bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics model of convective drying
Authors: Akenchenko M A , Arapov V M , Kvashnin B N , Litvinov E V , Lihacheva L B , Matveeva E V
Published: February 2021

The article considers various approaches to modeling the drying of finely dispersed products: based on the classical theory of diffusion, from the standpoint of the thermodynamics of an irreversible process. An analysis of the scientific and technical literature on the problem revealed not high accuracy of the convective drying models of finely dispersed products developed on the existing theoretical basis. It is shown that the improvement of drying modeling can be based on the kinetics theory of chemical reactions. In this case, drying is considered as a quasi-topochemical heterogeneous reaction. At the same time, a combined approach to drying modeling is proposed: the phenomenological equation of chemical kinetics, which describes the speed of the process, is supplemented by the experimentally established relationship between the temperature and moisture content of the material. Based on the proposed approach, mathematical models of the kinetics of convective drying of finely dispersed products for periods of constant and decreasing speed have been developed, which allow to establish a clear type of the influence of the temperature regime on the kinetics of the process and reduce the amount of experimental research. A mathematical model of the temperature curve of drying for a period of decreasing speed is developed. The relationship between the speed of the first and second drying periods is established. The reliability of the obtained mathematical models is confirmed by experimental verification of the kinetic equation obtained for a period of constant velocity.
Extrudate dehydration rate increase by modernization of the extruder vacuum chamber
Authors: Kurochkin A A , Frolov D I , Zimnyakov V M
Published: February 2021

This paper proposes to upgrade the vacuum chamber of the extruder to enhance the impact of thermovacuum effect on extrudate due to dispensing air into the working volume of the vacuum chamber of the extruder. An air valve is installed in the upgraded extruder chamber. This valve allows faster removal of the wet steam with the extrudate surface. Analytical expressions, which allow determining the volumetric flow rate of intake air of the machine in the vacuum chamber and determining its influence on the basic design and technological parameters of the system, were obtained. The obtained results can be useful and taken into account in the process of subsequent theoretical studies of extruders with a vacuum chamber and will improve the efficiency of machines that perform thermal vacuum extrusion of plant materials.
The design of the device for the solid carbon dioxide production
Authors: Neverov E N , Korotkiy I A , Rasshchepkin A N , Ibragimov M I , Grinyuk A N
Published: February 2021

We considered the method of carbon dioxide processing and recycling which is suitable for the use in food, refrigeration and other industries; moreover it provides a high level of carbon dioxide recycling and processing and its further use. The analysis of being in demand for this method was carried out in the field of processing liquid and solid carbon dioxide. A special feature of the method concept is the principle of solidification and the possibility of producing solid carbon dioxide with full use of raw materials without losses to the environment. A plant for producing solid carbon dioxide has been designed. The article presents the plant process flow diagram and describes its operation principle. We also mark the plant competitive advantages over analogues. Despite relatively small overall dimensions, the carbon dioxide return was anticipated by means of liquefaction back into the technological cycle. Feed connection can be carried out both from the cylinders with liquid carbon dioxide, and by connecting the liquid carbon dioxide pipeline from the liquefaction process flow at the enterprises.
Complex for the production of compressed carbon dioxide based on an industrial furnace for food production
Authors: Osintsev K V , Dudkin M M , Kuskarbekova S I
Published: February 2021

Today, the problem of the use of energy is the most common. In order to increase energy efficiency could be used at food enterprises. A new scheme of combined main production and auxiliary production has been developed. In particular, on the basis of industrial furnaces for the production of compressed carbon dioxide. In this system, the coolant is supplied from an industrial furnace. In addition, it is shown that the coolant may be a rotary kiln or an industrial steam generator. The developed scheme is universal and can be used at the enterprise for various purposes.
Research on brewing in a mash brewing and filtering apparatus
Authors: Ivanov P P , Plotnikov K B , Maytakov A L , Pachkin S G , GShevtsova T , Vetrova N T
Published: February 2021

The extensive development of craft brewing forms strong demand for technological equipment characterized by compactness, high-energy efficiency and ease of operation. Multifunctional apparatuses of low capacity and a high degree of modularity is becoming widespread. The design of 500-litre mash brewing and filtering apparatus (MBFA) offered in the article allows combining mashing, mash filtering and hopping within one technological unit. This process denies bringing inter-stage transfer of raw material to minimum values, reducing material losses and the length of the technological cycle. Besides, carrying out all brewing technological operations in one apparatus allows significantly reducing heat energy consumption due to the decrease in heat losses while heating relevant apparatuses. The offered design of MBFA is notable for directed circulation of extractant flows that forms optimal conditions for mass-transfer processes at the stage of malt mashing. Conducted brewing tests in a 50-litre apparatus proved the operability and high efficiency of the apparatus. Produced wort matched all controlled physicochemical parameters and was characterized by significant 33% decrease in turbidity and 6.5% reduction of polyphenol concentration that enhanced fermentation and made beer brightening easier improving its consumption properties at the same time. The degustation evaluation of finished beer showed the beer sample obtained from the MBFA-brewed wort had a prime soft and harmonious taste, pure flavour and saturated colour.
The use of the electronic nose device for the diagnosis of postpartum metritis in cows
Authors: Skorikov V N , Kuchmenko T A , Mikhalev V I , Umarkhanov R U
Published: February 2021

