Recurrent monomorphic ventricular tachycardia in a patient with myocarditis-Importance of understanding and targeting midmyocardial anatomic substrate.

INTRODUCTION: Patients with viral myocarditis can present with challenging life-threatening arrhythmias. Catheter ablation can be a life-saving procedure in some patients with recurrent drug-refractory ventricular arrhythmias. METHODS AND RESULTS: A patient with three prior ablations targeting two different monomorphic ventricular tachycardias (MMVTs) presented with recurrent ventricular tachycardia (VT). Consequently, he underwent epicardial mapping with adjuvant AI-enabled CT images with the creation of a three-dimensional model, which demonstrated a midmyocardial scar. Fractionated potentials were noted during mapping in this region, and entrainment suggested an inner loop. Interestingly, pacing showed two different QRS morphologies identical to his previously ablated VTs with a long stim-QRS at this region. Epicardial ablation carried on during the VT successfully terminated it, but the VT remained inducible and required endocardial ablation to make it noninducible. CONCLUSION: This case emphasizes the importance of recognizing possible three-dimensional VT circuits in some patients and the need to understand and target mid-myocardial substrate from both the endocardium and epicardium to achieve the elimination of the VT circuits.

Impact of intracardiac echocardiography versus transesophageal echocardiography guidance on left atrial appendage occlusion procedures: A meta-analysis.

BACKGROUND: Intracardiac echocardiography (ICE) is increasingly used during left atrial appendage occlusion (LAAO) as an alternative to transesophageal echocardiography (TEE). The objective of this study is to evaluate the impact of ICE versus TEE guidance during LAAO on procedural characteristics and acute outcomes, as well the presence of peri-device leaks and residual septal defects during follow-up. METHODS: All studies comparing ICE-guided versus TEE-guided LAAO were identified. The primary outcomes were procedural efficacy and occurrence of procedure-related complications. Secondary outcomes included lab efficiency (defined as a reduction in in-room time), procedural time, fluoroscopy time, and presence of peri-device leaks and residual interatrial septal defects (IASD) during follow-up. RESULTS: Twelve studies (n = 5637) were included. There were no differences in procedural success (98.3% vs. 97.8%; OR 0.73, 95% CI 0.42-1.27, p = .27; I2 = 0%) or adverse events (4.5% vs. 4.4%; OR 0.81 95% CI 0.56-1.16, p = .25; I2 = 0%) between the ICE-guided and TEE-guided groups. ICE guidance reduced in in-room time (mean-weighted 28.6-min reduction in in-room time) without differences in procedural time or fluoroscopy time. There were no differences in peri-device leak (OR 0.93, 95% CI 0.68-1.27, p = 0.64); however, an increased prevalence of residual IASD was observed with ICE-guided versus TEE-guided LAAO (46.3% vs. 34.2%; OR 2.23, 95% CI 1.05-4.75, p = 0.04). CONCLUSION: ICE guidance is associated with similar procedural efficacy and safety, but could result in improved lab efficiency (as established by a significant reduction in in-room time). No differences in the rate of periprocedural leaks were found. A higher prevalence of residual interatrial septal defects was observed with ICE guidance.

Adjunctive low-voltage area ablation for patients with atrial fibrillation: An updated meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of adjunctive low-voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain. METHODS: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses. RESULTS: Our meta-analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67-0.88; p < .01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35-0.85; p < .01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38-0.86; p < .01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39-1.56; p = .49). CONCLUSIONS: Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF.

Understanding Lesion Creation Biophysics and Improved Lesion Assessment during Radiofrequency Catheter Ablation. The Perfect Combination to Achieve Durable Lesions in Atrial Fibrillation Ablation.

Atrial fibrillation (AF) is a prevalent arrhythmia, while pulmonary vein isolation (PVI) has become a cornerstone in its treatment. The creation of durable lesions is crucial for successful and long-lasting PVI, as inconsistent lesions lead to reconnections and recurrence after ablation. Various approaches have been developed to assess lesion quality and transmurality in vivo, acting as surrogates for improved lesion creation and long-term outcomes utilizing radiofrequency (RF) energy. This review manuscript examines the biophysics of lesion creation and different lesion assessment techniques that can be used daily in the electrophysiology laboratory when utilizing RF energy. These methods provide valuable insights into lesion effectiveness, facilitating optimized ablation procedures and reducing atrial arrhythmia recurrences. However, each approach has its limitations, and a combination of techniques is recommended for comprehensive lesion assessment during AF catheter ablation. Future advancements in imaging techniques, such as magnetic Resonance Imaging (MRI), optical coherence tomography, and photoacoustic imaging, hold promise in further enhancing lesion evaluation and guiding treatment strategies.

