bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of microwave power on lignocellulose content, physical and chemical characteristics of biomass: A review
Authors: Indriani D W , Susilo B , Mashur
Published: December 2021

Bioethanol is alternative energy derived from biomass that can be obtained from the agricultural industry to replace fossil fuels. The issue with biomass to energy conversion is the presence of lignin in lignocellulose biomass which inhibits the hydrolysis process. Microwave-acid pre-treatment is a method that combines microwaves and H2SO4 to break down lignin. In other studies, various microwave power is studied. The aim of this review is to provide insight and novelty into the effect of microwave power that is used on the lignocellulose content of rape straw and the physical and chemical characteristics of biomass after pre-treatment. Various microwave powers on delignification processes were presented, while the physical and chemical characteristics of pretreated biomass and also the prospect of future applications of microwave-assisted pretreatment were also discussed.
Potential uses of the lesser-known tree: Timo (Timonius sericeus (Desf) K. Schum) from Timor Island, East Nusa Tenggara based on its chemical wood properties and calorific value
Authors: Rianawati H , Setyowati R , Siswadi  , Umroni A
Published: December 2021

This study determined the chemical properties and calorific value of Timo (Timoneus sericeus) wood originated from Reknamo village, Timor Island, East Nusa Tenggara. Timo is a potential wood that belongs to the Rubiaceae family, categorised as the lesser known tree. Its basic wood properties have not been thoroughly scientifically investigated. The chemical wood analyses were carried out at the laboratory of chemical forest products in the Forest Products Research and Development Center, Bogor. The Testing methods were according to the ASTM and TAPPI standard, included the content of extractive solubility (in cold water, hot water, benzene-alcohol, and in 1% NaOH), cellulose, pentose, lignin, ash, and silica. The calorific value was measured by the calorimeter. The result showed that the cellulose, pentose, and extractive solubility contents of Timo wood were high; the lignin and ash contents were moderate; the silica content was low; the calorific value was high (4400 cal/g). Based on the results of chemical wood analyses and calorific value, Timo wood is qualified for construction and wood energy; while it is not recommended for pulp and bioethanol.
The physical characteristics of analog cincau from different proportions of the cottonii organic powder
Authors: Sinurat E , Basmal J , Nurhayati
Published: December 2021

Black grass jelly often called black jelly, also known as blackcincau(“cincau”in Indonesian), was produced by boiling the black grass jelly to extract the jelly. It has a high soluble fiber content. This study investigated the analogcincauformulation using organic powder cottonii (OPC) ingredients as the gelling agent. The OPC was obtained from SeaweedEucheuma cottonii(Lampung) without an alkali treatment. The analogcincauformulation consists of OPC, konjac, KCl, tapioca flour,cincauflavor. A commercialcincauwas used as a reference. The physical quality characterization of analogcincauin this study includes gel strength, elasticity, and syneresis. Based on the physical analysis results, the best formula of analogcincauwas thecincauusing the following formula: OPC 65%, konjac 15%, tapioca flour 10%, and KCl 10%. Its physical characteristics were almost similar to the commercialcincau.The characteristics of thecincauwith the best formula were the gel strength of 532 g/cm2, elasticity 246 (g/sec), and syneresis 2.70%.
The potential of green seaweed (Caulerpa sp.) extract to synthesis ZnO nanoparticles with zinc nitrate as a precursor and pH variations
Authors: Sari R N , Sinurat E , Ayudiarti D L , Oktavia D A
Published: December 2021

The potential of green seaweed Caulerpa sp. as a reducing agent, stabilizer, and capping agent and the benefits of zinc oxide (ZnO) nanoparticles in the food and non-food is exciting to be developed. The research was aimed to understand the potential of green seaweed (Caulerpa sp.) to become ZnO nanoparticles capping agent with ten mM zinc nitrate as a precursor and pH variations of 8-12. The analysis included function groups, particle size distribution, and % mass O and Zn composition. The result found that spectra at wave number 574 cm−1 were Zn-O stretching vibration from solution pH synthesis of 11. Size distribution was homogeneous, but it still had not met the size of nano. The average particle size ranged from 992.37-1369.36 nm, and the smallest particle size was obtained at a ZnO synthesized at a pH of 8. The composition from ZnO synthesis at solution pH of 9 was 7.68% O and 92.32% Zn. Caulerpa sp. extract could produce a synthesis of ZnO with ten mM zinc nitrate as a precursor and solution pH variations. Although the biosynthesis had not produced a ZnO with nanoparticles size yet, the particle size distribution had been homogeneous. The biosynthesis at pH 9, %mass Zn and O for ZnO produced had been similar to the ZnO standard.
Determination of the effective operating hours of the intermittent lighting system for growing vegetables
Authors: Kondrateva N , Filatov D , Bolshin R , Krasnolutskaya M , Shishov A , Ovchukova S , Mikheev G
Published: December 2021

Around the world, one of the key challenges is the provision of food for a growing urbanized population. A vertical farming system will help solve this problem. Vertical farming in a controlled environment provides 4-6 times higher yields per unit area, but requires more electricity. The most economical light sources are light-emitting diodes but it is important to determine the rational operating mode of the lighting system. The aim of the study was to determine the specific operating hours of the intermittent lighting system to reduce the cost of electricity consumption when growing vegetables in vertical farming in a controlled environment. Continuous and periodic modes of operation of the lighting system with a total operating time of 16 hours per day were considered. In Russia, there are six price categories for consumed electricity. Research has shown that price level II is economically viable. and a rational operating mode: 8 hours of light/4 hours of darkness, etc. Thus, the intervals of operation of the lighting system are 11.00-19.00 and 23.00-7.00. The study of this regime for microgreening of Mitsun head cabbage showed that the productivity of the plants was preserved, since the length of the leaves did not change.
Metabolism in calves two weeks before diarrhea at the age of 19-52 days of life
Authors: Malkova N , Ostyakova M , Shcherbinina S , Irkhina V
Published: December 2021