The study aimed to assess the possibilities of applying electronic nose device for early diagnosis of postpartum endometritis in cows using secretions. The experiment included four clinically healthy cows, four cows with endometritis. Samples of secretions were obtained on days 1,3,6,8 after analysis of their odours was carried out with MAG-8 device (Russia). As and measuring array, there were used eight sensors based on piezoelectric crystals frequency of 10,0 MHz and film sorbents on electrodes that respond to compounds of C2-C4 alcohols, linear and cyclic ketones, aldehydes, aliphatic amines, and sulfur-containing organic compounds, acids, ammonia. It was found that during the first three days after calving in cows with postpartum endometritis in comparison with healthy animals, the area of the visual response of the sensors was exceeded by 28,4% the content of alcohols, ketones of linear a structure by 5,2-6,0%, aliphatic acids were less by 14,3% and alkyl amines by 9,2%. On 6-8 days after calving, in the clinical manifestation of endometritis, an excess of the “visual imprint” by 6.1 times (p <0.001), a decrease in the content of aliphatic acids by 22.7% (p < 0.05), and an increase in the concentration of sulfur-containing organic compounds - by 4.9%. Therefore, the electronic nose system can distinguish between the composition of the volatile compounds of the cervical postpartum secretions with the normal and pathological course of the postpartum period.
Electrochemical water treatment plant for food production
Authors: Egorov V G , Vasechkin M A , Davydov O Yu , Pribytkov A V , Chertov E D
Published: February 2021

The development of new methods or equipment for water purification in recent years has been an important task. Of the existing methods as promising ones, we can distinguish electrochemical non-reagent purification methods. A design of a water treatment plant has been developed, the main elements of which are a device for electrochemical treatment with electrodes made of titanium alloys and a filter for fine mechanical cleaning. This plant has passed a set of laboratory tests and testing as part of a mobile integrated water treatment plant. According to the test results, it has been found that electrodes made of titanium alloys with the highest titanium content have the best resistance to electrochemical destruction. The rational current density and the range of the gap between the electrodes are determined, which ensure effective water purification with an extended overhaul cycle and sufficiently low metal consumption and energy consumption.
Cause analysis and Countermeasures for shaft fracture of closed pump
Authors: Liu Jun
Published: February 2021

Two 350MW supercritical wet cooling units in a power plant, the closed water pump adopts horizontal single-stage double suction split centrifugal pump. In recent two years, the shaft of the closed pump B of 1 unit has been fractured twice. In this paper, the fracture causes of the closed pump shaft are analyzed from the aspects of closed pump operation, material analysis and micro organization, and treatment measures are taken to solve the problem.
Research on contribution analysis method of lubricating oil performance index
Authors: Sun Yuanyuan , Wang Yuexing , Wang Pujian , Cao Zehui
Published: February 2021

In the application of entropy weight method and oil performance index test, the weights of various indexes of lubricating oil in use are objectively assigned, and the correlation among multiple samples is investigated by normalization of multi-sample data of the same monitoring index, so that the weight results are more accurate and reasonable, and provide theoretical basis for oil formula optimization or life promotion.
Research on Optimization of NEV Power Battery Recycling Network
Authors: Ma Jun , Liu Lu
Published: February 2021

With the increasing number of new energy vehicles (NEV), the NEV industry is facing a situation of large amounts of retired power battery. In this study, first, the relevant research of the power battery recycling mode is sort out. And this paper proposes a four-level power battery recycling network, which includes nodes such as collection warehouse, storage warehouse, transfer hub, echelon utilization enterprise, etc.Then, a Mixed-Integer Non-Linear Programming model is proposed to minimize the cost of the network.
Case analysis and preventive measures of limestone-gypsum wet flue gas desulfurization slurry poisoning for 320MW unit
Authors: Wang Qunkui , Liu Jing , Xue Fangming
Published: February 2021

The slurry poisoning of the desulfurization system is a difficult problem in the current desulfurization operation. This paper analyzes the abnormality of the limestone-gypsum wet flue gas desulfurization slurry poisoning of a 320MW unit, and proposes a solution. Through the test method, the slurry composition and gypsum quality the analysis was carried out and effective measures were taken according to the actual situation to solve the slurry poisoning phenomenon and ensure the safe operation of the desulfurization system, which is of great significance to the flue gas emission standard of the desulfurization system of the power plant.
A New Approach to the Implementation of Multivariable Information Transfer Models of Smart Sensors for Ubiquitous Power Energy Internet of Things
Authors: Chen Shiyu , Li Bin , Sun Wei , Wang Lei , Li Lin , Zhang Dewen
Published: February 2021

As an important cornerstone of the construction of the energy Internet, the ubiquitous power Internet of Things is of great significance for improving the overall efficiency and social efficiency of the power grid, and promoting the development of emerging services that meet the needs of users. The thesis first elaborates the basic concepts and characteristics of the ubiquitous power Internet of Things, and analyzes its system architecture in detail; secondly, discusses the key technologies of the ubiquitous power Internet of Things from three aspects: smart chips, 5G and LPWA, and Internet of Things platform; Third, in order to overcome the influence of the interference of the sensor’s mutual sensing area of the Internet of Things on the transmission success rate, it is necessary to design the interference avoidance algorithm of the sensor’s mutual sensing area, and propose an Internet of Things based on adaptive link equalization configuration and inter-code interference suppression The algorithm for avoiding interference between sensors in the mutual sensing area. The simulation results show that using this method for sensor interference avoidance, the output error rate is lower, the purity of sensor sensing area information is higher, and the anti-interference is better.
The theoretical study on intermittency and propagation of geodesic acoustic mode in L-mode discharge near tokamak edge
Authors: LIU Zhaoyang , ZHANG Yangzhong , MAHAJAN Swadesh Mitter , LIU Adi , XIE Tao , ZHOU Chu , LAN Tao , XIE Jinlin , LI Hong , ZHUANG Ge , LIU Wandong
Published: February 2021

