REVIEW | doi:10.20944/preprints202310.0261.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: left atrial appendage; left atrial appendage occlusion; atrial fibrillation
Online: 5 October 2023 (09:29:40 CEST)
In patients with atrial fibrillation, the left atrial appendage may serve as the site of thrombus formation due to stasis that occurs within the appendage because of its shape and trabeculations. Although thrombus formation can be reduced with anticoagulants, this may be contraindicated in some patients. The need for a better alternative treatment prompted study of left atrial appendage occlusion for thromboembolism prophylaxis. Due to this, procedures that excise or occlude the left atrial appendage have gained attention because of its ability to prevent thromboembolic events. This article provides a comprehensive review of the left atrial appendage and its associated procedures' clinical utility.
REVIEW | doi:10.20944/preprints202306.0876.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Transseptal puncture; TSP; left atrium catheterization; left heart catheterization
Online: 13 June 2023 (04:33:32 CEST)
Transseptal puncture is an established technique for achieving left atrium access during cardiac procedures. It is associated with low overall complication rate and high success rates. Although being almost a century old technique, recent years brought a substantial development in the field, allowing for faster and safer left atrium catheterization. In this paper we discuss its history, complications, available techniques and current state of the art.
ARTICLE | doi:10.20944/preprints202203.0140.v1
Subject: Computer Science And Mathematics, Computer Vision And Graphics Keywords: Left ventricular ejection fraction; Left ventricle segmentation; Convolutional long short-term memory; Echocardiography
Online: 10 March 2022 (04:19:30 CET)
Cardiovascular disease is the leading cause of death worldwide. A key factor in assessing the risk of cardiovascular disease is left ventricular functional evaluation. Left ventricular (LV) systolic function is evaluated by measuring the left ventricular ejection fraction (LVEF) using echocardiography data. Therefore, quick and accurate left ventricle segmentation is important for estimating the LVEF. However, it is difficult to accurately segment the left ventricle due to changes in the shape and area of the left ventricle during cardiac cycles. In this study, we proposed a framework that considers changes in the shape and area of the left ventricle during the cardiac cycle by applying the convolutional long short-term memory (CLSTM) approach. In addition, we evaluated the left ventricular segmentation and multidimensional quantification of the proposed system in comparison to manual and automated segmentation methods. In addition, to assess the validity of CLSTM, the values of multi-dimensional quantification metrics were compared and analyzed using graphs and Bland–Altman plots on a frame-by-frame basis. We demonstrated that the CLSTM method effectively segments the left ventricle by considering the LV activity. In conclusion, we demonstrated that LV segmentation based on our framework may be utilized to accurately estimate LVEF values.
ARTICLE | doi:10.20944/preprints201907.0139.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: grip force modulation; embodied language; left hand; right hemisphere; left hemisphere; unimanual task
Online: 10 July 2019 (07:37:58 CEST)
Background and objectives: The language-induced grip force modulation (GFM) can be used to better understand the link between the language and motor functions as an expression of the embodied language. However, the contribution of each brain hemisphere to the language-induced GFM is still unclear. Using six different action verbs as stimuli, this study evaluated the GFM of the left hand in unimanual task to characterize the left- and right-hemisphere contributions. Materials and Methods: The left-hand GFM of 20 healthy consistent right-handers subjects was evaluated using the verbs “to write”, “to hold”, “to pull”(left-lateralized central processing actions), “to draw”, “to tie”, and “to drive” (bi-hemispheric central processing actions) as linguistic stimuli. The time between the word onset and the first interval of statistical significance regarding the baseline (RT) was also measured. Results: The six verbs produced language-induced GFM. The modulation intensity was similar for the six verbs, but the RT was variable. The verbs “to draw”, “to tie”, and “to drive”, whose central processing of the described action is bihemispheric showed a longer Rt compared to the other verbs. Conclusions: The possibility that an action is performed by the left-hand does not interfere with the occurrence of GFM when this action verb is employed as linguistic stimulus. Therefore, the language-induced GFM seems mainly rely on the left hemisphere, and the engagement of the right hemisphere seems to slow down the increase in the GFM intensity.
CASE REPORT | doi:10.20944/preprints202201.0190.v1
Subject: Medicine And Pharmacology, Urology And Nephrology Keywords: left renal vein; urology; radiology
Online: 13 January 2022 (13:19:21 CET)
Retroaortic left renal veins are an often overlooked, but no so rare anatomic anomaly that might cause a few aspecific symptoms and signs, especially flank or inguinal pain, microscopic or even gross hematuria; in the vast majority of cases it is, thought, totally asymptomatic. The nutcracker syndrome that might arise in the case of RLRV is mainly due to the re- duced space between aorta and the vertebral body and the consequent compression on the venal rein; this might in turn cause upstream hypertension, hematuria, varicocele, pain. The compression of RLRV leads to hematuria because of renal venous hypertension, consequent left renal congestion. This upstream venous congestion might result, in some cases, in left-sided varicocele in men and pelvic congestion syndrome in women. From a radiologic point of view, the presence of RLRV and the precise reporting its subtypes is mandatory.
ARTICLE | doi:10.20944/preprints202307.1290.v2
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Endosonographic ultrasound; transesophageal echocardiography; left atrial appendage thrombus; mitral and aortic valve; left ventricle
Online: 27 September 2023 (14:24:14 CEST)
Background: Ultrasonography in medicine allows real time “dynamic” assessment of structure where the procedure takes place. This feature and design could be more advantageous than radiological “static” view imaging. Thus, it is the convincing imaging tool for many structural cardiovascular and gastrointestinal interventions. Technically, the image resolution for Endosonography (EUS) is noticeably higher than that of transesophageal echocardiography (TOE). The benefits of investigating the cardiovascular structures using this high-resolution endoscope are unknown. Clinical applications: We present clinical applications of incidentally diagnosed cardiovascular structures, which demonstrated during routine gastrointestinal endosonographic procedures. These diagnoses could influence changes in management strategies. Discussion: The introduction of high resolution endosonography (EUS) in cardiology allows "panoramic" and “dynamic” real-time assessment of cardiovascular structures with an accurate definition of the variable cardiovascular anatomy. Using this advantage during routine gastrointestinal procedures allows for the early detection of asymptomatic cardiac pathologies and accompanying diseases, prevents double investigations for patients and operators, eliminates the risk of esophageal trauma, highlights interdisciplinary teamwork benefits, and could facilitate in the future the indications for cardiac-based structural procedures, which could influence management strategies with improved safety, efficacy, and economic outcomes. Conclusion: The introduction of endosonography (EUS) in cardiology provide high-resolution real-time assessments of cardiovascular anatomy. Thus, it can be used for early detections of variable cardiovascular pathologies during routine gastrointestinal procedures.
ARTICLE | doi:10.20944/preprints202306.1860.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: arterial hypertension; echocardiography; left ventricular hypertrophy; Shors
Online: 27 June 2023 (08:43:53 CEST)
The current echocardiography reference values are derived primarily from populations in North America and Europe. It becomes necessary to study ethnically different groups of the population, which often have different living conditions, food habits and lifestyle. The aim of the study was to compare echocardiography indicators in urbanized patients with arterial hypertension of the Shor and non-indigenous ethnic groups living in the Gornaya Shoria region. The study included patients with arterial hypertension: 58 Shors (20 men and 38 women) and 50 non-indigenous residents (15 men and 35 women) of Gornaya Shoria. All underwent an echocardiographic study with an assessment of the left heart parameters. We assessed the left ventricular hypertrophy (LVH) severity, LV geometry and diastolic function in the ethnic and sex groups. Shor with hypertension no showed a significant difference in left ventricular dimensions compared to Caucasian. Severe abnormal LVH was associated in the Shors with glucose levels (OR 3.24, 95%CI 1.56-6.7, p=0,001), and in Caucasians with systolic (p=0.021) and diastolic (p=0.011) blood pressure, and heart rate (p=0.033). The Shor men were more likely to have normal LV diastolic function (p=0.029) and LV concentric remodeling (p=0.023), and less often to have normal LV geometry (p=0.015) compared to non-indigenous men. Thus, this study can be useful in assessing the impact of the development of arterial hypertension, as well as the impact of changing the lifestyle of the Shors when moving to the city from rural areas on ethnic differences in echocardiography.
ARTICLE | doi:10.20944/preprints202306.1359.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: left atrial function, heart failure; stepwise exercise
Online: 19 June 2023 (12:59:37 CEST)
Background: the aim of this study was to assess acute changes on left atrial (LA) function a during a progressive exercise in patients with heart failure with mid-range ejection fraction (HFmrEF) in comparison to healthy controls (HS). Methods: twenty patients with established HFmrEF were compared with 10 HS, age-matched controls. All subiects performed a stepwise exercise test on cyclette. Echocardiography was performed at baseline, during submaximal effort, at peak of exercise, and after 5 minutes of recovery. Results: HS obtained an higher value of METs at peak exercise than HFmrEF (7.4 vs 5.6; between group p 0.002). Heart rate and systolic blood pressure presented a greater increase in the HS group than in HFmrEF (between-groups p 0.006 and p 0.003 respectively). In the HFmrEF group peak atrial longitudinal strain (PALS), and conduit strain were both increased at submaximal exercise (p<0.05 for both versus baseline) and remained constant at peak exercise. Peak atrial contraction strain (PACS) did not show significant changes during the exercise. In the control group PALS and PACS increased significantly at submaximal level (p<0.05 for both versus baseline) but PALS returned near baseline values at peak exercise; conduit strain decreased progressively during the exercise in HS. Stroke volume (SV) increased in both groups at submaximal exercise; at peak exercise SV remained constant in the HFmrEF while it decreased in controls (between-groups p 0.002). Conclusions: Patient with HFmrEF, show a proper increase of LA reservoir function during incremental exercise that contributes to maintain SV throughout the exercise.