The article presents data on the study of metabolism in calves two weeks before diarrhea at the age of 19-52 days of life. For this purpose, three groups of conditionally healthy animals of the Holstein breed were formed at the age of 19, 30, 52 days of life. To assess the metabolic status of young cattle, biochemical and general clinical blood tests were carried out. In the course of a laboratory blood test in young cattle, two weeks before disease manifestation, disorders of mineral and protein metabolism, a decrease in liver function were established. At the same time, with the increase in the age of the calves, the imbalance in protein metabolism was aggravated against the background of a change in diet and mineral metabolism improved as a result of the maturation of the digestive system.
Silicon-based natural zeolites in feeding store pigs
Authors: Yu Lavrentev A , Evdokimov N V , Larionov G A , Yu Nemtseva E , Mikhaylova L R , Zhestyanova L V , Sherne V S
Published: December 2021

To realize the genetic potential of pig productivity and balance diets, it is perhaps to use various additives, including silicon-containing zeolite trepel. The novelty of the work - the use of zeolite in feeding as a preventive and therapeutic additive allows you to increase productivity and reduce the cost of feed and feed costs compared to similar additives. For the experiment, 4 recipes of mixed feeds were developed: one without the content of zeolite trepel and 3 with 3, 4, 5% of this additive. It is proved that the best dose of this drug is 3% of the mass of feed. It was found that the body weight gain in II group increased by 13.5%, in III group by 7.2%, and in IV group decreased by 4.41% compared to the control group. The addition of silicon-containing zeolite in the II and III experimental groups did not affect the consumption of mixed feed, and in the IV experimental group, a decrease in the consumption of mixed feed was observed. Feed consumption in the I, III and IV experimental groups decreased by 12.1%, 6.7% and 0.3%.
Feeding stimulates functional abilities of queen bees of the Carpathian subspecies
Authors: Ulugov O P , Sharipov A , Sattarov V N , Semenov V G , Skvortsov A I
Published: December 2021

The researches were conductedon queen bees of the Carpathian subspecies in conditions of Tajikistan. Four groups of similar families were formed, 10 in each group. In the control group, sugar syrup (1:2) was given as a stimulating feeding, in small portions of 700 ml. Bees of the first experimental group were fed with the sugar syrup, with the addition of drone larvas’ homogenate. The second group was fed with the sugar syrup with addition of a feed mixture “Similak”, the third group - sugar syrup with the addition of a compositional form consisting of a feed mixture “Similak” and the drone larvas’ homogenate. In the experimental groups, in contrast to the control group, an increase in the egg production of queen bees and the brood breeding reflex by 1.3-1.44 times was found.In general, it has been established that to stimulate the physiological processes in bee’ organism, growth and development of colonies in spring, it is necessary to use stimulating feeding by sugar syrup in combination with drone larvas’ homogenate and feed mixture “Similak” 700 ml each.
Effect of hop growing technology on the accounting system in the agricultural entity
Authors: Malinina L Y , Ivanov E A , Khristolyubov S N , Pushkarenko N N
Published: December 2021

With the beginning of market relations, Russian hop-growing practically ceased to function due to the lack of purchases from the side of brewing companies. But the government policy of import substitution, pursued in recent years, has given a certain impetus to the revival of this industry. The purpose of this study is to describe the agrobiological and technological features of hop growing and their impact on the accounting process in an agricultural organization. To reveal the main scientific provisions, such general scientific techniques and methods were used as observation, comparison, analysis and synthesis, operation research, etc. Hops as a perennial crop require large capital and current expenditures. When carrying out agrotechnical measures related to the cultivation of hops, it becomes necessary to group costs in a certain system. The study shows that in the international and Russian scientific community, the issue of cost formation and accounting is considered within the framework of crop production in general. The article reveals the main stages of the formation of costs in hop-growing with an indication of accounting objects. Separately, innovations in the regulatory framework for accounting for non-current assets in connection with the reform of the national accounting system are touched upon.
Hitchin systems for invariant and anti-invariant vector bundles
Authors: Hacen Zelaci
Published: December 2021

Given a smooth projective complex curve

X
X

with an involution

σ
\sigma

, we study the Hitchin systems for the locus of anti-invariant (resp. invariant) stable vector bundles over

X
X

under

σ
\sigma

. Using these integrable systems and the theory of the nilpotent cone, we study the irreducibility of these loci. The anti-invariant locus can be thought of as a generalisation of Prym varieties to higher rank.
Small eigenvalues of closed Riemann surfaces for large genus
Authors: Wu Yunhui , Xue Yuhao
Published: December 2021

In this article we study the asymptotic behavior of small eigenvalues of hyperbolic surfaces for large genus. We show that for any positive integer

k
k

, as the genus

g
g

goes to infinity, the minimum of

k
k

-th eigenvalues of hyperbolic surfaces over any thick part of moduli space of Riemann surfaces of genus

g
g

is uniformly comparable to

1

g
2

\frac {1}{g^2}

in

g
g

. And the minimum of

a
g

ag

-th eigenvalues of hyperbolic surfaces in any thick part of moduli space is bounded above by a uniform constant only depending on

ε
\varepsilon

and

a
a

.

