bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of the simulation-based learning (SBL) assisted with scaffolding approach to address students’ misconceptions about projectile motion
Authors: Fongsamut Kanokkarn , Tanasittikosol Monsit , Phaksunchai Mingkhuan
Published: December 2022

This research studied the effectiveness of the simulation-based learning assisted with scaffolding approach to address students’ misconceptions (MCs) about projectile motion. The five MCs were related to the direction of the force acting on an object (MC1), the acceleration of an object at the top of the trajectory (MC2), the directions of velocity and acceleration during projectile motion (MC3), the time of flight of objects (MC4), and the relationship between the range of projectile motion and angle of projection (MC5). This study was a pre-experimental design using both quantitative and qualitative data. The sample comprised 35 tenth-grade Thai high school students who were chosen using the cluster sampling technique. The teaching method consisted of three steps: a briefing, simulation, and debriefing. Each step was assisted with scaffolding to guide and help the students. The MCs tests consisted of five multiple-choice questions with a four-tier diagnostic test, and the tests were used as a pre-test, end-of-class test, and end-of-topic test. Six semi-structured interview questions were used to obtain in-depth data. The results indicated that MC1, MC2, MC3, MC4, and MC5 were addressed by 11.1%, 85.7%, 57.2%, 57.2%, and 61.5%, respectively, at the end-of-topic test. Students who had MCs in the pre-test changed their understanding of the concepts in MC2, MC3, MC4, and MC5 by 57.1%, 14.3%, 28.6%, and 53.8%, respectively. None of the MC students in MC1 understood the concept at the end-of-topic test. Nevertheless, the overall results showed increased students’ understanding of all conceptions.
Spectral CT reconstruction via low-rank representation and structure preserving regularization
Authors: He Yuanwei , Zeng Li , Xu Qiong , Wang Zhe , Yu Haijun , Shen Zhaoqiang , Yang Zhaojun , Zhou Rifeng
Published: December 2022

Objective: With the development of computed tomography (CT) imaging technology, it is possible to acquire multi-energy data by spectral CT. Being different from conventional CT, the X-ray energy spectrum of spectral CT is cut into several narrow bins which leads to the result that only a part of photon can be collected in each individual energy channel.This can severely degrade the image qualities. To address this problem, we propose a spectral CT reconstruction algorithm based on low-rank representation and structure preserving regularization in this paper. Approach: To make full use of the prior knowledge about both the inter-channel correlation and the sparsity in gradient domain of inner-channel data, this paper combines a low-rank correlation descriptor with a structure extraction operator as priori regularization terms for spectral CT reconstruction. Furthermore, a split-Bregman based iterative algorithm is developed to solve the reconstruction model. Finally, we propose a multi-channel adaptive parameters generation strategy according to CT values of each individual energy channel. Main results: Experimental results on numerical simulations and real mouse data indicate that the proposed algorithm achieves higher accuracy on both reconstruction and material decomposition than the methods based on simultaneous algebraic reconstruction technique (SART), total variation minimization (TVM), total variation with low-rank (LRTV), and spatial-spectral cube matching frame (SSCMF). Compared with SART, our algorithm improves the feature similarity (FSIM) by 40.4% on average for numerical simulation reconstruction, whereas TVM, LRTV, and SSCMF correspond to 26.1%, 28.2%, and 29.5%, respectively. Significance: We outline a multi-channel reconstruction algorithm tailored for spectral CT. The qualitative and quantitative comparisons present a significant improvement of image quality, indicating its promising potential in spectral CT imaging.
Effect of detector geometry and surface finish on Cerenkov based time estimation in monolithic BGO detectors
Authors: Maebe Jens , Vandenberghe Stefaan
Published: December 2022

Objective. Time-of-flight positron emission tomography based on bismuth germanate (BGO) detectors is made possible due to fast emission of Cerenkov light. Only around 17 Cerenkov photons are produced per 511 keV photoelectric event, making high photon collection efficiency crucial for obtaining good time-of-flight capabilities. In this study, we investigate how different lateral and back surface finishes affect the photon collection efficiency and Cerenkov based timing performance in monolithic BGO. Approach. The study is performed using GATE for gamma and optical photon modeling, with surface reflections of photons simulated by the LUT Davis model. We compare for different detector configurations (regarding size and surface finishes) the photon collection efficiency, detection delays of the first few optical photons and coincidence time resolution estimations obtained by modeling the SiPM signals and performing leading edge discrimination. An additional comparison is made to LYSO scintillators and pixelated detectors. Main results. Although Cerenkov photon emission is directional, many high incidence angle Cerenkov photons are emitted due to electron scattering in the crystal. Substituting a polished back (photodetector side) surface for a rough surface increases the collection efficiency of these high angle of incidence photons. Results show that for a monolithic 50 × 50 × 12 mm3 BGO detector with reflective side surfaces, this leads to an overall increase in photon collection efficiency of 34%. Cerenkov photon collection efficiency is also improved, resulting in a reduction of the photon detection delays (and the variation therein) of the first few optical photons. This leads to a better coincidence time resolution, primarily achieved by a shortening of the tails in the time-of-flight kernel, with an 18% reduction in full width at tenth maximum. Significance. This study shows the importance of the photon collection efficiency for timing performance in Cerenkov based monolithic detectors, and how it can be improved with different surface finishes.
TOPAS simulations of the response of a mini-TEPC: benchmark with experimental data
Authors: Bianchi Anna , Selva Anna , Reniers Brigitte , Vanhavere Filip , Conte Valeria
Published: December 2022

