Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 418
Filtrar
Más filtros

Publication year range
1.
Cell ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38942013

RESUMEN

The ability of proteins and RNA to coalesce into phase-separated assemblies, such as the nucleolus and stress granules, is a basic principle in organizing membraneless cellular compartments. While the constituents of biomolecular condensates are generally well documented, the mechanisms underlying their formation under stress are only partially understood. Here, we show in yeast that covalent modification with the ubiquitin-like modifier Urm1 promotes the phase separation of a wide range of proteins. We find that the drop in cellular pH induced by stress triggers Urm1 self-association and its interaction with both target proteins and the Urm1-conjugating enzyme Uba4. Urmylation of stress-sensitive proteins promotes their deposition into stress granules and nuclear condensates. Yeast cells lacking Urm1 exhibit condensate defects that manifest in reduced stress resilience. We propose that Urm1 acts as a reversible molecular "adhesive" to drive protective phase separation of functionally critical proteins under cellular stress.

2.
N Engl J Med ; 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38767244

RESUMEN

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

3.
N Engl J Med ; 387(14): 1292-1302, 2022 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-36036522

RESUMEN

BACKGROUND: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known. METHODS: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system. The primary efficacy end point was successful defibrillation at implantation. The efficacy objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients with successful defibrillation was greater than 88%. The primary safety end point was freedom from major system- or procedure-related complications at 6 months. The safety objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients free from such complications was greater than 79%. RESULTS: A total of 356 patients were enrolled, 316 of whom had an implantation attempt. Among the 302 patients in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol, the percentage of patients with successful defibrillation was 98.7% (lower boundary of the one-sided 97.5% confidence interval [CI], 96.6%; P<0.001 for the comparison with the performance goal of 88%); 299 of 316 patients (94.6%) were discharged with a working ICD system. The Kaplan-Meier estimate of the percentage of patients free from major system- or procedure-related complications at 6 months was 92.6% (lower boundary of the one-sided 97.5% CI, 89.0%; P<0.001 for the comparison with the performance goal of 79%). No major intraprocedural complications were reported. At 6 months, 25 major complications were observed, in 23 of 316 patients (7.3%). The success rate of antitachycardia pacing, as assessed with generalized estimating equations, was 50.8% (95% CI, 23.3 to 77.8). A total of 29 patients received 118 inappropriate shocks for 81 arrhythmic episodes. Eight systems were explanted without extravascular ICD replacement over the 10.6-month mean follow-up period. CONCLUSIONS: In this prospective global study, we found that extravascular ICDs were implanted safely and were able to detect and terminate induced ventricular arrhythmias at the time of implantation. (Funded by Medtronic; ClinicalTrials.gov number, NCT04060680.).


Asunto(s)
Desfibriladores Implantables , Arritmias Cardíacas/terapia , Desfibriladores Implantables/efectos adversos , Cardioversión Eléctrica/efectos adversos , Humanos , Estudios Prospectivos , Resultado del Tratamiento
4.
Circulation ; 147(19): 1422-1432, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-36877118