In the proof of the upper bound, for any constant

ε
>
0

\varepsilon >0

, we will construct a closed hyperbolic surface of genus

g
g

in any

ε
\varepsilon

-thick part of moduli space such that it admits a pants decomposition whose curves all have length equal to

ε
\varepsilon

, and the number of separating systole curves in this surface is uniformly comparable to

g
g

.
Concepts and contentions of coral snake resemblance: Batesian mimicry and its alternatives
Authors: Sena Anthony Thomas , Ruane Sara
Published: December 2021

Venomous coral snakes and non-venomous coral snake lookalikes are often regarded as a classic example of Batesian mimicry, whereby a harmless or palatable organism imitates a harmful or less palatable organism. However, the validity of this claim is questionable. The existing literature regarding coral snake mimicry presents a divisive stance on whether Batesian mimicry is occurring or whether the similarity between snakes is attributable to alternative factors. Here, we compile available literature on coral snake mimicry and assess the support for Batesian mimicry. We find that most of the recent relevant literature (after approximately 2000) supports the Batesian mimicry hypothesis. However, this is not strongly supported by empirical evidence. Potential considerations addressed here for both the Batesian and alternative hypotheses include the function of the colour pattern, predatory learning and the biogeographical distribution of similar snakes. The analyses performed previously by mimicry researchers show that the interpretation of the conditions for mimicry is not consistent throughout the scientific community when applied to coral snake systems. This review focuses on this division and stresses the need to reach an agreement about the adaptive significance of New World coral snakes and their lookalikes.
Foreign Relations Law on Treaty Matters from Restatement (Third) to Restatement (Fourth): More a Filter Than a Bridge
Authors: Miron Alina , Palchetti Paolo
Published: December 2021

The remarks contained in this article are a candid reading of Part III of the Restatement of the Law (Fourth): Foreign Relations Law of the United States (‘Treaties as Law of the United States’) through the lens of international lawyers who wonder about the role of international law in the US legal system. They turn essentially on the promise and peril of domesticating international law: Does foreign relations law as determined by Part III the Restatement (Fourth) promote compliance with international treaty law or does it rather emphasize constitutional law concerns that may limit its domestic application? To what extent do domestic judicial authorities give effect to treaties at the domestic level? Is the question of the self-executing character of a treaty provision exclusively a matter of domestic law or does it depend also on treaty interpretation? Our conclusion is that, on treaties, the Restatement (Fourth) marks a retreat in the engagement with international law from the Restatement (Third).
A systematic review and meta-analysis of beta-blockers and renin–angiotensin system inhibitors for preventing left ventricular dysfunction due to anthracyclines or trastuzumab in patients with breast cancer
Authors: Lewinter Christian , Nielsen Torsten Holm , Edfors Lars Robert , Linde Cecilia , Bland John Martin , LeWinter  M , Cleland John G F , Køber Lars , Braunschweig Frieder , Mansson-Broberg Agneta
Published: December 2021

Aims

Trastuzumab and anthracyclines, often used in the treatment of breast cancer, may impair myocardial function, and reduce left ventricular ejection fraction (LVEF), potentially causing heart failure. Randomized controlled trials (RCTs) have evaluated the effects of beta-blockers (BBs), angiotensin receptor blockers (ARBs), and angiotensin-converting enzyme inhibitors (ACEI) on trastuzumab- and anthracycline-associated cardiotoxicity. We report a meta-analysis of these RCTs in patients with breast cancer.

Methods and results

The primary analysis was on the effect of BBs and ACEI/ARBs on LVEF in patients treated with either trastuzumab or anthracyclines. A secondary analysis was done investigating the effect of BBs or ACEI/ARBs on LVEF in trastuzumab and anthracycline treatments. Only RCTs were included using the search term ‘ARBs, ACEIs, BBs, anthracyclines, trastuzumab, and breast cancer’ in PubMed, Embase, and CENTRAL up to 31 March 2021. A meta-analysis was conducted to estimate the mean difference (MD) in LVEF between intervention and placebo groups at follow-up. A total of nine RCTs (n = 1362) were included in the analysis. All patients were women. BBs and ACEI/ARBs were shown to attenuate the decline in LVEF during trastuzumab and anthracycline treatments [MD: 2.4; 95% confidence interval (CI): 0.3–4.2 and MD: 1.5; 95% CI: –0.6 to 3.7]. Compared with placebo, LVEF was significantly higher in patients assigned to BB or ACEI/ARB on trastuzumab (MD: 2.3; 95% CI: 0.0–4.6) but not on anthracyclines (MD: 1.9; 95% CI: –0.5 to 4.2).

Conclusion

Both BB and ACEI/ARB therapies were associated with the preservation of LVEF during trastuzumab and anthracycline-containing regimens as compared with placebo, suggesting both to be beneficial.
606 Predictive value of left atrial and left ventricular strain for the detection of atrial fibrillation in patients with cryptogenic stroke
Authors: Bufano Gabriella , Radico Francesco , D’Angelo Carolina Maria , Pierfelice Francesca , Vittoria De Angelis Maria , Faustino Massimiliano , Pierdomenico Sante Donato , Gallina Sabina , Renda Giulia
Published: December 2021

Aims

Cryptogenic stroke (CS) is associated with high rate of recurrences and adverse outcomes at long-term follow-up, especially in light of its unknown etiology that often leads to ineffective secondary prevention. In such scenario, asymptomatic misdiagnosed atrial fibrillation (AF) episodes could play an important pathophysiological role. Some studies have pointed left atrial (LA) and left ventricular (LV) systolic and diastolic dysfunction as surrogate markers of AF. The aim of this study was to evaluate the relationship between echocardiographic parameters of LA and LV function, and the occurrence of AF revealed by continuous electrocardiogram (ECG) monitoring in a cohort of CS patients.

