Development and Characterization of Multi-Alkali Antimonide Photocathodes for High-Brightness RF Photoinjectors.

Due to their excellent photoemissive properties, especially low thermal emittance and high sensitivity in the green wavelength, multi-alkali antimonide photocathodes, in particular, cesium-potassium-antimonide, emerged as prominent photoemissive materials for the electron sources of high-repetition-rate FEL applications. To explore its feasibility of operating in a high-gradient RF gun, DESY collaborated with INFN LASA to develop multi-alkali photocathode materials. In this report, we describe the recipe of K-Cs-Sb photocathodes, which were grown on a Mo substrate by varying the foundational Sb layer thickness using sequential deposition techniques. This report also illustrates the information regarding the film thickness, substrate temperature, deposition rate, and its possible effects on the photocathode's properties. In addition, the influence of temperature on the cathode degradation is also summarized. Furthermore, in the framework of density functional theory (DFT), we investigated the electronic and optical properties of the K2CsSb material. The optical properties, such as dielectric function, reflectivity, refracting index, and extinction coefficient, were evaluated. The correlation between the calculated and measured optical properties, such as reflectivity, provides a better and more efficient strategy to rationalize and understand the photoemissive material's properties.

FLASHlab@PITZ: New R&D platform with unique capabilities for electron FLASH and VHEE radiation therapy and radiation biology under preparation at PITZ.

At the Photo Injector Test facility at DESY in Zeuthen (PITZ), an R&D platform for electron FLASH and very high energy electron radiation therapy and radiation biology is being prepared (FLASHlab@PITZ). The beam parameters available at PITZ are worldwide unique. They are based on experiences from 20 + years of developing high brightness beam sources and an ultra-intensive THz light source demonstrator for ps scale electron bunches with up to 5 nC bunch charge at MHz repetition rate in bunch trains of up to 1 ms length, currently 22 MeV (upgrade to 250 MeV planned). Individual bunches can provide peak dose rates up to 1014 Gy/s, and 10 Gy can be delivered within picoseconds. Upon demand, each bunch of the bunch train can be guided to a different transverse location, so that either a "painting" with micro beams (comparable to pencil beam scanning in proton therapy) or a cumulative increase of absorbed dose, using a wide beam distribution, can be realized at the tumor. Full tumor treatment can hence be completed within 1 ms, mitigating organ movement issues. With extremely flexible beam manipulation capabilities, FLASHlab@PITZ will cover the current parameter range of successfully demonstrated FLASH effects and extend the parameter range towards yet unexploited short treatment times and high dose rates. A summary of the plans for FLASHlab@PITZ and the status of its realization will be presented.

Simplified Integrated Clinical and Electrocardiographic Algorithm for Differentiation of Wide QRS Complex Tachycardia: The Basel Algorithm.

BACKGROUND: Prompt differential diagnosis of wide QRS complex tachycardia (WCT) is crucial to patient management. However, distinguishing ventricular tachycardia (VT) from supraventricular tachycardia (SVT) with wide QRS complexes remains problematic, especially for nonelectrophysiologists. OBJECTIVES: This study aimed to develop a simple-to-use algorithm with integration of clinical and electrocardiographic (ECG) parameters for the differential diagnosis of WCT. METHODS: The 12-lead ECGs of 206 monomorphic WCTs (153 VT, 53 SVT) with electrophysiology-confirmed diagnoses were analyzed. In the novel Basel algorithm, VT was diagnosed in the presence of at least 2 of the following criteria: 1) clinical high risk features; 2) lead II time to first peak >40 ms; and 3) lead aVR time to first peak >40 ms. The algorithm was externally validated in 203 consecutive WCT cases (151 VT, 52 SVT). Its' diagnostic performance and clinical applicability were compared with those of the Brugada and Vereckei algorithms. RESULTS: The Basel algorithm showed a sensitivity, specificity, and accuracy of 92%, 89%, and 91%, respectively, in the derivation cohort and 93%, 90%, and 93%, respectively, in the validation cohort. There were no significant differences in the performance characteristics between the 3 algorithms. The evaluation of the clinical applicability of the Basel algorithm showed similar diagnostic accuracy compared with the Brugada algorithm (80% vs 81%; P = 1.00), but superiority compared with the Vereckei algorithm (72%; P = 0.03). The Basel algorithm, however, enabled a faster diagnosis (median 36 seconds vs 105 seconds for the Brugada algorithm [P = 0.002] and 50 seconds for the Vereckei algorithm [P = 0.02]). CONCLUSIONS: The novel Basel algorithm based on simple clinical and ECG criteria allows for a rapid and accurate differential diagnosis of WCT.