Measures to Prevent Infection in Cardiac Implantable Electronic Device Replacements or Upgrades.

Cardiac implantable electronic device (CIED) infections represent one of the most threatening complications associated with device implantation, due to an increase in morbidity and mortality rates, as well as healthcare costs. Besides, it is important to highlight that when compared to the initial implantation of a device, the risks associated with procedures like generator changes, lead and pocket revisions, or device upgrades double. Consequently, to address this issue, various scoring systems, like the PADIT (Prior Procedures, Age, Depressed Renal Function, Immunocompromised Status, Type of Procedure), the RI-AIAC (Ricerca Sulle Infezioni Associate a ImpiAnto o Sostituzione di CIED), and the Shariff score, along with predictive models, have been developed to identify patients at a greater risk of infection. Moreover, several interventions have been assessed to evaluate their role in infection prevention ranging from improving skin preparation and surgical techniques to considering alternative strategies such as the subcutaneous Implantable Cardioverter-Defibrillator (ICD). Methods like antimicrobial prophylaxis, pocket irrigation, chlorhexidine gluconate pocket lavage, capsulectomy, and the use of antibacterial envelopes have been also explored as preventive measures. In this review, we provide a comprehensive assessment of CIED infections in patients undergoing repeat procedures and the strategies designed to reduce the risk of these infections.

Third stage of labor: evidence-based practice for prevention of adverse maternal and neonatal outcomes.

The third stage of labor is defined as the time period between delivery of the fetus through delivery of the placenta. During a normal third stage, uterine contractions lead to separation and expulsion of the placenta from the uterus. Postpartum hemorrhage is a relatively common complication of the third stage of labor. Strategies have been studied to mitigate the risk of postpartum hemorrhage, leading to the widespread implementation of active management of the third stage of labor. Initially, active management of the third stage of labor consisted of a bundle of interventions including administration of a uterotonic agent, early cord clamping, controlled cord traction, and external uterine massage. However, the effectiveness of these interventions as a bundle has been questioned, leading to abandonment of some components in recent years. Despite this, upon review of selected international guidelines, we found that the term "active management of the third stage of labor" was still used, but recommendations for and against individual interventions were variable and not necessarily supported by current evidence. In this review, we: (1) examine the physiology of the third stage of labor, (2) present evidence related to interventions that prevent postpartum hemorrhage and promote maternal and neonatal health, (3) review current global guidelines and recommendations for practice, and (4) propose future areas of investigation. The interventions in this review include pharmacologic agents to prevent postpartum hemorrhage, cord clamping, cord milking, cord traction, cord drainage, early skin-to-skin contact, and nipple stimulation. Treatment of complications of the third stage of labor is outside of the scope of this review. We conclude that current evidence supports the use of effective pharmacologic postpartum hemorrhage prophylaxis, delayed cord clamping, early skin-to-skin contact, and controlled cord traction at delivery when feasible. The most effective uterotonic regimens for preventing postpartum hemorrhage after vaginal delivery include oxytocin plus ergometrine; oxytocin plus misoprostol; or carbetocin. After cesarean delivery, carbetocin or oxytocin as a bolus are the most effective regimens. There is inconsistent evidence regarding the use of tranexamic acid in addition to a uterotonic compared with a uterotonic alone for postpartum hemorrhage prevention after all deliveries. Because of differences in patient comorbidities, costs, and availability of resources and staff, decisions to use specific prevention strategies are dependent on patient- and system-level factors. We recommend that the term "active management of the third stage of labor" as a combined intervention no longer be used. Instead, we recommend that "third stage care" be adopted, which promotes the implementation of evidence-based interventions that incorporate practices that are safe and beneficial for both the woman and neonate.

Depletion forces in dense mixtures of spheres and rods.

We evaluate depletion forces in molecular dynamics simulation of a binary mixture of spheres (depleted particles) and rods (depletant particles) for a wide range of densities for both species. This evaluation was carried out using a recently proposed least squares fitting algorithm. We found that the restriction of the rods' rotational degrees of freedom, when the distance between two spheres is less than the rods length, creates a shallow, and apparently linear, attractive force ramp. For intersphere distances smaller than the rods' diameter, a much stronger attractive force is found, and a large repulsive barrier appears between these aforementioned regimes, roughly at the distance of the rods' thickness. The evaluated forces are validated via a comparison of the pairwise correlation functions obtained from molecular dynamics simulation of a mono-disperse sphere fluid, using the evaluated effective forces, against the original (full system) pairwise correlation functions. Agreement is excellent. We also record the angular pairwise correlation function, using the P2(x) Legendre polynomial, and find that for high densities of both species, a local nematic ordering starts to appear. This nematic order may be a factor in the small differences found between original and effective pairwise correlation functions at high densities of rods.

