO3 under different temperature conditions is calculated. Furthermore, the temperature behaviors of a DMS filter on 42º YX-LiTaO3 are also analyzed based on the proposed method. Accurate predictions of the temperature behaviors for both resonator and filter were achieved and discussed. This investigation provides guidelines for design of high-performance SAW devices with good temperature stability.
High Order Rayleigh-Type SAW Devices for Advanced 5G Front-ends with Improved Performance
Authors: Liu Luyao , Zhang Qiaozhen , Sun Hao , Yang Yang , Zhao Xiangyong
Published: October 2024

This paper presents a piezoelectric layered structure composed of a rotated LiNbO3 thin film combined with a diamond film for improved comprehensive performance SAW devices. Theoretical analysis of SAW resonator on the proposed structure is performed to calculate its SAW characteristics including electromechanical coupling coefficient (K2
), frequency (f), and quality factor (Q). It is found that a high-order Rayleigh mode is effectively excited and exhibits not only high frequency but also large K2
and high Q. The influences of the Euler angles, layer stack configurations of LiNbO3, and the electrode on the SAW properties are investigated systematically to optimize the device performance of the proposed structure. The results show the resonator can operate at frequency of 6.6 GHz with a large K2
of 13.58% and high Q of 2134, which makes the proposed layered structure a good potential solution for high-performance wideband SAW filters operating over 5 GHz.
Ultrasonic imaging assisted by Phase Coherence and Synthetic Aperture Focusing Technology
Authors: Li Zhengdong , Jiang Xueping , Zhang Meng , Zhu Tiaoyin
Published: October 2024

B-Scan is widely applied in ultrasonic testing. However, the imaging quality is affected by noise and acoustic diffusion. This paper proposed a method combining synthetic aperture focusing technology (SAFT) and phase-coherent imaging (PCI) technology to improve image quality. In SAFT, a transducer at different positions is utilized to form an array, which represents a large aperture transducer to obtain high resolution. By constructing a weight matrix based on the phase of signals, PCI is used to modify the SAFT imaging, thus the signal-to-noise ratio is significantly improved.

In this paper, finite element models were built and the corresponding simulations were carried out first. Then, the Hilbert transform was implemented to all the simulated echoes with artificial white noise. The amplitudes and phases were extracted, whilst the amplitudes were used to construct SAFT images. The phases were used to construct a coherent weight matrix. Finally, images of SAFT modified by phase-coherent matrix were reconstructed and compared with SAFT images and B-scan. It verifies that the SAFT-PCI method can improve the image effectively.
Enhancing the performance of a resonance-based sensor network for soft robots using binary excitation
Authors: Chubb Kevin , Berry Damon , Burke Ted
Published: October 2024

Embedded, flexible, multi-sensor sensing networks have shown the potential to provide soft robots with reliable feedback while navigating unstructured environments. Time delay associated with extracting information from these sensing networks and the complexity of constructing them are significant obstacles to their development. This paper presents a novel enhancement to an existing class of embedded sensor network with the potential to overcome these challenges. In its original version, this sensor network extracts information from multiple reactive sensors on a two-wire electrical circuit simultaneously. This paper proposes to change the excitation signal applied to this sensor network to a binary signal. This change offers two key advantages: it provides the ability to employ small, inexpensive microcontrollers and results in a faster data extraction process. The potential of this enhanced system is demonstrated here with a proof of concept implementation. The self-inductance of all inductance-based sensors within this proof of concept sensor network can be measured at a rate of over 5000 times per second with an average measurement error of less than 2%.
Gallic acid functionalized silk fibroin/gelatin composite wound dressing for enhanced wound healing
Authors: Li Ping , Tan Ding , Su Aihua , Xiong Xingliang , Gao Shasha , Zhang Haiyang , Yang Jiaqi , Jian Jie , Zheng Jun , Jiang Qifeng
Published: October 2024

