343 research outputs found
The Hot Horizontal-Branch Stars in NGC288 - Effects of Diffusion and Stratification on Their Atmospheric Parameters*
No full textContext. NGC288 is a globular cluster with a well developed blue horizontal branch covering the so-called u-jump which indicates the onset of diffusion. It is therefore well suited to study the effects of diffusion in blue horizontal branch (HB) stars. Aims. We compare observed abundances to predictions from stellar evolution models calculated with diffusion and from stratified atmospheric models. We verify the effect of using stratified model spectra to derive atmospheric parameters. In addition we investigate the nature of the overluminous blue HB stars around the u-jump. Methods. We define a new photometric index sz from uvby measurements that is gravity sensitive between 8 000K and 12 000 K. Using medium-resolution spectra and Stroemgren photometry we determine atmospheric parameters (Teff, logg) and abundances for the blue HB stars. We use both homogeneous and stratified model spectra for our spectroscopic analyses. Results. The atmospheric parameters and masses of the hot HB stars in NGC288 show a behaviour seen also in other clusters for temperatures between 9 000K and 14 000 K. Outside this temperature range, however, they follow rather the results found for such stars in (omega)Cen. The abundances derived from our observations are for most elements (except He and P) within the abundance range expected from evolutionary models that include the effects of atomic diffusion and assume a surface mixed mass of 10(exp 7) M. The abundances predicted by stratified model atmospheres are generally significantly more extreme than observed, except for Mg. The use of stratified model spectra to determine effective temperatures, surface gravities and masses moves the hotter stars to a closer agreement with canonical evolutionary predictions. Conclusions. Our results show definite promise towards solving the long-standing issue of surface gravity and mass discrepancies for hot HB stars, but there is still much work needed to arrive at a self-consistent solution
Cardiac electrophysiologist׳s perspective on minimally invasive surgery for atrial fibrillation
No full textMisleading Long Post-Pacing Interval After Entrainment of Typical Atrial Flutter From the Cavotricuspid Isthmus
No full textObjectivesThe purpose of this study was to evaluate the prevalence and mechanism of a misleading long post-pacing interval (PPI) upon entrainment of typical atrial flutter (AFL) from the cavotricuspid isthmus (CTI).BackgroundIn typical AFL, the PPI from entrainment at the CTI is expected to closely match the tachycardia cycle-length (TCL).MethodsSixty patients with confirmed CTI-dependent AFL were retrospectively analyzed and grouped into short (≤30 ms) or long (>30 ms) PPI-TCL. Thereafter, we prospectively studied 16 patients to acquire the PPI-TCL at 4 CTI sites with entrainment at pacing cycle-lengths (PCLs) 10 to 40 ms shorter than the TCL. Conduction times during AFL and entrainment were compared in 5 segments of the AFL circuit.ResultsEleven patients (18%) in the retrospective analysis had a long PPI-TCL after entrainment from the CTI. Subjects with long PPI-TCL had similar baseline characteristics but greater beat-to-beat TCL variability. In the prospective cohort, PPI-TCL was influenced by the difference between PCL and TCL and site of entrainment. Conduction delays associated with a long PPI-TCL were located predominantly in the segment activated first by the paced orthodromic wave front, and were mainly due to local pacing latency, as confirmed by the use of monophasic action potential catheters.ConclusionsA long PPI upon entrainment of typical AFL from the CTI is common and due to delayed conduction with entrainment. Whether these findings apply to other macro–re-entrant tachycardias warrants further investigation
The Recent Evolution of Retirement Patterns in Canada
No full textUsing data from three waves of the General Social Survey on retirement and older workers (1994, 2002 and 2007), we document the evolution of retirement patterns over the last three decades. We combined the analysis of retirement ages of actual retirees with data on expected retirement ages of current workers to create a longer perspective on changes in retirement behaviour in Canada. We also investigate trends in work after retirement. Our findings are in line with findings from other countries. There is an upward trend in retirement ages which likely started around year 2000 for cohorts born after 1945. This trend contrasts with the slow decline in retirement ages observed prior to the end of the millennium. While the downward trend was likely due to factors such as the offering of early retirement programs in private firms, the upward trend is likely to be caused by a wider variety of sources, including better health, less pervasive defined benefit pensions and in general less generous pensions.Retirement, aging, older workers, expectations