Through a systematically developed theory, we demonstrate that the motion of Instanton identified in Zhang et al (2017 Phys. Plasmas
24 122304) is highly correlated to the intermittent excitation and propagation of geodesic acoustic mode (GAM) that is observed in tokamaks. While many numerical simulations have observed the phenomena, it is the first theory that reveals the physical mechanism behind GAM intermittent excitation and propagation. The preceding work is based on the micro-turbulence associated with toroidal ion temperature gradient mode, and slab-based phenomenological model of zonal flow. When full toroidal effect is introduced into the system, two branches of zonal flow emerge: the torus-modified low frequency zonal flow (TLFZF), and GAM, necessitating a unified exploration of GAM and TLFZF. Indeed, we observe that the transition from the Caviton to Instanton is triggered by a rapid zero-crossing of radial group velocity of drift wave and is found to be strongly correlated with the GAM onset. Many features peculiar to intermittent GAMs, observed in real machines, are thus identified in the numerical experiment. The results will be displayed in figures and in a movie; first for single central rational surface, and then with coupled multiple central rational surfaces. The periodic bursting first shown disappears as being replaced by irregular one, more similar to the intermittent characteristics observed in GAM experiments.
The divine hiddenness objection is not costly for atheists
Authors: Curtis Benjamin L
Published: February 2021

Perry Hendricks has recently argued that endorsing the divine hiddenness objection to the existence of God ‘eliminates’ or ‘does away with’ all de jure objections to theism. So, he says, anyone who endorses the divine hiddenness objection must ‘reject’ any de jure objection. ‘And this,’ he says, ‘means that the argument from divine hiddenness is costly for atheists’. However, although Hendricks's argument is an interesting one, it does not establish any of these things, at least on any natural understanding of his claims.
Paucity of Entorhinal Cortex Pathology of the Alzheimer’s Type in SuperAgers with Superior Memory Performance
Authors: Gefen Tamar , Kawles Allegra , Makowski-Woidan Beth , Engelmeyer Janessa , Ayala Ivan , Abbassian Payam , Zhang Hui , Weintraub Sandra , Flanagan Margaret E , Mao Qinwen , Bigio Eileen H , Rogalski Emily , Mesulam M Marsel , Geula Changiz
Published: February 2021

Advancing age is typically associated with declining memory capacity and increased risk of Alzheimer’s disease (AD). Markers of AD such as amyloid plaques (AP) and neurofibrillary tangles (NFTs) are commonly found in the brains of cognitively average elderly but in more limited distribution than in those at the mild cognitive impairment and dementia stages of AD. Cognitive SuperAgers are individuals over age 80 who show superior memory capacity, at a level consistent with individuals 20–30 years their junior. Using a stereological approach, the current study quantitated the presence of AD markers in the memory-associated entorhinal cortex (ERC) of seven SuperAgers compared with six age-matched cognitively average normal control individuals. Amyloid plaques and NFTs were visualized using Thioflavin-S histofluorescence, 6E10, and PHF-1 immunohistochemistry. Unbiased stereological analysis revealed significantly more NFTs in ERC in cognitively average normal controls compared with SuperAgers (P < 0.05) by a difference of ~3-fold. There were no significant differences in plaque density. To highlight relative magnitude, cases with typical amnestic dementia of AD showed nearly 100 times more entorhinal NFTs than SuperAgers. The results suggest that resistance to age-related neurofibrillary degeneration in the ERC may be one factor contributing to preserved memory in SuperAgers.
Finding diverse ways to improve algebraic connectivity through multi-start optimization
Authors: Mackay Sarah , Ponce Colin , Osborn Sarah , McGarry Meghan
Published: February 2021

The algebraic connectivity, also known as the Fiedler value, is a spectral measure of network connectivity that can be increased through edge addition. We present an algorithm for producing many diverse ways to add a fixed number of edges to a network to achieve a near optimal Fiedler value. Previous Fielder value optimization algorithms (i.e. the greedy algorithm) output only one solution. Obtaining a single solution is rarely good enough for real-world network redesign problems, as practical constraints (political, physical or financial) may prevent implementation. Our algorithm takes a multi-start optimization approach, adding a random initial edge and then applies a greedy heuristic to improve the Fiedler value. The random choice moves us to a new region of the search space, enabling discovery of diverse solutions. Additionally, we present a Determinantal Point Process framework for quantifying diversity. We then apply a Markov chain Monte Carlo technique to sift through the large number of output solutions and locate a smaller, more manageable collection of highly diverse solutions that can be presented to network redesign engineers. We demonstrate the effectiveness of our algorithm on real-world graphs with varied structures.
Echocardographic changes in anorexia nervosa: a pathophysiological adaptation or a disease?
Authors: Toriello F , Santangelo G , Bursi F , Epis E , Tamagni ME , Massironi L , Bertelli S , Benetti A , Cattaneo M , Carugo S
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Anorexia nervosa (AN) is one of the most common form of eating disorders and it is a severe and potentially fatal disease with high rates of morbidity and mortality especially in the population aged 15-25 years. Cardiac involvement occurs in approximately 80% of patients with AN. Cardiovascular complications include changes in the autonomic regulation (increased vagal tone, bradycardia, orthostatic hypotension, syncope), arrhythmias, congestive heart failure and sudden death. Few reports have described, in small series, a variety of echocardiographic abnormalities including decreased cardiac mass, mitral valve prolapse, pericardial effusion and reduced left ventricular (LV) dimensions. No previous studies, however, examined if there is a change in these abnormalities with weight fluctuations. 