Objective. Microdosimetry offers a fast tool for radiation quality (RQ) verification to be implemented in treatment planning systems in proton therapy based on variable LET or RBE to move forward from the use of a fixed RBE of 1.1. It is known that the RBE of protons can increase up to 50% higher than that value in the last few millimetres of their range. Microdosimetry can be performed both experimentally and by means of Monte Carlo (MC) simulations. This paper has the aim of comparing the two approaches. Approach. Experimental measurements have been performed using a miniaturized Tissue equivalent proportional counter developed at the Legnaro National Laboratories of the Italian National Institute for Nuclear Physics with the aim of being used as RQ monitors for high intensity beams. MC simulations have been performed using the microdosimetric extension of TOPAS which provides optimized parameters and scorers for this application. Main results. Simulations were compared with experimental microdosimetric spectra in terms of shape of the spectra and their average values. Moreover, the latter have been investigated as possible estimators of LET obtained with the same MC code. The shape of the spectra is in general consistent with the experimental distributions and the average values of the distributions in both cases can predict the RQ increase with depth. Significance. This study aims at the comparison of microdosimetric spectra obtained from both experimental measurements and the microdosimetric extension of TOPAS in the same radiation field.
Improved stellar limits on a light CP-even scalar
Authors: Balaji Shyam , Dev P.S. Bhupal , Silk Joseph , Zhang Yongchao
Published: December 2022

We derive improved stellar luminosity limits on a generic light CP-even scalar field S mixing with the Standard Model (SM) Higgs boson from the supernova SN1987A, the Sun, red giants (RGs) and white dwarfs (WDs). For the first time, we include the geometric effects for the decay and absorption of S particles in the stellar interior. For SN1987A and the Sun, we also take into account the detailed stellar profiles. We find that a broad range of the scalar mass and mixing angle can be excluded by our updated astrophysical constraints. For instance, SN1987A excludes 1.0 × 10-7 ≲ sinθ ≲ 3.0 × 10-5 and scalar mass up to 219 MeV, which covers the cosmological blind spot with a high reheating temperature. The updated solar limit excludes the mixing angle in the range of 1.5 × 10-12 < sinθ < 1, with scalar mass up to 45 keV. The RG and WD limits are updated to 5.3 × 10-13 < sinθ < 0.39 and 2.8 × 10-18 < sinθ < 1.8 × 10-4, with scalar mass up to 392 keV and 290 keV, respectively.
Correction of the Temperature Effect of Muon Counts Observed at the Guangzhou Station
Authors: Xu Cao-Long , Wang Yang , Qin Gang , Zuo Ping-Bing
Published: December 2022

Muons are the main component of secondary cosmic rays, and the variation in muon intensity indicates the variation in primary cosmic ray intensity. However, before using muons to study the variation in the intensity of cosmic rays, it is necessary to eliminate the atmospheric effects, such as pressure and temperature effects. In this work, the temperature effect of the muons is corrected in terms of empirical method by using ground temperature. The temperature correction is applied to the muon data observed at the Guangzhou station during the period 2010–2021 after a barometric correction. It is found that the effect of seasonal variations in temperature on muon counts is greatly eliminated in the corrected data. Furthermore, the muon data are well correlated with the neutron data in comparison, which verifies the reliability of the corrected muon data. Our results show that the correction of muon data by using ground temperature is an effective method.
Anisotropic thermal expansion in high-entropy multicomponent AlB2-type diboride solid solutions
Authors: Monteverde Frédéric , Gaboardi Mattia , Saraga Federico , Feng Lun , Fahrenholtz William , Hilmas Gregory
Published: December 2022

High-entropy (HE) ultra-high temperature ceramics have the chance to pave the way for future applications propelling technology advantages in the fields of energy conversion and extreme environmental shielding. Among others, HE diborides stand out owing to their intrinsic anisotropic layered structure and ability to withstand ultra-high temperatures. Herein, we employed in-situ high-resolution synchrotron diffraction over a plethora of multicomponent compositions, with four to seven transition metals, with the intent of understanding the thermal lattice expansion following different composition or synthesis process. As a result, we were able to control the average thermal expansion (TE) from 1.3 × 10−6 to 6.9 × 10−6 K−1 depending on the combination of metals, with a variation of in-plane to out-of-plane TE ratio ranging from 1.5 to 2.8.
Are the nanobots nigh?
Authors: Moriarty Philip
Published: December 2022

This chapter describes the movie Star Trek’s replicator technology: a compact device that can conjure up virtually any material or object. In Star Trek, that raw material is pure energy and it is unclear how the energy-matter conversion process takes place, emphasizing the science fiction genre of the film. However, the chapter highlights a variety of synthetic nanostructures that resulted from raw chemical ingredients being broken down via chemical reactions. What is it about the replicator in Star Trek that makes it appear so ‘magical’ to 21st-century perspectives? For one, it is conjuring matter out of thin air and, second, the ‘on demand’ aspect of technology that seems other-worldly.
Combinations of Physical Activity, Sedentary Behavior, and Sleep Duration and Their Associations With Physical, Psychological, and Educational Outcomes in Children and Adolescents: A Systematic Review
Authors: Wilhite Katrina , Booker Bridget , Huang Bo-Huei , Antczak Devan , Corbett Lucy , Parker Philip , Noetel Michael , Rissel Chris , Lonsdale Chris , del Pozo Cruz Borja , Sanders Taren
Published: December 2022

