Early detection of the onset of a caldera collapse can provide crucial information to understand their formation and thus to minimize risks for the nearby population and visitors. Here, we analyse ...the 2007 caldera collapse of Piton de la Fournaise on La Réunion Island recorded by a broadband seismic station. We show that this instrument recorded ultra-long period (ULP) signals with frequencies in the range (0.003-0.01 Hz) accompanied by very-long period (VLP) signals (between 0.02 and 0.50 Hz) prior to and during the caldera formation suggesting it is possible to detect the beginning of the collapse at depth and anticipate its surface formation. Interestingly, VLP wave packets with a similar duration of 20 s are identified prior to and during the caldera formation. We propose that these events could result from repeating piston-like successive collapses occurring through a ring-fault structure surrounding a magma reservoir from the following arguments: the source mechanism from the main collapse, the observations of slow source processes as well as observations from the field and the characteristic ring-fault seismicity.
The intense unrest of the Yellowstone volcanic plateau is manifested through diffuse seismic activity, earthquake swarms, and episodes of complex surficial deformation that have been related to ...magmatic fluid transfer in the upper crust over the past several decades. While past studies have focused on modeling contemporary geophysical data, there has not been a fully-integrated evaluation of seismicity, fault kinematics, and stress field. Here we analyze a catalog of 10,201 relocated earthquakes recorded between 2010 and 2016 and determine 224 well-constrained double-couple focal mechanisms. The majority of the focal mechanisms (65%) are associated with the 2010 Madison Plateau seismic swarm. The focal mechanisms are predominantly strike-slip with subordinate normal faulting mechanisms. Possible causes of this predominance and of the concurrence of both kinematics are here discussed, in order to unravel the influence of magmatic processes such as past sill intrusions. The earthquake catalog has been analyzed in terms of location, time, and kinematics according to the phases of surficial deformation documented by GPS data in order to identify systematic patterns of deformation and has been compared to the 1988–2009 seismicity. The continuous downwarping of the overburden from 2010 to 2016 was accomodated by structural adjustment of the shallow crust through strike-slip motions on a multitude of scattered small fault planes. Furthermore, the predominance of strike-slip faulting during seismic swarms occurs when the fluid overpressure induces horizontal propagation of vertical fractures with strike-slip motions, followed by horizontal fluid flow.
•224 new double-couple focal mechanism solutions have been computed at Yellowstone.•Most give strike-slip faulting, with subordinate normal and a few reverse motions.•Fault kinematics have been compared with magma inflation and deflation phases.•The causes of dominant horizontal fluid migration are discussed.
Pulmonary vein isolation is the mainstay of treatment in catheter ablation of paroxysmal atrial fibrillation (AF). Cryoballoon ablation has been introduced more recently than radiofrequency ablation, ...the standard technique in most centres. Pulmonary veins frequently display anatomical variants, which may compromise the results of cryoballoon ablation. We aimed to evaluate the mid-term outcomes of cryoballoon ablation in an unselected population with paroxysmal AF from an anatomical viewpoint.
Consecutive patients with paroxysmal AF who underwent a first procedure of cryoballoon ablation or radiofrequency were enrolled in this single-centre study. All patients underwent systematic standardized follow-up. Comparisons between radiofrequency and cryoballoon ablation (Arctic Front™ or Arctic Front Advance™) were performed regarding safety and efficacy endpoints, according to pulmonary vein (PV) anatomical variants. A total of 687 patients were enrolled (376 radiofrequency and 311 cryoballoon ablation). Baseline characteristics and distribution of PV anatomical variants were generally similar in the groups. After a mean follow-up of 14 ± 8 months, there was no difference in the incidence of relapse (17.0% cryoballoon ablation vs. 14.1% radiofrequency, P = 0.25). We observed no interaction of PV anatomical variants on mid-term procedural success.
Our findings suggest that mid-term outcomes of cryoballoon ablation for paroxysmal AF ablation are similar to those of radiofrequency, regardless of PV anatomy. The presence of anatomical variants of PVs should not discourage the referral of patients with paroxysmal AF for cryoballoon ablation.
Among septic patients admitted to the intensive care unit (ICU), early recognition of those with the highest risk of death is of paramount importance. Since clinical judgment is sometimes uncertain ...biomarkers could provide additional information likely to guide critical illness management. We evaluated the prognostic value of soluble Triggering Receptor Expressed by Myeloid cells 1 (sTREM-1), procalcitonin (PCT) and leucocyte surface expression of CD64.
This was a prospective cohort study, which included 190 septic patient admitted to the ICU in two hospitals. Blood samples for biomarker measurements were obtained upon admission and thereafter. The Simplified Acute Physiology Score (SAPS) II and the Sequential Organ Failure Assessment (SOFA) score were calculated. The primary outcome was all-cause death in the ICU.
