SpadaHC: a database to improve the classification of variants in hereditary cancer genes in the Spanish population.

Accurate classification of genetic variants is crucial for clinical decision-making in hereditary cancer. In Spain, genetic diagnostic laboratories have traditionally approached this task independently due to the lack of a dedicated resource. Here we present SpadaHC, a web-based database for sharing variants in hereditary cancer genes in the Spanish population. SpadaHC is implemented using a three-tier architecture consisting of a relational database, a web tool and a bioinformatics pipeline. Contributing laboratories can share variant classifications and variants from individuals in Variant Calling Format (VCF) format. The platform supports open and restricted access, flexible dataset submissions, automatic pseudo-anonymization, VCF quality control, variant normalization and liftover between genome builds. Users can flexibly explore and search data, receive automatic discrepancy notifications and access SpadaHC population frequencies based on many criteria. In February 2024, SpadaHC included 18 laboratory members, storing 1.17 million variants from 4306 patients and 16 343 laboratory classifications. In the first analysis of the shared data, we identified 84 genetic variants with clinically relevant discrepancies in their classifications and addressed them through a three-phase resolution strategy. This work highlights the importance of data sharing to promote consistency in variant classifications among laboratories, so patients and family members can benefit from more accurate clinical management. Database URL: https://spadahc.ciberisciii.es/.

Users' expectations of the new pre-exposure prophylaxis for the HIV modalities. / Concepciones de usuarios sobre nuevas vías de administración de profilaxis pre-exposición para el VIH.

This article aims to discuss the expectations of Homosexual Men, Bisexual Men and a Transgender Woman, who use or want to use an oral pre-exposure prophylaxis (PrEP) for the human immunodeficiency virus (HIV) about PrEP modalities. Sixteen PrEP users, who are followed up in the BCN Checkpoint, were interviewed,. The interviews were audio-recorded, subjected to thematic categorical analysis within the theoretical framework from the praxiographic perspective. They are all adapted to the use of daily oral and event-based PrEP. In relation to the new PrEP modalities (monthly pill; intramuscular injection every two months; subcutaneous injection every six months), they are all very receptive to these possibilities, but they lack information on the specificities of each and specific assessment of their needs. Comments about the use of oral PrEP are positive, and expectations regarding the new PrEP modalities are visibly high. However, the most important thing for the interviewees is the guarantee that they will have follow-up appointments to continue taking care of their affective-sexual health, which is not dependent on the type of PrEP modalities.

Este artículo tiene como objetivo discutir las concepciones de los Hombres Gay, Hombres Bisexuales y una Mujer Transgénero que usan o quieren usar profilaxis previa a la exposición por el virus de la inmunodeficiencia humana oral (PrEP) sobre nuevas vías de administración. Fueron entrevistados 17 usuarios del BCN Checkpoint. Las entrevistas fueron grabadas en audio, sometidas a análisis categorial temático teniendo en cuenta la perspectiva praxeográfica. Todos están adaptados al uso de la PrEP diaria y a demanda. En relación con las nuevas vías de administración (PrEP inyección intramuscular cada dos meses; pastilla mensual; inyección subcutánea cada seis meses) todos son muy receptivos a esas posibilidades, pero les falta información sobre las especificidades de cada una de ellas y una evaluación específica de sus necesidades. Tanto la satisfacción con el uso de PrEP oral, como las expectativas sobre las nuevas vías de administración son positivas. Sin embargo, lo más importante para los/a entrevistados/a es la garantía de que tendrán seguimiento para continuar cuidando de la salud afectivo-sexual, lo que no depende del tipo de vía de administración.

Concepciones de usuarios sobre nuevas vías de administración de profilaxis pre-exposición para el VIH / Users' expectations of the new pre-exposure prophylaxis for the HIV modalities

Resumen Este artículo tiene como objetivo discutir las concepciones de los Hombres Gay, Hombres Bisexuales y una Mujer Transgénero que usan o quieren usar profilaxis previa a la exposición por el virus de la inmunodeficiencia humana oral (PrEP) sobre nuevas vías de administración. Fueron entrevistados 17 usuarios del BCN Checkpoint. Las entrevistas fueron grabadas en audio, sometidas a análisis categorial temático teniendo en cuenta la perspectiva praxeográfica. Todos están adaptados al uso de la PrEP diaria y a demanda. En relación con las nuevas vías de administración (PrEP inyección intramuscular cada dos meses; pastilla mensual; inyección subcutánea cada seis meses) todos son muy receptivos a esas posibilidades, pero les falta información sobre las especificidades de cada una de ellas y una evaluación específica de sus necesidades. Tanto la satisfacción con el uso de PrEP oral, como las expectativas sobre las nuevas vías de administración son positivas. Sin embargo, lo más importante para los/a entrevistados/a es la garantía de que tendrán seguimiento para continuar cuidando de la salud afectivo-sexual, lo que no depende del tipo de vía de administración.