We conducted a systematic review to evaluate combinations of physical activity, sedentary behavior, and sleep duration (defined as “movement behaviors”) and their associations with physical, psychological, and educational outcomes in children and adolescents. MEDLINE, CINAHL, PsychInfo, SPORTDiscus, PubMed, EMBASE, and ERIC were searched in June 2020. Included studies needed to 1) quantitatively analyze the association of 2 or more movement behaviors with an outcome, 2) analyze a population between 5 and 17 years of age, and 3) include at least an English abstract. We included 141 studies. Most studies included the combination of physical activity and sedentary behavior in their analyses. Sleep was studied less frequently. In combination, a high level of physical activity and a low level of sedentary behavior were associated with the best physical health, psychological health, and education-related outcomes. Sleep was often included in the combination that was associated with the most favorable outcomes. Sedentary behavior had a stronger influence in adolescents than in children and tended to be associated more negatively with outcomes when it was defined as screen time than when defined as overall time spent being sedentary. More initiatives and guidelines combining all 3 movement behaviors will provide benefit with regard to adiposity, cardiometabolic risk factors, cardiorespiratory fitness, muscular physical fitness, well-being, health-related quality of life, mental health, academic performance, and cognitive/executive function.
Functional reconstruction of the basal ganglia neural circuit by human striatal neurons in hypoxic–ischaemic injured brain
Authors: Ji Xiaoli , Zhou Yingying , Gao Qinqin , He Hui , Wu Ziyan , Feng Ban , Mei Yuting , Cheng Yan , Zhou Wenhao , Chen Yuejun , Xiong Man
Published: December 2022

Perinatal hypoxic–ischaemic encephalopathy is the leading cause of neonatal death and permanent neurological deficits, while the basal ganglia is one of the major nuclei that is selectively and greatly affected in the brains of hypoxic–ischaemic encephalopathy patients, especially in severe cases. Human embryonic stem cell-derived neurons have shown great potential in different types of brain disorders in adults. However, it remains unknown whether and how grafted human embryonic stem cell-derived neurons can repair immature brains with hypoxic–ischaemic encephalopathy.

Here, by administrating genetically labelled human embryonic stem cell-derived striatal neural progenitors into the ipsilateral striatum of hypoxic–ischaemic encephalopathy-injured mice, we found that the grafted cells gradually matured into GABA spiny projection neurons morphologically and electrophysiologically, and significantly rescued the area loss of hypoxic–ischaemic encephalopathy-injured brains. Intriguingly, using immunohistochemical staining combined with enhanced ascorbate peroxidase-based immunoelectron microscopy and rabies virus-mediated trans-synaptic tracing, we show that the grafts start to extend axonal projections to the endogenous target areas (globus pallidus externa, globus pallidus internus, substantia nigra), form synapses with host striatal, globus pallidus and nigra neurons, and receive extensive and stable synaptic inputs as early as 2 months post-transplantation. Importantly, we further demonstrated functional neural circuits re-established between the grafted neurons and host cortical, striatal and substantial nigra neurons at 3–6 months post-transplantation in the hypoxic–ischaemic encephalopathy-injured brain by optogenetics combined with electrophysiological recording. Finally, the transplanted striatal spiny projection neurons but not spinal GABA neurons restored the motor defects of hypoxic–ischaemic encephalopathy, which were reversed by clozapine-N-oxide-based inhibition of graft function.

These findings demonstrate anatomical and functional reconstruction of the basal ganglia neural circuit including multiple loops by striatal spiny projection neurons in hypoxic–ischaemic encephalopathy-injured immature brains, which raises the possibility of such a cell replacement therapeutic strategy for hypoxic–ischaemic encephalopathy in neonates.
The Impact of Sequestration on Artemisinin-Induced Parasite Clearance inPlasmodium falciparumMalaria in Africa
Authors: Fukuda Naoyuki , Balikagala Betty , Ueno Tsuyoshi , Anywar Denis A , Kimura Eisaku , Palacpac Nirianne Marie Q , Odongo-Aginya Emmanuel I , Ogwang Martin , Horii Toshihiro , Miida Takashi , Mita Toshihiro
Published: December 2022

Background

Artemisinin-resistant Plasmodium falciparum is spreading in Southeast Asia and Africa. In vivo susceptibility to artemisinin is studied by looking at the rate of decline of peripheral parasitemia (parasite clearance half-life). However, parasites that are adhered/sequestered to the endothelium and undetectable in the peripheral blood are not considered in the estimation of parasite clearance. Here, we evaluated the influence of sequestration on in vivo artemisinin efficacy in Uganda, where artemisinin resistance is spreading.

Methods

We analyzed 133 patients with P. falciparum malaria included in an in vivo study on artemisinin efficacy in northern Uganda in 2018 and 2019. The parasite clearance half-life was estimated from peripheral parasitemia after artemisinin monotherapy. P. falciparum histidine-rich protein 2 (PfHRP2) was measured in pretreatment plasma. The number of sequestered parasites was estimated from PfHRP2 concentration and peripheral parasitemia.

Results

The estimated number of sequestered parasites per plasma volume ranged from 0 to 2 564 000/μL. Inflammation, thrombocytopenia, and dyslipidemia were significantly associated with sequestration independent of peripheral parasitemia. The median parasite clearance half-lives were 1.65 hours in patients infected with Pfkelch13 wild-type parasites (n = 104) and 3.95 hours in those with A675V artemisinin-resistant mutant (n = 18). In the multivariable model for the wild-type population, 1 000 000/μL of sequestered parasites were estimated to delay parasite clearance by 16.8% (95% confidence interval, 5.1%–28.5%), although it was not clear in the A675V population.