Pulmonary vein isolation in the treatment of atrial fibrillation
No full textSaurabh Kumar, Gregory F Michaud Cardiac Arrhythmia Service, Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA Abstract: Atrial fibrillation (AF) is the commonest arrhythmia in humans and is associated with marked reduction in quality of life and an elevated thromboembolic risk. Paroxysmal, persistent, and permanent forms of AF have been recognized. Whilst antiarrhythmic drugs are considered as first-line therapy, the role of catheter ablation is increasing due to its superior efficacy in terms of quality of life and reduction in AF burden. The central paradigm for catheter ablation of AF is that triggers for AF are located near and within the pulmonary veins (PVs), and electrical isolation of the PVs from the left atrium forms the cornerstone of most catheter ablation strategies. Whilst paroxysmal form is generally trigger dependent, persistent and permanent forms are associated with variable interaction between triggers and "substrate" comprised of atrial and PV electrical and structural remodeling. Nevertheless, isolation of the PVs still forms a critical component of catheter ablation strategies, regardless of AF type. Procedural efficacy, however, is limited by PV conduction recovery. This is likely due to deficiencies in ablation tools or limitations of intraprocedural assessment of lesion efficacy. Careful attention to surrogates of tissue heating, such as impedance decrease and electrogram morphology changes, along with advances in catheter technology like contact force catheters may improve rates of durable PV isolation and single-procedural success. This review discusses the mechanism of paroxysmal AF with particular focus on the role of the PVs in AF initiation and PV isolation in the management of AF. Keywords: contact force, lesion transmurality, radiofrequency catheter ablation, paroxysmal atrial fibrillation, electrophysiology, A
In-Situ Monitoring of Weld Line Thickness in Continuous Ultrasonic Welding of Thermoplastic Composites
No full textContinuous ultrasonic welding (CUW) is one of the most efficient integration methods of thermoplastic composites. Researchers from our group have already utilized CUW method by using both frame based and robotic welding platforms to achieve sufficient amount of joint strength for aerospace applications [1-3]. On the other hand, the implementation of this method into an industrial manufacturing process still requires the ability of consistent and high-quality welding. It is obvious that a sophisticated monitoring system, which is developed for ensuring the highest-level of weld quality, will play a key role to transform CUW method into a commonly relied on industrial tool. Typically, experimental techniques like micrograph, mechanical testing and fracture surface examination are used to determine the performance of a welded composite joint, which provide the opportunity of correlating the process parameters and other process data with the welded joint performance. Within the context of this study, several experiments are conducted using the welded composite plates by robotic CUW system. It’s seen that the overall weld-line thickness, among other parameters, indicates a remarkable correlation with lap shear strength of welded joints. The results show that for weld line thicknesses above the original energy director thickness, considerable voids can be found in the weld interface. On the other hand, samples with a lower thickness than the original energy director show less voids and improved lap shear performance. After evaluating the aforementioned experimental outcomes, a weld monitoring system is designed for continuous measurement of weld line thickness for in-situ monitoring purposes. Weld monitoring system is built on a frame based continuous ultrasonic welding platform as seen in Figure 1, where the laser sensors are utilized to perform very precise thickness distribution analysis along the weld line during the continuous monitoring applications. A specialized python code is created to analyze the raw sensor data for monitoring purposes. Different monitoring system iterations and python code pairs tested and compared to achieve the most accurate monitoring experience. Results indicate that laser sensor based monitoring system provides very sensitive weld line thickness measurements, which can be related to the weld quality for industrial applications.Aerospace Structures & Computational MechanicsAerospace Manufacturing Technologie
English as a lingua franca: globalization, ownership, and the diversification of English
No full textEnglish, EAP, EFL, lingua franca, globalization, linguistic
Should an abnormal serum potassium concentration be considered a correctable cause of cardiac arrest?