Abstract This article aims to discuss the expectations of Homosexual Men, Bisexual Men and a Transgender Woman, who use or want to use an oral pre-exposure prophylaxis (PrEP) for the human immunodeficiency virus (HIV) about PrEP modalities. Sixteen PrEP users, who are followed up in the BCN Checkpoint, were interviewed,. The interviews were audio-recorded, subjected to thematic categorical analysis within the theoretical framework from the praxiographic perspective. They are all adapted to the use of daily oral and event-based PrEP. In relation to the new PrEP modalities (monthly pill; intramuscular injection every two months; subcutaneous injection every six months), they are all very receptive to these possibilities, but they lack information on the specificities of each and specific assessment of their needs. Comments about the use of oral PrEP are positive, and expectations regarding the new PrEP modalities are visibly high. However, the most important thing for the interviewees is the guarantee that they will have follow-up appointments to continue taking care of their affective-sexual health, which is not dependent on the type of PrEP modalities.

Role of Prolonged Intubation in Vocal Fold Motion Impairment in Critically Ill Patients.

OBJECTIVE: COVID-19 upsurge in orotracheal intubation (OTI) has opened a new opportunity for studying associated complications. Vocal fold motion impairment (VFMI) is a known complication of OTI. The present study sought to determine the impact of OTI and prolonged OTI on the risk of developing VFMI; to identify both risk and protective factors associated with it. STUDY DESIGN: Retrospective cohort study. SETTING: Multicenter. METHODS: Medical charts were reviewed for all patients that received invasive mechanical ventilation with a subsequent flexible laryngoscopic assessment between March 2020 and March 2022. The main outcomes were the presence of VFMI, including immobility (VFI) and hypomobility (VFH). RESULTS: A total of 155 patients were included, 119 (76.8%) COVID-19 and 36 (23.2%) non-COVID-19 patients; overall 82 (52.9%) were diagnosed with VFMI. Eighty (52.3%) patients underwent a tracheostomy. The median (IQR) intubation duration was 18 (11-24.25) days, while the median (IQR) time to tracheostomy was 22 (16-29). In the adjusted model, we observed there was a 68% increased risk for VFMI from day 21 of intubation (RR: 1.68; 95% CI 1.07-2.65; P = 0.025). CONCLUSIONS: VFMI is a frequent complication in severely ill patients that undergo intubation. A prolonged OTI was associated with an increased risk of VFMI, highlighting the importance of timely tracheostomy. Further research is needed to confirm these findings in other subsets of critically ill patients.

Inhibiting CRF Projections from the Central Amygdala to Lateral Hypothalamus and Amygdala Deletion of CRF Alters Binge-Like Ethanol Drinking in a Sex-Dependent Manner.

Background: Binge alcohol drinking is a dangerous pattern of consumption that can contribute to the development of more severe alcohol use disorders (AUDs). Importantly, the rate and severity of AUDs has historically differed between men and women, suggesting that there may be sex differences in the central mechanisms that modulate alcohol (ethanol) consumption. Corticotropin releasing factor (CRF) is a centrally expressed neuropeptide that has been implicated in the modulation of binge-like ethanol intake, and emerging data highlight sex differences in central CRF systems. Methods: In the present report we characterized CRF+ neurocircuitry arising from the central nucleus of the amygdala (CeA) and innervating the lateral hypothalamus (LH) in the modulation of binge-like ethanol intake in male and female mice. Results: Using chemogenetic tools we found that silencing the CRF+ CeA to LH circuit significantly blunted binge-like ethanol intake in male, but not female, mice. Consistently, genetic deletion of CRF from neurons of the CeA blunted ethanol intake exclusively in male mice. Furthermore, pharmacological blockade of the CRF type-1 receptor (CRF1R) in the LH significantly reduced binge-like ethanol intake in male mice only, while CRF2R activation in the LH failed to alter ethanol intake in either sex. Finally, a history of binge-like ethanol drinking blunted CRF mRNA in the CeA regardless of sex. Conclusions: These observations provide novel evidence that CRF+ CeA to LH neurocircuitry modulates binge-like ethanol intake in male, but not female mice, which may provide insight into the mechanisms that guide known sex differences in binge-like ethanol intake.