Conclusions

In patients with P. falciparum malaria without artemisinin-resistant mutations, intensive sequestration delays parasite clearance after treatment, which may contribute to reduced artemisinin efficacy.
Writing Development in DHH Students: A Bimodal Bilingual Approach
Authors: Gärdenfors Moa
Published: December 2022

This article describes the lexical and syntactic development of written narratives in 24 deaf and hard-of-hearing (DHH) students aged between 8 and 18 and takes into account how their varying linguistic backgrounds may predict their written performance. All participants use spoken Swedish, but the study also considers their proficiency in Swedish Sign language, which ranged from zero to fluent. Their narrative texts were analyzed in regard to syntax and lexicon, which demonstrated a strong developmental trend in which increased age predicted more complex texts. Age of acquisition did not predict any writing outcome, which is suggested to occur because all participants were exposed to language early, that is, within the critical time window for language acquisition. Sign language proficiency showed a tendency to predict adjective density and number of clauses, which encourages future research in this area, especially since this connection argues for the benefits of early access to a language and the positive relationship between sign language proficiency and writing.
824 HEMODYNAMIC EFFECTS OF LEVOSIMENDAN IN PATIENTS WITH ACUTE HEART FAILURE AND SEVERE RENAL FAILURE
Authors: Baldetti Luca , Romagnolo Davide , Peveri Beatrice , Frias André , Calvo Francesco , Gramegna Mario , Pazzanese Vittorio , Sacchi Stefania , Ajello Silvia , Scandroglio Anna Mara
Published: December 2022

Background

The inodilator levosimendan has shown improved outcomes in acute heart failure (AHF) and cardiac surgery. Its hemodynamic effect is persistent, owing to a long (70-80 hours) elimination half-life of its active metabolites. No robust data is available of the use of levosimendan in patients with severe renal failure (SRF), thus its use is contraindicated in patients with estimated glomerular filtration rate (eGFR≤30 mL/min).

Hypothesis

Different pharmacokinetics due to renal failure may alter levosimendan active metabolites elimination, causing more pronounced hemodynamic effects. We aimed to characterize the hemodynamic effect of levosimendan in a real-world cohort of SRF patients.

Methods

We reviewed patients who received levosimendan (12.5 mg) for AHF or cardiogenic shock in our CICU (N=132), excluding those without invasive hemodynamics (n=85), and those without data before and during levosimendan infusion (n=11), a total of 36 patients were finally included in this analysis. We compared hemodynamics before and during levosimendan infusion in the study cohort with CKD-EPI eGFR≤30 mL/min/1.73 m2 or CRRT and those without.

Results

Patients with low eGFR (n=11) were older, they had similar LVEF and invasive hemodynamics before levosimendan infusion to the higher eGFR cohort. Visual inspection of the LOESS regression plots (Figure) revealed an higher drop in mean arterial pressure (MAP) and diastolic arterial pressure (DAP) in the low eGFR cohort. The maximum drop was observed at day 4 from levosimendan initiation, invasive hemodynamics at this timepoint revealed a lower DAP (44.6±8.8 vs 62.6±11.9 mmHg; p=0.014) and a tendentially lower MAP (73.6±5.5 vs 84.4±11.5 mmHg; p=0.079) while systolic arterial pressure (125.0±24.6 vs 121.3±21.8 mmHg; p=0.779), cardiac index (2.1±0.5 vs 2.5±0.7 L/m2; p=0.211), and mean pulmonary arterial pressure (25.8±8.3 vs 24.8±9.6 mmHg; p=0.844) did not differ between groups. In-hospital death was not different in the two cohorts (27.3 vs 16.0%; p=0.650).

Conclusions

Patient with eGFR≤30 mL/min/1.73 m2 demonstrated a higher drop in DAP and MAP four days after levosimendan infusion start, without impact on hospital mortality. These findings may suggest a more pronounced hemodynamic effect of levosimendan in patients with SRF, possibly due to altered pharmacokinetics of its active metabolites.
854 SODIUM NITROPRUSSIDE IN ACUTE HEART FAILURE: EFFECTS ON LV AFTERLOAD AND VENTRICULO-ARTERIAL COUPLING
Authors: Baldetti Luca , Gagliardi Maria Felicia , Boccellino Antonio , Calvo Francesco , Pazzanese Vittorio , Gramegna Mario , Sacchi Stefania , Cappelletti Alberto
Published: December 2022

Background

Acute heart failure (AHF) with left ventricle (LV) dysfunction is characterized by a condition of afterload mismatch without preload reserve. LV ejection fraction (LVEF) and stroke volume (SV) become thus dependent on the afterload. Owing to its arteriolar vasodilator properties, sodium nitroprusside (SNP) may reduce LV afterload and result particularly beneficial in this setting, improving LV ejection and ventriculo-arterial coupling (VAC).

Hypothesis

We aimed to assess the effect of SNP on LV afterload (arterial elastance, Ea), LV contractility (end-systolic elastance, Ees) and VAC (Ea/Ees ratio) in AHF patients.

Methods

Patients with AHF receiving SNP were prospectively enrolled and underwent Ea and Ees estimation with a single-beat echocardiographic method, before and after SNP infusion. The method was described by Chen et al (J Am Coll Cardiol, 2001) and Kelly et al (Circulation, 1992). Echocardiography was analyzed by a physician blinded to the images timing.

Results

A total of 36 AHF patients [69% male, age 70 (68, 76) years] received SNP infusion and were enrolled. Patients were admitted for acute coronary syndrome (47%) and for worsening heart failure (53%). SNP median dose was low: 0.30 (0.21-0.57) mcg/kg/min.

SNP led to a trend to SBP reduction [140 (131-150) vs 158 (140-168) mmHg; p=0.002]. Heart rate did not change: 84 (75, 92) vs 83 (72, 94) bpm; p=0.800. Afterload (Ea) was reduced following SNP infusion: 2.2 (1.9, 2.7) vs 2.8 (2.4, 3.4) mmHg/mL; p<0.001. LV contractility (Ees) was unchanged: 1.3 (0.8, 2.2) vs 1.5 (0.9, 3.4) mmHg/mL; p=0.13. End-diastolic volume did not change: 148 (110, 205) vs 146 (108, 213) mL; p=0.880. These effects led to an increased SV: 56 (47, 67) vs 50 (38, 56) mL; p<0.001; p<0.001 and, subsequently to an increased EF [40 (30, 50) vs 30 (20, 40)%; p<0.001]. The VAC did not significantly change after SNP infusion: 1.5 (0.9-2.8) vs 1.6 (0.9-2.7); p=0.64.