No full textAbstractAccording to American Heart Association/American College of Cardiology Practice Guidelines, electrolyte abnormalities, including abnormal serum potassium concentrations, are considered a correctable cause of a life-threatening ventricular arrhythmia. Ventricular defibrillator therapy in this situation is a class III indication, and thought to be ineffective and perhaps harmful, although there are minimal data to support this recommendation. The steady-state serum potassium concentration frequently changes during a cardiac arrest. Additionally, the vast majority of cardiac arrest patients have structural heart disease and are commonly treated with a variety of medications that can alter the serum potassium concentration. In the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial, patients with a correctable cause of an electrolyte imbalance were excluded from study participation but were followed in the AVID registry. Similar outcomes were observed among patients in the AVID registry and the main trial. Spironolactone therapy in patients with congestive heart failure decreases all-cause mortality and sudden and nonsudden cardiac death. In a preliminary study of 169 patients with an episode of a sustained ventricular arrhythmia treated with an implantable defibrillator, freedom from appropriate defibrillator therapy was 18% after five years. The probability of appropriate defibrillator therapy was independent of the initial serum potassium concentration. For these reasons, our current clinical practice is to use an implantable defibrillator to treat an initial episode of sustained ventricular tachycardia or ventricular fibrillation that occurs in a patient with structural heart disease and an abnormal serum potassium concentration
Echinoderes angelae Cepeda & Gayet & Spedicato & Michaud & Zeppilli 2022, sp. nov
No full text<i>3.2. Echinoderes angelae sp. nov</i> urn:lsid:zoobank.org:act: 482926BC-199C-4168-BB67- 92E21CB0ACF5. <p>(Figs. 2–8, Tables 1 and 2)</p> <p> <i>3.2.1. Material examined</i></p> <p> Holotype, adult female, collected in November 2017 at the confluence of the Cayenne and Montsin´ery Rivers, French Guiana (western Atlantic Ocean): 04 ◦ 53 ′ 49.2288 ′′ N, 52 ◦ 22 ′ 27.714 ′′ W at the intertidal zone in mud; mounted in Fluoromount G ®, deposited at MNHN under catalogue number: 655 Ma. Paratypes, three adult males and five adult females, same collecting data as holotype; mounted in Fluoromount G ®, deposited at MNHN under catalogue numbers: 656Ma–663Ma. Additional material, 29 adult males, 23 adult females, 3 adults of unknown sex, 83 juveniles and 12 exuvia, some of them with same collecting data as type material, mounted in Fluoromount G ®, others collected in November 2017 ca. 14 km upstream of the Cayenne River, French Guiana (western Atlantic Ocean): 04 ◦ 51 ′ 31.9716 ′′ N, 52 ◦ 23 ′ 59.5248 ′′ W at the intertidal zone in mud; mounted in Fluoromount G ®, deposited at MNHN under catalogue numbers: 666Ma–815Ma; seven adult males, eight adult females, three adults of unknown sex and eight juveniles, same collecting data as type and remaining additional material, mounted for SEM, deposited at IFREMER.</p> <p> <i>3.2.2. Diagnosis</i></p> <p> <i>Echinoderes</i> with short, poorly sclerotized, weakly articulated spines in middorsal position on segment 4 and sublateral position on segments 6–7. Tubes in lateroventral position on segment 5, lateral accessory position on segment 8 and laterodorsal position on segment 10. Modified type 2 glandular cell outlets in subdorsal position on segments 2 and 5–8, laterodorsal position on segments 2, 4 and 10, midlateral position on segments 2, 6 and 8, and lateroventral position on segments 7–8. Large, rounded sensory spots on segment 1 with a transversal row of conspicuously elongated hairs at the posterior edge of the papillae area. Enlarged, oval sieve plate in sublateral position on segment 9, consisting of an anterior, slightly convex region with numerous pores and a posterior, slightly concave area with a single, central pore.