RESUMEN

BACKGROUND: Pulsed field ablation uses electrical pulses to cause nonthermal irreversible electroporation and induce cardiac cell death. Pulsed field ablation may have effectiveness comparable to traditional catheter ablation while preventing thermally mediated complications. METHODS: The PULSED AF pivotal study (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF) was a prospective, global, multicenter, nonrandomized, paired single-arm study in which patients with paroxysmal (n=150) or persistent (n=150) symptomatic atrial fibrillation (AF) refractory to class I or III antiarrhythmic drugs were treated with pulsed field ablation. All patients were monitored for 1 year using weekly and symptomatic transtelephonic monitoring; 3-, 6-, and 12-month ECGs; and 6- and 12-month 24-hour Holter monitoring. The primary effectiveness end point was freedom from a composite of acute procedural failure, arrhythmia recurrence, or antiarrhythmic escalation through 12 months, excluding a 3-month blanking period to allow recovery from the procedure. The primary safety end point was freedom from a composite of serious procedure- and device-related adverse events. Kaplan-Meier methods were used to evaluate the primary end points. RESULTS: Pulsed field ablation was shown to be effective at 1 year in 66.2% (95% CI, 57.9 to 73.2) of patients with paroxysmal AF and 55.1% (95% CI, 46.7 to 62.7) of patients with persistent AF. The primary safety end point occurred in 1 patient (0.7%; 95% CI, 0.1 to 4.6) in both the paroxysmal and persistent AF cohorts. CONCLUSIONS: PULSED AF demonstrated a low rate of primary safety adverse events (0.7%) and provided effectiveness consistent with established ablation technologies using a novel irreversible electroporation energy to treat patients with AF. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04198701.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Humanos , Fibrilación Atrial/cirugía , Fibrilación Atrial/tratamiento farmacológico , Estudios Prospectivos , Resultado del Tratamiento , Antiarrítmicos/uso terapéutico , Electrocardiografía , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Recurrencia
5.
Small ; 20(22): e2306203, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38128031

RESUMEN

Semiconductor core/shell quantum dots (QDs) are considered promising building blocks to fabricate photoelectrochemical (PEC) cells for the direct conversion of solar energy into hydrogen (H2). However, the lattice mismatch between core and shell in such QDs results in undesirable defects and severe carrier recombination, limiting photo-induced carrier separation/transfer and solar-to-fuel conversion efficiency. Here, an interface engineering approach is explored to minimize the core-shell lattice mismatch in CdS/CdSexS1-x (x = 0.09-1) core/shell QDs (g-CSG). As a proof-of-concept, PEC cells based on g-CSG QDs yield a remarkable photocurrent density of 13.1 mA cm-2 under AM 1.5 G one-sun illumination (100 mW cm-2), which is ≈54.1% and ≈33.7% higher compared to that in CdS/CdSe0.5S0.5 (g-CSA) and CdS/CdSe QDs (g-CS), respectively. Theoretical calculations and carrier dynamics confirm more efficient carrier separation and charge transfer rate in g-CSG QDs with respect to g-CSA and g-CS QDs. These results are attributed to the minimization of the core-shell lattice mismatch by the cascade gradient shell in g-CSG QDs, which modifies carrier confinement potential and reduces interfacial defects. This work provides fundamental insights into the interface engineering of core/shell QDs and may open up new avenues to boost the performance of PEC cells for H2 evolution and other QDs-based optoelectronic devices.

6.
J Cardiovasc Electrophysiol ; 35(2): 240-246, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38047465

RESUMEN

INTRODUCTION: The pivotal study of the extravascular implantable cardioverter-defibrillator (EV ICD) recently demonstrated primary efficacy and safety endpoints comparable to previous ICD systems. Patient experience with this novel device has not been reported. The current study examined the standardized patient-reported outcome (PRO) metrics of quality of life (QOL) and patient acceptance of the device. METHODS: The EV ICD Pivotal Study was a prospective, single-arm, nonrandomized, global, premarket approval trial. Patients completed the 12-Item Short Form Survey (SF-12) QOL surveys at baseline and at 6 months following implant. Additionally, patients completed the Florida Patient Acceptance Survey (FPAS) QOL survey at 6 months. RESULTS: From baseline to 6 months, patients within the EV ICD Pivotal Study (n = 247) reported statistically significant SF-12 improvements in physical QOL (45.4 ± 9.4 vs. 46.8 ± 9.1 respectively, p = .020) and no changes in mental QOL (49.3 ± 10.4 vs. 50.5 ± 9.7, p = .061). No differences were noted by sex, atrial fibrillation, or the experience of ICD shock. EV ICD patients reported better total FPAS patient acceptance of their ICD than TV-ICD or S-ICD patients using historical norms comparisons (80.4 ± 15.7 vs. 70.2 ± 17.8, p < .0001 for S-ICD and 73.0 ± 17.4, p = .004 for TV-ICD). CONCLUSION: The initial PROs for EV ICD patients indicated that patients had improvements in physical QOL from baseline to 6-month follow-up and markedly better overall acceptance of their ICD compared to a previous study with S-ICD and TV-ICD data. These initial results suggest that the EV ICD is evaluated positively by patients.