As the incidence of chronic wounds increases, the requirements for wound dressings are rising. The specific aim of this study is to propose a novel gallic acid (GA) functionalized silk fibroin (SF) and gelatin (Gel) composite wound dressing in which GA is used as an antibacterial and wound healing substance. Via electrospinning, SF, Gel, and GA mixed solutions could be conveniently fabricated into a composite nanofiber mat (SF-Gel-GA), consisting of uniform fibers with an average diameter around 134.57 ± 84 nm. The internal mesh structure of SF-Gel-GA provides sufficient drug loading capacity, proper moisture permeability, and proper degradation rate. SF-Gel-GA presents excellent biocompatibility. NIH-3T3 fibroblast cells could adhere and spread stably on the SF-Gel-GA surface with slightly promoted proliferation. In the presence of SF-Gel-GA, the growth of both Gram-positive and Gram-negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa, is significantly inhibited in both plate and suspension cultures. A cutaneous excisional mouse wound model proves the efficient ability of SF-Gel-GA to promote wound healing. Compared with pure SF dressing and commercial Tegaderm Hydrocolloid3M dressing, the wound closure rate with SF-Gel-GA treatment is significantly improved. The histological assessments further demonstrate SF-Gel-GA could facilitate collagen deposition, neovascularization, and epithelialization at wound sites to promote wound healing. In conclusion, a novel SF-Gel-GA composite wound dressing with efficient wound healing activities have been developed for chronic wound treatment with broad healing potential.
Claiming Madness
Authors: Rembis Michael
Published: October 2024

Many former asylum inmates who entered public conversations in the decades between 1830 and 1890—years of significant growth of the asylum system—worked to establish themselves as trustworthy informants on the ill-defined but widely discussed topic of madness. The popular belief that madness eluded easy definition opened a critical cultural space from which mad writers could offer their own thoughts about the nature and causes of it. Whether or not they spoke directly to physicians and legislators, former inmates who shared their stories influenced popular, legal, and medical conceptualizations of madness at a time when most Americans seemed to be groping toward a more modern understanding of the many different forms of what they generally referred to as “insanity.”
Reforming the System
Authors: Rembis Michael
Published: October 2024

From the 1830s through the 1890s, dozens, if not hundreds, of former inmates became asylum reformers. They learned through experience and from friends and allies how to organize and how to enact legislative change. Former inmates did not always succeed; they were not always believed by legislators, and they continued to face fierce opposition from some physicians. Yet they persisted in their efforts to share their stories and rewrite what they considered deficient and problematic public policy. Levels of engagement and success varied among former inmates, but the collective force for change generated by their actions cannot be denied. Former inmates turned reformers played a crucial role in bringing about changes in the asylum system that persisted well after their individual reform work ended.
Multi-view learning framework for predicting unknown types of cancer markers via directed graph neural networks fitting regulatory networks
Authors: Wang Xin-Fei , Huang Lan , Wang Yan , Guan Ren-Chu , You Zhu-Hong , Sheng Nan , Xie Xu-Ping , Hou Wen-Ju
Published: October 2024

The discovery of diagnostic and therapeutic biomarkers for complex diseases, especially cancer, has always been a central and long-term challenge in molecular association prediction research, offering promising avenues for advancing the understanding of complex diseases. To this end, researchers have developed various network-based prediction techniques targeting specific molecular associations. However, limitations imposed by reductionism and network representation learning have led existing studies to narrowly focus on high prediction efficiency within single association type, thereby glossing over the discovery of unknown types of associations. Additionally, effectively utilizing network structure to fit the interaction properties of regulatory networks and combining specific case biomarker validations remains an unresolved issue in cancer biomarker prediction methods. To overcome these limitations, we propose a multi-view learning framework, CeRVE, based on directed graph neural networks (DGNN) for predicting unknown type cancer biomarkers. CeRVE effectively extracts and integrates subgraph information through multi-view feature learning. Subsequently, CeRVE utilizes DGNN to simulate the entire regulatory network, propagating node attribute features and extracting various interaction relationships between molecules. Furthermore, CeRVE constructed a comparative analysis matrix of three cancers and adjacent normal tissues through The Cancer Genome Atlas and identified multiple types of potential cancer biomarkers through differential expression analysis of mRNA, microRNA, and long noncoding RNA. Computational testing of multiple types of biomarkers for 72 cancers demonstrates that CeRVE exhibits superior performance in cancer biomarker prediction, providing a powerful tool and insightful approach for AI-assisted disease biomarker discovery.
2D Echocardiographic aortic root dimensions and longitudinal analysis with artificial intelligence using an open dataset from a UK-wide collaborative
Authors: Ng T , Hannan S H , Julea M , Singh A , Zetani M , Vimalesvaran K , Tawil M , Rana B , Demetrescu C , Ghosh A , Sehmi J , Bhattacharyya S , Stowell C , Shun-Shin M J , Francis D P
Published: October 2024