</p> <p> <i>3.2.3. Etymology</i></p> <p>The species is dedicated to Angela´Cepeda Gomez´, sister of the first author, for all these years of unconditional support.</p> <p> <i>3.2.4. Description</i></p> <p>See Table 1 for measurements of selected morphological features and body dimensions, and Table 2 for summary of spine, tube, nephridiopore, glandular cell outlet and sensory spot locations.</p> <p>Despite the high number of studied specimens, only a few had the head everted, hence only some data of the morphology and appendage arrangement are provided. Ring 00 of mouth cone with nine outer oral styles alternating in size between slightly larger and smaller ones. Outer oral styles composed of two jointed subunits: a rectangular, basal sheath with distal fringe and a triangular, hooked, distally pointed end-piece. Outer oral styles located anterior to each introvert sector, except in the middorsal sector 6 where a style is missing (Fig. 2; 4B).</p> <p>Introvert with seven concentric rings of spinoscalids (one ring of primary spinoscalids and six rings of regular-sized spinoscalids) and 10 longitudinal sectors defined by the arrangement of the primary spinoscalids. Ring 01 with 10 primary spinoscalids, larger than remaining scalids, composed of a basal sheath and a distal, elongated, flexible end-piece. Ring 02 with 10 spinoscalids, arranged as one medially in each sector; spinoscalids on this and following rings are morphologically similar to the primary spinoscalids but smaller. Ring 03 with 20 spinoscalids, arranged as two in each sector. Ring 04 with 10 spinoscalids, arranged as one medially in each sector. Ring 05 with 20 spinoscalids, arranged as two in each sector. Ring 06 with five spinoscalids, arranged as one medially in each odd-numbered sector. Ring 07 with an unknown number of smaller spinoscalids, as only those of sectors 1, 3 and 4 could be observed (sectors 1 and 3 with three spinoscalids, sector 4 with two leaving space for the corresponding trichoscalid and its plate); sectors 9 and 8 are likely similar to sectors 3 and 4 in this arrangement due to the typical radial symmetry of the kinorhynch introvert. Scalid arrangement identical in all sectors from rings 02–05, with one unpaired scalid in ring 02 followed by a quincunx in rings 03–05; in sector 1 (and likely 9), ring 06 with an unpaired scalid followed by three smaller scalids in ring 07; in sector 4 (and likely 8), ring 06 without scalids followed by two smaller scalids in ring 07 leaving space for the corresponding trichoscalid and its plate; rings 06–07 unknown for remaining sectors. A fringed ring around the introvert at the level of rings 04–05, with tips more elongated in sectors where a spinoscalid is missing in ring 06 (Fig. 2; 6B–C).</p> <p>Neck with 16 trapezoidal placids, wider at the base, closely adjacent each other, with distinct joint between the neck and first trunk segment. Midventral placid widest (ca. 10–11 μm at base), remaining ones slightly narrower (ca. 6–8 μm at base). A ring of six short, superficially haired trichoscalids associated with the placids, attached to quadrangular trichoscalid plates in sectors 2, 4, 5, 7, 8 and 10 (Fig. 2; 3 A-B; 4C-D; 6A- D).</p> <p>Trunk fusiform, heart-shaped in cross-section, composed of 11 segments. Segments 1–2 closed, ring-like cuticular plates; remaining ones with one tergal and two sternal cuticular plates (Fig. 3A–D; 4A; 5 A-F; 6A; 7B). Maximum sternal width at segment 8, relatively narrow compared to total trunk length (MSW8/TL average ratio = 19.6%). Cuticular hairs throughout segments 2–11 (absent on segment 1), acicular, non-bracteate, emerging from rounded to slightly oval perforation sites. Cuticular hairs arranged as 6–12 transversal, uninterrupted rows covering the cuticular surface of segments 2–3 (except in the ventromedial region where hairs are missing); as 6–16 transversal rows that become wavy at subdorsal and ventrolateral to ventromedial regions, interrupted by large, oval, muscular scars in laterodorsal position throughout segments 4–10; as 6–8 