The mortality rate reached 25.8 %. The best predictive value of the three biomarkers was obtained with baseline sTREM-1, although clinical scores outperformed this. Accuracy was greater in patients without prior exposure to antibiotics and in those with proven bacterial infection. Adding sTREM-1 levels to SAPS II increased its specificity to 98 %. The soluble TREM-1 level, core temperature and SAPS II value were the only independent predictors of death after adjustment for potential confounders. A decrease in sTREM-1 with time was also more pronounced in survivors than in non-survivors.
sTREM-1 was found to be the best prognostic biomarker among those tested. Both baseline values and variations with time seemed relevant. Although SAPS II outperformed sTREM-1 regarding the prediction of ICU survival, the biomarker could provide additional information.
Empirically determined noninvasive ventilation (NIV) settings may not achieve optimal ventilatory support. Some ventilators include monitoring modules to assess ventilatory quality. We conducted a ...bench-to-bedside study to assess the ventilatory quality of the VPAPIII-ResLink (ResMed, North Ryde, Australia). We tested the accuracy of minute ventilation (MV) and leak calculations given by VPAPIII-ResLink compared to those measured by a bench model at varied leak levels and ventilator settings. We systematically assessed NIV efficacy using this system from 2003 to 2006. Ventilation was considered inadequate if leak (>24 L x min(-1)), continuous desaturation (>30% of the trace) or desaturation dips (>3%) were present. On the bench test, both methods were highly correlated (r = 0.947, p>0.0001 and r = 0.959, p<0.0001 for leak and MV, respectively). We performed 222 assessments in 169 patients (aged 66.42+/-16 yrs, 100 males). Abnormalities were detected on 147 (66%) out of 222 occasions. Leak was the most common abnormality (34.2%) followed by desaturation dips (23.8%). The most effective therapeutic solutions were a chin strap if leak was detected (61.2%) and expiratory positive airway pressure increase for desaturation dips (59.5%). In 15.7% of cases, when abnormalities persisted, a polygraphy was performed. The systematic use of this device enables NIV to be optimised, limiting the indication of sleep studies to complex cases.
To determine whether synovial expression of triggering receptor expressed on myeloid cells 1 (TREM-1) is upregulated in patients with distinct types of inflammatory or non-inflammatory arthritis.
...Synovial fluid (SF) samples were analysed for levels of soluble TREM-1 (sTREM; n = 132), tumour necrosis factor alpha (TNFalpha, n = 78) and leucocyte TREM-1 messenger RNA (n = 48). Synovial tissue from four rheumatoid arthritis (RA) patients, two patients with Crohn's-associated arthritis, one patient with ankylosing spondylitis and one patient with osteoarthritis were examined for TREM-1 expression by immunohistology, and three of the RA samples were also analysed by Western blotting.
Synovial fluid sTREM-1 levels in septic arthritis and RA were similar to each other and were each greater than those in gouty arthritis, non-septic/non-RA inflammatory arthritis and non-inflammatory arthritis. Synovial fluid TNFalpha and sTREM-1 levels correlated with each other, and sTREM-1 and leucocyte TREM-1 mRNA levels each correlated with SF leucocyte counts. TREM-1 in RA was expressed in situ in synovial tissue by cells of myelomonocytic lineage but was not detectably expressed in control osteoarthritis synovial tissue.
Synovial TREM-1 expression is increased in septic arthritis and RA. In patients with acute inflammatory arthritis, elevated SF sTREM-1 levels may point the clinician to a diagnosis of septic arthritis or RA. In RA patients, targeting TREM-1 may have therapeutic benefits by reducing local proinflammatory cytokine and chemokine release.
Summary
Desulfovibrio are sulfate‐reducing anaerobic gram‐negative rods that have been proposed as potential periodontopathogens. We investigated the capacity of Desulfovibrio to invade epithelial ...cells and induce cytokine secretion from these cells. Desulfovibrio strains were co‐cultured with KB cells and counts of intracellular bacteria evaluated up to 3 days after infection. Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis were able to survive within epithelial cells. Intracytoplasmic location of both bacterial species was confirmed by confocal laser scanning microscopy and transmission electron microscopy. Invasion was sensitive to nocodazole, an inhibitor of microtubule polymerization, but not to cytochalasin D, a microfilament inhibitor, suggesting that microtubule rearrangements were involved in the internalization of Desulfovibrio strains by KB cells. Infection by Desulfovibrio resulted in increased production of IL‐6 and IL‐8 by KB cells. The ability of D. desulfuricans and D. fairfieldensis to survive within oral epithelial cells and to modulate the epithelial immune response may contribute to the initiation and progression of periodontal diseases.
Abstract
Introduction
Remote monitoring (RM) has revolutionized implantable cardiac device care in adults. It has demonstrated its safety on hard criteria, a reduction in the number of ...hospitalizations and emergency room visits, early detection of events and a reduction in inappropriate therapies. However, while pediatric population is becoming emerging, particularly considering congenital heart diseases, there is no contemporary study.
Objective
The aim of our study was to characterize in our cohort of RM patients the population of children (below 18 yo) implanted with a pacemaker or an ICD and under RM for more than 1 year.
Method
The data collection was carried out retrospectively within the cohort of RM patients at our university hospital. The outcome combined occurrence of ventricular (VT)/supraventricular (SVT) arrhythmias, appropriate or inappropriate therapies, lead dysfunction/fracture and ERI.