Asunto(s)
Desfibriladores Implantables , Humanos , Calidad de Vida , Estudios Prospectivos , Encuestas y Cuestionarios , Medición de Resultados Informados por el Paciente
7.
Europace ; 26(4)2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38291925

RESUMEN

A significant proportion of patients who suffer from atrial fibrillation (AF) and are in need of thromboembolic protection are not treated with oral anticoagulation or discontinue this treatment shortly after its initiation. This undertreatment has not improved sufficiently despite the availability of direct oral anticoagulants which are associated with less major bleeding than vitamin K antagonists. Multiple reasons account for this, including bleeding events or ischaemic strokes whilst on anticoagulation, a serious risk of bleeding events, poor treatment compliance despite best educational attempts, or aversion to drug therapy. An alternative interventional therapy, which is not associated with long-term bleeding and is as effective as vitamin K anticoagulation, was introduced over 20 years ago. Because of significant improvements in procedural safety over the years, left atrial appendage closure, predominantly achieved using a catheter-based, device implantation approach, is increasingly favoured for the prevention of thromboembolic events in patients who cannot achieve effective anticoagulation. This management strategy is well known to the interventional cardiologist/electrophysiologist but is not more widely appreciated within cardiology or internal medicine. This article introduces the devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. Almost all physicians who care for adult patients will have many with AF. This practical guide, written within guideline/guidance boundaries, is aimed at those non-implanting physicians who may need to refer patients for consideration of this new therapy, which is becoming increasingly popular.


Asunto(s)
Apéndice Atrial , Fibrilación Atrial , Médicos , Accidente Cerebrovascular , Tromboembolia , Adulto , Humanos , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/complicaciones , Cierre del Apéndice Auricular Izquierdo , Consenso , Hemorragia/inducido químicamente , Hemorragia/prevención & control , Anticoagulantes/efectos adversos , Tromboembolia/etiología , Tromboembolia/prevención & control , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Vitamina K , Apéndice Atrial/cirugía , Resultado del Tratamiento
8.
Cardiology ; 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38986462

RESUMEN

Introduction Patients undergoing left atrial appendage occlusion (LAAO) are at increased risk for bleeding or thromboembolic events. Concurrently, biomarkers are of growing importance in risk stratification for atrial fibrillation patients. We aimed to evaluate the association of hematological markers and clinical characteristics with the occurrence of thromboembolic and bleeding events following LAAO. Methods Seven implanting centers retrospectively gathered data on hematological markers (i.e. platelet count (PC), mean platelet volume (MPV), and fibrinogen) prior LAAO. Prespecified thromboembolic and major bleeding outcomes were collected and the association with pre-procedural hematological markers and clinical characteristics was evaluated using Cox regression analysis. Results In total, 1315 patients were included (74±9 years, 36% female, CHA2DS2-VASc 4.3±1.5, HAS-BLED 3.3±1.1). Over a total follow-up duration of 2682 patient years, 77 thromboembolic events and 107 major bleeding events occurred after LAAO. Baseline PC was the only biomarker showing a signal for a relation to thromboembolic events (HR 1.18, 95% CI: 1.00-1.39) per 50*109 increment, p=0.056). Thrombotic event rates, including device-related thrombus, increased within higher PC quartiles. Thromboembolism was associated with age (HR 1.05, 95% CI: 1.00-1.10, per year increase) and prior thromboembolism (HR 2.08, 95% CI: 1.07-4.03), but with none of the biomarkers in multivariate analysis. No association of any of the hematological markers with major bleeding was observed. Major bleeding following LAAO was associated with prior major bleeding (HR 5.27, 95% CI: 2.71-10.22), renal disease (HR 1.93, 95% CI: 1.17-3.18) and discharge on dual antiplatelet therapy (HR 1.71, 95% CI: 1.05-2.77). Conclusion Most thrombotic events occurred in the highest PC quartile, but no association of any of the hematological markers with thromboembolism or major bleeding was observed in our analysis. In multivariate analysis, older age and prior thromboembolism were associated with thromboembolism. Prior major bleeding, renal disease and discharge on DAPT were multivariate predictors of major bleeding after LAAO.