ARTICLE | doi:10.20944/preprints202305.0387.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: concurrent training; heart failure; left atrial dysfunction
Online: 6 May 2023 (07:51:04 CEST)
Left atrial dysfunction is associated with exercise intolerance and poor prognosis in heart failure (HF). The effects of exercise training on atrial function in patients with HF with mid-range ejection fraction (HFmrEF) are unknown. The purpose of the present study was to assess the effects of a 12-weeks supervised concurrent, aerobic continuous plus resistance, exercise training (SCT) pro-gram on left atrial function of patients with HFmrEF. The study included 70 stable patients, who were randomly assigned into two groups: SCT with (three session/week) or a control (CON) group directed to follow contemporary exercise preventive guidelines at home. Before starting the training program and at 12-weeks, all patients performed: ergometric test, 6-minute walk test and echocardiography. At 12-weeks, exercise duration at ergometric test and distance walked at 6-minute walk test presented a significant greater increase in the SCT compared to control (be-tween-groups p 0.0001 and p 0.004 respectively). Peak atrial longitudinal strain and conduit strain presented an increase of 29% and 34% respectively in the SCT and were unchanged in the CON (between-groups p 0.008 and p 0.001 respectively). Peak atrial contraction strain increased of 21% in the SCT with no changes in the CON (between-groups p 0.002). Left ventricular global longi-tudinal strain increased significantly SCT compared to control (between-groups p 0.03). In con-clusions SCT improved left atrial and left ventricular function in HFmrEF
ARTICLE | doi:10.20944/preprints202201.0042.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Left ventricular hypertrophy; Echocardiography; Magnetic Resonance; Prognosis
Online: 5 January 2022 (13:10:00 CET)
Background: Left ventricular hypertrophy (LVH) may be due to different causes, ranging from benign secondary forms to severe cardiomyopathies. Transthoracic Echocardiography (TTE) and ECG are the first level examination for LVH diagnosis. Cardiac magnetic resonance (CMR) defines accurately LVH type, extent and severity. Objectives: to evaluate the diagnostic and prognostic role of CMR in patients with TTE and/or ECG evidence of LVH. Methods: We performed CMR in 300 consecutive patients with echocardiographic and/or ECG signs of LVH. Results: Overall, 275 patients had TTE evidence of LVH with initial suspicion of hypertrophic cardiomyopathy (HCM) in 132 (44%), cardiac amyloidosis in 41 (14%), hypertensive LVH in 48 (16%), aortic stenosis in 4 (1%), undetermined LVH in 50(16%). The initial echocardiographic diagnostic suspicion of LVH was confirmed in 172 patients (57.3%) and changed in 128 patients (42.7%, p<0.0001): the diagnosis of HCM increased from 44% to 71% of patients; hypertensive and undetermined LVH decreased significantly (respectively to 4% and 5%). CMR allowed a diagnosis in 41 out of 50 (82%) with undetermined LVH at TTE. CMR also identified HCM in 17 out of 25 patients with apparently normal echo but with ECG criteria for LVH. Finally, the reclassification of the diagnosis by CMR was associated with a change of survival risk of patients: after CMR reclassification no events occurred in patients with undetermined or hypertensive LVH. Conclusions: CMR changed echocardiographic suspicion in almost half of patients with LVH. In the subgroup of patient with abnormal ECG, CMR identified LVH (particularly HCM) in 80% of patients. This study highlights the indication of CMR to better characterize the type, extent and severity of LVH detected at echocardiography and suspected with ECG.
ARTICLE | doi:10.20944/preprints202309.1881.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: DIBH; breast cancer; left descending artery; breast irradiation
Online: 27 September 2023 (10:53:11 CEST)
Background: to assess the benefit of a deep inspiration breath hold (DIBH) over standard irradiation technique, and eventually to identify anatomical and/or treatment preplanning characteristics correlated with LAD dose. Methods: We retrospectively identified patients with left-sided breast cancer who underwent whole breast radiotherapy in DIBH. All patients had both plans in DIBH and free-breathing (FB). Receiving operating characteristics (ROC analysis) were performed to define the cut-off point of parameters to predict LAD maximum dose >10 Gy and LAD mean dose > 4 Gy. Areas under the curve (AUCs) were calculated for all variables. Post-test probability has been calculated to evaluate advantage for parameters combination. Results: One hundred ninety-seven patients were identified. LAD dose was significantly reduced in DIBH plans with maximum and mean dose reduced by 31.7% (mean value 3.5 Gy vs 4.8 Gy, p=<0.001) and 28.1% (mean value 8.2 Gy vs 12.8 Gy, p=<0.001) in DIBH plans compared to FB plans. The strongest predictor of LAD maximum dose > 10 Gy and a LAD mean dose > 4 Gy was the minimum distance of LAD from tangent open fields. Other parameters were lung volume and heart volume for LAD Dmax > 10 Gy and lung volume, heart volume and breast separation for LAD Dmean > 4 Gy. Conclusion: The dosimetric benefit of DIBH is valid for all patients and DIBH should be preferred for all left sided patients.
REVIEW | doi:10.20944/preprints201811.0075.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: sepsis cardiomyopathy; left ventricular function; global longitudinal strain
Online: 5 November 2018 (02:51:26 CET)
Myocardial deformation imaging (strain imaging) is a technique to directly quantify the extent of myocardial contractility and overcomes several of the limitations of ejection fraction. The application of the most commonly used strain imaging method; speckle-tracking echocardiography to patients with sepsis cardiomyopathy heralds an exciting development to the field. However; the body of evidence and knowledge on the utility, feasibility and prognostic value of left ventricular global longitudinal strain in sepsis cardiomyopathy is still evolving. We conducted a review of literature on utility of left ventricular global longitudinal strain in sepsis cardiomyopathy. We discuss the role of left ventricular global longitudinal strain in mortality prediction, utility and limitations of the technique in the context of sepsis cardiomyopathy.
ARTICLE | doi:10.20944/preprints202108.0533.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: glaucoma progression; nycthemeral intraocular pressure; right-left comparison; laterality
Online: 30 August 2021 (09:52:58 CEST)
Purpose: To determine whether 24-hour IOP monitoring can be a predictor for glaucoma progression and to analyze the inter-eye relationship of IOP, perfusion and progression parameters. Methods: We extracted data from manually drawn IOP curves with HIOP-Reader, a software suite we developed. The relationship between measured IOPs and mean ocular perfusion pressures (MOPP) to retinal nerve fiber layer (RNFL) thickness was analyzed. We determined the ROC curves for peak IOP (Tmax), average IOP (Tavg), IOP variation (IOPvar) and historical IOP cut-off levels to detect glaucoma progression (rate of RNFL loss). Bivariate analysis was conducted to check for various inter-eye relationships. Results: 217 eyes were included. The average IOP was 14.8±3.5 mmHg, with a 24-hour variation of 5.2±2.9 mmHg. 52% of eyes with RNFL data showed disease progression. There was no significant difference in Tmax, Tavg and IOPvar between progressors and non-progressors (all p>0.05). Except for Tavg and the temporal RNFL, there was no correlation between disease progression in any quadrant, Tmax, Tavg and IOPvar. 24-hour and outpatient IOP variables had poor sensitivities and specificities in detecting disease progression. The correlation of inter-eye parameters was moderate; correlation with disease progression was weak. Conclusion: In line with our previous study, IOP data obtained during a single visit (outpatient or inpatient monitoring) make for a poor diagnostic tool, no matter the method deployed. Glaucoma progression and perfusion pressure in left and right eyes correlated weakly to moderately with each other.
CASE REPORT | doi:10.20944/preprints202012.0704.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: left ventricular noncompaction; apical hypertrophic cardiomyopathy; next generation sequencing
Online: 28 December 2020 (13:19:41 CET)
Left ventricular noncompaction (LVNC) and hypertrophic cardiomyopathy (HCM) commonly occur as separate disorders with distinct clinical and pathoanatomical features. However, these cardiomyopathies may have a similar genetic origin with mutations encoding sarcomeric proteins. The described case demonstrates an example, in which phenotypic expression of both diseases occurs in the same patient.
REVIEW | doi:10.20944/preprints202310.0482.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: epicardial adipose tissue; atrial fibrillation; inflammation; cardiac arrhythmia; left atrium
Online: 10 October 2023 (02:59:16 CEST)
Atrial fibrillation (AF) is a common cardiac arrhythmia associated with significant morbidity and mortality. The role of epicardial adipose tissue (EAT), particularly in the left atrium, has garnered attention in the pathophysiology of AF. This review aims to provide an overview of the association between the thickness of left atrial epicardial adipose tissue (LA-EAT) and the incidence of AF, while exploring the arrhythmogenic effects of LA-EAT and the impact of epicardial fat tissue changes with age and in pathological conditions. A comprehensive search of PubMed was conducted, and relevant studies were selected based on their inclusion criteria. The findings suggest that increased LA-EAT thickness is associated with an elevated risk of AF, potentially mediated through inflammatory and proarrhythmic effects. Age-related changes in epicardial fat tissue and alterations in pathological conditions, such as obesity, metabolic syndrome, and cardiovascular diseases, further contribute to the development and progression of AF. Further research is needed to deepen our understanding of these mechanisms and their clinical implications.
REVIEW | doi:10.20944/preprints202303.0228.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: heart failure; ejection fraction; left ventricle; systolic dysfunction; diastolic dysfunction
Online: 13 March 2023 (10:15:43 CET)
Heart failure (HF) diagnosis, phenotyping, prognosis, and treatment decisions are all based on the left ventricular ejection fraction (EF). Heart failure with mid-range EF (HFmrEF) is a third EF category for heart failure with an EF between 40 and 49 percent. Comparatively, heart failure with preserved EF or reduced EF has been largely unexplored. 10–25% of patients with HF have HFmrEF. Although HFmrEF has an intermediate clinical profile, it is more similar to HF with reduced EF, particularly because these patients have a high incidence of ischaemic heart disease. Heart failure with preserved EF has a lower risk of cardiovascular events than heart failure with reduced EF, which is milder. HFmrEF and HF with preserved EF patients have a similar or higher risk of non-cardiovascular adverse events than patients with HF with reduced EF. There is still a great deal of mystery surrounding HFmrEF. The purpose of this review is to describe the major pathophysiology of HFmrEF and its similarities and differences with the other two types of EF. It is the purpose of this paper to present a comprehensive overview of the currently available evidence in support of the pathophysiology of patients with HFmrEF. Further investigation of the pathophysiology, treatment, and prognosis of this condition will be needed in the future in order to better understand it.