Purpose

To describe echocardiographic findings among male and female patients with AN and to examine the effect of weight gain on clinical and echocardiographic parameters.

Methods

We performed a single center, retrospective, study of  patients diagnosed with AN using the diagnostic and statistical manual of mental disorders, fifth edition (DSM-5). Clinical, laboratory and ECG-graphic data were obtained by reviewing each patient’s medical records. Echocardiographic parameters were measured off-line.

Results

The study population consisted of 81 patients, mean age 24.5 ± 11.6 years, 92.6% females. 75% showed an extreme AN degree. Mean body mass index (BMI) was 15.2 ± 2.1 kg/m2. Mean heart rate was 57.2 ± 12.7 beats per minute. Some patients showed right bundle branch block (7.4%) or prolonged QT interval (14.8%). Patients with BMI below the mean value had more often pericardial effusion, smaller LV mass and LV end-diastolic volume and thinner interventricular septum (all p < 0.05). However, when index to BSA, LV mass and volumes were within normal range in the 90% of the population. They also showed mitral valve abnormalities and low values of white blood cells and platelets. The presence of pericardial effusion was not related to inflammatory parameters or protein deficiency. For 39 patients echocardiographic exams at the highest and the lowest weight were available. With weight gain, there was an improvement in LV mass, interventricular septum thickness, pericardial effusion and an increase in white blood cells and platelet count.

Conclusions

Our study showed that patients with AN have a specific echocardiographic pattern which seems to be proportional to the body size, suggesting a pathophysiological adaptation to the lack of substrates, hypothesis confirmed by the regression with weight gain. It is possible that pericardic effusion fills the gap left by mass loss.
Phenotyping right heart function for prognosticating heart failure
Authors: Cho J , Uejima T , Hayama H , Yajima Y , Yamashita Y
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Right heart failure has been shown to portend poor prognosis. The pathophysiology of right heart function is complex, as right ventricular (RV) function is easily affected by preload and afterload.

Purpose

To test the hypothesis that machine learning would detect heterogeneity in right heart function and improve risk stratifications in a heart failure population

Methods

This study included 403 heart failure patients who had a history of hospitalization for decompensation. Patients were excluded if they had primary heart valve disease or pericardial disease or a previous cardiac surgery. Hierarchical clustering was undertaken on right heart variables (RV strain, right ventricular systolic pressure (RVSP), vena contracta of tricuspid regurgitation (TR) and diameter of inferior vena cava) to identify homogenous groups of patients with similar profiles of the variables. Cox hazard analysis was used to elucidate the benefit of clustering over each variable for prognosticating heart failure. Endpoint was hospitalization for worsening heart failure.

Results

Cluster analysis identified three groups with distinct right heart function. Cluster 1 (n = 191) represented patients with preserved RV function and low RVSP (figure A).  On the other hand, cluster 2 (n = 144) had reduced RV function and low RVSP, while cluster 3 (n = 68) had preserved RV function and high RVSP, associated with severe TR and high central venous pressure. The latter 2 clusters carried worse outcome than cluster 1 (p < 0.001, figure B). Cox hazard analysis demonstrated that, although the addition of each right heart variable to baseline model constructed from left heart variables did not improve predictive power, clusters predicted events with a hazard ratio of 1.566, independent from and incremental to the left heart variables (Figure C).

Conclusion

Cluster analysis identified two distinct phenotypes of right heart failure that were associated with adverse outcomes. This data-driven phenotyping can help in categorizing right heart failure and better prognosticating heart failure.

Abstract Figure.
Beneficial effect of angiotensin converter enzyme inhibitors on left ventricular deformation in patients with hematologic malignancies after bone marrow transplantation
Authors: Ikonomidis I , Katogiannis K , Stamouli M , Makavos G , Frogoudaki A , Vrettou AR , Birba D , Thymis J , Tsilivarakis D , Tsirigotis P , Eliodromitis EK
Published: February 2021

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Hellenic society of lipidiology, atherosclerosis and cardiovascular disease

Background/Introduction:  Optimal medical treatment for heart failure may reverse myocardial dysfunction in the early stages of cardiotoxic treatment.

Patients and methods

60 patients age 46,3 ± 12,9 years old, 19 male) with preserved ejection fraction, who suffered from hematologic malignancies (lymphoma, leukemia) and underwent bone marrow transplantation, were randomized to receive 2,5 mg enalapril bid daily or placebo. We measured at baseline, before transplantation, and after three months: i) Global Longitudinal Strain of left ventricle (LV) (GLS), ii) LV Epicardial Strain (GLSepi), iii) LV Endocardial Strain (GLSendo), by speckle tracking imaging, iv) LV End Diastolic ,End Systolic Volume and Ejection Fraction (LVEF).