9.
Nano Lett ; 23(7): 2883-2889, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37001024

RESUMEN

Strong hot-spots can facilitate photocatalytic reactions potentially providing effective solar-to-chemical energy conversion pathways. Although it is well-known that the local electromagnetic field in plasmonic nanocavities increases as the cavity size reduces, the influence of hot-spots on photocatalytic reactions remains elusive. Herein, we explored hot-spot dependent catalytic behaviors on a highly controlled platform with varying interparticle distances. Plasmon-meditated dehalogenation of 4-iodothiophenol was employed to observe time-resolved catalytic behaviors via in situ surface-enhanced Raman spectroscopy on dimers with 5, 10, 20, and 30 nm interparticle distances. As a result, we show that by reducing the gap from 20 to 10 nm, the reaction rate can be sped up more than 2 times. Further reduction in the interparticle distance did not improve reaction rate significantly although the maximum local-field was ∼2.3-fold stronger. Our combined experimental and theoretical study provides valuable insights in designing novel plasmonic photocatalytic platforms.

10.
Angew Chem Int Ed Engl ; 63(11): e202319920, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38236010

RESUMEN

Due to their broken symmetry, chiral plasmonic nanostructures have unique optical properties and numerous applications. However, there is still a lack of comprehension regarding how chirality transfer occurs between circularly polarized light (CPL) and these structures. Here, we thoroughly investigate the plasmon-assisted growth of chiral nanoparticles from achiral Au nanocubes (AuNCs) via CPL without the involvement of any chiral molecule stimulators. We identify the structural chirality of our synthesized chiral plasmonic nanostructures using circular differential scattering (CDS) spectroscopy, which is correlated with scanning electron microscopy imaging at both the single-particle and ensemble levels. Theoretical simulations, including hot-electron surface maps, reveal that the plasmon-induced chirality transfer is mediated by the asymmetric distribution of hot electrons on achiral AuNCs under CPL excitation. Furthermore, we shed light on how this plasmon-induced chirality transfer can also be utilized for chiral growth in bimetallic systems, such as Ag or Pd on AuNCs. The results presented here uncover fundamental aspects of chiral light-matter interaction and have implications for the future design and optimization of chiral sensors and chiral catalysis, among others.

11.
Circulation ; 145(5): 321-329, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34779221

RESUMEN

BACKGROUND: The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. METHODS: The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. RESULTS: In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). CONCLUSIONS: In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.


Asunto(s)
Arritmias Cardíacas/terapia , Desfibriladores Implantables/normas , Anciano , Arritmias Cardíacas/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento
12.
N Engl J Med ; 383(6): 526-536, 2020 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-32757521