High systemic inflammation as a novel cardiovascular risk factor and target for anti-cytokine therapy: comment regarding the triglyceride glucose index.

In the last century, there has been more than enough research that proved the association of high lipid and glucose levels with cardiovascular disease, thus establishing the current well-known traditional cardiovascular risk factors such as dyslipidemia, diabetes, and metabolic syndrome. Hence, these cardiovascular risk factors are target therapy for glucose and lipid-lowering agents to prevent adverse cardiovascular events. However, despite controlling the lipid and glucose levels, some studies demonstrated the subclinical atherosclerosis suggesting that these cardiovascular risk factors alone cannot account for the entire atherosclerosis burden. In the last years, large-scale clinical trials demonstrated the operation of the inflammatory pathway in atherosclerotic cardiovascular disease (ASCVD) by the immune system, both the innate (neutrophils, macrophages) and adaptive (T cell and other lymphocytes) limbs, contribute to atherosclerosis and atherothrombosis. In this regard, some studies that use antiinflammatory therapy targeting the immune system by modulating or blocking interleukins, also known as anti-cytokine therapy, have been shown to reduce the risk of adverse cardiovascular events in patients with previous coronary artery disease. In this regard, the U.S. Food and Drug Administration (FDA) approved the use of colchicine 0.5 mg once daily for reducing cardiovascular events in patients who have established ASCVD and high residual systemic inflammation. Therefore, measuring the systemic inflammation can improve the cardiovascular risk assessment and identify the subsets of patients that will benefit from anti-cytokine therapy after diagnosis of ASCVD or after myocardial revascularization.

High Body Mass Index and Response to Anti-Tumor Necrosis Factor Therapy in Pediatric Crohn's Disease.

INTRODUCTION: Obesity is common among patients with pediatric Crohn's disease (PCD). Some adult studies suggest obese patients respond less well to anti-tumor necrosis factor (TNF) treatment. This study sought compares anti-TNF response and anti-TNF levels between pediatric patients with normal and high body mass index (BMI). METHODS: The COMBINE trial compared anti-TNF monotherapy with combination therapy with methotrexate in patients with PCD. In this secondary analysis, a comparison of time-to-treatment failure among patients with normal BMI vs BMI Z -score >1, adjusting for prescribed anti-TNF (infliximab [IFX] or adalimumab [ADA]), trial treatment assignment (combination vs monotherapy), and relevant covariates. Median anti-TNF levels across BMI category was also examined. RESULTS: Of 224 participants (162 IFX initiators and 62 ADA initiators), 111 (81%) had a normal BMI and 43 (19%) had a high BMI. High BMI was associated with treatment failure among ADA initiators (7/10 [70%] vs 12/52 [23%], hazard ratio 0.29, P = 0.007) but not IFX initiators. In addition, ADA-treated patients with a high BMI had lower ADA levels compared with those with normal BMI (median 5.8 vs 12.8 µg/mL, P = 0.02). IFX trough levels did not differ between BMI groups. DISCUSSION: Overweight and obese patients with PCD are more likely to experience ADA treatment failure than those with normal BMI. Higher BMI was associated with lower drug trough levels. Standard ADA dosing may be insufficient for overweight children with PCD. Among IFX initiators, there was no observed difference in clinical outcomes or drug levels, perhaps due to weight-based dosing and/or greater use of proactive drug monitoring.

Rescue and rehabilitation of maned wolf (Chrysocyon brachyurus) in Paraguay: Case description.