transversal, uninterrupted rows covering the cuticular surface of segment 11 (hairs of this segment conspicuously shorter) (Fig. 3A–D; 5 A-F; 7B, D, F, H, L). Posterior segment margins straight, with serrated primary pectinate fringe (Fig. 3A–D); primary pectinate fringe of segment 1 with larger tips (Fig. 7B); segments 2 and 10 with posterior segment margin extended as a triangle in the ventrolateral to ventromedial region, with tips of primary pectinate fringe conspicuously shorter and tighter than those on other regions on the same segment (Fig. 3A–D; 7B, L); segments 3–9 with tips of primary pectinate fringes noticeable shorter and tighter in the ventromedial region than those on other regions on the same segment (Fig. 7B); segment 11 with elongated tips of primary pectinate fringe in middorsal to subdorsal and lateroventral to ventrolateral regions (Fig. 3A–D; 6 F-G). Secondary pectinate fringes finely serrated (Fig. 7K).</p> <p> Segment 1 with type 1 glandular cell outlets in middorsal and lateroventral positions (Fig. 3A and B; 5A). Large, rounded sensory spots in subdorsal, laterodorsal and ventromedial positions, the former two located near the anterior segment margin, the latter near the posterior segment edge; these sensory spots have a transversal row of conspicuously elongated hairs at the posterior edge of the papillae area (except in seven specimens mounted for SEM that lacked these hairs, see subsection <i>3.1.5 Notes on intraspecific variability</i>) (Fig. 3A and B; 5A; 7A).</p> <p>Segment 2 with one pair of droplet-shaped sensory spots in middorsal and ventromedial positions, and two pairs in laterodorsal position (Fig. 3A and B; 5A); on this and following segments, these sensory spots usually have one or two central pores with emerging cilia (Fig. 7D). Modified type 2 glandular cell outlets in subdorsal, laterodorsal and midlateral positions (Fig. 3B; 5A; 7D); on this and following segments, modified type 2 glandular cell outlets are minute, oval, glandular openings surrounded by a tuft of short cuticular extensions (Fig. 7C).</p> <p>Segment 3 with type 1 glandular cell outlets in middorsal and ventromedial positions (Fig. 3A and B). Droplet-shaped sensory spots in subdorsal and midlateral positions (Fig. 3B; 7H).</p> <p>Segment 4 with short (ca. 4–8 μm length), poorly sclerotized, weakly articulated, acicular spine in middorsal position (Fig. 3B; 7G). Type 1 glandular cell outlets in subdorsal and ventromedial positions (Fig. 3A and B). Modified type 2 glandular cell outlets in laterodorsal position (Fig. 3B; 7C).</p> <p>Segment 5 with tubes in lateroventral position (Fig. 3A; 5C). Type 1 glandular cell outlets in subdorsal and ventromedial positions (Fig. 3A and B). Modified type 2 glandular cell outlets in subdorsal position (Fig. 3B). Droplet-shaped sensory spots in subdorsal, midlateral and ventromedial positions; subdorsal sensory spots more lateral than subdorsal modified type 2 glandular cell outlets (Fig. 3A and B; 5B–C; 7B).</p> <p>Segment 6 with short (ca. 4–6 μm length), poorly sclerotized, weakly articulated, acicular spines in sublateral position (Fig. 3A; 5C). Type 1 glandular cell outlets in subdorsal and ventromedial positions (Fig. 3A and B). Modified type 2 glandular cell outlets in subdorsal and midlateral positions (Fig. 3B; 5B). Droplet-shaped sensory spots in subdorsal, midlateral and ventromedial positions; subdorsal sensory spots more mesial than subdorsal modified type 2 glandular cell outlets (Fig. 3A and B; 5B–C; 7B).</p> <p>Segment 7 similar to segment 6 regarding spine, glandular cell outlet and sensory spot arrangement, but with modified type 2 glandular cell outlets in lateroventral instead of midlateral position and sensory spots in ventrolateral instead of ventromedial position (Fig. 3A and B; 5B, F; 7J).</p> <p>Segment 8 with tubes in lateral accessory position (Fig. 3A; 5F; 7J). Type 1 glandular cell outlets in subdorsal and ventromedial positions (Fig. 3A and B). Modified type 2 glandular cell outlets in subdorsal, midlateral and lateroventral positions (Fig. 3A and B; 5D, F; 7F). Droplet-shaped sensory spots in subdorsal position (Fig. 3B; 5D; 7F).