Background

Surveillance of aortic dimensions requires reproducible measurements, and knowledge of the rate of progression in those with dilatation.

Purpose

To develop an open machine-learning method for measuring the aortic root and proximal ascending aorta on echocardiograms, validate it through a multi-expert panel from the Unity UK Echocardiography AI Collaborative, and applying the AI to derive the rate of progression in historical databases.

Methods

The neural network was trained on 1478 parasternal long-axis images. Each image was labelled with key points for the aortic annulus, sinus and sinotubular junction, and proximal ascending aorta dimensions. Labels accommodated inner-to-inner and leading-to-leading conventions.

For validation, the end-diastolic and mid-systolic images were identified (accommodating different guidelines recommendations) from 100 studies, and 10 expert echocardiographers made the aortic measurements. The consensus of experts defined the reference standard, and the variation between individual experts defined the acceptable variation for the AI.

The AI was then applied to 724 echocardiograms of 102 patients under surveillance spanning 12 years (ranging from 4 to 17 scans per patient) without intervention. Training data labels and networks are made freely available on our project website.

Results

The median absolute deviations between the AI and the expert consensus ranged from 0.06cm to 0.17cm across the 16 measurements. For the individual expert opinions this was from 0.08cm to 0.19cm. For 7/16 measurements, there was no statistically significant difference between the AI deviation and the individual-expert deviation. The AI’s confidence level was a useful indicator of the reliability of the AI measure. For the top 9 deciles of AI confidence level, the AI measurements had significantly smaller deviations than the individual experts.

The rates of progression averaged across the three aortic measurements was 2.0 mm/decade (95% CI 1.0 to 3.0; p =0.007).

Conclusion

Expert consensus can be used to both define the reference standard and also the range of acceptable deviation from consensus. Overall, the AI performs similarly to experts and more importantly, provides an automated estimate of confidence. The validated AI is consistent over time, and when applied retrospectively to patients with dilated aortic roots, found the rate of progression was more rapid than in previously reported healthy patients. This approach could be applied generally in developing medical AI to not only make reproducible measurements but to automate large scale longitudinal studies with little input, and ultimately serves as a useful research and clinical tool.Figure: AI(red) vs Expert (blue)Table: AIDeviations from Consensus
Aortic integral distensibility based on the auto-segmented dynamic motion of the aortic wall
Authors: Choi J H , Lee C A , Paeng D G
Published: October 2024

Background

Aortic stiffness is important in cardiovascular diseases and predicting outcomes. Echocardiography is a widely used noninvasive imaging modality for assessing aortic stiffness, but its accuracy can be limited by the low spatial resolution of ultrasound-based images and the subjectivity of manual measurements of aortic dimensions. Automated segmentation analysis can provide a more accurate and objective measure.

Objective

An automated algorithm and software have been developed for segmenting the aortic wall. A new measurement technique called "Aortic Integral Distensibility (AID)" has been formulated using this framework. This method overcomes limitations of traditional method focusing solely on the two positions of Aortic Distensibility (AD).