The maned wolf, Chrysocyon brachyurus, is the largest South American canid, with a natural distribution that stretches across Peru, Bolivia, Brazil, Argentina, Paraguay and Uruguay. The present study reports the case of a rescued specimen of maned wolf that underwent a rehabilitation process in Paraguay, starting in October 2020 with its rescue, and finalising in May 2021 with the reintroduction. Herein, we document findings regarding the general management, biometrics, feeding and environmental enrichment; chemical immobilisation and monitoring; haematology, blood biochemistry and specific serology-relevant pathogens; skin examination and bone marrow cytology; orthopaedic, ophthalmological and dental evaluation; abdominal and cardiac ultrasonography; radiology and copro-parasitology. Main findings include the feeding habits of the individual and enrichment opportunities. The animal weighed 7 kg on arrival, with an estimated age of 5 months, and 18 kg on reintroduction, with an estimated age of 1 year. The animal tested negative to serologic tests for Brucella canis, Dirofilaria, canine distemper, Toxoplasmosis and canine parvovirus. Leptospira testing showed antibodies against L. grippotyphosa on both samplings, L. wolffi and L. ictero on the first sampling, and L. pomona on the second sampling. Abdominal organs were examined and measured through ultrasound evaluation and kidneys showed no alterations. Echocardiography showed preserved mitral, tricuspid and aortic valve flows, but turbulent pulmonary valve flow. Copro-parasitology reported the presence of Lagochilascaris sp. and Balantidium sp. All the information gathered aided in diagnosing the health status of the individual, and the response to environmental enrichment helped assess the behaviour, which led to the suggestion of reintroducing the animal. These data constitute the first published health check of a maned wolf in Paraguay, which can contribute to the species' conservation in the country. The protocol presented in this study can serve as a basis for developing an action plan for the maned wolf in Paraguay.

Photoprotective effect of topical treatment with Lopezia racemosa extract against deleterious UVB irradiation effects in the skin of hairless mice.

Lopezia racemosa is known as a "mosquito flower or perlilla." It is commonly found in corn crops. In traditional Mexican medicine, this plant is used to treat stomach cancer and urinary tract infections. Likewise, compounds and extracts isolated from plants have shown cytotoxic and anti-inflammatory effects. The objective of this study was to evaluate the photochemoprotective effect of topical treatment with the methanolic extract of L. racemosa (MELR) as a photochemoprotective agent against the harmful effects of UV irradiation (UVR) on a bacterial model and hairless mice. The MELR components were separated and analyzed via HPLC-UV-ESI-MS. Antioxidant activity was evaluated by the ability of MERL to scavenge DPPH and ABTS free radicals and by its FRAP capacity. The toxicity of MELR was evaluated in keratinocyte cultures. The photoprotective capacity of MELR was assessed through challenge experiments using models with bacteria and hairless CD1 et/et mice; cytokines related to the damage caused by UVR were also measured. In the methanolic extract of L. racemosa, five metabolites were detected and identified: two isomers of quercetin 6-C glycoside, orientin, quercetin 3-(6″-acetylglycoside) and quercetin 3-(6″-galloylglycoside) 7-(2,3-dihydroxytetrahydro-2H-pyran-4-yl acetate). MELR exhibited DPPH and ABTS radical scavenging properties, in addition to Fe ion reducing activity. MELR showed a photoprotective effect against UVB radiation-induced death in Escherichia coli bacteria. At the histological level, topical treatment of CD-1 et/et mice with MERL reduced the damage caused by UVR. Quantification of interleukins in the blood of mice revealed that the expression of IL-12 was greater in the control group treated with ultraviolet radiation than in the group protected with MELR. The methanolic extract of L. racemosa has photochemoprotective properties.

Cannon A wave validation as a diagnostic tool in paroxysmal supraventricular tachycardias.

OBJECTIVE: The presence of cannon A waves, the so called "frog sign", has traditionally been considered diagnostic of atrioventricular nodal re-entrant tachycardia (AVNRT). Nevertheless, it has never been systematically evaluated. The aim of this study is to assess the independent diagnostic utility of cannon A waves in the differential diagnosis of supraventricular tachycardias (SVTs). METHODS: We prospectively included 100 patients who underwent an electrophysiology (EP) study for SVT. The right jugular venous pulse was recorded during the study. In 61 patients, invasive central venous pressure (CVP) was registered as well. CVP increase is thought to be related with the timing between atria and ventricle depolarization; two groups were prespecified, the short VA interval tachycardias (including typical AVNRT and atrioventricular reciprocating tachycardia (AVRT) mediated by a septal accessory pathway) and the long VA interval tachycardias (including atypical AVNRT and AVRT mediated by a left free wall accessory pathway). RESULTS: The relationship between cannon A waves and AVNRT did not reach the statistical significance (OR: 3.01; p = .058); On the other hand, it was clearly associated with the final diagnosis of a short VA interval tachycardia (OR: 10.21; p < .001). CVP increase showed an inversely proportional relationship with the VA interval during tachycardia (b = -.020; p < .001). CVP increase was larger in cases of AVNRT (4.0 mmHg vs. 1.2 mmHg; p < .001) and short VA interval tachycardias (3.9 mmHg vs. 1.2 mmHg; p < .001). CONCLUSION: The presence of cannon A waves is associated with the final diagnosis of short VA interval tachycardias.