</p> <p>Segment 9 with type 1 glandular cell outlets in subdorsal and ventromedial positions (Fig. 3A and B; 7K). One pair of droplet-shaped sensory spots in midlateral and ventrolateral positions, and two pairs in subdorsal position (Fig. 3A and B; 5 D-E; 7F, M). Nephridiopores in sublateral position as enlarged sieve plate openings with an anterior, elongated, slightly convex area with numerous pores and a posterior, slightly concave region with a single, central pore (Fig. 3A; 5E; 7E).</p> <p>Segment 10 with tubes in laterodorsal position, larger in males (Fig. 3B, D; 4E; 7I). Two type 1 glandular cell outlets in middorsal position, longitudinally arranged; type 1 glandular cell outlets also in ventromedial position (Fig. 3A and B). Modified type 2 glandular cell outlets in laterodorsal position, anterior to the tubes (Fig. 3B). Droplet-shaped sensory spots in subdorsal and ventrolateral positions (Fig. 3A–D; 5E; 7L).</p> <p>Segment 11 with relatively short lateral terminal spines (LTS:TL average ratio = 17.9%), distally pointed, with hollow central cavity, superficially covered by hairs (Fig. 3A–D; 4A, E-F, H–I; 6A, E-G). Males with three pairs of penile spines that emerge from laterodorsal position in the intersegmental joint with the preceding segment; penile spines tube-like, covered by hairs, abruptly tapering near their distal tips (Fig. 3D; 4E; 6F). Females with short (LTAS:LTS average ratio = 28.5%), distally frayed, covered by hairs, lateral terminal accessory spines, and oval, ventrolateral gonopores near the intersegmental joint with the preceding segment (Fig. 3A and B; 4F; 6G). Droplet-shaped sensory spots in subdorsal and ventromedial positions (Fig. 3A–D; 7L). Tergal extensions triangular, distally pointed, covered by hairs, distally elongated as hair-like extensions (Fig. 3A–D; 4F; 6E).</p> <p> <i>3.2.5. Notes on intraspecific variability</i></p> <p> <i>Echinoderes angelae</i> sp. nov. shows certain degree of intraspecific variability not related to sex or sampling station. One of the most remarkable features of the species is the presence of three pairs of large sensory spots on segment 1 with a transversal row of conspicuously elongated hairs at the posterior edge of the papillae area (Fig. 3A and B; 5A; 7A). However, seven specimens mounted for SEM (four males and three females) showed these sensory spots without such kind of hairs (Fig. 7A). Neither juveniles of the species possess the elongated hairs,</p> <p>which suggests that the observed specimens could be pre-adults that did not develop the structures yet.</p> <p>Shape and position of nephridiopores also showed variation among the studied specimens. This structure varies from completely oval or slightly triangular, located near the anterior margin of segment 9 without rows of hairs on top (ca. 70% of the examined specimens) to more buttonhole-shaped, posteriorly displaced having a few rows of hairs on top (ca. 30% of the examined specimens) (Fig. 5E; 7E). These differences were observed in both LM and SEM specimens.</p> <p>Segments 10 and 11 also showed conspicuous intraspecific variability regarding the length of the tergal extensions and the primary pectinate fringe. Thus, some specimens had shorter tergal extensions, without the hair-like distal end, as well as a primary pectinate fringe with barely elongated tips (ca. 20% of the examined specimens) (Fig. 6E). Others had tergal extensions with an elongated, hair-like distal end and primary pectinate fringes with longer tips (ca. 80% of the examined specimens) (Fig. 3A–D; 4 E-F; 6F-G). The primary pectinate fringe of segment 10 also showed some intraspecific variation concerning the length of the tips at the ventrolateral region, with ca. 30% of the examined specimens showing conspicuously elongated tips (reaching the edge of segment 11) at this area. Finally, the relative length of the lateral terminal spines also showed intraspecific variability (LTS:TL ratio of 6–10% in 15 out of 52 measured specimens vs. 15–25% in 37 out of 52 measured specimens). These differences were observed in both LM and SEM specimens.