Method

In this particular investigation, 112 participants were subjected to echocardiography in order to quantify the dynamics of the aortic wall. An automated algorithm was devised to delineate the aortic wall by utilizing an M-mode echocardiography scan. The statistical analysis encompassed the measurement of AD and AID before and after the age of 65 group. This analysis was conducted considering various risk factors, including age, gender, weight, BMI, smoking, and blood pressure. Additionally, clinical parameters, specifically AIx @75 (Augmentation Index) and Framingham Risk Score (FRS), were evaluated as well. Inter-rater reliability was conducted between the traditional AD and the newly implemented AID.

Results

The results indicate that the group under 65 had more distensibility than the group over 65, and AID measurements were slightly higher than AD measurements. SBP showed a strong correlation with AID, rather than AD. AIx @75 and FRS had a negative relationship with distensibility. In the 65 years or older group, there was a significant negative correlation observed between AIx @75 and AID (r = -0.4, p = 0.012). Furthermore, a strong correlation was also observed between FRS and AID (r = -0.53, p = 0.002). Bland-Altman analysis demonstrated that the automated methodology had better reproducibility and less variability in distensibility measurements than the manual methodology.

Conclusion

The study suggests that AID could be valuable for assessing aortic stiffness. AID could help clinicians diagnose and manage cardiovascular diseases more accurately. The automatic approach provides reliable measurements for aortic distensibility and strain, which has clinical implications.Schematic Chart of the Study Process
Right ventricular-pulmonary artery coupling assessed by two-dimensional strain predicts in- hospital complications in takotsubo syndrome
Authors: La Vecchia G , Iannaccone G , Russo M , Scarica V , Lillo R , Camilli M , Sanna T , Lombardo A , Lanza G A , Graziani F , Leone A M , Trani C , Burzotta F , Crea F , Montone R A
Published: October 2024

Background and purpose

Takotsubo syndrome (TTS) may lead to serious in-hospital complications. Our study aims to investigate the prognostic impact of right ventricular-to-pulmonary artery (RV-PA) coupling in patients with TTS.

Methods

Consecutive TTS patients were prospectively enrolled. RV function was evaluated by RV global longitudinal strain (RVGLS) and RV free wall strain (RVFWS) and RV-PA coupling was measured as the ratio of either tricuspid annular plane systolic excursion (TAPSE), RVGLS or RVFWS to pulmonary artery systolic pressure (PASP). Data about in-hospital complications (defined as acute heart failure, life-threatening arrhythmias and death from any cause) were collected.

Results

A total of 80 patients were analysed (71±11 years, female 77.5%) and in-hospital complications occurred in 33 (41%). Patients who experienced in-hospital complications had lower LV ejection fraction (LVEF), lower TAPSE/PASP, RVFWS/PASP and RVGLS/PASP and higher left atrial volume indexed (LAVi) values. LVEF (OR 0.913, 95% CI [0.858–0.971], p=0.004) and RVGLS/PASP (OR 0.098, 95% CI [0.012–0.788], p= 0.029) were independent predictors of in-hospital complications. Receiver operating characteristics (ROC) curve analysis showed an area under the curve (AUC) of 0.696 (95% CI [0.57–0.82], p= 0.002) of RVGLS/PASP for the prediction of in-hospital complications. A cut-off value of RVGLS/PASP of ≤ 0.48 %/mmHg showed a sensitivity and specificity of 75% and 60%, and allowed to identify 24% of patients who experienced in-hospital complications despite a preserved LVEF (≥50%).

Conclusion

RV-PA coupling assessed by RVGLS/PASP may help identifying TTS patients at higher risk of cardiovascular complications with an additional prognostic value to LVEF alone.
Left fascicular pacing is not inferior to left bundle branch pacing in preserving ventricular mechanical synchrony and cardiac function
Authors: Mao Y , Yang Y , Sheng X I A , Zhang J F , Ye Y , Wang M I N , Yang Y , Sun Y , Ma M M , Fu G S
Published: October 2024

Background

Left bundle branch pacing (LBBP) has emerged as a more physiological alternative to right ventricular pacing.However, capturing the pre-divisional LBB is not easy to accomplish. This study investigates if left fascicular pacing(LFP), defined as the capture of one of the LBB fascicles, could achieve comparable left ventricular (LV) mechanical synchronicity and cardiac function compared to LBBP.