Methods and results

This is a single-centre prospective cohort study. Seventy-two CS patients with continuous ECG monitoring with insertable cardiac monitor (ICM) underwent transthoracic echocardiography (TTE). TTE was focused on LA and LV function, including both standard and longitudinal strain-derived parameters. All detected AF episodes lasting more than 2 min were considered. Patients with and without AF were homogeneous in all baseline characteristics, except for CHA2DS2-VASc score, which was significantly higher in AF group, and prevalence of hypercholesterolaemia, that was significantly higher in no-AF group. ICM revealed AF in 23 patients (32%), on average 196 days after ICM implantation. Among echocardiographic parameters, LV ejection fraction (LVEF, P = 0.007), LA end systolic area (LAES area, P = 0.006), LA volume index (LAVI, P = 0.008), total LA emptying fraction (LATEF, P = 0.013), E velocity (P = 0.042), pulmonary veins AR duration (P = 0.01), septal and median TDI E/e′ (respectively, P = 0.045 and P = 0.039), peak atrial longitudinal strain (PALS) in 4-chamber and in 2-chamber view (respectively, P < 0.001 and P = 0.011), peak atrial contraction strain (PACS, P < 0.001), LA conduit strain (P = 0.005), and LV longitudinal strain (LVLS, P = 0.001) were significantly associated to the occurrence of AF, suggesting worst atrial function in AF group. Furthermore, multivariable regression analysis revealed that PACS and LV strain were the only echocardiographic parameters independently associated with AF [confidence interval (CI) 95%: 0.48–0.90, P = 0.005 and CI 95%: 0.46–0.95, P = 0.041 respectively].

Conclusions

In a cohort of CS patients, continuous ECG monitoring with ICM revealed subclinical AF episodes in about one-third of patients. In such population, LA and LV strain analysis add predictive value for occurrence of AF over clinical and morpho-functional echocardiographic parameters. Impaired booster pump strain and LVLS strain are strong and independent predictors of AF.
754 Non-conducted premature atrial complexes: a new predictor for atrial fibrillation in cryptogenic stroke patients
Authors: Vetta Giampaolo , Parlavecchio Antonio , Caminiti Rodolfo , Magnocavallo Michele , Lavalle Carlo , Della Rocca Domenico G , Marano Giovanni , Ruggieri Chiara , Crea Pasquale , Dattilo Giuseppe , Ferrau Ludovica , Musolino Rosa , Zito Concetta , Luzza Francesco , Micari Antonio , Carerj Scipione , Di Bella Gianluca
Published: December 2021

Aims

Atrial fibrillation (AF) is the main cardiac cause of stroke, but it frequently remains undetected. In these patient monitoring for AF is recommended using a Holter electrocardiogram (ECG). The aim of the present study is to study non-conducted atrial complexes (ncPAC) recorded on Holter ECG as a new predictor of AF.

Methods and results

Patients admitted to the Stroke Unit of our hospital for cryptogenic stroke from December 2018 to January 2020 who underwent 24-h electrocardiographic monitoring were prospectively enrolled in the study and were subsequently submitted to 3-month and 6-month follow-up to investigate the occurrence of AF. The study recruited 112 patients. At follow-up visit, AF was diagnosed in 21.4% of the population. The only statistically significant difference between the group with and without a AF diagnosis was the presence of ncPAC (83.3% vs. 16.7%; P < 0.0001). ROC analysis was performed and showed that ncPAC had the best diagnostic accuracy in the AF diagnosis [AUC: 0.798; confidence interval (CI): 0.675–0.921]. The AUC of ncPAC was significantly better than the AUC of premature atrial complexes (PACs) (P < 0.05), CHA2DS2-VASc, HATCH, HAVOC, and C2HEST scores (P < 0.01). Kaplan–Meier curve survival estimate for AF onset by the presence of ncPAC revealed that there was a significant difference in the AF onset between patients with ncPAC and those without (P < 0.0001) and multivariate Cox-proportional hazard analysis revealed that ncPAC presence was an independent predictors of AF onset [hazards ratio (HR): 9.28; CI 95%: 2,66–32,40; P = 0.0001].

Conclusions

The presence of ncPAC represents a new predictor of AF that could further guide the investigation of AF in patients with cryptogenic stroke.
703 Koch’s triangle voltage mapping for cryoablation of slow pathway in children: preliminary data of a novel high density technique
Authors: Cazzoli Ilaria , Tamborrino Pietro Paolo , Porco Luigina , Campisi Marta , Fanti Veronica , Annibali Roberta , Silvetti Massimo Stefano , Drago Fabrizio
Published: December 2021

Aims

Different authors have described three-dimensional (3D) voltage mapping of the Koch’s triangle (KT) in order to find low-voltage bridges (LVBs) as targets for a successful transcatheter ablation (TCA) of the slow pathway (SP) in children. Recently, the advisor high density (HD) Grid™ mapping catheter was introduced as new multipolar catheter for HD mapping. The aim of the study was to describe our preliminary experience with the use of HD Grid™ catheter in LVB and electrophysiologically guided cryoablation of SP in children.