RESUMEN

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) was designed to avoid complications related to the transvenous ICD lead by using an entirely extrathoracic placement. Evidence comparing these systems has been based primarily on observational studies. METHODS: We conducted a noninferiority trial in which patients with an indication for an ICD but no indication for pacing were assigned to receive a subcutaneous ICD or transvenous ICD. The primary end point was the composite of device-related complications and inappropriate shocks; the noninferiority margin for the upper boundary of the 95% confidence interval for the hazard ratio (subcutaneous ICD vs. transvenous ICD) was 1.45. A superiority analysis was prespecified if noninferiority was established. Secondary end points included death and appropriate shocks. RESULTS: A total of 849 patients (426 in the subcutaneous ICD group and 423 in the transvenous ICD group) were included in the analyses. At a median follow-up of 49.1 months, a primary end-point event occurred in 68 patients in the subcutaneous ICD group and in 68 patients in the transvenous ICD group (48-month Kaplan-Meier estimated cumulative incidence, 15.1% and 15.7%, respectively; hazard ratio, 0.99; 95% confidence interval [CI], 0.71 to 1.39; P = 0.01 for noninferiority; P = 0.95 for superiority). Device-related complications occurred in 31 patients in the subcutaneous ICD group and in 44 in the transvenous ICD group (hazard ratio, 0.69; 95% CI, 0.44 to 1.09); inappropriate shocks occurred in 41 and 29 patients, respectively (hazard ratio, 1.43; 95% CI, 0.89 to 2.30). Death occurred in 83 patients in the subcutaneous ICD group and in 68 in the transvenous ICD group (hazard ratio, 1.23; 95% CI, 0.89 to 1.70); appropriate shocks occurred in 83 and 57 patients, respectively (hazard ratio, 1.52; 95% CI, 1.08 to 2.12). CONCLUSIONS: In patients with an indication for an ICD but no indication for pacing, the subcutaneous ICD was noninferior to the transvenous ICD with respect to device-related complications and inappropriate shocks. (Funded by Boston Scientific; PRAETORIAN ClinicalTrials.gov number, NCT01296022.).


Asunto(s)
Arritmias Cardíacas/terapia , Desfibriladores Implantables/efectos adversos , Anciano , Cardiomiopatías/terapia , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/prevención & control , Electrodos Implantados/efectos adversos , Falla de Equipo , Femenino , Estudios de Seguimiento , Cardiopatías/terapia , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Diseño de Prótesis
13.
Chemistry ; 29(19): e202203625, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-36571402

RESUMEN

Sulfones and carboxylic acids are prominent motifs widely present in the chemical structure of agrochemicals, pharmaceuticals and many other highly valuable compounds. Herein, we describe a conjunctive strategy for the precise installation of these functionalities onto styrenes using sodium sulfinates and CO2 as coupling partners. The protocol allowed the preparation of carboxy-sulfonylated compounds in good yields and broad functional group tolerance. Additionally, taking advantage of the leaving group ability of the sulfone moiety, a one-pot photocatalytic carboxy-sulfonylation-elimination strategy was developed for the synthesis of α-aryl-acrylates.

14.
Europace ; 25(5)2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37072340

RESUMEN

AIMS: RECOVER AF evaluated the performance of whole-chamber non-contact charge-density mapping to guide the ablation of non-pulmonary vein (PV) targets in persistent atrial fibrillation (AF) patients following either a first or second failed procedure. METHODS AND RESULTS: RECOVER AF was a prospective, non-randomized trial that enrolled patients scheduled for a first or second ablation retreatment for recurrent AF. The PVs were assessed and re-isolated if necessary. The AF maps were used to guide the ablation of non-PV targets through elimination of pathologic conduction patterns (PCPs). Primary endpoint was freedom from AF on or off antiarrhythmic drugs (AADs) at 12 months. Patients undergoing retreatment with the AcQMap System (n = 103) were 76% AF-free at 12 months [67% after single procedure (SP)] on or off AADs (80% free from AF on AADs). Patients who had only received a pulmonary vein isolation (PVI) prior to study treatment of non-PV targets with the AcQMap System were 91% AF-free at 12 months (83% SP). No major adverse events were reported. CONCLUSION: Non-contact mapping can be used to target and guide the ablation of PCPs beyond the PVs in persistent AF patients returning for a first or second retreatment with 76% freedom from AF at 12 months. The AF freedom was particularly high, 91% (43/47), for patients enrolled having only a prior de novo PVI, and freedom from all atrial arrhythmias for this cohort was 74% (35/47). These early results are encouraging and suggest that guiding individualized targeted ablation of PCPs may therefore be advantageous to target at the earliest opportunity in patients with persistent AF.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Humanos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Fibrilación Atrial/etiología , Estudios Prospectivos , Venas Pulmonares/cirugía , Retratamiento , Antiarrítmicos , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Resultado del Tratamiento , Recurrencia
15.
Pacing Clin Electrophysiol ; 46(7): 574-582, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37254956