Conclusion

In this report on consecutive AHF, low-dose SNP did not significantly affect VAC but led to a significant reduction in LV afterload and to a significant increase in SV and LVEF.
108 PHEOCHROMOCYTOMA-INDUCED CARDIOGENIC SHOCK: A MULTICENTRE ANALYSIS OF CLINICAL PROFILES, MANAGEMENT AND OUTCOMES
Authors: Angelis Elena De , Bochaton Thomas , Ammirati Enrico , Tedeschi Andrea , Polito Maria Vincenza , Pieroni Maurizio , Merlo Marco , Van De Heyning Caroline M , Cipriani Alberto , Camilli Massimiliano , Sanna Tommaso , Cabassi Aderville , Piepoli Massimo F , Sinagra Gianfranco , Bonnefoy-cudraz Eric , Ravera Amelia , Hayek Ahmad
Published: December 2022

Aims

There is still uncertainty on the management of patients with pheochromocytoma-induced CS (PICS), as only a few clinical cases have been reported. The aim of this study is to investigate the clinical presentation, management, and outcome of patients with PICS.

Methods

We collected retrospectively 18 patients without previously known pheochromocytoma with histologically proven PICS admitted to 8 European hospitals.

Results

Among the 18 patients with a mean age of 50 years, 50% were men. The main clinical features at presentation were pulmonary congestion (83%) and cyclic fluctuation of hypertension crises and hypotension (72%). On echocardiography, mean left ventricular ejection fraction (LVEF) was 25% with an atypical-Takotsubo pattern (basal/midventricular) in 50%. Laboratory exams showed increased inflammatory markers, in particular, the mean white blood count was 21.9*109/L. Inotropes/vasopressors were started in all patients and a temporary mechanical circulatory support (t-MCS) was required in 11 (61.1%) patients. All patients underwent surgical removal of the pheochromocytoma but 4 (22.2%) on t-MCS. Echocardiogram (16/17 patients) revealed a mean LVEF of 55% at discharge. Only one patient required heart transplantation (5.5%), and all patients were alive at a median follow-up of 679 days.

Conclusions

In patients with PICS, characteristically, an atypical Takotsubo pattern was observed in almost half of the cases. Although the use of exogenous catecholamine can be perceived as deleterious, we showed a fairly good mid-term prognosis with rapid improvement of LVEF in most, even if adrenalectomy often occurred on t-MCS.
609 LUPUS IN SHEEP'S CLOTHING: A CARDIAC TAMPONADE DUE TO ACUTE POLYSIEROSITIS IN A SLE PATIENT.
Authors: Alberti Giorgia , Dotto Alberto , Roccabruna Alessandra , Zagarese Giorgia , Piccolo Solange , Cubich Mattia , Prati Daniele , Pazzi Sara , Gambaro Alessia , Butturini Caterina , Scarsini Roberto , Ferrero Valeria , Tavella Domenico , Ribichini Flavio Luciano
Published: December 2022

This case describes a cardiac tamponade in systemic lupus erythematosus (SLE), an uncommon but life-threatening condition that needs prompt recognition.

A 33-year-old woman with therapy-resistant SLE presented to the Emergency Department with chest pain and fever for 3 days. She was hemodynamically stable, the ECG showed signs of pericarditis and echocardiography showed a minimal pericardial effusion. Pericarditis was diagnosed and the patient was admitted to the Cardiology Ward. Seven hours later her symptoms deteriorated, presenting hemodynamic instability with hypotension and tachycardia. The ECG showed low QRS voltage and electrical alternans, echocardiography confirmed cardiac tamponade. The patient underwent an emergency pericardiocentesis with 220 mL of serous citrine liquid removed and immediate regression of symptoms. The cytology exam revealed inflammatory cells with no evidence of malignancy, blood culture and effusion fluid's tests came back negative. A Thoraco-abdominal CT revealed also bilateral pleural effusion (not present at the admission) and ascites. Signs, symptoms and medical history suggested SLE flare-up and high-dose oral glucocorticoid therapy was started.

Our report highlights a rare presentation of life-threatening polyserositis in SLE flare-up. Although pericarditis and pericardial effusion are frequently-reported SLE's cardiovascular complications, rapid development of cardiac tamponade is far from common. Acute cardiac tamponade, like in our case, is an indication for emergency pericardial drainage to restore an adequate cardiac output.

We describe an out of ordinary case of a patient in whom an accurate and timely diagnosis of SLE–related cardiac tamponade has been live–saving.
819 PSEUDO-MOBITZ VAGAL ATRIOVENTRICULAR BLOCK: TWO CASE REPORTS IN YOUNG HEALTHY MEN
Authors: Bonanno Salvatore , Cocuzza Federica , Carciotto Gabriele , Marco Paride Di , Ferrara Nicola , Vetta Giampaolo , Caminiti Rodolfo , Parlavecchio Antonio , Crea Pasquale , Dattilo Giuseppe , Luzza Francesco , Carerj Scipione , Micari Antonio , Di Bella Gianluca
Published: December 2022

We reported the cases of two young men with II degree AV block. The first one was a 17 yo asymptomatic boy, soccer player, undergoing 24 hours Holter-ECG for sporadic RVOT ventricular extrasystoles at resting ECG. During the night, an apparent Mobitz type 2 II degree AV block was observed. Detailed analysis showed: Sinusal bradycardia at 50 bpm;Absence of prolongation of P-R intervals before the pause;The pause is longer than double the basic P-P interval;Prolongation of P-P interval in the beats before the pause.