Methods

Thirty-one patients with pacing indication for bradycardia were retrospectively collected: LBBP was successfully performed in 13 patients and 18 achieved LFP. All patients underwent echocardiography before and after implantation and at one-year follow-up. Left ventricular (LV) volumes, ejection fraction (EF) and global longitudinal strain (GLS) were measured. The lateral-septal (LW-SW) work difference was used as a measure of mechanical dyssynchrony. Septal flash, apical rocking and septal strain patterns were also assessed.

Results

Although LW-SW work difference were significantly higher in the LBBP groups than that in the LFP group at baseline(272±269 mmHg*% vs 25±279mmHg*%,p=0.02), a similar increase in LW-SW work difference was observed during follow-up(199±342 mmHg*% vs 371±384mmHg*%,p=0.21). In addition, both LFP and LBBP induced septal flash or apical rocking in some patients, and resulted in subtle changes in strain patterns, which were not significantly different between groups. At one year follow-up, LV ejection fraction (EF) remained almost unchanged in both LBBP and LFP patients(ΔLVEF: 1.1+3.1% vs -0.3±4.8%,p=0.35) , and global longitudinal strain (GLS) was slightly and equally decreased in LFP compared to LBBP (ΔLVGLS: -1.6±2.3% vs -1.2±2.7%,p=0.69).

Conclusion

LFP and LBBP did not differ in mechanical dyssynchrony or LV remodelling.
The implementation of speckle tracking echocardiography for cardiac resynchronization therapy optimization. A rotational myocardial mechanics interpretation
Authors: Stefanidis A , Korlou P , Margos P , Ikonomidis I , Paraskevaidis I , Gatzoulis K , Aivalioti E , Routsakou E , Delakis J , Kostopoulos K
Published: October 2024

Background

Cardiac resynchronization therapy (CRT) has an additive therapeutic influence on left ventricular (LV) function in heart failure (HF) patients, but the underlying mechanisms through which it works are not completely explained. Our aim was to further elucidate the role of this intervention via rotational mechanics using 2D speckle tracking echocardiography (2D-STE).

Methods

We investigated 46 patients (65 ± 9 years) who received CRT. All enrolled patients were assessed on admission by 2D-STE and 6 min walk test (6m WT) and followed in the outpatient device clinic by 2D-STE (at one week and 6 months post-implantation) and 6m WT (at 6 months post-implantation). On their first appointment all biventricular systems were optimized by atrioventricular delay optimization and by changing the temporal activation of ventricular electrodes aiming to reach the highest effective LV stroke volume (eff SV) across all activation options. A new 2D-STE based index (twist integral – TI) targeting to assess the rotational mechanics of the whole cardiac cycle was also measured to further explain the CRT response. For the calculation of LV TI of the full cardiac cycle, serial isochronal apical and basal rotation measurements (in degrees) were exported to a worksheet Excel file and the final algebraic summation was calculated by the formula: Twist Integral = (systolic twist integral – diastolic twist integral) Σ twisti= twist1+twist2+...+twistn (table 1).

Results

Twenty-two (48%) patients with dilated cardiomyopathy as the predominant aetiology of HF were responders at 6-month follow-up. The commonest selected mode that was related with the greatest LV performance response was the simultaneous activation of the 2 ventricular leads (39%). The strongest predictor of CRT response was the improvement of eff SV between admission and first appointment at clinic, followed by the improvement of TI, the non-existence of CAD, and the improvement of peak systolic twist (table 2).

