Prognostic role of subsequent atrial tachycardias occurring during ablation of persistent atrial fibrillation: a prospective randomized trial

BACKGROUND The role of subsequent atrial tachycardias (AT) in the context of persistent atrial fibrillation (AF) remains undetermined. This study evaluated the prognostic role of subsequent ATs for arrhythmia recurrences after catheter ablation of persistent AF. METHODS AND RESULTS A total of 110 patients with persistent AF (63±9 years; 22 women; 61 long-lasting persistent AF) underwent pulmonary vein isolation followed by electrogram-guided ablation. After AF terminated to AT, patients were separated by the randomization protocol to receive either direct cardioversion (group A) or further ablation of subsequent ATs to sinus rhythm (group B). After a mean follow-up of 20.1±13.3 months after the first procedure, significantly more group B patients were in sinus rhythm as compared with patients in group A (30 [57%] versus 18 [34%]; P=0.02). Moreover, recurrences of AF were significantly less frequent of group B than in group A patients (10 [19%] versus 26 [49%]; P=0.001). After the last procedure (follow-up, 34.0±6.4 months), significantly more group B patients were free of AF as compared with patients of group A (49 [92%] versus 39 [74%]; P=0.01). The proportion of AT recurrences did not differ between the 2 groups after the first and final procedures. The strongest predictor for an arrhythmia-free survival after a single procedure was randomization to the procedural end point of termination to sinus rhythm by elimination of subsequent ATs (P=0.004). CONCLUSIONS Catheter ablation of subsequent ATs increases freedom from AF but not AT, suggesting a contributing role of subsequent ATs in the mechanisms of persistent AF. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01896570.

Feasibility of Using EMG for Early Detection of the Facial Nerve During Robotic Direct Cochlear Access

HYPOTHESIS Facial nerve monitoring can be used synchronous with a high-precision robotic tool as a functional warning to prevent of a collision of the drill bit with the facial nerve during direct cochlear access (DCA). BACKGROUND Minimally invasive direct cochlear access (DCA) aims to eliminate the need for a mastoidectomy by drilling a small tunnel through the facial recess to the cochlea with the aid of stereotactic tool guidance. Because the procedure is performed in a blind manner, structures such as the facial nerve are at risk. Neuromonitoring is a commonly used tool to help surgeons identify the facial nerve (FN) during routine surgical procedures in the mastoid. Recently, neuromonitoring technology was integrated into a commercially available drill system enabling real-time monitoring of the FN. The objective of this study was to determine if this drilling system could be used to warn of an impending collision with the FN during robot-assisted DCA. MATERIALS AND METHODS The sheep was chosen as a suitable model for this study because of its similarity to the human ear anatomy. The same surgical workflow applicable to human patients was performed in the animal model. Bone screws, serving as reference fiducials, were placed in the skull near the ear canal. The sheep head was imaged using a computed tomographic scanner and segmentation of FN, mastoid, and other relevant structures as well as planning of drilling trajectories was carried out using a dedicated software tool. During the actual procedure, a surgical drill system was connected to a nerve monitor and guided by a custom built robot system. As the planned trajectories were drilled, stimulation and EMG response signals were recorded. A postoperative analysis was achieved after each surgery to determine the actual drilled positions. RESULTS Using the calibrated pose synchronized with the EMG signals, the precise relationship between distance to FN and EMG with 3 different stimulation intensities could be determined for 11 different tunnels drilled in 3 different subjects. CONCLUSION From the results, it was determined that the current implementation of the neuromonitoring system lacks sensitivity and repeatability necessary to be used as a warning device in robotic DCA. We hypothesize that this is primarily because of the stimulation pattern achieved using a noninsulated drill as a stimulating probe. Further work is necessary to determine whether specific changes to the design can improve the sensitivity and specificity.