ARTICLE | doi:10.20944/preprints202201.0358.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: left ventricular noncompaction; cardiomyopathy; imaging; echocardiography; cardiovascular magnetic resonance; children
Online: 24 January 2022 (13:59:45 CET)
Background: Left ventricular noncompaction (LVNC) is a distinct cardiomyopathy characterized by the presence of a two-layer myocardium with prominent trabeculation and deep intertrabecular recesses. The diagnosis of LVNC can be challenging because the diagnostic criteria are not uniform. The aim of our study was to evaluate echocardiographic and CMR findings in a group of children with isolated LVNC. Methods: From February 2008 to July 2021, pediatric patients under 18 years of age at the time of diagnosis with echocardiographic evidence of isolated LVNC were prospectively enrolled. The patients underwent echocardiography and contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement to assess myocardial noncompaction, ventricular size, and function. Results: A total of 34 patients with a median age of 11.9 years were recruited. Patients were followed prospectively for a median of 5.1 years. Of the 31 patients who met Jenni’s criteria in echocardiography, CMR was performed in 27 (79%). Further comprehensive analysis was performed in the group of 25 patients who met the echocardiographic and CMR criteria for LVNC. In echocardiography, the median NC/C ratio in systole was 2.60 and in diastole 3.40. In 25 out of 27 children (93%), LVNC was confirmed by CMR according to Petersen’s criteria, with a median NC/C ratio of 3.27. Conclusions: 1) Echocardiography precisely identifies patients with LVNC. 2) Echocardiography is a good method for monitoring LV systolic function, but CMR is indicated for the precise assessment of LV remodeling and RV size and function as well as for the detection of myocardial fibrosis.
ARTICLE | doi:10.20944/preprints202104.0403.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: echocardiography; speckle-tracking; frame rate; global longitudinal strain; left ventricle
Online: 15 April 2021 (09:39:24 CEST)
Background: global longitudinal strain (GLS) measures myocardial deformation and is a sensitive modality for detecting subclinical myocardial dysfunction and predicting cardiac outcomes. The accuracy of speckle-tracking echocardiography (STE) is dependent on temporal resolution. A novel software enables relatively high frame rate (Hi-FR) (~200 fps) echocardiographic images acquisition which empowers us to investigate the impact of Hi-FR imaging on GLS analysis. The goal of this pilot study was to demonstrate the feasibility of Hi-FR for STE. Methods: In this prospective study, we acquired echocardiographic images using clinical scanners on patients with normal left ventricular systolic function using Hi-FR and conventional frame rate (Reg-FR) (~50 FPS). GLS values were evaluated on apical 4-, 2- and 3-chamber images acquired in both Hi-FR and Reg-FR. Inter-observer and intra-observer variabilities were assessed in Hi-FR and Reg-FR. Results: There were 143 resting echocardiograms with normal LVEF included in this study. The frame rate of Hi-FR was 190 ± 25 and Reg-FR was 50 ± 3, and the heart rate was 71 ± 13. Strain values measured in Hi-FR were significantly higher than those measured in Reg-FR (all p < 0.001). Inter-observer and intra-observer correlations were strong in both Hi-FR and Reg-FR. Conclusions: We demonstrated that strain values were significantly higher using Hi-FR when compared with Reg-FR in patients with normal LVEF. It is plausible that higher temporal resolution enabled the measurement of myocardial strain at desired time point. The result of this study may inform clinical adoption of the novel technology. Further investigations are necessary to evaluate the value of Hi-FR to assess myocardial strain in stress echocardiography in the setting of tachycardia.
ARTICLE | doi:10.20944/preprints202003.0229.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: heart failure; left ventricular assist device; cardiac recovery; mechanical circulation
Online: 13 March 2020 (10:11:43 CET)
In this paper, we aim to assess the electric current parameters and report the analysis of the associated degree of ventricular recovery during left ventricular assist device (LVAD) support. An assumption was made there is a linear relationship between ventricular recovery degree and the pump electric current pulsatility index (PI). The experimental study was carried out using the ViVitro Pulse Duplicator System with Sputnik 1 LVAD connected. Cardiac output (CO) and cardiac power output (CPO) were used as a measure of ventricular recovery degree. Different heart rates (HR) (59, 73, 86 bpm) and pump speeds (7600–8400 rpm in 200 rpm steps) were investigated. Ventricular stroke volumes in the range of 30–80 ml for each heart rate at certain pump speed were used. The obtained relationships of CO and CPO vs. PI was linear as the coefficients of determination for each regression curve were more than 0.8. CO vs. PI: R2=0.9218; 0.9271; 0.9172 and CPO vs. PI: R2=0.8517; 0.841; 0.8244 for HR=59 bpm; 73 bpm; 86 bpm, respectively. Study findings suggest that adequate interpretation of parameters could potentially serve as a valuable clinical tool to assess ventricular recovery based on LVAD infrastructure without requiring any special hemodynamic assessment.
ARTICLE | doi:10.20944/preprints201608.0080.v2
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: left ventricle; myofibre; myocardium structure; rule-based model; mathematical anatomy
Online: 20 October 2016 (08:22:39 CEST)
Computer simulation of normal and diseased human heart activity requires a 3D anatomical model of the myocardium, including myofibres. For clinical applications, such a model has to be constructed based on routine methods of cardiac visualisation such as sonography. Symmetrical models are shown to be too rigid, so an analytical non-symmetrical model with enough flexibility is necessary. Based on previously made anatomical models of the left ventricle, we propose a new, much more flexible spline-based analytical model. The model is fully described and verified against DT-MRI data. We show a way to construct it on the basis of sonography data. To use this model in further physiological simulations, we propose a numerical method to utilise finite differences in solving the reaction-diffusion problem together with an example of scroll wave dynamics simulation.
ARTICLE | doi:10.20944/preprints202309.1093.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: generalized fuzzy numbers; ranking; normalized height coefficient; left area; right area
Online: 18 September 2023 (14:49:30 CEST)
To avoid loss of information and incorrect ranking, this paper proposes a method for ranking generalized fuzzy numbers, which guarantees both horizontal and vertical values are important parameters affecting the final ranking score. In this method, the normalized height coefficient is introduced to evaluate the influence of the height of fuzzy numbers on the final ranking score. The higher the normalized height coefficient of a fuzzy number is, the higher its ranking. The left area and the right area are presented to calculate the impact of vertical value on the final ranking score. The left area is considered the benefit area. The right area is considered the cost area. The fuzzy number is preferred if the benefit area is larger and the cost area is smaller. The proposed method can be employed to rank both normal and non-normal fuzzy numbers without normalization or height minimization. Numerical examples and comparison with other methods highlight the feasibility and robustness of the proposed method, which can overcome the shortcomings of some existing methods and can support decision-makers to select the best alternative.
ARTICLE | doi:10.20944/preprints202308.2126.v1
Subject: Medicine And Pharmacology, Internal Medicine Keywords: structural heart disease; left atrial appendage closure; fusion imaging; learning curve
Online: 31 August 2023 (10:36:53 CEST)
Due to the complex and variable anatomy of the left atrial appendage, percutaneous left atrial appendage closure (LAAC) can be challenging. In this study, we investigated the impact of fusion imaging (FI) on the LAAC learning curve of 2 interventionalists. The first interventionalist (IC 1) was initially trained without FI and continued his training with FI. The second interventionalist (IC 2) performed all procedures with FI. We compared the first 36 procedures without FI of IC 1 (group 1) with his next 36 interventions with FI (group 2). Furthermore, group 1 was compared to 36 procedures of IC 2 who directly started his training with FI (group 3). Group 1 demonstrated that the learning curve without FI has a flat course with weak correlations for fluoroscopy time, contrast volume, and procedure time, but not for dose area product. Group 2 with FI showed improvement with a steep course and strong correlations for all 4 parameters. In group 3 we also saw a steep progression with strong correlations. Furthermore, the mean measurements of the procedural parameters in the groups with FI decreased significantly as indicator for procedural efficacy. We demonstrated that FI may improve the learning curve of experienced and non-experienced ICs.
ARTICLE | doi:10.20944/preprints202307.1541.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: cardiac computed tomography; electrcardiography; pulmonary veins; P wave; left atrial appendage
Online: 23 July 2023 (16:18:43 CEST)
Electrocardigraphy remains as a first-line evaluation method for cardiac function, recording the electrical activity of the heart from the body surface. Since atrial activation is seen on the ECG as P-wave, several factors are known to impact the appearance of the P-wave, such as direction of electric impulse, conduction abnormalities and anatomical characteristics of the atria. The aim of this retrospective study was to find statistically significant associations between anatomy of pulmonary veins (PVs) osberved in cardiac computed tomography (CT) and P-wave appearance during sinus rhythm on resting ECG. For each patient, a resting 12-lead ECG was recorded, the field of analysis was P wave – its’ duration, morphology and axis. The evaluation of the CT scan recordings was performed by creating 3D models of the left atrium and analyzing anatomy of the PVs and left atrial appendage (LAA). Noteworthy correlations were found: anatomy of the left PVs showed an association with LAA volume, LAA morphology and P-wave notching in lead II. The right PVs demonstrated relation with P wave axis and amplitude. Although these correlations cannot be classified as strong, they may play a role in significant scientific discoveries in future research projects.
ARTICLE | doi:10.20944/preprints202103.0382.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: diastolic dysfunction; heart failure; atrial fibrillation; atrial hypertension; left atrial pressure
Online: 15 March 2021 (13:02:14 CET)
Introduction: Left atrial hypertension is one of the pathophysiologies of heart failure with preserved ejection fraction. We hypothesized that left atrial pressure response (LAPR) to incremental pacing is higher in patients with atrial fibrillation (AF) and can predict left ventricular diastolic dysfunction. Methods: Patients requiring left atrial access as a part of a therapeutic procedure for AF (n=204, AF group) or supraventricular tachycardia (n=34, control group) were analyzed (male n=183, 54±12 years old). LAPR was measured during incremental pacing. Results: Baseline left atrial pressure and LAPR at all pacing rates were not different between the AF and control groups. They were higher in patients with a high E/e’ (≥ 8) than in those with a low E/e’ (< 8). LAPR at a pacing interval of 400ms and E/e' were positively correlated (r=0.373, p<0.001). Body mass index and a high E/e' were independent predictors of pacing-induced left atrial hypertension. Conclusions: The LAPR to incremental pacing was constant regardless of AF. The non-invasive echocardiographic marker E/e' reflected pacing-induced left atrial hypertension.