RESUMEN

INTRODUCTION: Over the past years, mapping and ablation techniques for the treatment of ventricular tachycardia (VT) have evolved rapidly. High Density (HD) substrate mapping is now routine and pre-procedural imaging is increasingly used. The additional value of these techniques for long-term VT-free survival is not clear. METHODS: We compared baseline and procedural characteristics, procedural success, safety and outcome of mapping and ablation of ventricular tachycardia in patients with ischemic heart disease between two groups. (1) Low Density (LD) group: VT mapping and ablation with a 4 mm single tip catheter (2) HD group: HD substrate mapping with the Pentaray (Biosense Webster, USA) or HD Grid (Abbott, USA) catheter and ablation with a 4 mm single tip catheter. RESULTS: VT ablation was performed in 133 patients (71 patients in LD group and 62 patients in HD group). The median follow-up was 5.0 years in LD group and 2.0 years in HD group. One-, two-, and five-year VT recurrence rates were 47%, 56%, and 65% in the LD group versus 39%, 50%, and 55% in the HD group (log-rank test for VT recurrence p = .70). One-, two-, and five-year ICD shock recurrence rates were 14%, 18%, and 24% in the LD group versus 8%, 15%, and 19% in the HD group (log-rank test for ICD-shock p = .79). All-cause mortality, cardiac (non-arrhythmic), and arrhythmic death, were similar in both groups. Severe procedural complications (tamponade, stroke, or procedural death) occurred in four patients (5%, 1 vascular, 3 tamponade) in the LD group versus two patients (3%, both tamponade) in the HD group (NS). In univariate and multivariable analysis, only a higher LVEF was significantly associated with VT-free survival. HD mapping was not significantly associated with VT-free survival. Anterior infarct location and age were significantly associated with ICD recurrent shock in both univariate and multivariable analyses. CONCLUSIONS: In patients with ischemic cardiomyopathy, a HD substrate mapping, and ablation strategy did not lead to higher VT-free survival and shock-free survival compared to a single tip mapping and ablation strategy. In this study, only LVF is an independent predictor for VT recurrence. Anterior infarct location and age predict recurrent ICD shocks.


Asunto(s)
Cardiomiopatías , Ablación por Catéter , Isquemia Miocárdica , Taquicardia Ventricular , Humanos , Resultado del Tratamiento , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/cirugía , Cardiomiopatías/complicaciones , Cardiomiopatías/cirugía , Infarto/complicaciones , Infarto/cirugía , Ablación por Catéter/métodos , Recurrencia
16.
Pacing Clin Electrophysiol ; 46(11): 1403-1411, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37724739