Hyaluronic Acid Levels Predict Risk of Hepatic Encephalopathy and Liver-Related Death in HIV/Viral Hepatitis Coinfected Patients

Background Whereas it is well established that various soluble biomarkers can predict level of liver fibrosis, their ability to predict liver-related clinical outcomes is less clearly established, in particular among HIV/viral hepatitis co-infected persons. We investigated plasma hyaluronic acid’s (HA) ability to predict risk of liver-related events (LRE; hepatic coma or liver-related death) in the EuroSIDA study. Methods Patients included were positive for anti-HCV and/or HBsAg with at least one available plasma sample. The earliest collected plasma sample was tested for HA (normal range 0–75 ng/mL) and levels were associated with risk of LRE. Change in HA per year of follow-up was estimated after measuring HA levels in latest sample before the LRE for those experiencing this outcome (cases) and in a random selection of one sixth of the remaining patients (controls). Results During a median of 8.2 years of follow-up, 84/1252 (6.7%) patients developed a LRE. Baseline median (IQR) HA in those without and with a LRE was 31.8 (17.2–62.6) and 221.6 ng/mL (74.9–611.3), respectively (p<0.0001). After adjustment, HA levels predicted risk of contracting a LRE; incidence rate ratios for HA levels 75–250 or ≥250 vs. <75 ng/mL were 5.22 (95% CI 2.86–9.26, p<0.0007) and 28.22 (95% CI 14.95–46.00, p<0.0001), respectively. Median HA levels increased substantially prior to developing a LRE (107.6 ng/mL, IQR 0.8 to 251.1), but remained stable for controls (1.0 ng/mL, IQR –5.1 to 8.2), (p<0.0001 comparing cases and controls), and greater increases predicted risk of a LRE in adjusted models (p<0.001). Conclusions An elevated level of plasma HA, particularly if the level further increases over time, substantially increases the risk of contracting LRE over the next five years. HA is an inexpensive, standardized and non-invasive supplement to other methods aimed at identifying HIV/viral hepatitis co-infected patients at risk of hepatic complications.

Die Entwicklung und Implementierung einer neuen staatlichen Schlussprüfung Humanmedizin am Beispiel Schweiz – Ergebnisse und Daten zur Prüfungsqualität der ersten 2 Kohorten sowie Überlegungen zur Qualitätssicherung und zur Weiterentwicklung der Prüfung

Hintergrund: Im Rahmen des neuen nationalen Medizinalberufegesetzes [http://www.admin.ch/ch/d/as/2007/4031.pdf], [http://www.bag.admin.ch/themen/berufe/07918/07919/index.html], der Entwicklung hin zu Kompetenz-basierten Curricula [1] und der Einführung der Bologna-Reform in den medizinischen Studiengängen [2] wurde in der Schweiz eine neue eidgenössische Schlussprüfung Humanmedizin unter Aufsicht des Bundes und in Zusammenarbeit mit den medizinischen Fakultäten in zwei Sprachen (D/F) entwickelt und 2011 erstmals durchgeführt. Projektbeschreibung: Im vorliegenden Beitrag werden die Rahmenbedingungen für die Implementierung aufgezeigt und die Entwicklung der Gesamtprüfung als Pass/Fail-Prüfung einschliesslich ihrer 2 Einzelprüfungen beschrieben. Die 1. Einzelprüfung besteht aus einer schriftlichen Prüfung (MCQ) an 2 Prüfungstagen zu je 4.5 h mit je 150 interdisziplinären, taxonomisch auf Anwendungswissen ausgerichteten Fragen. Die 2. Einzelprüfung umfasst eine strukturierte, klinisch-praktische CS-Prüfung (OSCE) mit insgesamt 12 Rotationsposten über je 13 min Dauer und je 2 min Rotationszeit zwischen den Posten. Zur Qualitätssicherung wurden zahlreiche Massnahmen ergriffen wie z.B. die Schulung der standardisierten Patienten anhand zentraler Standardisierungsvorlagen. Der Gesamtblueprint ist abgestimmt auf den Schweizer Lernzielkatalog Humanmedizin [http://sclo.smifk.ch] und beinhaltet die 2 Hauptdimensionen „General Objectives/CanMed Roles“ und „Problems as Starting Points“. Ergebnisse: Die Prüfung wurde an allen 5 Standorten 2011 und 2012 erfolgreich durchgeführt. Die Prüfungsresultate der ersten 2 Kohorten differenziert nach Gesamtprüfung und Einzelprüfungen zeigen in etwa die erwarteten Werte hinsichtlich der Bestehensquote. Die Metadaten zur Prüfungsqualität zeigen für beide Jahre, dass die angestrebte Messzuverlässigkeit der Prüfung mit einem Cronbach Alpha als Mass für die Reliabilität von im Mittel α=0.9 für die MCQ Einzelprüfung und von im Mittel α>0.8 für die CS-Einzelprüfung erreicht wurde. Diskussion und Schlussfolgerungen: Basierend auf den Erfahrungen und Daten der ersten 2 Prüfungskohorten kann gesagt werden, dass die Implementierung einer neuen nationalen Prüfung, die neben der neu ausgerichteten MCQ-Einzelprüfung erstmals mit einem strukturierten, objektivierbaren und national standardisierten Instrument klinische Fähigkeiten und Fertigkeiten misst, grundsätzlich gelungen ist. In diesem Kontext muss die Relevanz der intensiven Koordination und Abstimmung von der Gesetzgebung und den Verordnungsvorgaben bis hin zum Lernzielkatalog und dem korrespondierenden Gesamtblueprint der Prüfung hervorgehoben werden. Bezüglich der zukünftigen Entwicklung werden Aspekte der Qualitätssicherung und der Weiterentwicklung der Gesamtprüfung auch im Sinne von ergänzenden Prüfungsformaten diskutiert werden.