Methods and results

Twenty-one children (mean age 13 ± 3 years) with atrioventricular nodal re-entrant tachycardia (AVNRT) underwent cryoablation of SP guided by voltage HD mapping of the KT using HD Grid™ catheter. In order to better highlight the differences with conventional mapping, point collection was performed in each patient with this new multipolar catheter and with a quadripolar catheter. The conventional mapping collected 871 ± 262 points and used 211 ± 80 points in 887 ± 275 s, whereas HD mapping collected 7468 ± 2947 points, using 604 ± 165 points in 513 ± 181 s (P < 0.001). Moreover, the LVB area mapped with HD Grid™ was about one-half smaller and clearly delineated. Cryoablation acute success rate was 100%. Overall median fluoroscopy exposure was 0.08 (0.01–5.42) µGy/m2, with a median fluoroscopy time of 0.1 (0.0–0.6) min. During the follow-up (4.8 ± 3.7 months), there were no recurrences. No complications occurred.

Conclusions

Our preliminary experience shows that HD mapping is faster and offers higher spatial resolution and definition. Procedural time can be reduced maintaining the TCA safe, with reduced fluoroscopy use, and successful.
512 Long-term survival in patients with post-operative atrial fibrillation after cardiac surgery: analysis from a prospective-cohort study
Authors: Marazzato Jacopo , De Ponti Roberto , Verdecchia Paolo , Blasi Federico , Golino Michele , Ferrarese Sandro , Angeli Fabio
Published: December 2021

Aims

Post-operative atrial fibrillation (POP AF) is frequent in patients who undergo cardiac surgery. However, its prognostic impact in the long-term remains unclear.

Methods and results

We followed for an average of 10 ± 3 years 1386 patients who underwent a variety of cardiac surgical procedures (cardiac transplantation and surgery for heart failure included) while they were in sinus rhythm. Among 1178 patents without a history of AF, 726 (62%) did not develop AF during the entire duration of the study and 452 (38%) developed new-onset POP AF during the first 30 peri-operative days after heart surgery. Other 125 patients with a positive history of paroxysmal or persistent AF were in sinus rhythm at the time of surgery and 87 of them (70%) developed POP AF. Finally, 83 patients had permanent AF when they underwent surgery. All-cause mortality was the primary outcome of the study. We tested the associations of potential determinants with all-cause mortality using univariable and multivariable statistical analyses by means of Cox proportional hazard models. Overall, 473 patients (34%) died during a long-term follow-up. Compared with patients who never developed AF, neither the patients with new-onset POP AF [adjusted HR = 1.31 (95% CI: 0.90–1.89); P = 0.1609], nor those with history of AF at the time of surgery (adjusted HR = 1.33, 95% CI: 0.71–2.49; P = 0.3736) showed a significantly increased risk of mortality (Figure 1). In new-onset POP AF patients, oral anticoagulation was not associated with mortality [adjusted HR = 1.13 (95% CI: 0.83–1.54), P = 0.4299].

Conclusions

In this huge prospective cohort of patients who underwent different types of heart surgery, POP AF was not associated with an increased risk of mortality. In this setting, the role of long-term anticoagulation remains unclear.
204 Permanent his bundle pacing using stylet-driven lead in patients with right atriomegaly: a single-centre experience
Authors: Marinaccio Leonardo , Vetta Francesco , Rocchetto Eros , Napoli Paola , Marchese Domenico
Published: December 2021

Aims

His bundle pacing (HBP) is becoming an increasing widespread approach for physiological pacing. However, successful HBP procedure could be hampered by limited implantation tools especially in challenging anatomies. We aimed to report our experience with HBP technique using a novel stylet-driven lead system in patients with right atriomegaly.

Methods and results

Consecutive patients with right atrium (RA) volume >25 ml/m2 in men and >21 ml/m2 in women who underwent permanent HBP for standard indications were enrolled from March 2020 to March 2021. The tool of first choice for HBP attempt was a stylet-driven lead (Solia S 60, Biotronik) delivered via a dedicated introducer sheath (Selectra 3D, Biotronik). The acute, 1-month and 6-month procedural success rates were assessed. We enrolled 24 patients [median age: 75 (70–79) years, 85% men] with an average RA volume of 50.7 ± 7.8 ml/m2. At implant, conduction system pacing using stylet-driven lead was achieved in 21 patients (87%): 12 (50%) selective HBP, 6 (25%) non-selective HBP, and 3 (12.5%) left bundle branch area pacing. In the three failures, HBP was further attempted with a lumen-less lead with fixed helix (SelectSecure 3830, Medtronic) with final procedural success in two cases. In the successful cases, there was a significant reduction of QRS duration between paced and spontaneous beats [152.5 (130–167.5) ms vs. 130 (122.5–137.5) ms, P = 0.003]. No lead dislodgment nor significant pacing threshold increase was observed at 1-month (1.30 ± 0.76 V@0.4 vs. 1.32 ± 0.80 V@0.4 ms, P > 0.9) and 6-month follow-up (1.30 ± 0.76 V@0.4 vs. 1.38 ± 0.97 V@0.4 ms, P = 0.66).

Conclusions

In patients with right atriomegaly, the novel stylet-driven lead system showed high implant success rates with stable pacing thresholds.
460 Assessment of long-term arrhytmic sequelae in patients recovering from COVID-19 infection
Authors: Curnis Antonio , Arabia Gianmarco , Salghetti Francesca , Cerini Manuel , Milidoni Antonino , Calvi Emiliano , Beretta Daniele , Bisegna Stefano , Ahmed Ashraf , Mitacchione Gianfranco , Bontempi Luca
Published: December 2021

Aims

COVID-19 has been associated with acute cardiac complications including cardiac arrhythmias. We aimed to assess the prevalence of long-term cardiac arrhythmias in patients recovering from severe COVID-19 infection with proved or suspected of cardiac involvement.