RESUMEN

BACKGROUND: High-density (HD) mapping is increasingly used to characterize arrhythmic substrate for ablation of atypical atrial flutters (AAFl). However, results on clinical outcomes and factors that are associated with arrhythmia recurrence are scarce. METHODS: Single-center, prospective, observational cohort study that enrolled patients with catheter ablation for AAFl using a HD mapping system and a grid-shaped mapping catheter. Procedural characteristics, rates of atrial flutter recurrence, and factors that were associated with atrial flutter recurrence were evaluated. RESULTS: Sixty-one patients with a total of 94 AAFl were included in the cohort. HD mapping was used to successfully identify the flutter circuit of 80/94 AAFl. The circuit was not identified for 14/94 AAFl in 11 patients. Critical isthmuses were identified and ablated in 29 patients (48%). Acute procedural success was achieved in 52 patients (85%), and 37 patients (61%) remained free from atrial flutter recurrence during a follow up of 1.3 [1.0-2.1] years. Atrial flutter recurrence was univariably associated with presence of a non-identified flutter circuit (HR:2.6 95% CI [1.1-6.3], p = .04) and critical isthmus-targeted ablation (HR:0.4 [0.15-0.90], p = .03). In multivariable regression analyses, critical isthmus ablation remained significant (HR:0.4 [0.16-0.97], p = .04), whereas presence of a non-identified flutter did not (HR:2.4 [0.96-5.8], p = .06). CONCLUSION: HD mapping was successfully used to identify the majority of AAFl circuits. Ablation resulted in freedom from atrial flutter recurrence in 61% of the cohort. Successful identification of all flutter circuits and critical isthmuses appears to be beneficial for long-term outcomes.


Asunto(s)
Aleteo Atrial , Ablación por Catéter , Humanos , Estudios Prospectivos , Estudios de Cohortes , Ablación por Catéter/métodos
17.
An Acad Bras Cienc ; 95(suppl 3): e20210528, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37820118

RESUMEN

The impact of the Antarctic Ozone Hole Influence over Southern Brazil in October 2015 was analyzed using daily mean data of the Total Column Ozone (TCO), Ultraviolet Index (UVI) and Radiative Cloud Fraction (RCF) from the Ozone Monitoring Instrument satellite instrument. Vertical profiles and fields of ozone content and Potential Vorticity available from the European Centre for Medium-Range Weather Forecast reanalysis, air masses backward trajectories from the HYbrid Single-Particle Lagrangian Integrated Trajectory model and channel 3 water vapor images from the Geostationary Operational Environmental Satellite GOES-13 were also analyzed. The five identified events showed an -7.4±2.3% average TCO reduction, leading to an +16.6±54.6% UVI increase even with a predominance of partly cloudy days. Other impacts were observed in the ozone profiles, where the most significant anomalies occurred from 650 K reaching 1.2 ppmv at the 850 K level. In the ozone fields at 700 K, the presence of a polar origin tongue was observed causing negatives anomalies between -0.2 and 0.4 ppmv in a transient system format forced with eastward-traveling Rossby waves passing through the Southern of Brazil and Uruguay.


Asunto(s)
Pérdida de Ozono , Ozono , Brasil , Tiempo (Meteorología) , Regiones Antárticas
18.
Eur Heart J ; 43(21): 2037-2050, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35090007

RESUMEN

AIMS: To report 5-year outcomes of EFFORTLESS registry patients with early generation subcutaneous implantable cardioverter-defibrillator (S-ICD) devices. METHODS AND RESULTS: Kaplan-Meier, trend and multivariable analyses were performed for mortality and late (years 2-5) complications, appropriate shock (AS) and inappropriate shock (IAS) rates. Nine hundred and eighty-four of 994 enrolled patients with diverse diagnoses (28% female, 48 ± 17 years, body mass index 27 ± 6 kg/m2, ejection fraction 43 ± 18%) underwent S-ICD implantation. Median follow-up was 5.1 years (interquartile range 4.7-5.5 years). All-cause mortality was 9.3% (95% confidence interval 7.2-11.3%) at 5 years; 703 patients remained in follow-up on study completion, 171 withdrew including 87 (8.8%) with device explanted, and 65 (6.6%) lost to follow-up. Of the explants, only 20 (2.0%) patients needed a transvenous device for pacing indications. First and final shock efficacy for discrete ventricular arrhythmias was consistent at 90% and 98%, respectively, with storm episode final shock efficacy at 95.2%. Time to therapy remained unaltered. Overall 1- and 5-year complication rates were 8.9% and 15.2%, respectively. Early complications did not predict later complications. There were no structural lead failures. Inappropriate shock rates at 1 and 5 years were 8.7% and 16.9%, respectively. Self-terminating inappropriately sensed episodes predicted late IAS. Predictors of late AS included self-terminating appropriately sensed episodes and earlier AS. CONCLUSION: In this diverse S-ICD registry population, spontaneous shock efficacy was consistently high over 5 years. Very few patients underwent S-ICD replacement with a transvenous device for pacing indications. Treated and self-terminating arrhythmic episodes predict future shock events, which should encourage more personalized device optimization.