ARTICLE | doi:10.20944/preprints202103.0064.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: fractional integral inequalities, right and left - Hilfer and Hilfer fractional derivatives.
Online: 2 March 2021 (09:58:00 CET)
Here we present Hilfer-Polya, psi-Hilfer Ostrowski and psi-Hilfer-Hilbert- Pachpatte types fractional inequalities. They are univariate inequalities involving left and right Hilfer and -Hilfer fractional derivatives. All estimates are with respect to norms ||.||p, 1 <_ p <_infinite. At the end we provide applications.
ARTICLE | doi:10.20944/preprints201903.0103.v2
Subject: Physical Sciences, Particle And Field Physics Keywords: charged dark matters; left-handed neutrinos; Higgs mechanism, universe evolution; extended standard model
Online: 15 April 2019 (12:53:22 CEST)
In the present work, the charged dark matters of B1, B2 and B3 bastons are explained as the right-handed partners of the left-handed neutrinos. The new Higgs mechanism of SU(2)DM×SU(2)Weak×SU(2)Strong including electromagnetic and gravitational forces is applied. And the rest masses of the elementary particles depend on their charge configurations. The left-handed neutrinos have only the lepton charges (LC) and the right-handed dark matters have only the electric charges (EC). This explains the fact that the rest masses of the left-handed neutrinos are so small, and the rest masses of the right-handed dark matters are relatively very large. The proposed rest mass (26.12 eV/c2) of the B1 dark matter is indirectly confirmed from the supernova 1987A data. The missing neutrinos are newly explained by using the dark matters and lepton charge force. The neutrino excess anomaly of the MinibooNE data is explained by the B1 dark matter scattering within the Cherenkov detectors. The quark mixing and neutrino mixing are not required in the present model. It is shown that our matter universe and its partner antimatter universe can be created from the big bang in the point of view of time -, charge -, space -, and quantum state – symmetric universe evolution.
ARTICLE | doi:10.20944/preprints201810.0486.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: (left-, right-) pseudo-commutative; commutative; d/BCK-algebra; disjoint; (linear) groupoid
Online: 22 October 2018 (10:04:34 CEST)
In this paper, we investigate the effects of certain variants of the commutative laws on properties of several families of algebras which are in general not commutative, such as groups, linear algebras, or actually quite anti-commutative, such as $BCK$-algebras and $d$-algebras among others. From results obtained it becomes clear that by considering these variants in the presence of yet other axioms it is to be expected that a quite rich and varied set of results may be obtained both in the general and the particular setting of which what has been accomplished in this paper is a substantial sample.
ARTICLE | doi:10.20944/preprints202310.0903.v1
Subject: Medicine And Pharmacology, Anesthesiology And Pain Medicine Keywords: Gabapentin; Arterial Blood Pressure; Heart Rate; Left Ventricular Function; Proteomics; Bioinformatics; Calmodulin;
Online: 13 October 2023 (12:41:55 CEST)
Gabapentin (GBP), a GABA analogue, is primarily used as an anticonvulsant to treat partial seizures and neuropathic pain. While a majority of the side effects are associated with the nervous system, emerging evidence suggests a high risk for heart diseases in the patients taking GBP. In the present study, we used a preclinical model of rats to investigate (1) the acute cardiovascular responses to GBP (bolus i.v. injection, 50 mg/kg) and (2) the effects of chronic GBP treatment (i.p. 100 mg/kg/day x 7 days) on cardiovascular function and the myocardial proteome. Under isoflurane-anesthesia, rat blood pressure (BP), heart rate (HR), and left ventricular (LV) hemodynamics were measured using Millar pressure transducers. The LV myocardium and brain cortex were analyzed by proteomics, bioinformatics, and western blot to explore the molecular mechanisms underlying GBP-induced cardiac dysfunction. In experiment (1), we found that i.v. GBP significantly decreased BP, HR, maximal LV pressure, and maximal and minimal dP/dt, whereas it increased IRP-AdP/dt, Tau, systolic, diastolic, and cycle durations (*p < 0.05 and **p < 0.01 vs baseline; n = 4/group). In experiment (2), we found that chronic GBP treatment resulted in hypotension, bradycardia, and LV systolic dysfunction, with no change in plasma norepinephrine. In the myocardium, we identified 109 differentially expressed proteins involved in calcium pathways, cholesterol metabolism, and galactose metabolism. Particularly, we found that calmodulin, a key protein of intracellular calcium signaling, was significantly upregulated by GBP in the heart but not in the brain. In summary, we found that acute and chronic GBP treatments suppressed cardiovascular function in rats, which is attributed to abnormal calcium signaling in cardiomyocytes. These data reveal a novel side effect of GBP independent of the nervous system, providing important translational evidence to suggest that GBP can evoke adverse cardiovascular events by depression of myocardial function.
ARTICLE | doi:10.20944/preprints202106.0276.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: left ventricular noncompaction; cardiomyopathy; heart failure; arrhythmia; conduction disturbances; molecular etiology; children
Online: 10 June 2021 (08:06:33 CEST)
Background: Left ventricular noncompaction (LVNC) is a genetically determined cardiomyopathy, that occurs following a disruption of endomyocardial morphogenesis. The purpose of this study was to identify the clinical characteristics and genetic profile of children with LVNC. Methods: From February 2008 to July 2020, a total of 32 children (median 11.5 years) with LVNC were prospectively enrolled and followed up for the median of 4.02 years. Diagnosis was made based on characteristic features of LVNC in echocardiography and cardiovascular magnetic resonance (CMR). Patients’ clinical symptoms, family history, ECG, Holter ECG and genetic tests were also evaluated. Results: The most common presenting symptom was heart failure (31% of children). ECG abnormalities were noted in 56% of patients. The most prominent features were ventricular arrhythmias, sinus bradycardia and paroxysmal third-degree atrioventricular block. Most of the patients (94%) met the criteria for LVNC and CMR confirmed this diagnosis in 82% of cases. The molecular etiology was found in 53% of children. Conclusion: Although heart failure and arrhythmias were very frequent in our study group, thromboembolic events and genetic syndromes were rare. For accurate and reliable assessment of children with LVNC, it is necessary to get to know their family history and detailed clinical profile.
ARTICLE | doi:10.20944/preprints202308.1719.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: left ventricle segmentation; fully convolutional networks; U-NET; inception modules; medical image segmentation
Online: 24 August 2023 (07:20:53 CEST)
The automatic diagnosis of cardiovascular diseases has received much attention in the deep learning field. In this context, the segmentation of the left ventricle endocardium constitutes a major task in diagnosing heart conditions such as health failure and hypertrophic cardiomyopathy. The objective of this paper is to propose a "deep convolution network" for segmenting the internal cavity of the left ventricle (endocardium) using MRI images. In particular, we design an improved UNET model which handles additional inception modules for efficiently segmenting the internal cavity of the left ventricle. Our approach has been validated on the Sunnybrook Cardiac Data (SCD) dataset and has showed promising results in terms of precision. More specifically, the improved UNET largely outperforms the baseline UNET model and many existing state-of-the-art methods.
ARTICLE | doi:10.20944/preprints202307.0408.v1
Subject: Engineering, Bioengineering Keywords: pole placement; sliding mode control; left ventricular assist devices; cardiovascular system; heart failure
Online: 6 July 2023 (10:15:31 CEST)
The technology of left ventricular assist devices (LVADs) requires developing and implementing an intelligent control systems to optimize pump speed to achieve a physiological metabolic demands for heart failure (HF) patients. This work aimed to present an advanced control algorithm to drive an LVAD under different physiological conditions. Pole placement method in conjunction with of sliding mode control approach (PP-SMC) was utilized to design and construct the proposed control method. In this design, the method was adopted to use neural networks to eliminate system uncertainties of disturbances. An elastance function was also developed and used as an input signal to mimic the physiological perfusion of HF patients. Two scenarios ranging from rest to exercise were introduced to evaluate the proposed technique. In this technique, a lumped parameter model of cardiovascular system (CVS) was used for this evaluation. The results demonstrated that the designed controller was robustly tracking the input signal in the presence of the system parameter variations of CVS. In both scenarios, the proposed method shows that the controller automatically drive the LVAD with a minimum flow of 1.7 L/min to prevent suction and 5.7 L/min to prevent over-perfusion.
ARTICLE | doi:10.20944/preprints202202.0243.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: left ventricular noncompaction; cardiomyopathy; sinus bradycardia; HCN4 mutation; late gado-linium enhancement; children
Online: 21 February 2022 (03:16:22 CET)
Background: Left ventricular noncompaction (LVNC) is a genetically and phenotypically heterogeneous cardiomyopathy characterized by a two-layered myocardium consisting of compacted and noncompacted segments, prominent ventricular trabeculations, and intertrabecular recesses. Patients with LVNC are at increased risk to develop heart failure, atrial and ventricular arrhythmias, and/or systemic thromboembolic events. Familial forms of primary sinus bradycardia have been attributed to mutations in HCN4. There are very few reports about the association between HCN4 mutations and LVNC. The aim of our study was to characterize the clinical phenotype of families with LVNC and sinus bradycardia caused by mutation of the HCN4 gene. Methods: From March 2008 to July 2021 we prospectively enrolled 6 patients from 4 families with diagnosed isolated LVNC based on the clinical presentation, family history and echocardiographic and cardiovascular magnetic resonance (CMR) evidence of LVNC. Next generation sequencing (NGS) analysis was undertaken for evaluation of the molecular basis of the disease in each family. Results: A total of 6 children (median age 11 years) were enrolled and followed prospectively for the median of 12 years. All 6 patients were diagnosed with LVNC by echocardiography and 5 participants additionally by CMR. The presence of LGE was found in 3 children. Sinus bradycardia and dilation of the ascending aorta occurred in 5 studied patients. In 4 patients from 3 families the molecular studies demonstrated the presence of rare heterozygous HCN4 mutations. Conclusion: (1) The HCN4 mutation influences the presence of a complex LVNC phenotype, sinus bradycardia and dilation of the ascending aorta. (2) HCN4 mutation may be associated with the early presentation of clinical symptoms and the severe course of the disease. (3) It is particularly important to assess myocardial fibrosis not only within the ventricles, but also in the atria in patients with LVNC and sinus bradycardia.