Advanced Imaging in Cardiac Amyloidosis.

This review serves as a synopsis of multimodality imaging in cardiac amyloidosis (CA), which is a disease characterized by deposition of misfolded protein fragments in the heart. It emphasizes and summarizes the diagnostic possibilities and their prognostic values. In general, echocardiography is the first diagnostic tool in patients with an identified systemic disease or unclear left ventricular hypertrophy. Several echocardiographic parameters will raise suspicion and lead to further testing. Cardiac magnetic resonance and scintigraphy with bone avid radiotracers are crucial for diagnosis of CA and even enable a distinction between different subtypes. The subject is illuminated with established guidelines and innovative recent publications to further improve early diagnosis of cardiac amyloidosis in light of current treatment options.

Silent brain infarcts impact on cognitive function in atrial fibrillation.

AIMS: We aimed to investigate the association of clinically overt and silent brain lesions with cognitive function in atrial fibrillation (AF) patients. METHODS AND RESULTS: We enrolled 1227 AF patients in a prospective, multicentre cohort study (Swiss-AF). Patients underwent standardized brain magnetic resonance imaging (MRI) at baseline and after 2 years. We quantified new small non-cortical infarcts (SNCIs) and large non-cortical or cortical infarcts (LNCCIs), white matter lesions (WML), and microbleeds (Mb). Clinically, silent infarcts were defined as new SNCI/LNCCI on follow-up MRI in patients without a clinical stroke or transient ischaemic attack (TIA) during follow-up. Cognition was assessed using validated tests. The mean age was 71 years, 26.1% were females, and 89.9% were anticoagulated. Twenty-eight patients (2.3%) experienced a stroke/TIA during 2 years of follow-up. Of the 68 (5.5%) patients with ≥1 SNCI/LNCCI, 60 (88.2%) were anticoagulated at baseline and 58 (85.3%) had a silent infarct. Patients with brain infarcts had a larger decline in cognition [median (interquartile range)] changes in Cognitive Construct score [-0.12 (-0.22; -0.07)] than patients without new brain infarcts [0.07 (-0.09; 0.25)]. New WML or Mb were not associated with cognitive decline. CONCLUSION: In a contemporary cohort of AF patients, 5.5% had a new brain infarct on MRI after 2 years. The majority of these infarcts was clinically silent and occurred in anticoagulated patients. Clinically, overt and silent brain infarcts had a similar impact on cognitive decline. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02105844, https://clinicaltrials.gov/ct2/show/NCT02105844.

Drug-coated balloons for small coronary artery disease (BASKET-SMALL 2): an open-label randomised non-inferiority trial.

BACKGROUND: Drug-coated balloons (DCB) are a novel therapeutic strategy for small native coronary artery disease. However, their safety and efficacy is poorly defined in comparison with drug-eluting stents (DES). METHODS: BASKET-SMALL 2 was a multicentre, open-label, randomised non-inferiority trial. 758 patients with de-novo lesions (<3 mm in diameter) in coronary vessels and an indication for percutaneous coronary intervention were randomly allocated (1:1) to receive angioplasty with DCB versus implantation of a second-generation DES after successful predilatation via an interactive internet-based response system. Dual antiplatelet therapy was given according to current guidelines. The primary objective was to show non-inferiority of DCB versus DES regarding major adverse cardiac events (MACE; ie, cardiac death, non-fatal myocardial infarction, and target-vessel revascularisation) after 12 months. The non-inferiority margin was an absolute difference of 4% in MACE. This trial is registered with ClinicalTrials.gov, number NCT01574534. FINDINGS: Between April 10, 2012, and February 1, 2017, 382 patients were randomly assigned to the DCB group and 376 to DES group. Non-inferiority of DCB versus DES was shown because the 95% CI of the absolute difference in MACE in the per-protocol population was below the predefined margin (-3·83 to 3·93%, p=0·0217). After 12 months, the proportions of MACE were similar in both groups of the full-analysis population (MACE was 7·5% for the DCB group vs 7·3% for the DES group; hazard ratio [HR] 0·97 [95% CI 0·58-1·64], p=0·9180). There were five (1·3%) cardiac-related deaths in the DES group and 12 (3·1%) in the DCB group (full analysis population). Probable or definite stent thrombosis (three [0·8%] in the DCB group vs four [1·1%] in the DES group; HR 0·73 [0·16-3·26]) and major bleeding (four [1·1%] in the DCB group vs nine [2·4%] in the DES group; HR 0·45 [0·14-1·46]) were the most common adverse events. INTERPRETATION: In small native coronary artery disease, DCB was non-inferior to DES regarding MACE up to 12 months, with similar event rates for both treatment groups. FUNDING: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Basel Cardiovascular Research Foundation, and B Braun Medical AG.