Conclusions

Additional CRT optimization via changing the temporal activation of ventricular electrodes is beneficial for LV performance in HF patients. Rotational mechanics essentially explain the beneficial CRT contribution to these patients.
Association between CHA2DS2-VASc score and left atrial function by speckle tracking echocardiography in patients with sinus rhythm
Authors: Mostafa K , El Deeb H , Mahmoud K , Bakhoum S
Published: October 2024

Background

The CHA2DS2-VASc score is a scoring system that was first used for the risk assessment of cerebrovascular or thromboembolic events in patients with atrial fibrillation (AF). The factors that constitute the CHA2DS2-VASc scoring system can all individually have an impact on LA function. The application of this scoring system can also be applied to patients without AF. The LA structural remodeling and/or functional impairment play a part in the pathogenesis and development of AF and independent of rhythm, may result in atrial hemostasis and confer a prothrombotic diathesis, resulting in thromboembolic stroke. Speckle- tracking echocardiography (STE) makes it possible to measure LA function with relatively high accuracy and at the very early stage even in the absence of LA enlargement.

Purpose

The aim of our study was to assess the left atrial function in patients with sinus rhythm with different CHA2DS2-VASc scores (low, moderate and high) by speckle tracking echocardiography and to identify the association between them.

Methods

This study was conducted using prospectively collected data (1st May, 2022 to 30th October 2022) from patients with sinus rhythm and different CHA2DS2-VASc scores (50 Low risk score patients (1 for females and 0 for males), 50 moderate risk score patients (2 for females and 1 for males) and 50 high risk score patients (≥3 for females and ≥2 for males) After obtaining an informed consent, all volunteers underwent thorough history taking, 12 lead ECG and conventional transthoracic echocardiography and speckle-tracking echocardiography.

Results

LA strain during the reservoir (LASr) and conduit phases (LAScd) were statistically significantly lower in the high-risk score group (33.2 ± 7.1 and 20.3 ± 5.7) than the moderate-risk score group (36.9 ± 6.1 and 23.5 ± 4.8, p = 0.005 and 0.003 respectively) and low -risk score group (40.6 ± 5.6 and 26.9 ± 3.9, p < 0.001). In addition, LASr and LAScd were statistically significantly lower in moderate- risk score group (36.9 ± 6.1 and 23.5 ± 4.8) than the low -risk score group (40.6 ± 5.6 and 26.9 ± 3.9 ,p=0.007 and 0.001 respectively).

Conclusion

Higher CHA2DS2-VASc scores were associated with decreased LA strain during the reservoir and conduit phases as markers of LA function with relatively high accuracy and at the very early stage even in the absence of LA enlargement.
Right atrial strain: the hidden proof of bi-atrial cardiomyopathy in AF patients?
Authors: Ruscio E , Gabrielli F A , Pinnacchio G , Spera F R , Giordano F , Narducci M L , Bencardino G , Perna F , Crea F , Pelargonio G
Published: October 2024

Background

Although assessment of left atrium (LA) abnormalities has been extensively studied in atrial fibrillation (AF), structural and functional changes in the right atrium (RA) have remained almost unexplored in this context.

Purpose

We investigated the role of bi-atrial strain in patients with AF undergoing catheter ablation (CA).

Methods

Fifty-six consecutive patients undergoing catheter ablation of AF were prospectively studied with speckle-tracking echocardiography and electrophysiological study, before and after CA (median follow-up: 7±3 months). A group of 32 subjects undergoing CA of paroxysmal atrioventricular node-reentrant tachycardia, without structural heart disease, served as control group.