The clinical anatomy of the atrioventricular conduction axis.

It is axiomatic that the chances of achieving accurate capture of the conduction axis and its fascicles will be optimized by equally accurate knowledge of the relationship of the components to the recognizable cardiac landmarks, and we find it surprising that acknowledged experts should continue to use drawings that fall short in terms of anatomical accuracy. The accuracy achieved by Sunao Tawara (1906) in showing the location of the atrioventricular conduction axis is little short of astounding. Our purpose in bringing this to current attention is to question the need of the experts to have produced such inaccurate representations, since the findings of Tawara have been extensively endorsed in very recent years. The recent studies do no more than point to the amazing accuracy of the initial account of Tawara. At the same time, we draw attention to the findings described in the middle of the 20th century by Ivan Mahaim (1947). These observations have tended to be ignored in recent accounts. They are, perhaps, of equal significance to those seeking specifically to pace the left fascicles of the branching atrioventricular bundle.

Perioperative nutrition in the setting of pediatric inflammatory bowel disease.

BACKGROUND: Optimization of nutrition prior to inflammatory bowel disease (IBD)-related surgery could improve outcomes. The aim of this study was to assess the perioperative nutrition status and management of children undergoing intestinal resection for treatment of their IBD. METHODS: We identified all patients with IBD who underwent primary intestinal resection. We identified malnutrition using established criteria and methods of nutrition provision at various time points (preoperative outpatient evaluation, admission, and postoperative outpatient follow-up) for elective cases (who underwent their procedure at a scheduled admission) and urgent cases (who underwent an unplanned surgical intervention). We also recorded data on postsurgical complications. RESULTS: A total of 84 patients were identified in this single-center study (male sex: 40%, mean age: 14.5 years, Crohn's disease: 65%). Thirty-four patients (40%) had some degree of malnutrition. Prevalence of malnutrition in the urgent and elective cohorts was similar (48% vs 36%; P = 0.37). Of these patients, 29 (34%) were noted to be on some type of nutrition supplementation prior to surgery. Postoperatively, BMI z scores increased (-0.61 vs -0.42; P = 0.0008), but the percentage of patients who were malnourished did not change from preoperative status (40% vs 40%; P = 0.10). Despite this, use of nutrition supplementation was only noted in 15 (17%) patients at postoperative follow-up. Complications were not associated with nutrition status. CONCLUSION: Utilization of supplemental nutrition decreased postprocedure despite no change in malnutrition prevalence. These findings support the development of a pediatric-specific perioperative nutrition protocol in the setting of IBD-related surgery.

Factors related to the development of high antibody titres against SARS-CoV-2 in convalescent plasma donors from the ConPlas-19 trial.

BACKGROUND AND OBJECTIVES: The efficacy of COVID-19 convalescent plasma (CP) associates with high titres of antibodies. ConPlas-19 clinical trial showed that CP reduces the risk of progression to severe COVID-19 at 28 days. Here, we aim to study ConPlas-19 donors and characteristics that associate with high anti-SARS-CoV-2 antibody levels. MATERIALS AND METHODS: Four-hundred donors were enrolled in ConPlas-19. The presence and titres of anti-SARS-CoV-2 antibodies were evaluated by EUROIMMUN anti-SARS-CoV-2 S1 IgG ELISA. RESULTS: A majority of 80.3% of ConPlas-19 donor candidates had positive EUROIMMUN test results (ratio ≥1.1), and of these, 51.4% had high antibody titres (ratio ≥3.5). Antibody levels decline over time, but nevertheless, out of 37 donors tested for an intended second CP donation, over 90% were still EUROIMMUN positive, and nearly 75% of those with high titres maintained high titres in the second sample. Donors with a greater probability of developing high titres of anti-SARS-CoV-2 antibodies include those older than 40 years of age (RR 2.06; 95% CI 1.24-3.42), with more than 7 days of COVID-19 symptoms (RR 1.89; 95% CI 1.05-3.43) and collected within 4 months from infection (RR 2.61; 95% CI 1.16-5.90). Male donors had a trend towards higher titres compared with women (RR 1.67; 95% CI 0.91-3.06). CONCLUSION: SARS-CoV-2 CP candidate donors' age, duration of COVID-19 symptoms and time from infection to donation associate with the collection of CP with high antibody levels. Beyond COVID-19, these data are relevant to inform decisions to optimize the CP donor selection process in potential future outbreaks.