Results

  The two treatment groups had similar age, sex atherosclerotic risk factors and cardiotoxic medication before and after bone marrow transplantation. Compared to baseline, patients treated with enalapril did not show a deterioration of LV GLS and GLSepi [ p = 0,540 and p = 0,422)], Conversely, patients treated with placebo group, presented a significant impairment of LV GLS and GLSepi [p = 0,041 and p = 0,028)] three months after bone marrow  transplantation. No significant changes were found in LVEF after treatment with enalapril ( p = 0,692) or the placebo ( p = 0,892). Table 1

Conclusions

  Treatment with enalapril prevented deterioration of myocardial deformation three months after bone marrow transplantation

Table 1 group baseline 3 months follow-up p Longitudinal strain apical 4 chambers view placebo -20.56 ± 2.55 -19.46 ± 2.59 0.154 enalapril -20.41 ± 3.31 -19.70 ± 3.70 0.433 Longitudinal strain apical 2 chambers view placebo -20.5 ± 1.97 -16.11 ± 10.38 0.149 enalapril -20.30 ± 3.90 -20.00 ± 3.82 0.763 Longitudinal strain apical 3 chambers view placebo -19.55 ± 2.36 -18.55 ± 2.43 0.197 enalapril -20.01 ± 4.09 -19.26 ± 3.68 0.489 Global Longitudinal Strain placebo -20.19 ± 1.76 -18.96 ± 2.08 0.041 enalapril -20.24 ± 3.58 -19.66 ± 3.65 0.540 Average Global Epicardial Strain placebo -17.82 ± 1.45 -16.60 ± 1.68 0.028 enalapril -17.84 ± 3.09 -17.16 ± 3.20 0.422 Average Global Endocardial Strain placebo -23.03 ± 2.15 -21.96 ± 2.56 0.181 enalapril -23.07 ± 4.19 -23.60 ± 4.17 0.666 EF (Simpon’s method) placebo 59.46 ± 6.59 59.69 ± 6.79 0.892 enalapril 58.65 ± 7.63 59.45 ± 9.28 0.692 Left ventricular parameters during 3 months of follow-up.
Prognostic value of diastolic function assessment in patients undergoing cardiac resynchronization therapy
Authors: Galli E , Smiseth OA , Aalen JM , Larsen CK , Sade E , Le Rolle V , Hernandez A , Leclercq C , Duchenne J , Voigt J-U , Donal E
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Objective

The best modality to assess diastolic function in CRT-candidates is an object of debate and the relationship between diastolic function, CRT-response and survival are not

clearly understood.

Purpose of the study: to assess diastolic patterns in patients undergoing CRT according to the 2016 recommendations of the American Society of Echocardiography/European Association of Cardiovascular Imaging and to evaluate the prognostic value of diastolic dysfunction (DD) in CRT candidates.

Methods

193 patients (age: 67 ± 11 years, QRS width: 167 ± 21 ms) were included in this multicentre prospective study. Patients were stratified according to DD grades (grade I

to III). CRT-response was defined as a reduction of left ventricular (LV) end-systolic volume >15% at 6-month follow-up (FU). The primary endpoint was defined as a

composite of heart transplantation, LV assisted device implantation or all-cause death during FU.

Results

During FU, 132 (68%) patients were CRT-responders. CRT delivery was associated with diastolic function degradation in non-responders. Grade I DD was able to predict

CRT-response with a sensitivity, specificity and accuracy of 70%, 65%, and 63%, respectively. After a median period of 35 months, the primary endpoint occurred in 29

(15%) patients. Grade I DD was associated with a better outcome [HR 0.26 95% CI: (0.10-0.66)], independently from ischemic cardiomyopathy, LV dyssynchrony and CRT-response (Table 1). Non-responders with grade II or grade III DD had the worse prognosis (HR 4.36, 95%CI: 2.10-9.06) Figure 1.

Conclusions

Grade I DD is associated with LV remodelling after CRT and is an independent predictor of prognosis in CRT candidates.

Abstract Figure.
Regional myocardial work as determinant of heart failure in left bundle branch block
Authors: Sletten OJ , Aalen JM , Izci H , Duchenne J , Remme EW , Larsen CK , Hopp E , Galli E , Sirnes PA , Kongsgard E , Voigt JU , Donal E , Smiseth OA , Skulstad H
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association

Background

Left bundle branch block (LBBB) worsen prognosis in heart failure patients. LBBB may also cause heart failure in otherwise healthy individuals. The mechanical changes induced by LBBB are potential determinants of heart failure in these patients, but their relation to left ventricular (LV) systolic function is incompletely understood.

Purpose

This study investigates the contribution of regional contractile function to heart failure in patients with LBBB.

Methods

In 76 patients with LBBB and 11 healthy controls, myocardial strain was measured by speckle-tracking echocardiography and myocardial work by pressure-strain analysis. Patients with ischemic heart disease or myocardial scarring were excluded. LBBB patients were stratified by LV ejection fraction (EF) >50% (EFpreserved), 36-50% (EFmid), and ≤35% (EFlow). 62 LBBB patients subsequently underwent cardiac resynchronization therapy (CRT) implantation and was re-examined at 6 months.