Results

Patients with AF had worse LA, but also RA strain indexes compared to controls [RA strain parameters: peak RAS reservoir (pRASr): 22.1±12.6 vs 29.8±12.7%, p=0.009; RA dispersion: SD-regional-RA-time-to-peak (SD-regional-RA-TTP): 0.048±0.015 vs 0.038±0.009, p=0.020)]. Patients with persistent AF showed similar LA strain values, but worse RA strain indexes, compared to patients with paroxysmal AF (pRASr: 24.8±12.1 vs 15.9±11.7%,p=0.017; SD-regional-RA-TTP:0.043±0.023 vs 0.062±0.030, p=0.016). RA function showed a significant relation with both LA strain and volume indexes and with abnormal LA electroanatomical substrate (pRASr and pLASr, Pearson correlation: r 0.594, p< 0.001; pRASr and low-voltage LA area: -0.316, p=0.018). RA, but not LA, parameters were found significantly reduced in patients with AF recurrence post-CA compared to those who maintain sinus rhythm (pRASr: 14.1±11.7 vs 24.6±13.5, p=0.039; SD-regional-RA-TTP: 0.054±0.031 vs 0.032±0.010, p=0.002), while the only independent clinical predictor of AF recurrence remained cardiovascular risk profile (CHA2DS2 VASc Score: HR 1.47,CI 1.003-2.158, p= 0.048).

Conclusion

RA function, as assessed by strain imaging, resulted progressively impaired in worse subtypes of AF, showing a strong correlation with bi-atrial mechanical and electroanatomical parameters, and associated with AF recurrences post-ablation.Graphical Abstract
Echocardiographic left and right ventricular strain reference values and their associated characteristics in a healthy adult population from the ELSA-Brasil Study
Authors: Pianca E , Foppa M , Canon-Montanez W , Duncan B B , Santos A B S
Published: October 2024

Background/Introduction

Impaired left ventricular (LV) systolic function is a well-known predictor of cardiovascular morbidity and mortality. Global longitudinal strain (GLS) analysis has been shown a robust measure to detect early systolic dysfunction and a prognostic parameter beyond traditional echocardiographic systolic parameters. Standard reference values for echocardiography measures have been established by echocardiography societies. However, these data may not accurately represent diverse world populations.

Purpose

We aimed to describe, from a Brazilian multiethnic population, age and sex-specific reference values for left (LV) and right ventricles (RV) GLS in a sample free of cardiovascular disease and risk factors, and to describe the impact of these risk factors according to GLS distribution.

Methods

ELSA-Brasil is a prospective cohort to investigate cardiovascular disease and diabetes including 15,105 participants aged 35 to 74 years. A predefined representative randomly selected sample with echocardiographic exam was included. We categorized the sample in tertiles according to severity of LV and RV systolic function measured by GLS, and applied trend tests across ordered groups to illustrate the association between GLS and demographic characteristics and echocardiographic measures of cardiac structure and function.

Results

In the study population (n=527), the mean age was 50.2 years and 59% were women. The overall mean value of LVGLS was -19.0 ± 2.4%, while the mean value of RVFWLS was -28.35 ± 3.06%. Women had higher absolute values of LV and RV GLS compared to men.

Conclusion

Our study provided the reference ranges for LV and RV GLS in a large middle-aged healthy Brazilian sample, with sex-differences reflected on these values.Central FigureTable 1:Tertiles of LVGLS and RVFWLS
Improvement of myocardial contractility after iron replacement in stable heart failure patients
Authors: Benavent Garcia C , Romero Valero A , Garcia Suarez A , Del Rio Lopez M , Lledo Ortiz C , Izquierdo Hernandez A , Moreno Martinez M , Vicente Ibarra N , Garcia Honrubia A , Tormo Juarez P , Castillo Castillo J , Martin Torres J M , Garcia Cano L , Santos Martinez S , Morillas Blasco P
Published: October 2024

Background

Iron deficiency replacement with intravenous ferric carboxymaltose (FCM) has demonstrated to improve clinical and prognostic parameters in patients with heart failure with reduced left ventricular ejection fraction (HFrEF). Improvement of myocardial contractility is proposed as possible hypothesis and strain could behave as an early and high sensitive parameter to assess this improvement in myocardial deformation due to increased iron availability after replacement of iron deficiency.

Purpose

Evaluate the effect of iron deficiency replacement with FCM in the strain of both ventricles in patients with stable HFrEF.

