0034: Preexcitation syndrome and atrioventricular nodal reentrant tachycardia: coincidence or not?

BackgroundReciprocating tachycardia which occurs in patients with a preexcitation syndrome (PS) generally is directly related to the presence of the accessory pathway (AP) and is called atrioventricular re-entrant tachycardia (AVRT). The purpose of the study was to evaluate the incidence of re-entrant tachycardia of other nature among patients with a PS.Methods785 patients with paroxysmal tachycardia were admitted AP ablation, 294 patients with a concealed AP (group I) and 491 patients with a Wolff-Parkinson-White syndrome (WPW) (group II). Programmed atrial stimulation was performed in the control state and if necessary after isoproterenol to induce the clinical tachycardia and determine its mechanism.ResultsAVRT was induced in 760 patients (97%), 282 of group I (96%)and 478 of group II (97%) (NS). Atrioventricular nodal re-entrant tachycardia (AVNRT) was induced in 13 group I patients (4.6%) and 12 group II patients(2.5%) (NS; 0.11). In 9 group I patients (3%) and in 4 group II patients (1%) (p<0.015), both AVRT and AVNRT were induced. In patients with only induced AVNRT, slow pathway ablation was performed and accessory pathway was respected because there was no inducible tachycardia using AP and the conduction over AP was poor. These patients remained free of symptoms after ablation of AV node slow pathway. Among this population 3 families were identified as having either AVRT or AVNRT.ConclusionsIn patients with concealed or patent accessory pathway and complaining of paroxysmal tachycardia, a careful evaluation of the mechanism of tachycardia is required before ablation. Patients with concealed conduction over an AP have more frequently an association of AVRT and AVNRT than patients with a patent preexcitation syndrome. Rarely AVNRT can be the only mechanism of symptoms

Surface water dissolved aluminum and titanium: Tracers for specific time scales of dust deposition to the Atlantic?

Surface water distributions of dissolved Al (dAl) and dissolved Ti (dTi) were investigated along a meridional Atlantic transect and related to dust deposition estimates. In the zone of Saharan dust deposition, highest dAl concentrations occurred in the tropical salinity minimum and suggest increasing Al dissolution from Saharan aerosols with wet deposition. By contrast, the dTi distribution is not related to precipitation but agrees with the pattern of annual dust deposition. In the zone of Patagonian dust deposition, elevated dTi concentrations contrasted with decreased dAl concentrations, indicating excess dAl scavenging onto biogenic particles in surface waters. Estimated residence times range from months to years for dAl and are ∼10 times higher for dTi. This suggests that dAl reflects seasonal changes in dust deposition, while dTi is related to longer temporal scales. However, spatial variations in input and removal processes complicate the quantification of dust deposition from surface water concentrations

Impact of cardiac resynchronization therapy optimization inside a heart failure programme : a real‐world experience

Aims: This study sought to describe and evaluate the impact of a routine in‐hospital cardiac resynchronization therapy (CRT) programme, including comprehensive heart failure (HF) evaluation and systematic echo‐guided CRT optimization. Methods and results: CRT implanted patients were referred for optimization programme at 3 to 12 months from implantation. The program included clinical and biological status, standardized screening for potential cause of CRT non‐response and systematic echo‐guided atrioventricular and interventricular delays (AVd and VVd) optimization. Initial CRT‐response and improvement at 6 months post‐optimization were assessed with a clinical composite score (CCS). Major HF events were tracked during 1 year after optimization. A total of 227 patients were referred for CRT optimization and enrolled (71 ± 11 years old, 77% male, LVEF 30.6 ± 7.9%), of whom 111 (48.9%) were classified as initial non‐responders. Left ventricular lead dislodgement was noted in 4 patients (1.8%), and loss or ≤90% biventricular capture in 22 (9.7%), mostly due to arrhythmias. Of the 196 patients (86%) who could undergo echo‐guided CRT optimization, 71 (36.2%) required VVd modification and 50/144 (34.7%) AVd modification. At 6 months post‐optimization, 34.3% of the initial non‐responders were improved according to the CCS, but neither AVd nor VVd echo‐guided modification was significantly associated with CCS‐improvement. After one‐year follow‐up, initial non‐responders maintained a higher rate of major HF events than initial responders, with no significant difference between AVd/VVd modified or not. Conclusions: Our study supports the necessity of a close, comprehensive and multidisciplinary follow‐up of CRT patients, without arguing for routine use of echo‐guided CRT optimization

The MAORY laser guide star wavefront sensor: design status

MAORY will be the multi-adaptive optics module feeding the high resolution camera and spectrograph MICADO at the Extremely Large Telescope (ELT) first light. In order to ensure high and homogeneous image quality over the MICADO field of view and high sky coverage, the baseline is to operate wavefront sensing using six Sodium Laser Guide Stars. The Laser Guide Star Wavefront Sensor (LGS WFS) is the MAORY sub-system devoted to real-time measurement of the high order wavefront distortions. In this paper we describe the MAORY LGS WFS current design, including opto-mechanics, trade-offs and possible future improvements

Multiple star systems in the Orion nebula

This is the author accepted manuscript. The final fersion is available from EDP Sciences via the DOI in this record.This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for θ1 Ori B, θ2 Ori B, and θ2 Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for θ1 Ori A, θ1 Ori C, θ1 Ori D, and θ2 Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary θ1 Ori C and we are able to derive a new orbit for θ1 Ori D. We find a system mass of 21.7 M⊙ and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.Marie Skłodowska-Curie Grant AgreementFCT-PortugalERC Starting Gran

MAORY for ELT: preliminary design overview

MAORY is one of the approved instruments for the European Extremely Large Telescope. It is an adaptive optics module, enabling high-angular resolution observations in the near infrared by real-time compensation of the wavefront distortions due to atmospheric turbulence and other disturbances such as wind action on the telescope. An overview of the instrument design is given in this paper

The MAORY first-light adaptive optics module for E-ELT

The MAORY adaptive optics module is part of the first light instrumentation suite for the E-ELT. The MAORY project phase B is going to start soon. This paper contains a system-level overview of the current instrument design

Amplitude adaptive optics with a digital micro-mirror device for exoplanet high-contrast imaging

International audienceAmplitude adaptive optics with a digital micro-mirror device for exoplanet high-contrast imagin