ARTICLE | doi:10.20944/preprints202109.0244.v1
Subject: Engineering, Mechanical Engineering Keywords: Myocardium tissue; Left ventricle mechanics; right ventricle mechanics; cardiac septum mechanics; anisotropy index
Online: 14 September 2021 (15:12:23 CEST)
Heart myocardia are critical to the facilitation of heart pumping and blood circulating around the body. The biaxial mechanical testing of the Left Ventricle (RV) is utilised to build the computa-tional model of the whole heart with little importance given to the unique mechanical properties of Right Ventricle (RV) and Mid-wall (MDW). Most of those studies focussed on the LV of the heart, and then apply the obtained characteristics with a few modifications to the right side of the heart. However, that view has been contested over time with the realisation that the right side of the heart possesses its own unique mechanical properties that are widely distinct from that of the left side of the heart. This paper is aimed at reporting and evaluating the passive mechanical property dif-ferences in the three main walls of the rat heart based on biaxial tensile test data. Fifteen mature Wistar rats weighing 225 ± 25 g were euthanised by inhalation of 5 % halothane. The hearts were excised after which all the top chambers comprising the two atria, pulmonary and vena cava trunks, aorta and valves are all dissected out. Then 5 x 5 mm sections from the middle of each wall were carefully dissected with a surgical knife to avoid over-prestraining the specimens. The specimens were subjected tensile test. The elastic moduli, peak stresses in the toe region and stresses at 40 % strain, anisotropy indices as well as the stored strain energy in the toe and linear region up to 40 % strain are used for statistical significance tests. The following are the main findings of this study: (1) LV and MDW tissues have relatively shorter toe regions of 10 - 15 % strain as compared to RV tissue whose toe region extends up to twice as much as that (2) LV tissues have higher strain energy storage in the linear region despite being lower in stiffness than the RV (3) the MDW has the highest strain energy storage along both directions which might be directly related to its high level of anisotropy. These findings, though for a specific animal species at similar age and around the same body mass, emphasize the importance of application of wall specific material parameters to obtain accurate ventricular hyperelastic models. The findings further enhance our understanding of the desired mechanical behaviour of the different ventricle walls.
ARTICLE | doi:10.20944/preprints202106.0592.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: arterial stiffness; brachial-ankle pulse wave velocity; left ventricular mass index; echocardiography; hypertension
Online: 24 June 2021 (08:39:17 CEST)
Background: Brachial-ankle pulse wave velocity (baPWV) is widely used as a marker of arterial stiffness. It has been suggested as a simple method for detecting arterial loads that can trigger left ventricular hypertrophy in the heart. Increased left ventricular hypertrophy in hypertensive patients is a predictor that will have an impact on increasing morbidity and mortality. Objective: This study aimed to evaluate the correlation between the baPWV and the left ventricular mass index (LVMI) in hypertensive patients. Methods: This cross-sectional study was conducted by collecting secondary data from hypertensive patients at the Heart Outpatient Clinic, with inclusion: aged more than 40 years old, suffering hypertension more than one year, and had baPWV and echocardiography data. Correlation between baPWV and LVMI was evaluated using the Pearson correlation test. Results: A total of 40 hypertensive patients were enrolled in this study. 60% were women. The mean age was 52.92 ± 9.50 years. Mean LVMI was 107.20 + 21.01 gram/m2. LVMI showed a significant association with age and systolic blood pressure (p=0.001 and 0.019, respectively). Mean baPWV was 1832.90 + 336.22 cm/sec. A significant association was found between baPWV and age and systolic blood pressure (p=0.000 and 0.049, respectively). There was a significant positive correlation between baPWV and LVMI (r=0.493, p=0.001); and between baPWV and Relative Wall Thickness (RWT) (r=0.404, p=0.01). Conclusion: This study shows that elevated baPWV is an indicator of increased LVMI in hypertensive patients. Examination of baPWV should be carried out routinely to detect earlier arterial stiffness as a morbidity and mortality prevention strategy in hypertensive patients.
ARTICLE | doi:10.20944/preprints202105.0677.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: heart failure, phenotype, left ventricular ejection fraction, primary care, artificial intelligence, supervised analysis
Online: 27 May 2021 (14:08:53 CEST)
Artificial Intelligence are creating a paradigm shift in health care, being phenotyping patients through clustering techniques one of the areas of interest. Objective: To develop a predictive model to classify heart failure (HF) patients according to their left ventricular ejection fraction (LVEF), by using available data in Electronic Health Records (EHR). Subjects and methods: 2854 subjects more than 25 years old with diagnose of HF and LVEF measured by echocardiography were selected to develop an algorithm to predict patients with reduced EF using supervised analysis. Performance of the algorithm developed were tested in heart failure patients from Primary Care. To select the most influencing variables, LASSO algorithm setting was used and to tackle the issue of one class exceed the other one by a large proportion we used the Synthetic Minority Oversampling Technique (SMOTE). Finally, Random Forest (RF) and XGBoost models were constructed. Results: Full XGBoost model obtained the maximized accuracy, a high negative predictive value and the highest positive predictive value. Gender, age, unstable angina, atrial fibrillation and acute myocardial infarct are the variables that most influence FE value. Applied in the EHR data set with a total 25594 patients with an ICD-code of HF and no regular follow-up in Cardiology clinics, 6170 (21.1%) were identified as those pertaining to the reduced EF group. Conclusion: The algorithm obtained is able to rescue a number of HF patients with reduced ejection fraction that can be take benefit for a protocol with strong recommendation to succeed. Furthermore, the methodology can be used for studies with data extracted from the Electronic Health Records.
ARTICLE | doi:10.20944/preprints202005.0313.v1
Subject: Business, Economics And Management, Business And Management Keywords: Vehicle Routing Problem; Delivery and Pickup; Time Windows; Left-over Cost; Reusable Container
Online: 19 May 2020 (09:27:52 CEST)
A lot of previous research have proposed various frameworks and algorithms to optimize routes to reduce the total transportation cost, which accounts for over 70% of overall logistics cost. However, it is very hard to find the cases applied the mathematical models or algorithms to the practical business environment cases, especially daily operating logistics services like convenient stores. Most of previous research have considered the developing an optimal algorithm which can solve the mathematical problem within the practical time while satisfying all constraints such as the capacity of delivery and pick-up, and time windows. For the daily pick-up and delivery service like supporting several convenient stores, it is required to consider the unit transporting container as well as the demand, capacity of trucks, traveling distance and traffic congestion. Especially, the reusable transporting container, trays, should be regarded as the important asset of logistics center. However, if the mathematical model focuses on only satisfying constraints related delivery and not considering the cost of trays, it is often to leave the empty trays on the pick-up points when there is not enough space in the track. In this research, it has been proposed to build the mathematical model for optimizing pick-up and delivery plans by extending the general vehicle routing problem of simultaneous delivery and pickup with time windows while considering left-over cost. With the numerical experiments, it has been proved that the proposed model may reduce the total delivery cost. It may be possible to apply the proposed approach to the various logistics business which uses the reusable transporting container like shipping containers, refrigerating containers, trays, and pallets.
ARTICLE | doi:10.20944/preprints202002.0066.v3
Subject: Physical Sciences, Thermodynamics Keywords: information theory; causal inference; causal tensors; transfer entropy; partial information decomposition; left monotonicity; identity property; unobserved common cause
Online: 27 February 2020 (10:55:05 CET)
We propose a partial information decomposition based on the newly introduced framework of causal tensors, i.e., multilinear stochastic maps that transform source data into destination data. The innovation that causal tensors introduce is that the framework allows for an exact expression of an indirect association in terms of the constituting, direct associations. This is not possible when expressing associations only in measures like mutual information or transfer entropy. Instead of a priori expressing associations in terms of mutual information or transfer entropy, the a posteriori expression of associations in these terms results in an intuitive definition of a nonnegative and left monotonic redundancy, which also meets the identity property. Our proposed redundancy satisfies the three axioms introduced by Williams and Beer. Symmetry and self-redundancy axioms follow directly from our definition. The data processing inequality ensures that the monotonicity axiom is satisfied. Because causal tensors can describe both mutual information as transfer entropy, the partial information decomposition applies to both measures. Results show that the decomposition closely resembles the decomposition of other another approach that expresses associations in terms of mutual information a posteriori. A negative synergistic term could indicate that there is an unobserved common cause.
ARTICLE | doi:10.20944/preprints202310.0058.v1
Subject: Medicine And Pharmacology, Other Keywords: Care left undone, health services misuses, medical errors of omission, missed nursing care, workload.
Online: 3 October 2023 (03:10:26 CEST)
Background The workload of nurses in the intensive care unit (ICU) can affect the quality of nursing services. Aim This study aimed to determine the relationship between the nursing activity score and missed care in patients hospitalized in the ICU in Zanjan, Iran. Methods This observational and prospective study was conducted from April 3 to September 18 in 2021. In this study, the tools used included a patient and nurses' profile questionnaire, Nursing Activity Score (NAS). Missed care was observed in the 301 patients for whom the NAS was calculated. Analysis of variance (ANOVA) was used to investigate the differences in mean levels of missed care. Logistic regression models were used to assess the association between factors and missed nursing care. Results Results show that the Medical ICU's mean NAS was 76.31 (95% CI: -13.06 -14.89). In 9 dimensions of care, the extent of missed care was 40.7%. In the care dimensions of assessment, hand hygiene, and infection control, the mean NAS had a statistically significant increase at higher levels of missed care (P<.5). Furthermore, work experience was identified as a protective factor for missed care (OR =.59, 95% CI: .37–.94, χ2= =4.97, p =.026). Conclusion The study revealed a high incidence of missed care. The study revealed that the mean workload was high in certain dimensions of care such as assessment, hand hygiene, and infection control. The increase in workload for nurses results in lost care. Nonetheless, the utilization of experienced nurses can help mitigate this problem. However, utilizing experienced nurses can help reduce this problem.