Asunto(s)
Desfibriladores Implantables , Arritmias Cardíacas , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Volumen Sistólico , Resultado del Tratamiento
19.
Eur Heart J ; 43(47): 4872-4883, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36030464

RESUMEN

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. The PRAETORIAN trial demonstrated that the S-ICD is non-inferior to the TV-ICD with regard to the combined primary endpoint of inappropriate shocks and complications. This prespecified secondary analysis evaluates all complications in the PRAETORIAN trial. METHODS AND RESULTS: The PRAETORIAN trial is an international, multicentre, randomized trial in which 849 patients with an indication for ICD therapy were randomized to receive an S- ICD (N = 426) or TV-ICD (N = 423) and followed for a median of 49 months. Endpoints were device-related complications, lead-related complications, systemic infections, and the need for invasive interventions. Thirty-six device-related complications occurred in 31 patients in the S-ICD group of which bleedings were the most frequent. In the TV-ICD group, 49 complications occurred in 44 patients of which lead dysfunction was most frequent (HR: 0.69; P = 0.11). In both groups, half of all complications were within 30 days after implantation. Lead-related complications and systemic infections occurred significantly less in the S-ICD group compared with the TV-ICD group (P < 0.001, P = 0.03, respectively). Significantly more complications required invasive interventions in the TV-ICD group compared with the S-ICD group (8.3% vs. 4.3%, HR: 0.59; P = 0.047). CONCLUSION: This secondary analysis shows that lead-related complications and systemic infections are more prevalent in the TV-ICD group compared with the S-ICD group. In addition, complications in the TV-ICD group were more severe as they required significantly more invasive interventions. This data contributes to shared decision-making in clinical practice.


Asunto(s)
Muerte Súbita Cardíaca , Desfibriladores Implantables , Humanos , Resultado del Tratamiento , Desfibriladores Implantables/efectos adversos
20.
Mikrochim Acta ; 190(8): 297, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37460848

RESUMEN

A new electrochemical device fabricated by the combination of 3D printing manufacturing and laser-generated graphene sensors is presented. Cell and electrodes were 3D printed by the fused deposition modeling (FDM) technique employing acrylonitrile butadiene styrene filament (insulating material that composes the cell) and conductive filament (lab-made filament based on graphite dispersed into polylactic acid matrix) to obtain reference and auxiliary electrodes. Infrared-laser engraved graphene, also reported as laser-induced graphene (LIG), was produced by laser conversion of a polyimide substrate, which was assembled in the 3D-printed electrochemical cell that enables the analysis of low volumes (50-2000 µL). XPS analysis revealed the formation of nitrogen-doped graphene multilayers that resulted in excellent electrochemical sensing properties toward the detection of atropine (ATR), a substance that was found in beverages to facilitate sexual assault and other criminal acts. Linear range between 5 and 35 µmol L-1, detection limit of 1 µmol L-1, and adequate precision (RSD = 4.7%, n = 10) were achieved using differential-pulse voltammetry. The method was successfully applied to beverage samples with recovery values ranging from 80 to 105%. Interference studies in the presence of species commonly found in beverages confirmed satisfactory selectivity for ATR sensing. The devices proposed are useful portable analytical tools for on-site applications in the forensic scenario.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda