Background We investigated the impact of an elevated plasma volume status (PVS) in patients undergoing TAVI on early clinical safety and mortality and assessed the prognostic utility of PVS for outcome prediction. Materials and methods We retrospectively calculated the PVS in 652 patients undergoing TAVI between 2009 and 2018 at two centres. They were then categorized into two groups depending on their preoperative PVS (PVS ≤−4; n = 257 vs PVS>−4; n = 379). Relative PVS was derived by subtracting calculated ideal (iPVS = c × weight) from actual plasma volume (aPVS = (1 − haematocrit) × (a + (b × weight in kg)). Results The need for renal replacement therapy (1 (0.4%) vs 17 (4.5%); P = .001), re‐operation for noncardiac reasons (9 (3.5%) vs 32 (8.4%); P = .003), re‐operation for bleeding (9 (3.5%) vs 27 (7.1%); P = .037) and major bleeding (14 (5.4%) vs 37 (9.8%); P = .033) were significantly higher in patients with a PVS>−4. The composite 30‐day early safety endpoint (234 (91.1%) vs 314 (82.8%); P = .002) confirms that an increased preoperative PVS is associated with a worse overall outcome after TAVI. Conclusions An elevated PVS (>−4) as a marker for congestion is associated with significantly worse outcome after TAVI and therefore should be incorporated in preprocedural risk stratification.

Aim of the study Bystander-initiated basic life support (BLS) for the treatment of prehospital cardiac arrest increases survival but is frequently not performed due to fear and a lack of knowledge. A simple flowchart can improve motivation and the quality of performance. Furthermore, guidelines do recommend a chest compression (CC)-only algorithm for dispatcher-assisted bystander resuscitation, which may lead to increased fatigue and a loss of compression depth. Consequently, we wanted to test the hypothesis that CCs are more correctly delivered in a flowchart-assisted standard resuscitation algorithm than in a CC-only algorithm. Methods With the use of a manikin model, 84 laypersons were randomized to perform either flowchart-assisted standard resuscitation or CC-only resuscitation for 5min. The primary outcome was the total number of CCs. Results The total number of correct CCs did not significantly differ between the CC-only group and the standard group (63 [±81] vs. 79 [±86]; p = 0.394; 95% CI of difference: 21-53). The total hand-off time was significantly lower in the CC-only group than in the standard BLS group. The relative number of correct CCs (the fraction of the total number of CCs achieving 5-6cm) and the level of exhaustion after BLS did not significantly differ between the groups.

<p>GNSS antennas are a key factor in precise GNSS positioning. With the increasing availability of low-cost dual-frequency GNSS receivers also the demands on low-cost GNSS antennas increases. Unfortunately, the electronic center of most GNSS antennas is not located in the mechanical Antenna Reference Point (ARP). As a consequence, Phase Center Corrections (PCC) have to be introduced to correct for frequency-dependent signal delays within the antenna system. The PCCs are typically in the range of several millimeters to centimeters. Thus, uncorrected phase center variations can be a significant error source in precise positioning.</p><p>For the purpose of antenna calibration, the Institute of Geodesy and Photogrammetry at ETH Zürich acquired a six-axis industrial robot of type KUKA AGILUS KR 6 R900 sixx. In an initial study, the absolute accuracy of the robot has been determined to be better than 1.5 mm (standard deviation). By introducing a set of extended Denavit-Hartenberg parameters, the absolute position accuracy of the robot is further increased to 0.3 mm over the entire workspace and 0.1 mm for a predefined sequence of robot poses, respectively. Therefore, the robot operates well below the phase noise of the GNSS measurements (typically around 1 mm) and is therefore seen as suitable for the calibration of GNSS antennas with sub-millimeter accuracy.</p><p>Besides the numerous benefits of absolute field calibration with an industrial robot, several challenges remain if it comes to low-cost GNSS antennas. The main challenges are that for each antenna a specific mounting system has to be built and that low-cost antennas are in general less shielded against multipath (compared to geodetic antennas). Besides, only little information exists about the stability of the electronic reference point and how much the electronic properties change when the antenna is mounted on different platforms (cars, drones, cubesats, etc).</p><p>To address the critical issues in low-cost GNSS antenna calibration and study the impact of the PCCs on the positioning solution, a calibration campaign has been initiated at ETH Zürich in autumn 2020. In this campaign, a set of low-cost multi-GNSS dual-frequency patch and loop antennas - suited for centimeter-positioning - has been calibrated and tested. Therefore, in the vicinity of the GNSS reference station (ETH2) the robot has been installed and a sequence of randomized robot poses has been executed in which the ARP of each antenna was defined as rotation point. The GNSS signals recorded during this sequence were processed together with the robot attitude information using the time-differencing approach defined by D. Willi (2019) using a spherical harmonics parameterization.</p><p>The PCCs obtained from the calibration campaign were stored in ANTEX files for a subsequent validation. In this presentation, we will highlight the developed calibration procedures for low-cost GNSS antennas, summarize the main results of the calibration and validation campaign, and will give the framework in which a calibration of low-cost GNSS antennas is considered beneficial.</p><p>Willi D., GNSS receiver synchronization and antenna calibration, PhD Thesis, ETH Zürich, 2019, https://www.research-collection.ethz.ch/handle/20.500.11850/308750</p>