Methods and results

All patients with COVID-19 infection discharged from the cardiology department of our institution from the 1 March to the 30 April 2020 were considered eligible for this study. Patients were fitted out with an adhesive patch and a wireless single-lead 24-h electrocardiogram (ECG) Holter monitor (Rooti Rx® System, Rooti Labs Ltd, Taipei, Taiwan). RootiRx® is a small device consisting of an integrated sensor system, a microelectronic board with memory storage, and an internal rechargeable battery. This system can provide continuous ECG and was set to monitor heart rhythm for 24 h. The Holter system provides also blood pressure measurements and sleep apnea data which are evaluated through chest wall motion/cyclic variation of heart rate and reported along with the sleep efficiency (percentage of time spent asleep while in bed). Arrhythmic findings, sleep apnea detections, and residual COVID-19 symptoms were reported. The study follow-up was performed 174 (range = 166–190) days after hospital discharge in a cohort of 63 (76% males, median age 66 years) patients. New diagnosis of atrial fibrillation (AF) was performed in three sinus rhythm patients (4.8%). Eleven (18%) patients had asymptomatic bradycardia (<45 b.p.m.) with no pauses lasting more than 3 s. Non-sustained ventricular tachycardia (<30 s) episodes were recorded in two (3.2%) patients, while no sustained ventricular arrhythmia was documented. The Holter system indicated the presence of moderate-to-severe obstructive sleep apnea episodes in 33 (53%) patients without known history of sleep disorders. Some previously unrecognized long-lasting COVID-19 symptoms were also described: fatigue (10, 16%), myalgia (3, 4.8%), and impaired attention (1, 1.6%).

Conclusions

Six months after the infection, we performed new diagnoses of AF in patients who recovered from severe COVID-19 infection with proved or suspected cardiac involvement using 24-h Holter monitoring. No other arrhythmias were observed, but the Holter system identified obstructive sleep apnea episodes in half of the patients. A relevant percentage of patients also described persisting symptoms of COVID-19 infection. These findings suggest further prospective studies to better describe long-term arrhythmic manifestations and residual symptoms in patients hospitalized with COVID-19 infection.
689 Hybrid transvenous and surgical approach for the extraction of coronary sinus leads: a case series
Authors: Ahmed Ashraf , Arabia Gianmarco , Bontempi Luca , Cerini Manuel , Salghetti Francesca , Mitacchione Gianfranco , Milidoni Antonino , Stretti Lorenzo , Bernardi Nicola , Pezzola Elisa , Cimino Giuliana , Saccani Nicola , Curnis Antonio
Published: December 2021

Aims

The rates of cardiac device-related infection have increased substantially over the past years. Transvenous lead extraction is the standard therapy for such cases. In some patients, however, the procedure cannot be completed through the transvenous route alone. A hybrid surgical and transvenous approach may provide the solution in such cases.

Methods and results

We present three cases who underwent hybird transvenous and surgical extraction for coronary sinus leads due to infection of CRT-D systems. One patient had an Attain Starfix lead implanted in the coronary sinus. The procedures were performed under local anaesthesia with continuous haemodynamic and transthoracic echocardiographic monitoring. We highlight the characteristics of the patients, the features of the devices, the technical difficulties, and the outcomes of the procedures. In all cases, the right atrial and right ventricular leads were extracted through the transvenous route. In one patient, they were extracted using regular stylets and manual traction, while in the other two patients, telescoping dilator sheaths (Cook), Tightrail hand-powered mechanical sheaths (Spectranetics), and/or Glidelight Excimer Laser sheaths (Spectranetics) were used. The coronary sinus lead could not be retrieved due to extensive fibrosis after utilizing locking stylets and mechanical dilator sheaths in all three cases, in addition to rotational mechanical sheaths and laser sheaths in one case, so the patients were referred to surgery. Two patients underwent left mini-thoracotomy and one patient underwent midline sternotomy to extract the remaining CS lead. The target vein was identified and ligated, then the fibrosis around the lead was dissected, this was followed by lead retrieval through the surgical incision. The patient who underwent sternotomy suffered from mediastinitis, which required reoperation and mediastinal lavage. There were no complications in the other two patients. All three patients were reimplanted with a new CRT-D device on the contralateral side after the resolution of infection.

Conclusions

A hybrid surgical and transvenous approach can be complementary in case the transvenous route alone fails to completely extract the coronary sinus lead. The transvenous approach can be used to free the proximal part of the lead, while the distal adhesions can be removed surgically, preferably though a limited thoracic incision.
525 Incidence and possible determinants of device-pocket haematoma after cardiac implantable electronic devices in patients treated with a pressure dressing
Authors: Patti Alessandro , Santoro Francesco , Pellegrino Pierluigi , D’Arienzo Girolamo , Gianfrancesco Domenico , Bartolomucci Francesco , Brunetti Natale Daniele
Published: December 2021

Aims

Device-pocket haematoma (DPH) occurs in 2–15% of the implantations of cardiac rhythm devices. Major bleedings occur in 0.2–2% of the cases. The present study aims to evaluate the incidence of DPH in patients treated with a pressure dressing after implantation of a pacemaker and to investigate the impact of antiplatelet and anticoagulant therapy on DPH in the same cohort.

