Investigation of hemodynamics in an in vitro system simulating left ventricular support through the right subclavian artery using 4-dimensional flow magnetic resonance imaging.

OBJECTIVES Left ventricular assist devices are an important treatment option for patients with heart failure alter the hemodynamics in the heart and great vessels. Because in vivo magnetic resonance studies of patients with ventricular assist devices are not possible, in vitro models represent an important tool to investigate flow alterations caused by these systems. By using an in vitro magnetic resonance-compatible model that mimics physiologic conditions as close as possible, this work investigated the flow characteristics using 4-dimensional flow-sensitive magnetic resonance imaging of a left ventricular assist device with outflow via the right subclavian artery as commonly used in cardiothoracic surgery in the recent past. METHODS An in vitro model was developed consisting of an aorta with its supra-aortic branches connected to a left ventricular assist device simulating the pulsatile flow of the native failing heart. A second left ventricular assist device supplied the aorta with continuous flow via the right subclavian artery. Four-dimensional flow-sensitive magnetic resonance imaging was performed for different flow rates of the left ventricular assist device simulating the native heart and the left ventricular assist device providing the continuous flow. Flow characteristics were qualitatively and quantitatively evaluated in the entire vessel system. RESULTS Flow characteristics inside the aorta and its upper branching vessels revealed that the right subclavian artery and the right carotid artery were solely supported by the continuous-flow left ventricular assist device for all flow rates. The flow rates in the brain-supplying arteries are only marginally affected by different operating conditions. The qualitative analysis revealed only minor effects on the flow characteristics, such as weakly pronounced vortex flow caused by the retrograde flow via the brachiocephalic artery. CONCLUSIONS The results indicate that, despite the massive alterations in natural hemodynamics due to the retrograde flow via the right subclavian and brachiocephalic arteries, there are no drastic consequences on the flow in the brain-feeding arteries and the flow characteristics in the ascending and descending aortas. It may be beneficial to adjust the operating condition of the left ventricular assist device to the residual function of the failing heart.

Young medical educators' workshop: Finding the right mentor in Medical Education

Background: Finding the right mentor in medical education is challenging, especially if you are relatively new to the field. However, a mentor that is fit for purpose offers great potential. The workshop will explore strategies and pitfalls for successfully finding the best available mentor. Intended Outcomes: At the end of the workshop participants will be able to: (1) identify practical strategies for successfully finding the right mentor in medical education; (2) give feedback on a proposed idea of a platform for matching mentees and mentors within AMEE; (3) establish an electronic network for continued dialogue and support within the online platform of AMEE (MedEdWorld). Structure: After an introduction to mentorship in medical education and characteristics of effective mentors, participants will have the opportunity to develop their own concepts and questions and discuss them with other participants and facilitators. Senior mentors will give advice from their experience. Furthermore, a proposal of an online platform to help young medical educators find a mentor will be presented and discussed. Who Should Attend: Young medical educators interested in finding the right mentor and in exchanging ideas with colleagues in a similar situation. Level: Introductory

Myelination of the right parahippocampal cingulum is associated with physical activity in young healthy adults.

Recent evidence suggests that individual differences in physical activity (PA) may be associated with individual differences in white matter microstructure and with grey matter volume of the hippocampus. Therefore, this study investigated the association between PA and white matter microstructure of pathways connecting to the hippocampus. A total of 33 young, healthy adults underwent magnetic resonance imaging (MRI). High angular resolution diffusion-weighted imaging and multi-component relaxometry MRI scans (multi-component driven equilibrium pulse observation of T1 and T2) were acquired for each participant. Activity levels (AL) of participants were calculated from 72-h actigraphy recordings. Tractography using the damped Richardson Lucy algorithm was used to reconstruct the fornix and bilateral parahippocampal cinguli (PHC). The mean fractional anisotropy (FA) and the myelin water fraction (MWF), a putative marker of myelination, were determined for each pathway. A positive correlation between both AL and FA and between AL and MWF were hypothesized for the three pathways. There was a selective positive correlation between AL and MWF in the right PHC (r = 0.482, p = 0.007). Thus, our results provide initial in vivo evidence for an association between myelination of the right PHC and PA in young healthy adults. Our results suggest that MWF may not only be more specific, but also more sensitive than FA to detect white matter microstructural alterations. If PA was to induce structural plasticity of the right PHC this may contribute to reverse structural alterations of the right PHC in neuropsychiatric disorder with hippocampal pathologies.

The 2015 Swiss elections: A landslide win for the right, despite limited changes in vote share

Switzerland held federal elections on 18 October, with the conservative Swiss People’s Party winning the largest share of the votes. Daniel Bochsler, Marlène Gerber and David Zumbach write that while the increase in vote share for the Swiss People’s Party was relatively limited, the party managed to significantly increase the number of seats it holds in Switzerland’s lower house of parliament, the National Council. Nevertheless, the party is unlikely to make substantial gains in the country’s upper house, the Senate, as it traditionally struggles under the two-round electoral system used in Senate elections.