Results
The study population included 34 patients (17F/17M) with a mean age of 9.4+/-5.8 years (range 0-18 yo) and a mean remote follow-up of 4.6+/-3.9 years (range 1-13 y). The indications for pacing were postoperative atrioventricular block (AVB, n = 9) for operated congenital heart disease or hypertrophic cardiomyopathy (n=1), congenital AVB (n= 5), muscular dystrophy (n = 1) and genetic sinus node dysfunction (n = 1). Indications for an ICD were resuscitated sudden death in hypertrophic cardiomyopathy (n = 4), LQTS (n = 5), CPVT (n = 2), arrhythmogenic right ventricular dysplasia (n = 2), Brugada syndrome (n = 1) and congenital heart disease (n = 2). Pacing devices (n = 17) were mostly implanted with epicardial leads and abdominal box (n = 12). ICDs (n = 18) were implanted in primary (n = 4) or in secondary prevention with epicardial (n = 2)/ endovascular (n=9) /subcutaneous (n = 2) leads depending on children weight and anatomy. One 12 yo-boy had an S-ICD in addition to a previous pacemaker. There were a total of 13 patients with device-triggered alerts: VT in 8 including appropriate therapies in 6 and inappropriate shocks in 2, supraventricular tachycardia in 2, RV lead dysfunction in 2, RV lead fracture in 1 and no alert for ERI. All alerts were treated within 24h.
Conclusion
This is the first report of cardiac device remote monitoring in a pediatric population. In our population 13/34 patients experienced alerts necessitating intervention over a mean 4.6 year-follow-up. Remote monitoring through device-triggered alerts allowed efficient treatment of an arrhythmic event or a lead dysfunction. This is a preliminary study suggesting the need for further studies on a larger population. Remote monitoring should be considered in all eligible-device children and should be considered as standard of care.
Abstract
Funding Acknowledgements
Type of funding sources: None.
Introduction
Atrial wall perforation is a rare but serious complication of transeptal puncture in AF catheter ablation procedure. In ...patients with uninterrupted anticoagulation associated to non-fractionated heparin bolus this may lead to cardiac tamponade and dramatic consequences. Urgent surgical drainage and repair is mandatory in the most dramatic cases. We report the successful closure of such complication by an Amplatzer vascular plug leading to a rapid and total recovery in 3 patients.
Methods
Three patients (male, 43, 77 and 84 yo) referred for persistent atrial fibrillation ablation (1 RF and 2 cryoablations). After transeptal puncture, they became severely hypotensive with echographic evidence of tamponade.
Results
Heart perforation with massive leakage of contrast in the pericardial space was evident. The perforation was anterior near aorta in one, on the posterior wall of the right atrium in one and on the posterior wall of the left atria though the right atria in one. After heparin antagonization by protamin, the pericardial space was drained percutaneously (1 to 3 l drained and in 1 reinjected through a "cell saver" system). Rapidly, a 0,035 J guide wire was passed through the perforation and an Amplatzer vascular Plug 2 (4 mm in 2 patients and 6 mm in one) was released resulting in an immediate closure of the leak and recovery of the patient after completion of the pericardial drainage. The drainage was monitored 24h and patients were discharged on Day 2 with a good evolution over a median follow-up of 1.5 year. CT scan at 3 and 6 month showed total recovery.
Conclusion
In patients with left atrial wall perforation and tamponade related to failed transeptal puncture in patients under uninterrupted oral anticoagulation for AF ablation, rapid release of a closure device and pericardial evacuation allowed to successfully manage the cardiac tamponade and avoid a surgical option.
Fig 1
Background: Besides standard left ventricular (LV) stimulation via the coronary sinus, a transseptal approach allows left ventricular endocardial stimulation. We report our long‐term observations ...with biventricular stimulation, using a strictly endocardial system for patients presenting with severe congestive heart failure.
Methods: Six patients with nonischemic cardiomyopathy (mean age = 60 ± 9.6 years, women) in New York Heart Association (NYHA) functional class III (n = 5) or IV, despite optimal drug therapy, and a mean LV ejection fraction of 24 ± 3%, underwent implantation of biventricular stimulation systems between April 1998 and March 1999. All presented with left bundle branch block and an increased LV end‐diastolic diameter (mean = 66 ± 5 mm). In all patients, a bipolar pacing lead was implanted in the lateral LV wall using a direct transseptal approach. After implantation, all patients received oral anticoagulation.
Results: QRS duration decreased from 184 ± 22 ms to 108 ± 11 ms. NYHA functional class decreased to II in all patients within 1 month. Over a 85 ± 5 month follow‐up, two patients underwent cardiac transplantation, 2 and 4 years after device implantation, respectively; two patients died of end‐stage heart failure 4 years after system implantation; and two patients were alive in functional class II. One patient, who experienced syncope due to fast ventricular, underwent implantation of an ICD. One transient ischemic attack occurred in a patient whose anticoagulation was temporarily interrupted.
Conclusions: Long‐term endocardial biventricular stimulation via a transseptal approach was safe and effective in this small population. This approach needs to be further compared with conventional epicardial pacing via the coronary sinus
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