The second case was also a young man suffering by atypical episodes of palpitations. The 24h Holter-ECG showed, during the night, an apparent Mobitz type 2 II degree AV block. Also in this case analysis of the tracing highlighted a) progressive slowing of sinus cycle length before the pause b) pause longer than double of sinus cycle and c) absence of prolongation of P-R intervals before the pause.

Vagally mediated atrioventricular block and pseudo-Mobitz atrioventricular block.

Vagally mediated AV block can have heterogeneous presentation: Wenckebach type, pseudo-Mobitz type II, 2:1, advanced-degree, complete AV block or a combination of different types of AV block and ventricular asystole. The mechanism is mediated by a vagal input, which depresses contemporarily sinus node and AV junction. The site of vagally mediated AV block is usually within the AV node. Generally, it results in a Wenckebach II degree AV block associated with sinus bradycardia, which occurs more often during the night in young/trained people. So the blocked P wave is generally preceded by Wenckebach phenomenon. However, in some patients the prolongation of the P-R interval is not present and the AV block appears abruptly. In these cases, Mobitz type II AV block may be erroneously diagnosed if sinus slowing is ignored. A differential diagnosis between true Mobitz II AV block and pseudo-Mobitz II block is essential for clinical purposes. Simultaneous slowing of the sinus rate and a pause longer than the double of the sinus cycle length indicate clearly a vagal mechanism, ruling out true Mobitz type 2 AV block, especially in young asymptomatic healthy men. In case of doubt, an electrophysiological study may be indicated.
578 LONG-TERM OUTCOME OF VENTRICULAR TACHYCARDIA CATHETER ABLATION IN PATIENTS WITH CHRONIC CORONARY TOTAL OCCLUSION
Authors: Flore Francesco , Narducci Maria Lucia , Niccoli Giampaolo , Ballacci Federico , Giordano Federica , Perna Francesco , Bencardino Gianluigi , Montone Rocco Antonio , Pelargonio Gemma , Crea Filippo
Published: December 2022

Background

Chronic coronary total occlusions (CTO) are considered an emerging predictor of ventricular arrhythmias (VAs) but currently there are only few data on arrhythmic outcomes in patients affected by CTO undergoing radiofrequency catheter ablation of VAs.

Objective

This study sought to evaluate the impact of unrevascularized CTO on the recurrence of VAs after catheter ablation.

Methods

This was a single-center retrospective study that enrolled 120 patients, between 2015 and 2020. All patients were admitted for ventricular tachycardia (VT) or high premature ventricular contractions (PVCs) burden (>25% detected by Holter ECG), without evidence of acute coronary syndrome; they underwent coronary angiography, electrophysiology (EP) study and three-dimensional electroanatomic mapping (3D-EAM) followed by VAs ablation.

Results

Twenty-eight patients (23%) of 120 patients showed CTO at coronary angiography. At baseline, CTO group presented with higher prevalence of hypertension, chronic renal disease, systolic ventricular dysfunction, secondary prevention ICD implantation, higher rate of low abnormal activities by 3D-EAM compared to the non-CTO group. At a median follow-up of 15 months (range 1-96 months) after catheter ablation, the only independent predictor of VAs recurrence was the presence of moderate to severe left ventricular (LV) dysfunction (p=0.02).

Conclusion

The presence of CTO does not predict VAs recurrence after catheter ablation which is instead predicted by LV dysfunction.
613 QTC PROLUNGATION IN TAKOTSUBO: DIFFERENT PATTERN, DIFFERENT OUTCOME?
Authors: Piccolo Solange , Dotto Alberto , Rizzetto Francesca , Lia Micaela , Widmann Maddalena , Pazzi Sara , Ferrigni Francesca , Tomasi Luca , Scarsini Roberto , Prati Daniele , Castaldi Gianluca , Ferrero Valeria , Tavella Domenico , Luciano Ribichini Flavio
Published: December 2022

Introduction

QT prolongation has been widely described in Takotsubo Syndrome (TTS), but the pathophysiology and prognostic implications remain unclear, and it can still hold some surprise.

We have noticed two different populations based on electrocardiogram (ECG) findings that weren't described before. The aim of the study was to investigate the difference between the two of them, with a focus on prognosis.

Methods

We retrospectively analyzed in-hospital ECG from TTS (based on revised Mayo Clinic criteria) from 2014 to August 2022. QT interval was manually measured and corrected with Bazzett formula. Patients with bundle branch blocks or QT shorter than 460 (male), 470 msec (female) were excluded.

The population was divided into two groups, based on the lead with the longest QT: V5 (group A) or V2 (group B). Our primary endpoint was overall mortality. Secondary outcome ware either ventricular or supraventricular arrhythmias detected before discharge.

Results

Our final cohort was composed of 67 patients, 42 of which had the maximum QTc interval in V5 (group A) and the other 25 having the longest QTc in V2 (group B). These two populations did not differ much in terms of age, sex, comorbidities, and echocardiographic findings at presentation. Despite this, we observed a significant prognostic difference: patients in group B experienced more in-hospital arrhythmias than the other subgroup (p=0.035), but after a median follow up of 3.6 years their all-cause mortality was significantly lower (p=0.034).