REVIEW | doi:10.20944/preprints202309.1251.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: cardiac resynchronization therapy; His bundle pacing; Left bundle branch area pacing; conduction system pacing
Online: 19 September 2023 (07:11:41 CEST)
Cardiac resynchronization therapy (CRT) via biventricular pacing (BiVP-CRT) is considered a mainstay treatment for symptomatic heart failure patients with reduced ejection fraction and wide QRS. However, up to one third of patients receiving BiVP-CRT are considered non-responders to the therapy. Multiples strategies have been proposed to maximize the percentage of CRT responders including two new physiological pacing modalities that have emerged during the lasts years: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). Both pacing techniques aim at restoring the normal electrical activation of the ventricles through the native conduction system in opposition to the cell-to-cell activation of conventional right ventricular myocardial pacing. Conduction system pacing (CSP), including both HBP and LBBAP appears to be a promising pacing modality for delivering CRT and has proven to be safe and feasible in this particular setting. This article will review the current state of the art of CSP-based CRT, its limitations and future directions.
CASE REPORT | doi:10.20944/preprints202309.0330.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: Heart; Patent foramen ovale; Right to left shunt; Bubble contrast; Transcranial color coded doppler
Online: 5 September 2023 (14:49:24 CEST)
Traditional diagnosis of patent foramen ovale (PFO) in the heart has involved the use of transcranial doppler (TCD). However, TCD is essentially a blind test that cannot directly visualize the location of blood vessels. Since TCD relies on qualitative assessments by examiners, there is room for errors, such as misalignment of the ultrasound's angle of incidence with the actual blood vessels. This limitation affects the reproducibility and consistency of the examination. In this study, we presented an alternative approach for assessing right-to-left shunt (RLS) associated with PFO using contrast transcranial color-coded doppler (C-TCCD) with bubble contrast. The patient under consideration had been diagnosed with an ischemic stroke through imaging, but the subsequent cardiac work-up failed to determine the cause. Employing C-TCCD for RLS screening revealed a confirmed RLS of Spencer’s three grades. Subsequently, transesophageal echocardiography (TEE) was conducted to evaluate PFO risk factors, confirming an 8 mm PFO size, a 21 mm tunnel length, a hypermobile interatrial septum, and persistent RLS. The calculated high-risk PFO score was 4 points, categorizing it as a very high-risk PFO. This case underscores the importance of C-TCCD screening in detecting RLS associated with PFO, especially in cryptogenic stroke patients when identifying the underlying cause of ischemic stroke becomes challenging.
ARTICLE | doi:10.20944/preprints202101.0031.v1
Subject: Social Sciences, Psychology Keywords: ERPs; selective attention; global/local; cerebral hemispheres; VEPs; spatial frequency; Attentional tuning; Left hemisphere
Online: 4 January 2021 (12:27:21 CET)
A hemispheric asymmetry is known for the processing of global vs. local visual information. In this study, we investigated the existence of a hemispheric asymmetry for visual processing of low vs. high spatial frequency gratings. Event-related potentials were recorded in a group of healthy right-handed volunteers from 30 scalp sites. Six types of stimuli (1.5, 3 and 6 c/deg gratings) were randomly flashed 180 times in the left and right upper hemi-fields. Stimulus duration was 80 ms and ISI ranged between 850-1000 ms. Participants had to pay attention and respond to targets based on their spatial frequency and location, or to passively look at the stimuli. C1 and P1 visual responses, as well as a later Selection negativity and a P300 components of ERPs were quantified and subjected to repeated-measure ANOVAs. Overall, performance was faster for the RVF, thus suggesting a left hemispheric advantage for attentional selection of local elements. Similarly, the analysis of mean area amplitude of C1 (60-110 ms) sensory response showed a stronger attentional effect (F+L+ vs. F-L+) at left occipital areas, thus suggesting the sensory nature of this hemispheric asymmetry.
ARTICLE | doi:10.20944/preprints202312.0458.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Pericardium [A07.541.795]; Echocardiography [E01.370.350.130.750]; Ventricular Dysfunction, Left [C14.280.945.900]; Heart Failure, Diastolic [C14.280.434.611]; Abdominal Circumference [SP6.2188.8.131.52].
Online: 7 December 2023 (09:31:44 CET)
Background: Heart failure is a major cause of morbidity and mortality worldwide; left ventricular diastolic dysfunction plays a leading role in this clinical context. Diastolic dysfunction may be predisposed by increased abdominal fat and, consequently, increased pericardial and epicardial adiposity. This study aimed to determine whether pericardial and epicardial fat are associated with left ventricular diastolic function. Methods: 82 patients had their abdominal circumference measured and underwent transthoracic echocardiography to measure the thickness of pericardial and epicardial fat and assess the left ventricular diastolic function. Two groups were created based on mean pericardial fat thickness (4.644 mm) and were related to abdominal circumference and echocardiographic parameters. Results: Subjects in the PF High group showed a significant decrease in septal e' (p<0.0001), lateral e' (p<0.0001) and E/A ratio (p=0.003) and a significant increase in E/e' ratio (p<0. 0001), E wave deceleration time (p=0. 013), left atrial volume (p<0.0001), LV mass (p=0.003), tricuspid regurgitant jet velocity (p<0.0001) and LV diameter (p=0.014) compared to the PF Low group. Conclusions: Measurement of abdominal circumference, pericardial and epicardial fat is an early indicator of diastolic changes with transthoracic echocardiography being the gold standard exam.
ARTICLE | doi:10.20944/preprints202311.1434.v1
Subject: Physical Sciences, Theoretical Physics Keywords: Fermat principle; optical path; metamaterials; left-handed materials; graphs; Ramsey Theory; Ramsey Theorem; optical cycle.
Online: 22 November 2023 (13:48:33 CET)
Re-interpretation of the Fermat principle governing propagation of light in media within the Ramsey Theory is suggested. Complete bi-colored graphs corresponding to the light propagation in media are considered. The vertices of the graphs correspond to the points of the real physical space, in which light sources or sensors are placed. Red links in the graphs correspond to the actual optical paths, emerging from the Fermat principle. A variety of optical events: refraction, reflection, etc. may be involved in the light propagation. Green links, in turn, denote the trial/virtual optical paths, which actually do not occur. The Ramsey Theorem states that within the graph containing six points, inevitably, actual or virtual optical cycle will be necessarily present. Implementation of the Ramsey Theorem to the light propagation in metamaterials is discussed. The Fermat Principle states that in metamaterials a light ray in going from point S to point P must traverse an optical path length L that is stationary with respect to variations of this path. Thus, bi-colored graphs built of links corresponding to maxima or minima of optical paths become possible. Graphs, comprising six vertices, inevitably will demonstrate optical cycles, built of the mono-colored links corresponding to the maxima or minima of the optical path. The notion of the “inverse graph” is introduced and discussed. The total number of triangles in the “direct” (source) and “inverse” Ramsey optical graphs is the same, Optical interpretation of the infinite Ramsey Theorem is suggested.
ARTICLE | doi:10.20944/preprints202310.0099.v1
Subject: Engineering, Bioengineering Keywords: Intelligent Image Recognition; Left and Right Upper Limb Dislocation Surgery; Accuracy Rate; Recall Rate; IRB
Online: 3 October 2023 (09:17:35 CEST)
Our image recognition system mainly judges whether the left upper limb in the image is the left upper limb or the right upper limb through our deep learning model in the image. The doctor then could give the correct surgical position. From the experimental results, it could be found that the precision rate and recall rate of the intelligent image recognition system proposed in this paper for preventing the upper limb dislocation surgery could reach 98% and 93%, respectively. It proved that our artificial intelligent image recognition system, AIIRS, could indeed assist orthopedic surgeons to prevent the occurrence of left and right dislocation in upper limb surgery. At the same time, this paper also completes the IRB application approval through the prototype experimental results and will conduct the second phase of human trials in the future. It showed that the research results of this paper will be of great benefit and research value to upper limb orthopedic surgery.
ARTICLE | doi:10.20944/preprints202309.0290.v1
Subject: Engineering, Bioengineering Keywords: Intelligent Image Recognition; Left and Right Upper Limb Dislocation Surgery; Accuracy Rate; Recall Rate; IRB
Online: 5 September 2023 (09:20:54 CEST)
Our image recognition system mainly judges whether the left upper limb in the image is the left upper limb or the right upper limb through our deep learning model in the image. The doctor then could give the correct surgical position. From the experimental results, it could be found that the precision rate and recall rate of the intelligent image recognition system proposed in this paper for preventing the upper limb dislocation surgery could reach 98% and 93%, respectively. It proved that our intelligent image recognition system could indeed assist orthopedic surgeons to prevent the occurrence of left and right dislocation in upper limb surgery. At the same time, this paper also completes the IRB application approval through the prototype experimental results and will conduct the second phase of human trials in the future. It showed that the research results of this paper will be of great benefit and research value to upper limb orthopedic surgery.