Results

Septal work was significantly and successively reduced from controls, EFpreserved, EFmid, to EFlow (1977 ± 506, 1025 ± 342, 601 ± 494 and -41 ± 303 mmHg·%, respectively, all p < 0.01) (Figure 1). There was a strong correlation (R = 0.84, p < 0.01) between septal work and LVEF. In contrast, work in the LV lateral wall was preserved in both EFpreserved (2367 ± 459 mmHg·%) and EFmid (2252 ± 449 mmHg·%) vs controls (2062 ± 459 mmHg·%, all NS). In the EFlow group, however, LV lateral wall work was reduced (1473 ± 568 mmHg·%, p < 0.01 vs controls). Thus, lateral wall function was not correlated with LVEF in patients with LVEF >35% (NS). At six month CRT septal work was markedly increased (165 ± 485 vs 1288 ± 523 mmHg·%, p < 0.01) and LV lateral wall work reduced (1730 ± 620 vs 1264 ± 490 mmHg·%, p < 0.01). LVEF increased from 32 ± 8 to 47 ± 10 % (p < 0.01).

Conclusions

Heart failure in LBBB patients is determined by degree of septal dysfunction. LV lateral wall function, on the other hand, is preserved in the early phase of heart failure and was only reduced in patients with severe heart failure. Further clinical studies should investigate if measuring LV lateral wall function can increase precision in patient selection for CRT.

Abstract Figure.
Application of the current HFA-ESC consensus guidelines on diagnosis of heart failure with preserved ejection fraction to a population referred for echocardiography
Authors: Liang K , Hearse-Morgan R , Fairbairn S , Ismail Y , Nightingale AK
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

The recent Heart Failure Association (HFA) of the European Society of Cardiology (ESC) consensus guidelines on diagnosis of heart failure with preserved ejection fraction (HFpEF) have developed a simple diagnostic algorithm for clinical use.

PURPOSE

To assess whether echocardiogram (echo) parameters needed to assess diastolic function are routinely collected in patients referred for assessment of heart failure symptoms.

METHODS

Retrospective analysis of echo referrals in January 2020 were assessed for parameters of diastolic function as per step 2 of the HF-PEFF diagnostic algorithm.  Echo images and clinical reports were reviewed. Electronic records were utilised to obtain clinical history, blood results (NT-proBNP) and demographic data.

RESULTS

1330 patients underwent an echo in our department during January 2020. 83 patients were referred with symptoms of heart failure without prior history of cardiac disease; 20 patients found to have impaired left ventricular (LV) function were excluded from analysis.

Of the 63 patients with possible HFpEF, HF-PEFF score was low in 18, intermediate in 33 and high in 12. Median age was 68 years (range 32 to 97 years); 25% had a BMI >30. There was a high prevalence of hypertension (52%), diabetes (19%) and atrial fibrillation (40%) (cf. Table 1). Body surface area (BSA) was documented in 65% of echo reports. Most echo parameters were recorded with the exception of global longitudinal strain (GLS) and indexed LV mass (cf. image 1). NT-proBNP was recorded in only 20 patients (31.7%). 12 patients with an intermediate HF-PEFF score could have been re-categorised to a high score depending on GLS and NT-proBNP (which were not recorded).

CONCLUSION

More than three quarters of echoes acquired in our department obtained the relevant parameters to assess diastolic function. The addition of BSA, and inclusion of NT-proBNP, and GLS would have been additive to a third of ‘intermediate’ patients to determine definite HFpEF. Our study demonstrates that the current HFA-ESC diagnostic algorithm and HF-PEFF scoring system are easy to use, highly relevant and applicable to current clinical practice.

Age >70 years 29 (46.0%) Obesity (BMI >30) 16 (25.4%) Diabetes 12 (19%) Hypertension 33 (52.4%) Atrial Fibrillation 25 (39.7%) ECG abnormalities 18 (28.5%) Table 1. Prevalence of Clinical Risk Factors Abstract Figure. Image 1. HFPEFF score & echo parameters
Evaluation of left ventricular filling pressure by echocardiography: incremental diagnostic information from left atrial strain
Authors: Khan F , Inoue K , Remme EW , Ohte N , Garcia-Izquierdo E , Chetrit M , Andersen OS , Gude E , Andreassen AK , Kikuchi S , Stugaard M , Ha JW , Klein A , Nagueh SF , Smiseth OA
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Background

Elevated left ventricular (LV) filling pressure is an important diagnostic feature of heart failure.

Objectives

To investigate determinants of left atrial (LA) reservoir and pump strain and if these parameters may serve as markers of LV filling pressure.

Methods

In a multicenter study of 322 patients with cardiovascular disease of different etiologies, LA strain by speckle tracking echocardiography was compared to conventional echocardiographic markers using invasive pressure as reference.

Results

Left ventricular filling pressure correlated well with LA reservoir and pump strain (r-values

‑0.52 and ‑0.57, respectively) (Figure). However, LV global longitudinal strain (GLS) was the strongest determinant of LA reservoir strain (r = 0.64), and correlated well with LA pump strain (r = 0.51).  For both LA strains, association with filling pressure was strongest in patients with reduced LV ejection fraction. In patients with normal GLS (≥18%), atrial strains provided no information regarding filling pressure (Figure). Reservoir strain <18% and pump strain <8% predicted elevated LV filling pressure better (p < 0.05) than the conventional indices LA volume, ratio of mitral early filling velocity/annular velocity and tricuspid regurgitation velocity. Accuracy to classify filling pressure as normal or elevated was 75% for both LA strains . When any one of the conventional indices were missing, and were replaced by LA strains, the combination of indices had accuracy 82% to correctly classify filling pressure.