Kinetic Study and Reaction Mechanism of the Gas-Phase Thermolysis Reaction of Methyl Derivatives of 1,2,4,5-Tetroxane.

Tetroxane derivatives are interesting drugs for antileishmaniasis and antimalaric treatments. The gas-phase thermal decomposition of 3,6,-dimethyl-1,2,4,5-tetroxane (DMT) and 3,3,6,6,-tetramethyl-1,2,4,5-tetroxane (acetone diperoxide (ACDP)) was studied at 493-543 K by direct gas chromatography by means of a flow reactor. The reaction is produced in the injector chamber at different temperatures. The resulting kinetics Arrhenius equations were calculated for both tetroxanes. Including the parent compound of the series 1,2,4,5-tetroxane (formaldehyde diperoxide (FDP)), the activation energy and frequency factors decrease linearly with the number of methyl groups. The reaction mechanisms of ACDP and 3,6,6-trimethyl-1,2,4,5-tetroxane (TMT) decomposition have been studied by means of the DFT method with the BHANDHLYP functional. Our calculations confirm that the concerted mechanism should be discarded and that only the stepwise mechanism occurs. The critical points of the singlet and triplet state potential energy surfaces (S- and T-PES) of the thermolysis reaction of both compounds have been determined. The calculated activation energies of the different steps vary linearly with the number of methyl groups of the methyl-tetroxanes series. The mechanism for the S-PES leads to a diradical O···O open structure, which leads to a C···O dissociation in the second step and the production of the first acetaldehyde/acetone molecule. This last one yields a second C···O dissociation, producing O2 and another acetone/acetaldehyde molecule. The O2 molecule is in the singlet state. A quasi-parallel mechanism for the T-PES from the open diradical to products is also found. Most of the critical points of both PES are linear with the number of methyl groups. Reaction in the triplet state is much more exothermic than the singlet state mechanism. Transitions from the singlet ground state, S0 and low-lying singlet states S1-3, to the low-lying triplet excited states, T1-4, (chemical excitation) in the family of methyl tetroxanes are also studied at the CASSCF/CASPT2 level. Two possible mechanisms are possible here: (i) from S0 to T3 by strong spin orbit coupling (SOC) and subsequent fast internal conversion to the excited T1 state and (ii) from S0 to S2 from internal conversion and subsequent S2 to T1 by SOC. From these experimental and theoretical results, the additivity effect of the methyl groups in the thermolysis reaction of the methyl tetroxane derivatives is clearly highlighted. This information will have a great impact for controlling these processes in the laboratory and chemical industries.

Adsorption of Ciprofloxacin on Clay Minerals in Argentinian Santa Rosa-Corrientes Soils.

The presence of antibiotics in soils is increasing drastically in last decades due to the intensive farming industry and excessive human consumption. Clay minerals are one of the soil components with great adsorption capacity for organic pollutants. The study of interactions between antibiotics and mineral surfaces will give us scientific knowledge of these pollutants through soils. In this work, we study the adsorption of the antibiotic ciprofloxacin in the clay mineral fraction of soils from the Argentinian zone of Santa Rosa (Corrientes), in a collaborative research of experiments and atomistic modelling calculations of the intercalation of ciprofloxacin in the interlayer space of montmorillonite. Adsorption and desorption isotherms were performed and compared with different isotherm models. Additionally, enthalpy, entropy, and free energy were determined from equilibrium constants at a function of temperature. All these experiments and calculations lead to the conclusions that two adsorption types of ciprofloxacin are found on clay minerals: one weakly sorbed that is released during the desorption experiments, and other one strongly joined that remains in the soil.