Introduction In 2020 the Austrian government has ordered two complete lockdowns and two lockdown lights to maintain control over the infection rate of Covid-19. Several studies have analysed the frequency and outcome of patients with acute coronary syndrome (ACS) during the pandemic. Some have described a decrease in the admission rate of patients with ST-elevated-myocardial-infarction (STEMI) and no-ST-elevated-myocardial-infarction (NSTEMI), with the reasons still being discussed. Purpose The aim of this study is to analyse possible differences in frequency, comorbidities and outcome of all STEMI and NSTEMI admissions over various lockdown (L) periods in Austria and to provide a possible explanation for the results. Methods Analysis of prospectively gathered data on ACS patients in our heart center in the year 2020. Patients were split into 4 groups: no lockdown (NL): n=136; duration (dur): 36 weeks (w); lockdown 1 (L1): n=24; dur: 7w; lockdown 2 (L2): n=16; dur: 2.5w; lockdown light (LL): n=22; dur: 5.5w. To account for the different durations, we divided patients by lockdown duration (n/w). End of a L was defined as re-opening of shops; in LL period schools and restaurants were closed but shops were open. To compare the different groups, age, sex, BMI, comorbidities, cardiovascular risk factors (CVRF) duration of preclinical-symptomatic phase (onset of chest pain to PCI), blood parameters, indication, vascular access (femoral/radial) and target vessel were recorded. As outcome we defined CPR, shock and in hospital death. Results Out of 198 patients 126 were male (63.6%) and 72 female (36.4%), with a mean age of 65±12 years. There were no statistically significant differences in age, BMI or CVRF between the 4 groups. A 50% higher number of diabetics in the LL group as compared to 25.3% in the NL group (p=0.005) was noticed. STEMI admissions from 2.2 patients/week (n/w) without L decreased to 1.4/w during L1. During L2, the frequency rate rose to 3.2/w in the LL group and admission rates to 2/w, which is almost as high as in the NL group. No differences in NSTEMI admissions between the NL (1.3/w), the L1 (1.4/w) and the LL group (1.8/w) were found. During L2 the frequency of NSTEMI patients increased to 3.2/w. We found a rise in in-hospital death rates from 4.4% without L to 9.1% during LL, though with boarder line statistical significance (p=0.05). Conclusion Compared to the NL group, our data show a decrease of STEMI and NSTEMI admissions during L1. This trend was not confirmed during L2, despite identical government's restrictions. We, thus, postulate that the decrease of ACS admissions in L1 was caused by patients' concern regarding in-hospital Covid-19 infection rather than by actual restrictions. Funding Acknowledgement Type of funding sources: None.