Conclusions

Left atrial reservoir and pump strain may serve as clinical markers of LV filling pressure, but will be useful predominantly in patients with reduced systolic function.  Due to limited diagnostic accuracy, LA strain should be used in combination with other indices.

Abstract Figure
Asymptomatic severe aortic stenosis: what is the current role of exercise stress test and NT-proBNP in patient risk stratification
Authors: Campos I , Pereira J , Salome N , Pereira VH , Oliveira C , Marques Pires C , Medeiros P , Flores R , Mane F , Marques J , Vieira C
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Aortic stenosis (AS) is prevalent in the elderly population. When severe and the patient is symptomatic or left ventricular dysfunction arises, the prognosis deteriorates and valve replacement (AVR) is recommended. During the asymptomatic phase regular clinical evaluation is advised to detect early onset of symptoms and/or signs of myocardial maladaptation. Due to the inherent difficulties in the evaluation of symptoms, especially in the elderly, as well as the change in prognosis when symptoms appear (even if not perceived), it is crucial to evaluate the behavior of patients with effort and signs of myocardial injury.

Methods

An observational and retrospective study that included 74 patients followed at the Cardiology Service by severe AS (aortic valve area ≤ 1cm2 and/or aortic transvalvular mean gradient ≥40mmHg), who underwent exercise stress test (EST) and NT-proBNP evaluation for risk stratification. The outcome studied was hospitalization for heart failure (HF), or referral to SV, or death during the follow-up period. Independent predictors were obtained using multivariate Cox regression.

Results

Non-progression or decrease in systolic blood pressure (SBP) in EST is the only independent predictor of a short-term adverse event (p = 0.025). This parameter, NT-proBNP levels and interventricular septal thickness (IVS) were independent predictors of a medium (two (p = 0.025; p = 0.014; p = <0.001), three (p = 0.015; p = 0.007; p = 0.001) and four years (p = 0.007; p = 0.049; p = 0.005)) and a long term adverse event (p = 0.006; p = 0.028; p = 0.005).

Conclusion

In asymptomatic patients with severe AS, no progression or decrease in SBP in EST, increased NT-proBNP levels and thickness of IVS were independent predictors of hospitalization for HF, need for VS or death in short, medium and long term.
Assessment of aortic regurgitation mechanism with cardiac magnetic resonance: an echocardiography comparative study
Authors: Richardson M , Raad N , Coisne A , Ridon H , Polge AS , Mouton S , Silvestri V , Pagniez J , Longere B , Modine T , Soquet J , Juthier F , Montaigne D , Pontana F
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Aortic regurgitation (AR) quantification still remains challenging and requires an integrated approach. AR mechanism is one key parameter to take into account to assess its severity and repairability, and thus help to guide surgical decision. Although Cardiac Magnetic Resonance (CMR) has a growing interest in AR quantification, its performance to identify aortic AR mechanism has never been studied.

Purpose

We intended to define CMR Performance in this setting, by using echocardiography as reference.

Methods

AR mechanism was systematically evaluated in sixty-seven patients (81% male, mean age 46 ± 20 years) with chronic AR using CMR, and compared to transthoracic (TTE) and transesophageal (TEE) echocardiography as gold standard. AR were categorized as follows: type 1, aortic dilatation; type 2, Cusp prolapse; type 3, restrictive cusp motion. Jet direction, number of cusps and calcification (1 = no calcification, 2 = spots, 3 = big calcification interfering with cusp motion and 4 = Extensive with restricted cusp motion) were also evaluated.

Results

At TTE/TEE, mechanisms of AR were type 1 in 56 (83.5%), type 2 in 33 (49.2%), type 3 in 24 (35%). Agreement between TTE/TEE and CMR was modest, with respectively 74.6% (k= 0.4), 79.1% (k = 0.58) and 74.6% (k = 0.44). Bicuspid aortic valve was found in 44 (65.7%) patients at TTE/TEE, agreement with CMR was excellent, 98.5% (k = 0.97).  Jet was directed to the mitral valve in 42 (62.7%), at the inter ventricular septum in 12 (17.9%), and central in 13 (19.4%). Agreement with CMR was correct, respectively 80% (k = 0,6), 88% (k = 0.62) and 83.5% (K= 0.52). Calcification extension was 1 in 26 (38.8%), 2 in 25 (37.3%), 3 in 11 (16.4%) and 4 in 5 (7.5%). Agreement with CMR was poor, 44.7% (K= 0.28).

Conclusion

Accuracy between CMR and TTE/TEE to evaluate chronic AR mechanism and repairability was modest, with lower performance to define calcification extension.

Abstract Figure. AR classification TTE/TEE vs CMR
Influence of left ventricular systolic dysfunction on occurrence of pulsus tardus in patients with aortic stenosis
Authors: Ishizaka S , Iwano H , Kamiya K , Nagai T , Motoi K , Chiba Y , Tsujinaga S , Kaga S , Anzai T
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

The time between left ventricular (LV) and aortic systolic pressure peaks (TLV-Ao) which could reflect pulsus tardus (PT) is reported to be a marker of severity and be associated with poor prognosis in patients with aortic stenosis (AS). Despite its worldwide recognition, physiological mechanism of PT has not been well elucidated. We hypothesized that not only severity of the AS but also LV systolic dysfunction could be associated with occurrence of PT.