Evaluation of obstructive sleep apnea among consecutive patients with all patterns of atrial fibrillation using WatchPAT home sleep testing.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice and is associated with significant morbidity, mortality, and financial burden. Obstructive sleep apnea (OSA) is more common in individuals with AF and may impair the efficacy of rhythm control strategies including catheter ablation. However, the prevalence of undiagnosed OSA in all-comers with AF is unknown. DESIGN: This pragmatic, phase IV prospective cohort study will test 250-300 consecutive ambulatory AF patients with all patterns of atrial fibrillation (paroxysmal, persistent, and long-term persistent) and no prior sleep testing for OSA using the WatchPAT system, a disposable home sleep test (HST). The primary outcome of the study is the prevalence of undiagnosed OSA in all-comers with atrial fibrillation. RESULTS: Preliminary results from the initial pilot enrollment of approximately 15% (N = 38) of the planned sample size demonstrate a 79.0% prevalence of at least mild (AHI≥5) OSA or greater in consecutively enrolled patient with all patterns of AF. CONCLUSIONS: We report the design, methodology, and preliminary results of our study to define the prevalence of OSA in AF patients. This study will help inform approaches to OSA screening in patients with AF for which there is currently little practical guidance. CLINICAL TRIAL REGISTRATION: NCT05155813.

Ablation of atrial fibrillation beyond pulmonary vein isolation: Do additional ablation lesions impact left atrial function?

INTRODUCTION: Electrical isolation of pulmonary veins (PVI) is a cornerstone for atrial fibrillation (AF) ablation. The overall effect of AF ablation, and especially lesions beyond PVI, on left atrial (LA) function is currently poorly understood. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We performed non-inferiority analysis of LA function after PVI with additional nonpulmonary vein ablation lesions in LA (PVI+) and PVI alone. METHODS: We studied 68 patients consecutive patients who underwent AF ablation and who had complete transthoracic echocardiogram (TTE) within 12 months before AF ablation and 1-12 months after the procedure. Patients were stratified into two groups: PVI only and PVI+. Primary outcome was change in LA reservoir strain (LASr). Noninferiority margin was defined at 6%. RESULTS: The PVI only group had a higher proportion of patients with paroxysmal AF (70% vs. 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0% vs. 4.3%, p < .01 for noninferiority). LASr noninferiority was confirmed when adjusted for age, sex, coronary artery disease, hyperlipidemia, and AF type, rhythm at preprocedure TTE in a multivariable linear regression model, 90% CI (-5.46 to 2.04), p < .01. CONCLUSION: LA functional improvement evaluated by LASr was noninferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables, suggesting that more extensive ablation does not negatively affect LA function.

Outcomes of chlorhexidine lavage without capsulectomy versus complete capsulectomy after lead extraction for the treatment of cardiac implantable electronic device infection.

INTRODUCTION: Capsulectomy is recommended in patients with cardiac implantable electronic device (CIED) infection after transvenous lead extraction (TLE) but is time-consuming and requires extensive tissue debridement. In this study, we describe the outcomes of chlorhexidine gluconate (CHG) lavage in lieu of capsulectomy for the treatment of CIED infections. METHODS: This retrospective study included patients who underwent TLE for CIED-related infections in two institutions in Colombia. In the capsulectomy group, complete capsulectomy was performed after hardware removal. In the CHG group, exhaustive lavage of the generator pocket with 20 cc of CHG at 2% followed by irrigation with approximately 500 cc of normal saline (0.9% sodium chloride) was performed. The primary outcomes included reinfection and hematoma formation in the generator pocket. Secondary outcomes included the occurrence of any adverse reaction to chlorhexidine, the need for reintervention, infection-related mortality, and total procedural time. RESULTS: A total of 102 patients (mean age 67.2 ± 13 years, 32.4% female) underwent CIED extraction with either total capsulectomy (n = 54) or CHG (n = 48) lavage. Hematoma formation was significantly higher in the capsulectomy group versus the CHG group (13% vs. 0%, p = .014), with no significant differences in the reinfection rate. Capsulectomy was associated with longer procedural time (133.7 ± 78.5 vs. 89.9 ± 51.8 min, p = .002). No adverse reactions to CHG were found. Four patients (4.3%) died from worsening sepsis: three in the capsulectomy group and one in the CHG group (p = .346). CONCLUSIONS: In patients with CIED infections, the use of CHG without capsulectomy resulted in a lower risk of hematoma formation and shorter procedural times without an increased risk of reinfection or adverse events associated with CHG use.

Assisted reality device to guide cardiac implantable device programming in distant rural areas.