ARTICLE | doi:10.20944/preprints202202.0017.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: protein-protein interactions; interactome; congenital heart disease; developmental disorder; hypoplastic left heart syndrome; web application
Online: 1 February 2022 (16:00:59 CET)
Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease (CHD) affecting 1 in 5,000 newborns. We constructed the interactome of 74 HLHS-associated genes identified from a large-scale mouse mutagenesis screen, augmenting it with 408 novel protein-protein interactions (PPIs) using our High-precision Protein-Protein Interaction Prediction (HiPPIP) model. The interactome is available on a webserver with advanced search capabilities (http://severus.dbmi.pitt.edu/wiki-HLHS). 364 genes including 73 novel interactors were differentially regulated in tissues/iPSC-derived cardiomyocytes of HLHS patients. Novel PPIs facilitated the identification of TOR signaling and endoplasmic reticulum stress modules. 60.5% of the interactome consisted of housekeeping genes that may harbor large-effect mutations and drive HLHS etiology but show limited transmission. Network proximity of diabetes, Alzheimer’s disease, and liver carcinoma-associated genes to HLHS genes suggested a mechanistic basis for their comorbidity with HLHS. Interactome genes showed tissue-specificity for sites of extracardiac anomalies (placenta, liver and brain). The HLHS interactome shared significant overlaps with the interactomes of ciliopathy and microcephaly-associated genes, with the shared genes respectively enriched for genes involved in intellectual disability and/or developmental delay, and neuronal death pathways. This supported the increased burden of ciliopathy variants and prevalence of neurological abnormalities observed among HLHS patients with developmental delay and microcephaly respectively.
ARTICLE | doi:10.20944/preprints202112.0461.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Hypertrophic Cardiomyopathy; Left ventricular outflow tract obstruction; single nucleus RNA-sequencing; dendritic cells; integrin-b1.
Online: 29 December 2021 (09:43:00 CET)
Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder characterized by unexplained left ventricular hypertrophy, with or without left ventricular outflow tract (LVOT) obstruction. Single nuclei RNA-sequencing (snRNA-seq) of both obstructive and nonobstructive HCM patient samples have revealed alterations in communication between various cell types but a direct and integrated comparison between the two HCM phenotypes has not been reported. We performed a bioinformatic analysis of HCM snRNA-seq datasets from obstructive and nonobstructive patient samples to identify differentially expressed genes and distinctive patterns of intercellular communication. Differential gene expression analysis revealed 37 differentially expressed genes, predominantly in cardiomyocytes but also in other cell types, relevant to aging, muscle contraction, cell motility and the extracellular matrix. Intercellular communication was generally reduced in HCM, affecting the extracellular matrix, growth factor binding, integrin binding, PDGF binding and SMAD binding, but with increases in adenylate cyclase binding, calcium channel inhibitor activity, and serine-threonine kinase activity in nonobstructive HCM. Increases in neuron to leukocyte and dendritic cell communication, in fibroblast to leukocyte and dendritic cell communication and in endothelial cell communication to other cell types, largely through changes in expression of integrin-b1 and its cognate ligands, were also noted. These findings indicate both common and distinct physiological mechanisms affecting the pathogenesis of obstructive and nonobstructive HCM and provide opportunities for personalized management of different HCM phenotypes.
DATA DESCRIPTOR | doi:10.20944/preprints202108.0153.v1
Subject: Engineering, Mechanical Engineering Keywords: Cardiac mechanics; Biaxial testing; Rat heart; Left ventricle mechanics; Mid-wall mechanics; Right ventricle mechanics
Online: 6 August 2021 (08:24:19 CEST)
This article presents raw data of biaxial tensile measurements of rat heart passive myocardium conducted in lab scale environment. The passive myocardium of the rat was divided into three regions, namely: left ventricle, mid-wall and right ventricle. The biaxial dataset of passive rat myocardia is presented as stress vs strain of the passive rat myocardium in various regions. The determination of valid material properties of the heart plays an important role in the development computational models. These computational models are useful in studying various scenarios and mechanisms of heart diseases. In addition, valid and accurate materials are critical in the development of new therapies. The dataset presented here is useful in the area of soft tissue mechanics including studying the mechanisms of heart diseases such as myocardial infarction. Accordingly, the evaluation of stress and strain in left ventricle, mid-wall and right ventricle was performed.
CASE REPORT | doi:10.20944/preprints202306.0678.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Right-sided ligamentum teres; Three-dimensional computed tomography; Intraoperative ultrasonography; Laparoscopic hepatectomy; Expanded left lateral sectionectomy
Online: 9 June 2023 (07:14:27 CEST)
Right-sided ligamentum teres (RSLT) is a rare anatomic variant in which the fetal umbilical vein connects to the right portal vein. Patients with RSLT frequently have hepatic vasculature and bile duct anomalies, which increase the risk of complications with hepatectomy. Most patients with RSLT undergo open hepatectomy. We describe a patient with RSLT and hepatocellular carcinoma who underwent laparoscopic hepatectomy. The patient was a 69-year-old man with hepatocellular carcinoma located in the left liver based on computed tomography (CT) and magnetic resonance imaging. Imaging also demonstrated RSLT. Three-dimensional CT analysis revealed independent right lateral type anomalies of the portal vein and bile duct. Laparoscopic extended left lateral sectionectomy was performed after careful surgical planning. Ultrasonography was used frequently during surgery to avoid damaging the right hepatic vasculature. The left lateral and partial left median sections were removed as planned. The patient’s postoperative recovery was uneventful. Avoiding injury to the right hepatic vasculature is essential when performing left lobectomy, including left lateral sectionectomy, in patients with RSLT. Laparoscopic hepatectomy can be performed safely in patients with RSLT, provided that careful surgical planning is conducted using preoperative three-dimensional CT analysis and intraoperative ultrasonography is used.
ARTICLE | doi:10.20944/preprints202208.0343.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: 14-3-3; interactome; protein-protein interaction; mitochondria; metabolism; protein quality control; homeostasis; left ventricule; network
Online: 18 August 2022 (10:54:49 CEST)
Rationale: The 14-3-3 protein family is known to interact with many proteins in non-cardiac cell types to regulate multiple signaling pathways, particularly those relating to energy and protein homeostasis; and the 14-3-3 network is a therapeutic target of critical metabolic and proteostatic signaling in cancer and neurological diseases. Although the heart is critically sensitive to nutrient and energy alterations, and multiple signaling pathways coordinate to maintain the cardiac cell homeostasis, neither the structure of cardiac 14-3-3 protein interactome, nor potential functional roles of 14-3-3 protein-protein interactions (PPIs) in heart has been explored. Objective: To establish the comprehensive landscape and characterize the functional role of cardiac 14-3-3 PPIs. Methods and Results: We evaluated both RNA expression and protein abundance of 14-3-3 isoforms in mouse heart, followed by co-immunoprecipitation of 14-3-3 proteins and mass spectrometry in left ventricle. We identified 52 proteins comprising the cardiac 14-3-3 interactome. Multiple bioinformatic analyses indicated that more than half of the proteins bound to 14-3-3 are related to mitochondria; and the deduced functions of the mitochondrial 14-3-3 network are to regulate cardiac ATP production via interactions with mitochondrial inner membrane proteins, especially those in mitochondrial complex I. Binding to ribosomal proteins, 14-3-3 proteins likely coordinate protein synthesis and protein quality control. Localizations of 14-3-3 proteins to mitochondria and ribosome were validated via immunofluorescence assays. The deduced function of cardiac 14-3-3 PPIs is to regulate cardiac metabolic homeostasis and proteostasis. Conclusions: Thus, the cardiac 14-3-3 interactome may be a potential therapeutic target in cardiovascular metabolic and proteostatic disease states, as it already is in cancer therapy.
REVIEW | doi:10.20944/preprints202307.0002.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: heart failure with reduced ejection fraction; echocardiography; outpatient monitoring; left ventricular filling pressure; lung ultrasound; inferior vena cava
Online: 3 July 2023 (03:31:39 CEST)
Heart failure with reduced ejection fraction (HFrEF) is considered a major healthcare problem with frequent decompensations, high hospitalization and mortality rates. In severe heart failure (HF), the symptoms are refractory to medical treatment and require advanced therapeutic strategies. Early recognition of HF sub- and decompensation is the cornerstone of the timely treatment intensification and, therefore, improvement of the prognosis. Echocardiography is the gold standard for the assessment of systolic and diastolic functions. It allows to obtain accurate and non-invasive measurements of the ventricular function in HF. In severely compromised HF patients, advanced cardiovascular ultrasound modalities may provide a better assessment of intracardiac hemodynamic changes and subclinical congestion. Particularly, cardiovascular and lung ultrasound allow to make a more accurate diagnosis of subclinical congestion in HFrEF. The aim of this review is to summarize the advantages and limitations of currently available ultrasound modalities in the ambulatory monitoring of patients with HFrEF.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Heart failure with reduced ejection fraction; Real-life practice; Sacubitril/valsartan; Left ventricular ejection fraction recovery; Implantable cardioverter defibrillator
Online: 5 May 2021 (10:30:13 CEST)
Background: our purpose is to assess the effectiveness and safety of sacubitril/valsartan (SV) in “real-world” patients with heart failure and reduced ejection fraction (HFrEF), including a broader spectrum of patients than those in clinical trials and evaluating variables not previously described in the literature. Methods: real-world study in HFrEF patients (N:204), both in and out-patients, who started SV between October 2017 and December 2018. We performed a prospective analysis with a 12-month follow-up. The study outcomes were effectiveness and safety, measured by individual parameters and combined endpoints, comparing the pre and post practice periods. Results: at the end of follow-up, an improvement of left ventricle ejection fraction (LVEF): 29.8% vs 33.7; p<0.0001, a decrease in NT-proBNP levels (3928 pg/mL vs 2902 pg/mL; p=0.012), number of hospital admissions (141 vs 35; p<0.0001) and percentage of patients with implantable cardioverter defibrillator (ICD) indication (79.9% vs 49.5%; p<0.0001) were observed. Of our population, 81.3% met a combined efficacy endpoint (defined by increase of LVEF, reduction of hospital admission or improvement in functional class). No differences were observed in parameters regarding safety. Conclusions: Sacubitril/valsartan has brought about a revolution in the therapeutic management of HFrEF patients and its use may raise questions about what is considered "optimal medical therapy" prior to implantation of cardiac devices.