Observation of High Transformer Ratio Plasma Wakefield Acceleration.

Particle-beam-driven plasma wakefield acceleration (PWFA) enables various novel high-gradient techniques for powering future compact light-source and high-energy physics applications. Here, a driving particle bunch excites a wakefield response in a plasma medium, which may rapidly accelerate a trailing witness beam. In this Letter, we present the measurement of ratios of acceleration of the witness bunch to deceleration of the driver bunch, the so-called transformer ratio, significantly exceeding the fundamental theoretical and thus far experimental limit of 2 in a PWFA. An electron bunch with ramped current profile was utilized to accelerate a witness bunch with a transformer ratio of 4.6_{-0.7}^{+2.2} in a plasma with length ∼10 cm, also demonstrating stable transport of driver bunches with lengths on the order of the plasma wavelength.

Drug-coated balloons for de novo lesions in small coronary arteries: rationale and design of BASKET-SMALL 2.

The treatment of coronary small vessel disease (SVD) remains an unresolved issue. Drug-eluting stents (DES) have limited efficacy due to increased rates of instent-restenosis, mainly caused by late lumen loss. Drug-coated balloons (DCB) are a promising technique because native vessels remain structurally unchanged. Basel Stent Kosten-Effektivitäts Trial: Drug-Coated Balloons vs. Drug-Eluting Stents in Small Vessel Interventions (BASKET-SMALL 2) is a multicenter, randomized, controlled, noninferiority trial of DCB vs DES in native SVD for clinical endpoints. Seven hundred fifty-eight patients with de novo lesions in vessels <3 mm in diameter and an indication for percutaneous coronary intervention such as stable angina pectoris, silent ischemia, or acute coronary syndromes are randomized 1:1 to angioplasty with DCB vs implantation of a DES after successful initial balloon angioplasty. The primary endpoint is the combination of cardiac death, nonfatal myocardial infarction, and target-vessel revascularization up to 1 year. Secondary endpoints include stent thrombosis, Bleeding Academic Research Consortium (BARC) type 3 to 5 bleeding, and long-term outcome up to 3 years. Based on clinical endpoints after 1 year, we plan to assess the noninferiority of DCB compared to DES in patients undergoing primary percutaneous coronary intervention for SVD. Results will be available in the second half of 2018. This study will compare DCB and DES regarding long-term safety and efficacy for the treatment of SVD in a large all-comer population.

Conventional versus 3-D Echocardiography to Predict Arrhythmia Recurrence After Atrial Fibrillation Ablation.

BACKGROUND: Arrhythmia recurrence after atrial fibrillation (AF) ablation remains high and requires repeat interventions in a substantial number of patients. We assessed the value of conventional and 3-D echocardiography to predict AF recurrence. METHODS AND RESULTS: Consecutive patients undergoing AF ablation by means of pulmonary vein isolation were included in a prospective registry. Echocardiograms were obtained prior to the ablation procedure, and analyzed offline in a standardized manner, including 3-D left atrial (LA) volumetry and determination of LA function and sphericity. The primary endpoint, AF recurrence (>30 seconds) between 3 to 12 months after AF ablation, was independently adjudicated. We included 276 patients (73% male, mean age 59.9 ± 9.9 years). Paroxysmal and persistent AF were present in 178 (64%) and 98 (36%) patients, respectively. Mean left ventricular ejection fraction and indexed LA volume in 3-D (LAVI) were 52 ± 12% and 42 ± 13 mL/m2 , respectively. AF recurrence was observed in 110 (40%) patients after a single procedure. Median (interquartile range) time to AF recurrence was 123 (92; 236) days. In multivariable Cox regression models, the only predictors for AF recurrence were the minimal, maximal, and indexed 3-D LA volumes, P = 0.024, P = 0.016, and P = 0.014, respectively. Quartile specific analysis of 3-D LAVI showed an HR of 1.885 (95%CI 1.066-3.334; P for trend = 0.015) for the highest compared to the lowest quartile. CONCLUSION: Our results show the important role of LA volume for the long-term freedom from arrhythmia after AF ablation. These data also highlight the potential of 3-D echocardiography in this context and may facilitate patient selection for AF ablation.