Methods and results

A retrospective evaluation on 446 consecutive patients who underwent implantation or replacement of pacemaker/ICD between 2017 and 2018 was performed. Cardiovascular risk factors, clinical parameters, medical history of the patients, as well as their drug history were collected. The presence or absence of perioperative DPH was investigated. All patients were treated with a pressure dressing immediately after the procedure and for the first 24 h. The preliminary results obtained after reviewing the medical records of the 446 patients (age 76.8 ± 10.4 years; 67% males; left ventricular ejection fraction 47.3 ± 12.2%) show an incidence of DPH of 8.1% (n = 36). 332 (74%) of the patients had documented hypertension, 131 (29%) diabetes, 213 (48%) were taking antiplatelet medications, and 150 (34%) were taking anticoagulants. No significant differences were found directly comparing the main variables under study between patients who experienced DPH and those who did not. However, at binomial logistic regression analysis, performed including antithrombotic therapies, sex, and age, a tendency of patients treated with warfarin to experience DPH emerged (OR : 3.25, 95% CI : 1.00–10.50; P = 0.049).

Conclusions

The preliminary results of the present study show an incidence of DPH of 8.1% in patients treated with a pressure dressing after pacemaker implantation. Between antithrombotic therapies, sex and age, anticoagulation therapy with warfarin appeared to be correlated with an increased risk of DPH.
547 Supernormal conduction of an accessory pathway: the case of a young sportsman
Authors: Robles Antonio Gianluca , Petrungaro Mattia , Penco Maria , Romano Silvio , Sciarra Luigi
Published: December 2021

Aims

Ventricular pre-excitation is defined by the presence of all of the following electrocardiographic criteria: PQ interval duration ≤120 ms, QRS duration ≥120 ms, and presence of δ wave (defined as initial ‘slurring’ of the QRS complex). Ventricular pre-excitation together with the presence of symptoms (orthodromic and/or antidromic atrioventricular reentry tachycardia, atrial fibrillation) defines Wolff–Parkinson–White (WPW) syndrome. The anatomical substrate of ventricular pre-excitation consists of an extranodal accessory atrio-ventricular connection: the so-called Kent bundle. Such pathways can have antegrade, retrograde, or mixed conductive properties. Accessory pathways endowed with anterograde conductive capability may be responsible for manifest, intermittent, or non-manifest ventricular pre-excitation depending on whether it is respectively always visible on the ECG, not always visible on the ECG and not visible on the ECG even though the pathway has the ability to antegrade conduction. The rare phenomenon of supernormal conduction of anomalous pathways is part of the manifest pre-excitation, which represents the topic of the case reported below.

Methods and results

We report the clinical case of a young not agonist sportsman undergoing an electrophysiological study (SEF) because of he is suffering from ventricular pre-excitation. The SEF did not showed the inducibility of arrhythmias and, at the same time, apparently it showed low risk characteristics of the pathway even during adrenergic stimulus. However, a careful study, performed with atrial stimulation with couplings up to refractoriness of the atrioventricular node revealed supernormal conduction properties of the Kent bundle which proved to have high risk characteristics according to current guidelines and, therefore, was effectively treated with catheter ablation.

Conclusions

This case invites us to careful studying of accessory pathways properties, especially since, although rare, they may possess supernormal conduction characteristics capable of determining high ventricular rates in the case of sustained atrial tachyarrhythmias, especially in conditions of adrenergic hyperactivity.
179 ICD or not ICD? A difficult choice for a young patient presenting with palpitations in emergency department
Authors: Savo Maria Teresa , Balducci Elisa , Calzolari Vittorio , Cernetti Carlo
Published: December 2021

A fit-and-well 52-year-old worker, with negative familiar story, was admitted to Emergency Department (ED) with haemodynamically unstable but well bore broad complex tachycardia of 180 b.p.m. (Figure 1). Twenty years before the patient had heart-surgery to repair atrial septal venous sinus defect with patch. The defect determined anomalous pulmonary venous return in right atrium with left to right shunt and moderate pulmonary hypertension. The surgery, 20 years before, was complicated by a single event of supraventricular tachycardia pharmacology resolved. Next follow-up was normal although at transthoracic echocardiography severe right ventricular (RV) dilation was reported. In the ED the patient had palpitation but not chest pain or dyspnoea. General clinical examination was normal but he was hypertensive (170/137 mmHg) and with heart rate of 180 b.p.m. Valsalva manoeuver was performed and adenosine (6 mg–12 mg–12 mg) was administered without benefit. Eventually, the patient was cardioverted to sinus rhythm with a single 100 J shock. His baseline ECG (Figure 2) showed sinus rhythm, normal axis, as well as right bundle branch block and T-wave inversion in leads V1–V4 and a waves with a small spike upward in lead V1 which represent characteristic epsilon waves.

Successively patient was admitted to Cardiology Department where transthoracic echocardiography showed severe RV dilation and moderate hypokinesia with a tricuspid annular plane excursion of 15 mm, TAV 9.6 cm/s, fractional area change of 29%. The right atrium was moderate dilated (volume 70 ml, indexed volume 35.53 ml/m2). Left chambers were normal. No shunts were observed. An electrophysiology study with isoprenaline infusion was performed but no arrhythmias were induced. Cardiac magnetic resonance imaging (MRI) was normal save for global RV dilatation, increased RV end diastolic volume (156 ml/m2), and global RV systolic dysfunction (reduction of RV ejection fraction 31%). Arrhythmogenic cardiomyopathy was excluded as patient’s background suggested RV dilation was due the overload caused by the history of left–right shunt. Blood tests and personal history negative initially exclude myocarditis and cardiac MRI confirmed the absence of oedema. An accurate ECG analysis excluded Brugada syndrome. Following discussion between electrophysiologists, clinical cardiologists, and the patient who first need to be informed, trans-venous ICD was implanted. 179 Figure 1ECG in ED.               Figure 2 Baseline ECG.                 Figure 3 Cardiac MRI.
93 Melatonin and oxidative stress in the prevention of cardiovascular disease
Authors: Cersosimo Angelica , Franco Caterina , Sciatti Edoardo , Favero Gaia , Vizzardi Enrico , Rezzani Rita
Published: December 2021