ARTICLE | doi:10.20944/preprints202308.0119.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: echocardiography; non-invasive; global myocardial work; thoracotomy; video-assisted thoracoscopic surgery; VATS; lung resection; lung surgery; right ventricle; left ventricle
Online: 2 August 2023 (02:50:51 CEST)
Considering the controversial benefits of video-assisted thoracoscopic surgery (VATS), we intended to evaluate the impact of surgical approach on cardiac function after lung resection using myocardial work analysis. Echocardiographic data of 45 patients (25 thoracotomy vs. 20 VATS) were retrospectively analyzed. All patients underwent transthoracic echocardiography (TTE) 2 weeks before and after surgery, including two-dimensional speckle tracking and tissue doppler imaging. No notable changes in left ventricular (LV) function, assessed mainly using the LV global longitudinal strain (GLS), global myocardial work index (GMWI), and global work efficiency (GWE), were observed. Right ventricular (RV) TTE values, including tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (TASV), and RV free-wall GLS (RVFWGLS), indicated greater RV function impairment in the thoracotomy group than in the VATS group [TAPSE (mm): 17.90 ± 3.80 vs. 20.60 ± 3.50, p < 0.018; TASV (cm/s): 12.40 ± 2.90 vs. 14.60 ± 2.50, p < 0.010; RVFWGLS (%): −11.50 ± 8.50 vs. −17.50 ± 9.70, p < 0.033), respectively]. Unlike RV function, LV function remained preserved after lung resection. The thoracotomy group exhibited greater RV function impairment than did the VATS group. Further studies should evaluate the long-term impact of surgical approach on cardiac function.
Subject: Computer Science And Mathematics, Mathematics Keywords: equipment vendor selection; fuzzy TOPSIS; fuzzy weighted average left and right score; multi-choice goal programming; multi-aspiration goal programming
Online: 30 May 2019 (08:42:27 CEST)
The airport ground handling service (AGHS) equipment vendor selection (AGHSEVS) problem is critical for ramp work safety management, because AGHS equipment malfunctions affect airport ramp work safety. Appropriate vendor selection can prevent aircraft damage and delays in airlines schedules, and ensure reliable and high-quality ground handling service. The AGHSEVS problem is a time-consuming and complex process that requires professional knowledge and experience to make judgments. Specifically, AGHSEVS is a multi-criteria decision-making (MCDM) problem. Previous research has seldom integrated MCDM methods with linear and goal programming to solve the AGHSEVS problem. The objective of this study was to develop a new system evaluation model for AGHSEVS by considering both qualitative and quantitative methods. We test the proposed approach on an AGHS company in Taiwan.
ARTICLE | doi:10.20944/preprints202203.0026.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: Tc symmetry; CTP symmetry; Photon space; Elementary particles; Quantum wave functions; Modified Lorenz transformations; Left-handed neutrinos; Right-handed dark matters
Online: 1 March 2022 (15:01:52 CET)
The time symmetry of Tc = CT is redefined based on the 4-D Euclidean space. The time inversion symmetry of Tc = CT changes the signs of the charge (q) and absolute time (ct) of the particle. The P symmetry changes the signs of the space momenta and handedness of the particle. The Tc symmetry changes the signs of the time momentum (Pt=E/c) and charges. The handedness are classified as the left-handedness and right-handedness on the 3-D space. The charges (|q| = cDt) and energies (E= cDtDV) of the particles are originated from the upward warping (q>0) and downward warping (q<0) of the particles along the time axis. The evolution of our matter universe with Pt > 0 since the big bang can be interpreted based on the CTP symmetry with the partner antimatter universe with pt < 0. The photon space is called as the vacuum space. Then the E and M waves are the space fluctuations, and the gravitational G wave is the time fluctuations. And the E, M and G fields are newly explained. The zero E and M fields of the photon space indicates that the photon space and gamma ray are the 2EM waves. The rest mass energy of the particle is the 4-D space volume of the warped photon space. In the present work, the quantum wave function is considered as the 4-D vector with the space wave function and time axis wave function in the 4-D Euclidean space. The warped photon space corresponds to the squared wave function which is the probability density. It is concluded that, in the quantum mechanics, the imaginary number concept is introduced in the quantum wave functions instead of the time axis component of the 4-D wave function vector. The left-handed neutrino puzzle is explained from the handedness partner relation with the right-handed dark matters. Finally, the modified Lorentz transformations derived in the 4-D Euclidean space are compared with the Lorentz transformations of the special and general relativity theories in the 4-D Minkowski space.
COMMUNICATION | doi:10.20944/preprints202306.0473.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; echocardiography; left ventricular mass index; the ratio between the E and A waves; deceleration time of early mitral inflow; biomarkers
Online: 7 June 2023 (03:22:53 CEST)
Background: The manifestations, severity, and mortality of COVID-19 are considered to be associated with the changes in various hematological parameters and in immunity. Associations of immunoglobulin G antibodies against severe acute respiratory syndrome-linked coronavirus (IgG-SARS)-positive status with cardiac function and hematological and biochemical parameters in apparently health subjects are poorly understood. Methods: The present cross-sectional study included 307 healthy volunteers (24-69 years of age; 44.8±8.6 years; 80.4% men) and was initiated in 2019 before the COVID-19 pandemic. COVID-19 episodes were confirmed by detection of IgG-SARS against SARS-CoV-2 S1 RBD to reveal 70 IgG-SARS-positive and 237 negative participants. Numerous ultrasound characteristics were assessed by echocardiography, and 15 hematological and biochemical parameters were assayed in the blood. Descriptive and comparative analysis was based on the IgG-SARS status of the participants. Results: The left ventricular mass index, mitral ratio of peak early to late diastolic filling velocity or flow velocity across the mitral valve, and deceleration time of early mitral inflow were decreased (P<0.05) in IgG-SARS-positive participants versus those in IgG-SARS-negative participants according to multivariate logistic regression analysis. Erythrocyte sedimentation rate and platelet count were slightly increased, and blood hemoglobin was decreased in IgG-SARS-positive participants compared with those in IgG-SARS-negative participants. Conclusions: LV filling, inflammation, blood coagulation, and hemoglobin appear to be influenced by COVID-19 infection in healthy participants. These observations contribute to the development of a population recovery strategy after the episodes of COVID-19.
ARTICLE | doi:10.20944/preprints202304.0803.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: b-HCG; PAPP-A; s-FLT-1; PlGF; pulsatility index of the ductus venosus; pulsatility index of the right and left uterine arteries
Online: 23 April 2023 (13:45:23 CEST)
Background: In this study, we aimed to evaluate the effect of s-FLT-1 and PlGF concentrations in women in the first trimester of pregnancy on the pulsatility index of the ductus venosus and the right and left uterine arteries. Methods: A total of 108 pregnant women in their first trimester were included in the study, with 87 assigned to the experimental group and 21 to the control group. Ultrasound examination were performed to measure the uterine artery pulsatility index, resistance index, ductus venosus pulsatility index, and blood sampling levels of biomarkers such as b-HCG; PAPP-A; s-FLT-1 and PlGF. Results: There was a significant negative relationship between PAPP-A concentration and the risk of fetal growth restriction, and a significant negative relationship between PlGF concentration and the risk of preeclampsia and fetal growth restriction in women in their first trimester of pregnancy. There was also a significant positive relationship between sFLT-1/PLGF ratio and the risk of developing preeclampsia. No significant relationships were found between the concentrations of biomarkers beta-HCG, PAPP-A, sFLT-1, PlGF, and any of the parameters PIUARt, PIUALt, Mean uterine arteries, and DVPI. Summary: In conclusion, this study did not find conclusive evidence to support the hypothesis that beta-HCG, PAPP-A, s-FLT-1, and PlGF concentrations in women in the first trimester of pregnancy have a significant effect on the Pulsatility Index of the ductus venosus and the Right and left Uterine Arteries. Further research is needed to investigate these potential associations.
ARTICLE | doi:10.20944/preprints202108.0157.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: reptile, ventricular septation, endocardial cushions, semilunar valves, outflow tract, cartilage, foramen of Panizza, left aorta, right aorta, pulmonary trunk, pharyngeal arch arteries, coronary arter
Online: 6 August 2021 (11:08:56 CEST)
The outflow tract of crocodilians resembles that of birds and mammals as ventricular septation is complete. The arterial anatomy however, presents with a pulmonary trunk originating from the right ventricular cavum, and two aortae originating from either the right or left ventricular cavum. Mixing of blood in crocodilians cannot occur at ventricular level as in other reptiles, but instead takes place at aortic root level by a shunt, the Foramen of Panizza, the opening of which is guarded by two facing semilunar leaflets of both bicuspid aortic valves. Methods. Developmental stages of Alligator mississipiensis, Crocodilus niloticus and Caiman latirostris, have been studied. Results and Conclusions. The outflow tract septation complex can be divided into 2 components. The aorto-pulmonary septum divides the pulmonary trunk from both aortae, whereas the interaortic septum divides the systemic from the visceral aorta. Neural crest cells are most likely involved in the formation of both components. Remodeling of the endocardial cushions and both septa results in the formation of bicuspid valves in all three arterial trunks. The foramen of Panizza originates intracardially as a channel in the septal endocardial cushion.
REVIEW | doi:10.20944/preprints201912.0385.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: dilated cardiomyopathy (DCM); hypertrophic cardiomyopathy (HCM); restrictive cardiomyopathy (RCM); arrhythmogenic right ventricular cardiomyopathy (ARVC); left ventricular non-compaction cardiomyopathy (LVNC); Duchenne muscular dystrophy; dystrophin; genome editing; CRISPR/Cas9; Cpf1 (Cas12a)
Online: 29 December 2019 (13:41:48 CET)
Cardiomyopathies are diseases of heart muscle, a significant percentage of which are genetic in origin. Cardiomyopathies can be classified as dilated, hypertrophic, restrictive, arrhythmogenic right ventricular or left ventricular non-compaction, although mixed morphologies are possible. A subset of neuromuscular disorders, notably Duchenne and Becker muscular dystrophies, are also characterized by cardiomyopathy aside from skeletal myopathy. The global burden of cardiomyopathies is certainly high, necessitating further research and novel therapies. Genome editing tools, which include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR) systems have emerged as increasingly important technologies in studying this group of cardiovascular disorders. In this review, we discuss the applications of genome editing in the understanding and treatment of cardiomyopathy. We also describe recent advances in genome editing that may help improve these applications, and some future prospects for genome editing in cardiomyopathy treatment.