BACKGROUND: Patients with cardiac implantable electronic devices (CIEDs) living in rural areas have difficulty obtaining follow-up visits for device interrogation and programming in specialized healthcare facilities. OBJECTIVE: To describe the use of an assisted reality device designed to provide front-line workers with real-time online support from a remotely located specialist (Realwear HTM-1; Realwear) during CIED assistance in distant rural areas. METHODS: This is a prospective study of patients requiring CIED interrogation using the Realwear HMT-1 in a remote rural population in Colombia between April 2021 and June 2022. CIED interrogation and device programming were performed by a general practitioner and guided by a cardiac electrophysiologist. Non-CIED-related medical interventions were allowed and analyzed. The primary objective was to determine the incidence of clinically significant CIED alerts. Secondary objectives were the changes medical interventions used to treat the events found in the device interrogations regarding non-CIED related conditions. RESULTS: A total of 205 CIED interrogations were performed on 139 patients (age 69 ± 14 years; 54% female). Clinically significant CIED alerts were reported in 42% of CIED interrogations, consisting of the detection of significant arrhythmias (35%), lead malfunction (3%), and device in elective replacement interval (3.9%). Oral anticoagulation was initiated in 8% of patients and general medical/cardiac interventions unrelated to the CIED were performed in 52% of CIED encounters. CONCLUSION: Remote assistance using a commercially available assisted reality device has the potential to provide specialized healthcare to patients in difficult-to-reach areas, overcoming current difficulties associated with RM, including the inability to change device programming. Additionally, these interactions provided care beyond CIED-related interventions, thus delivering significant social and clinical impact to remote rural populations.

High-Power Short-Duration Ablation of Paroxysmal and Persistent Atrial Fibrillation.

Catheter ablation has become a cornerstone in atrial fibrillation (AF) therapy, improving freedom from all-atrial arrhythmias, as well as outperforming antiarrhythmic drugs in alleviating AF-related symptoms, reducing hospitalizations, and enhancing quality of life. Nevertheless, the success rate of traditional radiofrequency ablation (RFA) methods remains less than ideal. To address these issues, refinement in RFA strategies has been developed to improve efficacy and laboratory efficiency during pulmonary vein isolation (PVI). High-power short-duration (HPSD) RFA has emerged as a safe strategy to reduce the time required to produce durable lesions. This article reviews critical aspects of HPSD ablation in the management of both paroxysmal and persistent AF, covering aspects such as effectiveness, safety, procedural intricacies, and the underlying biophysics.

Pulsed Field Ablation of Atrial Fibrillation: A Comprehensive Review.

Pulsed-field ablation (PFA) has emerged as a promising nonthermal ablation alternative for treating atrial fibrillation (AF). By delivering ultra-rapid high-energy electrical pulses, PFA induces irreversible electroporation, selectively targeting myocardial tissue while sparing adjacent structures from thermal or other damage. This article provides a comprehensive review of multiple pre-clinical studies, clinical studies, and clinical trials evaluating the safety, efficacy, and long-term outcomes of PFA in various settings and patient populations. Overall, the reviewed evidence highlights PFA's potential as a revolutionary ablation strategy for AF treatment. Offering comparable procedural efficacy to conventional ablation methods, PFA distinguishes itself with shorter procedure times and reduced risks of complications such as phrenic nerve palsy and potential esophageal injury. While further research is warranted to establish long-term efficacy, PFA's distinct advantages and evolving clinical evidence suggest a promising future for this novel nonthermal ablation approach. As PFA continues to advance, it has the potential to transform AF ablation procedures, providing a safer alternative for patients with atrial fibrillation.

EHRA clinical consensus statement on conduction system pacing implantation: endorsed by the Asia Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS), and Latin American Heart Rhythm Society (LAHRS).

Conduction system pacing (CSP) has emerged as a more physiological alternative to right ventricular pacing and is also being used in selected cases for cardiac resynchronization therapy. His bundle pacing was first introduced over two decades ago and its use has risen over the last five years with the advent of tools which have facilitated implantation. Left bundle branch area pacing is more recent but its adoption is growing fast due to a wider target area and excellent electrical parameters. Nevertheless, as with any intervention, proper technique is a prerequisite for safe and effective delivery of therapy. This document aims to standardize the procedure and to provide a framework for physicians who wish to start CSP implantation, or who wish to improve their technique.

EHRA clinical consensus statement on conduction system pacing implantation: executive summary. Endorsed by the Asia-Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS) and Latin-American Heart Rhythm Society (LAHRS).