Aims

Arterial hypertension, especially if not well-controlled, is one of the main risk factors predisposing to fatal cardiovascular diseases (CVDs). Moreover, the diagnosis of essential hypertension are increasing, therefore oxidative stress and chronic inflammation have also been identified as potential responsible for the development of endothelial damage. Among all the molecules, melatonin (MT) was chosen for its role as a powerful antioxidant and anti-inflammatory endogenous molecule. This trial aims to evaluate the early intervention at the base of the inflammatory and oxidative cascade (that results in the development of hypertension), to restore an oxidative balance leading to positive results even at the endothelial and vascular level using MT in addition to anti-hypertensive therapy.

Methods

The trial is randomized, prospective and monocentric control. We enrolled 23 patients with hypertension in absence of other cardiovascular or autoimmune diseases that could alter the oxidative background, from March 2018 to April 2019 (recruitment period). Patients were randomly assigned to two groups: ‘melatonin group’ (in which 16 patients add 1 mg/day of melatonin for a year, to their already settled therapy), and a ‘control’ group (consisting of 7 patients with no changes in their therapy). The average follow-up was 1 year from randomisation. Patients were evaluated before and after a period of 1 year through MT plasma concentration and serum antioxidant capacity (TAC) by specific quantitative ELISA method. Therefore endothelial dysfunction and arterial stiffness were evaluated too (using the non-invasive methods of EndoPAT and SphygmoCor).

Results

In ‘melatonin group’ arterial stiffness index statistically decreased (P 0.022), according to a significant increase in plasma melatonin values (P 0.003) and significant decrease in TAC levels (P 0.041) despite the ‘control’ group. The improvement of endothelial function was not significant (P 0.688). Blood pressure had not a significative improvement too (P 0.401).

Conclusions

Data obtained could confirm the hypothesis of activation of plasma antioxidant system against a situation of altered oxidative balance. In fact, it is possible to hypothesize a correlation between TAC and arterial stiffness that confirm the antioxidant role of MT. The combination between antihypertensive therapy and antioxidant supplementation is able to improve the vascular stiffness. Data obtained are still preliminary and present some limitations but we can think of proposing this trial as a future basis for other extensive and prolonged studies.
306 Involvement of toll-like receptor 4 in PCSK9-mediated biological effects in cell culture models
Authors: Scalise Valentina , Sanguinetti Chiara , Lai Michele , Neri Tommaso , Celi Alessandro , Pedrinelli Roberto
Published: December 2021

Aims

The link between pro-protein convertase subtilisin/kexin 9 (PCSK9) and inflammatory-related disease was supported in several experimental and human studies, which show how the protein could acts independent its canonical mechanism, by activation of inflammatory, apoptotic and immune pathways. Among these, TLR4/NFKB signalling pathway was found to be one of the main pathways mediating the PCSK9-induced increase of pro-inflammatory and pro-thrombotic molecules, such as TNF-alpha, IL-6, IL-1, MCP-1, and TF. To investigate the direct involvement of hTLR4 in recognition of exogenous human recombinant (hr) PCSK9.

Methods

Experiments were carried out in three cell line: (i) HEK293-hTLR4-GFP cell lines obtained by stable co-transfection of HEK293 cells with the pUNO1-hTLR4-GFP, a plasmid expressing the hTLR4 gene fused to a GFP gene; (ii) HEK293-hTLR4+ cells obtained by co-transfection of hTLR4 receptor and its accessory proteins MD-2 and CD14, and an inducible secreted embryonic alkaline phosphatase (SEAP) reporter gene; (iii) HEK293-Null2 cells, a cell line lacking TLR4 expression, used as negative control. NFkB activity were measured by the SEAP reporter gene assay using a fluorescence detection method, while localization of hTLR4 and exogenous hrPCSK9 by confocal microscopy.

Results

hrPCSK9 (1 µg/mL) activates NFkB in HEK293-hTLR4+ cells [SEAP activity-OD 620 nm: from a baseline of 0.18 ± 0.06 to 0.68 ± 0.05 (N = 8), P < 0.001] to an extent comparable to Lipopolysaccharide (LPS), the specific agonist of TLR4. Colocalization of hrPCSK9 and TLR4s was clearly documented by quantitative confocal microscopy in HEK293-hTLR4-GFP cell line, that comprises the analysis of more than 80 fields in ∼2.105 cells/well and showing a percentage of co-localization of ∼4% in membrane spots (P < 0.01).

Conclusions

Our data support the results reported in previous studies that attribute to PCSK9 a pathophysiological role in development of chronic inflammation and related-diseases such as atherothrombosis. A behaviour that extends far beyond LDLR degradation, via a mechanism that might be mediated at least in part by recognition of PCSK9 by the TLRs and later activation of NFKB intracellular pathway. Future studies will be important to better investigate the specific binding site engaged in the PCSK9-TLR interaction and to discriminate the intracellular transduction pathways involved in this response, in order to provide a theoretical basis for the development of innovative therapeutic strategies.