Conclusion

Although quite similar in demographic characteristics and presentations, we observed that patients with longer QTc in V5 lead (Group A) seem to have a higher mortality rate, in comparison with patients with longer QTc in V2 (Group B). It could help to identify a high-risk subgroup of patients. This is a preliminary study, further investigation is needed to make more reliable inferences.
492 EMBOLIC STROKE OF UNDETERMINED SOURCE: ROLE OF IMPLANTABLE LOOP RECORDER IN ASYMPTOMATIC ATRIAL FIBRILLATION DETECTION AND SECONDARY PREVENTION OF NEW EMBOLIC EVENTS
Authors: Ravetti Emanuele , Gambino Andrea , Jorfida Marcella , Castagno Davide , Bergui Mauro , Cerrato Paolo , De Ferrari Gaetano Maria
Published: December 2022

Background and Aims

AF (Atrial Fibrillation) is the most important cause of Embolic Stroke of Undetermined Source (ESUS). Implantable Loop Recorder (ILR) demonstrated the highest sensitivity for detecting post-stroke asymptomatic AF.

This register was created to assess the prevalence of AF episodes in patients after ESUS and to verify possible benefits on clinical outcomes such as TIA or stroke recurrence and death using ILR.

Methods

278 patients admitted to the Stroke Unit of “Città della Salute e della Scienza” hospital in Torino between 2011 and 2019, underwent ILR implantation if they had at least one risk factor for AF including obesity, hyperthyroidism, atrial enlargement at transthoracic echocardiography, severe mitral valve disease, CHADS-VASc score ≥ 4, age > 70 years old and diabetes.

The control group was composed of 165 patients admitted in other departments of the same hospital diagnosed with ESUS, not implanted with ILR.

We used propensity score matching to select 132 patients from each group (matching age, sex, CHADS-VASc, and HAS-BLED baseline characteristics).

Risk and protective factors were estimated for clinical outcomes (deaths and TIA or stroke recurrence) and were evaluated with logistic regression univariate and multivariate analyses.

Results

The detection rate of AF episodes longer than 5 minutes was significantly higher in the ILR group (41.7% vs 15.9%, p<0.001).

On univariate analysis, we found a trend towards a protective role of ILR for the composite outcome of TIA or stroke recurrence and mortality (OR 0.52, CI 0.26–1.04, p 0.06).

On multivariate analysis, we found a protective role of ILR in terms of deaths (OR 0.4, CI 0.17–0.94, p 0.03) and for the composite outcome of ischemic event recurrences and deaths (OR 0.41, CI 0.19–0.87, p 0.02). Age was consistently identified as a risk factor for all the clinical outcomes.

Conclusion

In patients with ESUS and at least one risk factor for AF, episodes of AF longer than 5 minutes are identified in 41.7% of the cases thanks to ILR.

Our study demonstrated that a policy including ILR in patients with ESUS also gives a clinical benefit in terms of TIA or stroke recurrence and death, although limited size of the population and possible presence of selection bias may limit the generalisation of our results.
112 A CASE OF INCESSANT SLOW-FAST AVNRT TREATED WITH HIS BUNDLE PACING
Authors: Rizzello Davide , Francesca Notarangelo Maria , Crocamo Antonio , Gonzi Gianluca , Mattioli Maria , Paoli Giorgia
Published: December 2022

Introduction

Slow-fast AVNRT can rarely present as incessant SVT, particularly in patients with increased HV interval. We describe a case of incessant typical AVNRT, treated without transcatheter ablation.

Case Presentation

An 83-year-old man, with history of PAF, was admitted to our ICU complaining of dyspnea, dizziness and amaurosis. His ECG at presentation depicted sinus bradycardia, first degree AVB (PQ=400 ms) and RBBB (Fig 1A). After betablocker wash-out period, we decided to perform CSP using HBP to ensure AV synchrony and restore physiological pacing.

During wash-out period, an incessant regular wide complex tachycardia with RBBB morphology and ventricular rate of 110 bpm occurred: the tracing showed a P wave immediately after the QRS, with RP < PR (Fig 1B). The tachycardia was incessant also in the EP lab. By means of 2 pacing leads (RV lead in the apical septum and RA lead in right appendage) and one diagnostic decapolar catheter (Inquiry, 2-2-2 Abbott) in His region, all connected to the polygraph, we performed an EPS. HV interval in sinus rhythm was 60 ms, AH 340 ms. The electrograms during tachycardia showed HVA sequence and 1:1 VA association, VA< 70 ms, cycle length 520 ms. Pacing from RV lead, we performed the ventricular overdrive pacing maneuver obtaining a VAV response; PPI-TCL was 280 ms and SA-VA difference was 205 ms (Fig 2A). We also noted a VA linking response to atrial overdrive pacing, and AHA response at the end of maneuver excluding JT (Fig 2B). In addition, pacing by the His catheter during tachycardia, we interrupted the arrythmia: the V signal after the last paced beat was not followed by retro-conducted A signal (Fig 2C). Finally, by administrating adenosine 12 mg the tachycardia interrupted with A as last signal recorded (Fig 2D). All these findings were consistent with an incessant typical AVNRT. We chose to treat AVRNT with sequential atrial-His pacing, placing a third lead in His region and programming the device in DDD 70-120, with selective His bundle capture, not correcting the RBBB (Fig 1C, D).

Discussion

In patients with poor anterograde AV nodal conduction, also slow-fast AVNRT can present as incessant tachycardia. In fact, a shorter sinus cycle length or atrial extrasystole could initiate sufficient delay in anterograde conduction to allow for recovery in conduction in the retrograde direction led to a persistent tachycardia. This case highlights the value of performing EPS diagnostic maneuvers also during PM implantations in order to personalize therapy and programming.
975 SIMPLY-DETECTED INFLAMMATORY BLOOD MARKERS PREDICT INDEXED LEFT ATRIAL VOLUME AMONG PATIENTS UNDERGOING ATRIAL FIBRILLATION CATHETER ABLATION
Authors: Valeri Yari , Compagnucci Paolo , Volpato Giovanni , Falanga Umbero , Parisi Quintino , Cipolletta Laura , Ritq Enrico , Guerra Federico , Casella Michela , Dello Russo Antonio
Published: December 2022

Background

atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. Predisposing factors for priming and maintenance of AF include increased left atrial (LA) size, which correlates with LA disease and is a major risk factor for recurrence after AF catheter ablation (CA). The role of inflammation in the pathogenesis of AF and the associated atrial cardiomyopathy has been ill-defined

Objective

we hypothesized that simply-detected inflammatory blood markers could correlate with left atrial volume, and thus with the severity of AF-associated atrial cardiomyopathy.

Methods

we conducted a retrospective, observational study enrolling 472 consecutive patients (male gender, n= 357, 76%; mean age, 61±11 years) who underwent paroxysmal (n=318) or persistent (n=154) AF CA at our institution. In each patient, widely available laboratory markers of inflammation (C-reactive protein (PCR), uric acid, and red blood cells distribution width [RDW]) were measured prior to CA and correlated to LA volume, using univariable and stepwise multivariable linear regression.

Results

the mean left ventricular ejection fraction (EF) was 57,4±7,6%, whereas the mean indexed LA volume was 35,3±11,9 ml/m2. The mean RDW measured 13,5±1,3, the mean PCR value was 0,5±1 mg/L, and the mean uric acid value was 5,2±1,4 mg/dl. In univariable linear regression analysis, RDW (β 2.65; 95% CI [1.81-3.49]; p=0.0002), PCR (β 1.2; 95% CI [0.02-2.38]; p=0.047), CHA2DS2VASc (β 2,17; 95% CI [1.42-2.94]; p 0.001), uric acid (β 0.85; 95% CI [0.01-1.69]; p=0.05), EF (β -0.37; 95% CI [-0.51-0.23]; p=0.002) and age (β 0.35; 95% CI [0.25-0.45]; p=0.00004) were significantly related to LA volume. In multivariable linear regression model, EF (β -0.24; 95% CI [-0.39- -0.09]; p 0.002), age (β 02; 95% CI [0.08-0.32]; p 0.0017) and RDW (β 1.5; 95% CI [0.62-2.38]; p 0.00093) retained their independent association with LA volume.

Conclusion

RDW, a simple-detected blood marker, proved to be an independent predictor of LA size, suggesting a mechanistic link between inflammation and the severity of atrial cardiomyopathy. These observations may allow a very simple and low-cost identification of AF patients at higher risk of adverse outcomes and recurrences after CA, facilitating treatment plan decisions (e.g., rate vs. rhythm control).
1092 CATHETER ABLATION VERSUS MEDICAL THERAPY OF ATRIAL FIBRILLATION IN PATIENTS WITH HEART FAILURE: AN UPDATED SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS
Authors: Magnocavallo Michele , Parlavecchio Antonio , Vetta Giampaolo , Gianni Carola , Polselli Marco , Vuono Francesco De , Pannone Luigi , Mohanty Sanghamitra , Cauti Fillippo Maria , Caminiti Rodolfo , Miraglia Vincenzo , Monaco Cinzia , Chierchia Gian Battista , Rossi Pietro , Biase Luigi Di , Bianchi Stefano , De Asmundis Carlo , Natale Andrea , Della Rocca Domenico Giovanni
Published: December 2022

Background

Atrial fibrillation (AF) and heart failure (HF) often coexist and syner-gistically contribute to an increased risk of hospitalization, stroke, and mortality. Objective: To compare the efficacy of catheter ablation (CA) versus medical therapy (MT) in HF patients with AF.

Methods

Electronic databases were queried for randomized controlled trials (RCTs) of CA versus MT of AF in patients with HF. Risk ratios (RRs), mean differences (MDs), and 95% confidence in-tervals (CIs) were measured using the Mantel–Haenszel method.

Results

A total of nine RCTs enrolling 2155 patients met the inclusion criteria. Compared to MT, CA led to a significant reduction in the composite of all-cause mortality and HF hospitalization (24.6% vs. 37.1%; RR: 0.65 (95% CI: 0.53–0.80); p < 0.0001) (Figure 1), all-cause mortality (8.8% vs. 13.6%; RR: 0.65 (95% CI: 0.51–0.82); p = 0.0005), HF hospitalization (15.4% vs. 22.4%; (RR: 0.67 (95% CI: 0.54–0.82); p = 0.0001), AF re-currence (31.8% vs. 77.0%; RR: 0.36 (95% CI: 0.24–0.54); p < 0.0001), and cardiovascular (CV) death (4.9% vs. 8.4%; RR: 0.58 (95% CI: 0.39–0.86); p = 0.007). CA improved the left ventricular ejection fraction (MD:4.76% (95% CI: 2.35–7.18); p = 0.0001), 6 min walk test (MD: 20.48 m (95% CI: 10.83–30.14); p < 0.0001), peak oxygen consumption (MD: 3.1 2mL/kg/min (95% CI: 1.01–5.22); p = 0.004), Minnesota Living with Heart Failure Questionnaire score (MD: −6.98 (95% CI: −12–03, −1.93); p = 0.007), and brain natriuretic peptide levels (MD:−133.94 pg/mL (95% CI: −197.33, −70.55); p < 0.0001).

Conclusions

In HF patients, AF catheter ablation was superior to MT in re-ducing CV and all-cause mortality. Further significant benefits occurred within the ablation group in terms of HF hospitalizations, AF recurrences, the systolic function, exercise capacity, and quality of life.

Figure 1: Forest plot displaying a decrease in the composite endpoint in patients with AF and HF undergoing CA versus MT.