Determinants of Left Atrial Volume in Patients with Atrial Fibrillation.

INTRODUCTION: Left atrial (LA) enlargement is an important risk factor for incident stroke and a key determinant for the success of rhythm control strategies in patients with atrial fibrillation (AF). However, factors associated with LA volume in AF patients remain poorly understood. METHODS: Patients with paroxysmal or persistent AF were enrolled in this study. Real time 3-D echocardiography was performed in all participants and analyzed offline in a standardized manner. We performed stepwise backward linear regression analyses using a broad set of clinical parameters to determine independent correlates for 3-D LA volume. RESULTS: We included 210 patients (70.9% male, mean age 61±11years). Paroxysmal and persistent AF were present in 95 (45%) and 115 (55%) patients, respectively. Overall, 115 (55%) had hypertension, 11 (5%) had diabetes, and 18 (9%) had ischemic heart disease. Mean indexed LA volume was 36±12ml/m2. In multivariable models, significant associations were found for female sex (ß coefficient -10.51 (95% confidence interval (CI) -17.85;-3.16), p = 0.0053), undergoing cardioversion (ß 11.95 (CI 5.15; 18.74), p = 0.0006), diabetes (ß 14.23 (CI 2.36; 26.10), p = 0.019), body surface area (BSA) (ß 34.21 (CI 19.30; 49.12), p<0.0001), glomerular filtration rate (ß -0.21 (CI -0.36; -0.06), p = 0.0064) and plasma levels of NT-pro brain natriuretic peptide (NT-proBNP) (ß 6.79 (CI 4.05; 9.52), p<0.0001), but not age (p = 0.59) or hypertension (p = 0.42). Our final model explained 52% of the LA volume variability. CONCLUSIONS: In patients with AF, the most important correlates with LA volume are sex, BSA, diabetes, renal function and NT-proBNP, but not age or hypertension. These results may help to refine rhythm control strategies in AF patients.

Outcomes of electrical injuries in the emergency department: a 10-year retrospective study.

OBJECTIVE: Electrical injuries are challenging to assess and current guidelines are based on few studies and case reports. Recommendations on cardiac monitoring were published for certain risk factors, but indications for hospital observation are less clear. Furthermore, the risk of late arrhythmias is not known. Therefore, we aimed to assess possible cardiac complications, including death and immediate or delayed dysrhythmia, after an electrical accident in a sample of patients presenting to the Emergency Department (ED). METHODS: Medical records of patients presenting to the ED of the University Hospital Basel, Switzerland, during 2004-2013 were retrospectively reviewed. Follow-up in terms of the survival of these patients was performed through hospital databases, and direct contact with patients and caregivers. The primary endpoint was in hospital mortality and mortality within 10, 30, and 90 days, respectively. For our secondary endpoint, we investigated patient charts for the occurrence of dysrhythmias and laboratory findings. RESULTS: During the study period, a total of 240 patients were identified. Twelve patients were lost to follow-up. Initial ECG was performed in 234 (97.5%) patients and 149 (62.1%) patients received cardiac monitoring. During the time of monitoring, four dysrhythmias (sinus bradycardia, two ventricular premature beats, and atrial fibrillation) were observed. All patients survived, and no potential late serious dysrhythmia requiring a medical intervention was recorded. CONCLUSION: No cardiac complications occurred during ED stay or during the 90-day follow-up period. Therefore, the need for continued cardiac monitoring after electrical injury is not supported by our data.

Undertriage in older emergency department patients--tilting against windmills?