Conduction system pacing (CSP) has emerged as a more physiological alternative to right ventricular pacing and is also being used in selected cases for cardiac resynchronization therapy. His bundle pacing was first introduced over two decades ago and its use has risen over the last years with the advent of tools which have facilitated implantation. Left bundle branch area pacing is more recent but its adoption is growing fast due to a wider target area and excellent electrical parameters. Nevertheless, as with any intervention, proper technique is a prerequisite for safe and effective delivery of therapy. This document aims to standardize the procedure and to provide a framework for physicians who wish to start CSP implantation, or who wish to improve their technique. A synopsis is provided in this print edition of EP-Europace. The full document may be consulted online, and a 'Key Messages' App can be downloaded from the EHRA website.

Anatomical considerations and clinical interpretation of the 12-lead ECG in the prone position: a prospective multicentre study.

AIMS: The aim of this study is to provide guidance for the clinical interpretation of electrocardiograms (ECGs) in prone position and to establish the electroanatomic explanations for the possible differences to supine position ECGs that may be observed. Additionally, to determine if prone back ECG can be used as an alternative to standard ECG in patients who may benefit from prone position. METHODS AND RESULTS: The ECG in supine (standard ECG), prone back (precordial leads placed on the patient's back), and prone anterior position (precordial leads placed in the standard position with the subjects in prone position) were prospectively examined on 85 subjects. Comparisons of ECG parameters between these positions were performed. Computed tomography (CT) scans were performed in both positions to determine possible electroanatomic aetiologies for prone-associated ECG changes. There were significant differences in QRS amplitude in Leads V1-V5 between supine and prone positions. Q waves were more frequently observed in prone back position vs. supine position (V1: 74.1 vs. 10.6%, P < 0.0001; V2: 23.5 vs. 0%, P < 0.0001, respectively). Flat and inverted T waves were more common in prone back leads (V1: 98 vs. 66%, P < 0.0001; V2: 96 vs. 8%, P < 0.0001; V3: 45 vs. 7%, P < 0.0001). The 3D-CT reconstructions measurements corroborated the significant inverse correlation between QRS amplitude and the distance from the centre of the heart to the estimated lead positions. CONCLUSION: In prone back position ECG, low QRS amplitude should not be misinterpreted as low voltage conditions, neither should Q waves and abnormal T waves are considered anteroseptal myocardial infarction. These changes can be explained by an increased impedance (due to interposing lung tissue) and by the increased distance between the electrodes to the centre of the heart.

Global warming and recurrent mass bleaching of corals.

During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.

Immunoescape of HIV-1 in Env-EL9 CD8 + T cell response restricted by HLA-B*14:02 in a Non progressor who lost twenty-seven years of HIV-1 control.

BACKGROUND: Long-Term Non-Progressors (LTNPs) are untreated Human Immunodeficiency virus type 1 (HIV-1) infected individuals able to control disease progression for prolonged periods. However, the LTNPs status is temporary, as viral load increases followed by decreases in CD4 + T-cell counts. Control of HIV-1 infection in LTNPs viremic controllers, have been associated with effective immunodominant HIV-1 Gag-CD8 + T-cell responses restricted by protective HLA-B alleles. Individuals carrying HLA-B*14:02 control HIV-1 infection is related to an immunodominant Env-CD8 + T-cell response. Limited data are available on the contribution of HLA-B*14:02 CD8 + T -cells in LTNPs. RESULTS: In this study, we performed a virological and immunological detailed analysis of an HLA-B*14:02 LNTP individual that lost viral control (LVC) 27 years after HIV-1 diagnosis. We analysed viral evolution and immune escape in HLA-B*14:02 restricted CD8 + T -cell epitopes and identified viral evolution at the Env-EL9 epitope selecting the L592R mutation. By IFN-γ ELISpot and immune phenotype, we characterized HLA- B*14:02 HIV-1 CD8 + T cell responses targeting, Gag-DA9 and Env-EL9 epitopes before and after LVC. We observed an immunodominant response against the Env-EL9 epitope and a decreased of the CD8 T + cell response over time with LVC. Loss of Env-EL9 responses was concomitant with selecting K588R + L592R mutations at Env-EL9. Finally, we evaluated the impact of Env-EL9 escape mutations on HIV-1 infectivity and Env protein structure. The K588R + L592R escape variant was directly related to HIV-1 increase replicative capacity and stability of Env at the LVC. CONCLUSIONS: These findings support the contribution of immunodominant Env-EL9 CD8 + T-cell responses and the imposition of immune escape variants with higher replicative capacity associated with LVC in this LNTP. These data highlight the importance of Env-EL9 specific-CD8 + T-cell responses restricted by the HLA-B*14:02 and brings new insights into understanding long-term HIV-1 control mediated by Env mediated CD8 + T-cell responses.