</p> <p> <i>3.2.6. Other remarks</i></p> <p>Several specimens (ca. 15% of the total number) had epibionts. The most common ones were filamentous bacteria of different lengths (Fig. 4I; 6G; 8 A-C, F-G), but unicellular bacteria were also observed (Fig. 8D–E, H-I). Finally, unknown, rod-shaped epibionts, with a distal constriction, were also detected (Fig. 4H). Epibionts were more commonly found attached to the ventral surface of the posterior segments, the nephridiopore and the lateral terminal spines (Fig. 4H and I; 6G; 8G), but some of them were also present at the anterior segments near sensory spots, tubes, muscular scars and glandular cell outlets (Fig. 8A–F, H–I).</p> <p>Some specimens (ca. 10% of the total number) had ingested clusters of diatoms at the gut, and even though their frustules seemed to be unaltered, a partially digested, green content was observed (Fig. 4G). This could suggest that the specimens were able to extract the content of the diatom to digest it.</p>Published as part of <i>Cepeda, Diego, Gayet, Nicolas, Spedicato, Adriana, Michaud, Emma & Zeppilli, Daniela, 2022, Two new species of the Echinoderes coulli-group (Kinorhyncha: Cyclorhagida: Echinoderidae) from a low human-impacted mangrove swamp in French Guiana (western Atlantic Ocean), pp. 179-195 in Zoologischer Anzeiger 301</i> on pages 180-186, DOI: 10.1016/j.jcz.2022.10.008, <a href="http://zenodo.org/record/10375291">http://zenodo.org/record/10375291</a>
Multicenter Experience With Extraction of the Sprint Fidelis Implantable Cardioverter-Defibrillator Lead
No full textObjectivesThis study was undertaken to determine the safety and feasibility of extraction of the Sprint Fidelis (Medtronic, Minneapolis, Minnesota) lead.BackgroundThe reported failure rate of the Sprint Fidelis defibrillator lead has increased to a range greater than initially appreciated with emerging evidence of an accelerating rate of fracture. At present, consensus guidelines continue to recommend against prophylactic extraction of the lead, citing major complication rates between 1.4% and 7.3%. However, data regarding the safety and feasibility of extraction of small-diameter, backfilled implantable cardioverter-defibrillator leads such as the Sprint Fidelis are limited.MethodsWe performed a retrospective cohort study of consecutive patients undergoing extraction of Sprint Fidelis (models 6930, 6931, 6948, 6949) leads at 5 high-volume centers. Patient characteristics, indications for extraction, and use of countertraction sheath (CTS) assistance are reported. The risk of major and minor complications was determined. A multivariable logistic regression model was developed to predict factors associated with the use of CTS assistance.ResultsBetween May 2005 and August 2009, 349 Sprint Fidelis leads were extracted from 348 patients. All leads were removed completely. The average duration of the implanted lead was 27.5 months (range 0.03 to 58.8 months). Approximately one-half of the extracted leads were fractured (49.4%), and 26.5% were extracted prophylactically. The other major indication for extraction was infection (22.8%). Extraction was achieved with simple traction in 49.4% leads; CTS assistance was required in 174 cases (50.6%). In multivariable models, length of time since implantation was directly related to the need for CTS assistance (odds ratio per month since implantation: 1.035; 95% confidence interval: 1.010 to 1.061; p = 0.006). There were no major procedural complications or deaths.ConclusionsExtraction of the Sprint Fidelis lead can be performed safely by experienced operators at high-volume centers with a complication rate lower than that reported for older generation leads. However, leads with longer implant durations are associated with the use of CTS assistance. Recommendations regarding prophylactic Sprint Fidelis lead extraction may warrant reconsideration
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