Methods

Observational, analytical, longitudinal and prospective study that included 73 patients with stable HFrEF who presented iron deficiency without anemia defined as serum ferritin <100 ug/L or between 100 and 300 ug/L if the transferrin saturation was <20%. They were randomized 2:1 to iron replacement with FCM or control group. A central core lab, blinded to the treatment/control groups, performed 3D echocardiograms and strain analysis basal and four weeks after the randomization.

Results

Mean age of the study population was 70 years old, 77% were male, 75% had high blood pressure, 70% dyslipidemia and 41% diabetes. Of the total, 51 patients were assigned to the replacement group and 22 patients to the control group. Mean left ventricular ejection fraction (LVEF) was 33%, without basal differences between both groups. Four weeks after the randomization, a significant improvement of LVEF of 2.47±2.32% (p=0.018) was observed in the replacement group, as well as in the left ventricle global longitudinal strain (LV-GLS) of -0.96±2.08% (p=0.006). Nevertheless, these changes were not observed in the control group.

Conclusions

In patients with stable HFrEF replacement of iron deficiency with FCM is associated with an improvement of myocardial contractility, of LVEF measured by 3D and LV-GLS.Variation of parametersLV-GLS before and after FCM
Left atrial strain differences between hypertensive and sarcomeric left ventricular hypertrophy: a sign of sarcomeric auricular myopathy?
Authors: Ramos Jovani M , Forado I , Loncaric F , Doltra A , Sanchis L , Arenas A , Rodriguez-Arias J J , Sole E , Pereda D , Quintana E , Garcia-Alvarez A , Sitges M
Published: October 2024

Introduction

In clinical practice, left ventricular (LV) hypertrophy is a common finding that can be caused by physiologic or pathologic conditions. An etiologic diagnosis is extremely important because it may change the prognosis and management of the patient and his family. Left atrial (LA) dysfunction is common due to diastolic dysfunction but, in patients with sarcomeric LV hypertrophy, primary cardiomyopathy disease could also be present.

Purpose

To evaluate if there are differences in LA function between arterial hypertension (HT) and hypertrophic cardiomyopathy (HCM) patients.

Methods

73 patients with HCM (according to ESC guidelines criteria) and 82 patients with HT (under treatment with ≥1 hypertensive drug for ≥3 months) and ≥13mm of LV hypertrophy underwent an echocardiography to assess LA function with strain analysis and LV diastolic function. Continuous normally distributed variables were compared with T-student test and categoric variables with square-chi or exact Fisher test if required, accepting as significant a p-value <0.05.

Results

Globally, HCM patients showed thicker LV walls and larger LA indexed volumes (18.7±4.7 vs. 13.3±0,8 mm and 44.9±20.7 vs. 30.7±8.8 ml/m2, p<0.000 for both). Also, HCM patients presented diastolic dysfunction and atrial fibrillation history in a higher frequency (31 vs. 7.6% and 16.4% vs. 0%, p<0.000 for both). LA strain was significantly lower in HCM patients as compared to the HT group (LA contractile 11.5±5.8 vs. 17.2±4.4, p<0.000; LA conduit 12.2±5.4 vs. 13.3±3.8, p=0.041; and LA reservoir 23.9±8.7 vs. 31.1±5.9, p<0.000).

In the subgroup of patients with moderate-severe LV hypertrophy (<17mm) and no significant mitral regurgitation (n=103; HCM=21, HT=82), LA contractile strain remained lower in HCM as compared to HT patients (13.2±4.8% vs. 17.2±4.4%, p<0.000) (figure 1); without differences in diastolic dysfunction, LA volumes, significant mitral regurgitation or atrial fibrillation history.

Conclusions

Our results show that LA strain is more impaired in HCM patients as compared to HT patients. Specifically, contractile LA strain remained lower even in those patients with moderate-severe LV hypertrophy, despite having similar LV diastolic function, LA indexed volumes, significant mitral regurgitation, or atrial fibrillation history. These findings could be caused by HCM involvement of the LA myocytes. In the context of moderate-severe hypertrophy of unknown origin with non-significant mitral regurgitation, the detection of abnormally reduced LA strain could indicate the presence of an HCM.Figure 1