Predictive value of retinal atrophy for cognitive decline across disease duration in multiple sclerosis.

BACKGROUND: We investigated the association between changes in retinal thickness and cognition in people with MS (PwMS), exploring the predictive value of optical coherence tomography (OCT) markers of neuroaxonal damage for global cognitive decline at different periods of disease. METHOD: We quantified the peripapillary retinal nerve fibre (pRFNL) and ganglion cell-inner plexiform (GCIPL) layers thicknesses of 207 PwMS and performed neuropsychological evaluations. The cohort was divided based on disease duration (≤5 years or >5 years). We studied associations between changes in OCT and cognition over time, and assessed the risk of cognitive decline of a pRFNL≤88 µm or GCIPL≤77 µm and its predictive value. RESULTS: Changes in pRFNL and GCIPL thickness over 3.2 years were associated with evolution of cognitive scores, in the entire cohort and in patients with more than 5 years of disease (p<0.01). Changes in cognition were related to less use of disease-modifying drugs, but not OCT metrics in PwMS within 5 years of onset. A pRFNL≤88 µm was associated with earlier cognitive disability (3.7 vs 9.9 years) and higher risk of cognitive deterioration (HR=1.64, p=0.022). A GCIPL≤77 µm was not associated with a higher risk of cognitive decline, but a trend was observed at ≤91.5 µm in PwMS with longer disease (HR=1.81, p=0.061). CONCLUSIONS: The progressive retinal thinning is related to cognitive decline, indicating that cognitive dysfunction is a late manifestation of accumulated neuroaxonal damage. Quantifying the pRFNL aids in identifying individuals at risk of cognitive dysfunction.

Combination of unsupervised discretization methods for credit risk.

Creating robust and explainable statistical learning models is essential in credit risk management. For this purpose, equally spaced or frequent discretization is the de facto choice when building predictive models. The methods above have limitations, given that when the discretization procedure is constrained, the underlying patterns are lost. This study introduces an innovative approach by combining traditional discretization techniques with clustering-based discretization, specifically k means and Gaussian mixture models. The study proposes two combinations: Discrete Competitive Combination (DCC) and Discrete Exhaustive Combination (DEC). Discrete Competitive Combination selects features based on the discretization method that performs better on each feature, whereas Discrete Exhaustive Combination includes every discretization method to complement the information not captured by each technique. The proposed combinations were tested on 11 different credit risk datasets by fitting a logistic regression model using the weight of evidence transformation over the training partition and contrasted over the validation partition. The experimental findings showed that both combinations similarly outperform individual methods for the logistic regression without compromising the computational efficiency. More importantly, the proposed method is a feasible and competitive alternative to conventional methods without reducing explainability.

Decrement Evoked Potential (DEEP) Mapping of the Atria: Unmasking Atrial Fibrillation Substrate.

BACKGROUND: Atrial myopathy may underlie the progression of atrial fibrillation (AF) from a treatable disease to an irreversible condition with poor ablation outcomes. Electrophysiological methods to unmask areas prone to re-entry initiation could be key to defining latent atrial myopathy. METHODS: Consecutive patients referred for AF ablation were prospectively included at four institutions. Decrement evoked potential mapping (DEEP) was performed in eight left atrial sites and five right atrial sites, from two different pacing locations (endocardially from the left atrial appendage, epicardially from the proximal coronary sinus). The electrograms (EGMs) during S1 600 ms drive and after an extra stimulus (S2 at +30 ms above atrial refractoriness) were studied at each location and assessed for decremental properties. Follow-up was 12 months. RESULTS: Seventy-four patients were included and 85% had persistent AF. A total of 17,614 EGMs were individually analysed and measured. Nine percent of the EGMs showed DEEP properties (local delay of >10 ms after S2) with a mean decrement of 33±26 ms. DEEPs were more frequent in the left atrium than the right atrium (9.4% vs 8.0%; p<0.001) and more prevalent in persistent AF patients than paroxysmal AF patients (9.8% vs 4.6% p=0.001). Atrial DEEPs were more frequently unmasked in normal bipolar voltage areas and by epicardial pacing than endocardial pacing (9.6% vs 8.4%, respectively; p=0.004). Within the left atrium, the roof had the highest prevalence of DEEP EGMs. CONCLUSIONS: DEEP mapping of both atria is useful for highlighting areas with a tendency for unidirectional block and re-entry initiation. Those areas are more easily unmasked by epicardial pacing from the coronary sinus and more prevalent in persistent AF patients than in paroxysmal AF patients.