Space-qualified laser system for the BepiColombo Laser Altimeter

The space-qualified design of a miniaturized laser for pulsed operation at a wavelength of 1064 nm and at repetition rates up to 10 Hz is presented. This laser consists of a pair of diode-laser pumped, actively q-switched Nd:YAG rod oscillators hermetically sealed and encapsulated in an environment of dry synthetic air. The system delivers at least 300 million laser pulses with 50 mJ energy and 5 ns pulse width (FWHM). It will be launched in 2017 aboard European Space Agency’s Mercury Planetary Orbiter as part of the BepiColombo Laser Altimeter, which, after a 6-years cruise, will start recording topographic data from orbital altitudes between 400 and 1500 km above Mercury’s surface.

The new licencing examination for human medicine: from concept to implementation

A new Swiss federal licencing examination for human medicine (FLE) was developed and released in 2011. This paper describes the process from concept design to the first results obtained on implementation of the new examination. The development process was based on the Federal Act on University Medical Professions and involved all national stakeholders in this venture. During this process questions relating to the assessment aims, the assessment formats, the assessment dimensions, the examination content and necessary trade-offs were clarified. The aims were to create a feasible, fair, valid and psychometrically sound examination in accordance with international standards, thereby indicating the expected knowledge and skills level at the end of undergraduate medical education. Finally, a centrally managed and locally administered examination comprising a written multiple-choice element and a practical “clinical skills” test in the objective structured clinical examination (OSCE) format was developed. The first two administrations of the new FLE show that the examination concept could be implemented as intended. The anticipated psychometric indices were achieved and the results support the validity of the examination. Possible changes to the format or content in the future are discussed.

Simulation aus Fleisch und Blut: Schauspielpatienten

Der Begriff der Simulation wird manchmal vorschnell auf technische Simulatoren reduziert, welche mehr oder weniger aufwändig Anatomien oder bestimmte Szenarien des klinischen Alltages wiedergeben. In dem folgenden Kapitel soll nun der Begriff Simulation auch auf die sogenannten Simulationspatienten ausgeweitet und entsprechende Konzepte vorgestellt werde

Simulator Network project report: a tool for improvement of teaching materials and targeted resource usage in Skills Labs

During the last decade, medical education in the German-speaking world has been striving to become more practice-oriented. This is currently being achieved in many schools through the implementation of simulation-based instruction in Skills Labs. Simulators are thus an essential part of this type of medical training, and their acquisition and operation by a Skills Lab require a large outlay of resources. Therefore, the Practical Skills Committee of the Medical Education Society (GMA) introduced a new project, which aims to improve the flow of information between the Skills Labs and enable a transparent assessment of the simulators via an online database (the Simulator Network).