OBJECTIVES: The aim of this study was to investigate the long-term effect of a teaching intervention designed to reduce undertriage rates in older ED patients. Further, to test the hypothesis that non-adherence to the Emergency Severity Index (ESI) triage algorithm is associated with undertriage. Additionally, to detect patient related risk factors for undertriage. METHODS: Pre-post-test design. The study sample consisted of all patients aged 65 years or older presenting to the ED of an urban tertiary and primary care center in the study periods. A teaching intervention designed to increase adherence to the triage algorithm. To assess, if the intervention resulted in an increase of factual knowledge, nurses took a test before and immediately after the teaching intervention. Undertriage rates were assessed one year after the intervention and compared to the pre-test period. RESULTS: In the pre-test group 519 patients were included, and 394 in the post-test-group. Factual knowledge among triage nurses was high already before the teaching intervention. Prevalence of undertriaged patients before (22.5%) and one year after the intervention (24.2%) was not significantly different (χ2 = 0.248, df = 1, p = 0.619). Sex, age, mode of arrival, and type of complaint were not identified as independent risk factors for undertriage. However, undertriage rates increased with advancing age. Adherence to the ESI algorithm is associated with correct triage decisions. CONCLUSIONS: Undertriage of older ED patients remained unchanged over time. Reasons for undertriage seem to be more complex than anticipated. Therefore, additional contributing factors should be addressed.

Head-to-head comparison of two-dimensional and three-dimensional echocardiographic methods for left atrial chamber quantification with magnetic resonance imaging.

BACKGROUND: Limited data are available on the accuracy of quantification methods for left atrial (LA) volumes using two-dimensional (2D) and particularly real-time three-dimensional echocardiographic (RT3DE) methods in comparison with a reference standard. The aim of this study was to perform a head-to-head comparison between 2D and RT3DE methods with magnetic resonance imaging (MRI) as the reference standard. METHODS: LA volumes derived from 2D echocardiographic methods (i.e., biplane modified Simpson's, biplane area-length, and prolate ellipse methods) and from RT3DE methods (i.e., 4D LA Analysis and QLAB) in 60 consecutive patients were compared with MRI measurements. Offline analysis time was recorded. RESULTS: The biplane modified Simpson's and area-length methods showed good intraclass correlations with MRI for maximum (r = 0.70 and r = 0.69, P < .001) and minimum (r = 0.83 and r = 0.82, P < .001) volumes. Although RT3DE methods led to moderate increases in correlations for maximum (r = 0.94 and 0.70, P < .001) and minimum (r = 0.95 and r = 0.90, P < .001) volumes and narrower Bland-Altman limits of agreement than 2D echocardiographic methods, offline analysis time was higher for RT3DE (155-161 vs 103-144 sec). Compared with MRI, maximum and minimum LA volumes were underestimated by -4.7% and -8.9%, respectively, using 4D LA Analysis, by -15.7% and -14.9% using QLAB, by -12.3% and -4.4% using the biplane Simpson's method, by -13.7% and -6.8% using the area-length method, and by -48.2% and -50.5% using the prolate ellipse method. CONCLUSIONS: The biplane Simpson's and area-length methods offer reasonable accuracy for LA chamber quantification across a broad range of volumes, while RT3DE methods lead to a moderate improvement in accuracy at the cost of more elaborate offline analysis.

Pain in the emergency department: adherence to an implemented treatment protocol.

OBJECTIVES: Although pain is one of the most common presenting complaints in the Emergency Department (ED), pain management is often inadequate. Pain management protocols have been shown to be useful. The objective of this study was to assess the adherence to an already implemented pain management protocol in an urban ED. METHODS: Secondary analysis of a prospective single centre cohort study on patient preferences for analgesia in the ED. Patient charts were reviewed with a focus on selection, timing and dosage of analgesics according to a visual analogue scale (VAS) on arrival and during the ED stay. RESULTS: Three hundred and thirty-seven patient charts were reviewed. The adherence to the implemented pain management protocol was 42% at the time of initial evaluation and 43% during the course of therapy in all patients. Forty-two percent of the study population were discharged with at least moderate pain. However, 43% of the patients discharged with pain did not request analgesics. CONCLUSIONS: The benefits of pain management protocols are proven. However, adherence to these protocols needs to be monitored regularly in order to optimise pain management.