Methods

TLV-Ao and mean trans-aortic valvular pressure gradient (mean PG) were measured by simultaneous pressure tracing of left ventricle and basal aorta in 74 AS patients with at least moderate severity (78 ± 8 years old). Effective orifice area index (EOAI) was estimated by using continuity equation from transthoracic echocardiography and severe AS was defined as EOAI ± 0.60 cm²/m². Global longitudinal strain (GLS) was measured by using speckle-tracking method and expressed as an absolute value.

Results

TLV-Ao, mean PG, and EOAI was 87 ± 30 msec, 51 ± 21 mmHg, and 0.51 ± 0.14 cm² respectively. A weak correlation was observed between EOAI and TLV-Ao (Figure). In 9 out of 17 moderate AS patients (A in Figure), TLV-Ao was prolonged over the previously reported cut-off value (≥66 msec), on the other hand, it was not prolonged in 11 out of 57 severe AS patients (D in Figure). When the patients were divided by TLV-Ao of 66 msec, mean PG was not different between patients with prolonged TLV-Ao and those without in moderate AS patients (Figure, A vs B; NS), whereas GLS was significantly reduced in prolonged TLV-Ao group (P = 0.0383). In patients with severe AS, mean PG was significantly higher (P < 0.0001) in patients with prolonged TLV-Ao than in those without (Figure, C vs D), whereas GLS was comparable between the groups. In overall patients, multivariable analysis revealed that not only mean PG (β=0.54) but also GLS (β=-0.23) was an independent determinant of TLV-Ao.

Conclusion

The occurrence of pulsus tardus could be associated not only with severity of the AS but also with LV systolic dysfunction in patients with AS.

Abstract Figure
Effects of heat-not-burn compared to combustible cigarettes on coronary flow, myocardial work index and vascular function
Authors: Ikonomidis I , Katogiannis K , Vlastos D , Kostelli G , Kourea K , Tsoumani M , Parissis J , Thymis J , Andreadou I , Alexopoulos D
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Aim/Introduction:

Heat-not-burn cigarette (HNBC) constitutes a non-combustible smoke product.

Purpose

We compare the effects of heat-not-burn and conventional cigarettes on coronary flow, myocardial and vascular function, platelet activation and oxidative stress.

Methods

We compared the effects of HNBC to those of tobacco cigarette (TCig), on arterial stiffness, oxidative stress, and platelet activation, acutely and after 1 month of switching to HNBC, as well as on endothelial, myocardial, and coronary function after 1 month of switching to HNBC. In the acute study, 50 smokers were randomized into smoking a single Tcig or an HNBC and after 60 minutes were crossed over to the alternate smoking (HNBC or Tcig). For the chronic phase, 75 smokers were examined. Of those, 50 were switched to HNBC and 25 continued Tcig for 1 month. Pulse wave velocity (PWV) and biomarkers [malondialdehyde (MDA), protein carbonyls (PC), and thromboxane B2 (TXB2)] were assessed in the acute and chronic study. Myocardial deformation [global longitundinal strain (GLS), myocardial work index (GWI) and wasted myocardial work (GWW)], coronary flow reserve (CFR) by Doppler echocardiography, total arterial compliance (TAC), and flow-mediated dilation (FMD) were additionally assessed in the chronic study.

Results

Compared to baseline, TCig smoking acutely increased exhaled CO, PWV, MDA, and TxB2 (p < 0.05), while no changes were observed after HNBC. Compared to resuming Tcig smoking, switching to HNBC for 1 month improved CO (mean change: -55% vs -2.4%), FMD ( +55% vs +15%), CFR (+46% vs +4%), TAC (+9% vs -0.5%), GLS (+6% vs +1%), GWW (-19% vs +0.5%), MDA (-19% vs 1 %), and TxB2 (-12% vs 4%) (p < 0.05 for all comparisons).

Conclusions

HNBCs exert a less detrimental effect on vascular, cardiac and platelet function than combustible tobacco.
Tissue doppler imaging of left atrial appendage during transoesophageal echocardiography predicts successful cardioversion in patients with atrial fibrillation
Authors: Kostakou P , Kostopoulos V , Stamatelatou M , Tryfou E , Mihas K , Damaskos D , Tsougos E , Olympios C , Kouris N
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Restoration of sinus rhythm in patients with atrial fibrillation (AF) prevents from thromboembolic events, decreases the risk for cardiomyopathy and improves quality of life.

Purpose

This study aimed to determine whether Tissue Doppler Imaging (TDI) during transesophageal echo (TEE) could predict successful electrical cardioversion (CV) of AF lasting more than 48 hours but less than 6 months.

Methods

One hundred patients, 74 men and 26 women of mean age 64.7 ± 9.8 years old with non-valvular AF were included. Pulse wave (PW) Doppler velocities as well as TDI velocities of the medial and lateral walls of the left atrial appendage (LAA) were recorded during TEE before cardioversion. Synchronized electrical cardioversion was occurred within 12 hours after TEE using 100-200 Joules. We also evaluated LA size and the global strain of LAA.

Results

Sinus rhythm restoration was succeeded in 80% of patients and maintained until discharge, 48 hours later. TDI velocities > 8cm/s were correlated with successful cardioversion (sensitivity 70% and specificity 63%) and were more predictive compared to PW Doppler velocities of > 40cm/s. TDI recordings at the medial LAA wall were more accurate, with less artefacts and better positioning of the sample volume. Global longitudinal strain was not significantly correlated with CV outcome.

Conclusion

Our results indicate that TDI velocities of the LAA walls more than 8cm/s could be used as a cut-off value predicting successful cardioversion of AF.