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1.
Soft Matter ; 16(5): 1162-1169, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31913382

RESUMO

In this work we have characterized the phase behaviour and the dynamics of bidimensional mixtures of active and passive Brownian particles. We have evaluated state diagrams at several concentrations of the passive components finding that, while passive agents tend to hinder phase separation, active agents force crystal-like structures on passive colloids. In order to study how passive particles affect the dynamics of the mixture, we have computed the long-time diffusion coefficient of each species, concluding that active particles induce activity and super-diffusive behaviour on passive ones. Interestingly, at the density at which the system enters a MIPS state the active particles' diffusivity shows an inflection point and the passive particles' one goes through a maximum, due to the change in the dynamics of the active components, as shown in the displacement's probability distribution function.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31944978

RESUMO

Two-dimensional representation of 3D anatomical structures is a simple and intuitive way for analysing patient information across populations and image modalities. While cardiac ventricles, especially the left ventricle, have an established standard representation (bull's eye plot), the 2D depiction of the left atrium (LA) remains challenging due to its sub-structural complexity including the pulmonary veins (PV) and the left atrial appendage (LAA). Quasi-conformal flattening techniques, successfully applied to cardiac ventricles, require additional constraints in the case of the LA to place the PV and LAA in the same geometrical 2D location for different cases. Some registration-based methods have been proposed but surface registration is time-consuming and prone to errors when the geometries are very different. We propose a novel atrial flattening methodology where a 2D map of the LA is obtained quickly and without errors related to registration. The LA is divided into 5 regions which are then mapped to their analogue two-dimensional regions. 67 human left atria from magnetic resonance images (MRI) were studied to derive a population-based template representing the averaged relative locations of the PVs and LAA. The clinical application of our methodology is illustrated on different use cases including the integration of MRI and electroanatomical data.

3.
Sci Rep ; 10(1): 610, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953480

RESUMO

A lack of exercise leads to being overweight or obese affecting regional brain structure and functional connectivity associated with impaired cognitive function and dementia. In recent decades, several studies of healthy individuals suggest that adiposity may also produce negative independent effects on the brain. We aimed to investigate the relationship between body composition - total fat mass (TFM) and visceral adipose tissue (VAT) - with white matter (WM) integrity using a whole-brain approach in military pilots. Twenty-three military helicopter pilots (Mage = 36.79; SD = 8.00; MBMI = 25.48; SD = 2.49) took part in the study. Brain volumes were studied using diffusion tensor imaging technique by means of a 3T Magnetom Tim Trio. Measurements of body mass index (BMI), TFM and VAT were obtained using Dual-energy X-ray Absorptiometry (DXA). The results showed that, on one hand, higher TFM was associated with higher white matter fractional anisotropy (FA) and, on the other hand, higher VAT was associated with lower FA. Data showed that TFM and VAT are the critical factors underlying WM integrity in combat helicopter pilots. The authors suggest that fat presence enhance brain connectivity while there is no excess, specifically in VAT.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31957087

RESUMO

INTRODUCTION: Ablation with second-generation cryoballoon technology evolves as an effective and safe alternative to radiofrequency for atrial fibrillation ablation procedures. Nevertheless, the optimal freezing strategy remains unknown. Our objective was to identify the procedural cryoablation parameters predicting successful peri-pulmonary vein (PV) lesions by directly analyzing Postablation gaps in late-gadolinium-enhanced cardiac magnetic resonance (LGE-CMR). METHODS AND RESULTS: Forty-nine consecutive patients (196 PVs) undergoing ablation with second-generation cryoballoon at our center were included. The number and duration of cryoballoon application to achieve PV isolation were left to operator discretion. Gap number and length were quantified in all patients with a LGE-CMR performed 3 months postablation. Application time (420 ± 217 seconds), number of applications (2.1 ± 1.2), application time after electrical isolation (311 ± 194 seconds) and minimum temperature (-45.8 ± 6.5°C) were similar in the 4 PVs. Gaps were observed in 148 PVs (76%), averaging 1.3 ± 1 gaps per vein. Gaps were longer and more frequent in the right PVs (91% vs 59% in left PVs, P < .001). Neither the number, total duration of applications, nor postisolation application time predicted relative length or number of gaps. CONCLUSIONS: After successful PV isolation was achieved in patients undergoing cryoablation, increasing the number of applications, the total application time or application time postisolation did not result in a reduction in the number or the relative length of gaps.

5.
Europace ; 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31821484

RESUMO

AIMS: Cryoballoon (CB) ablation has emerged as a reliable modality to isolate pulmonary veins (PVs) in atrial fibrillation. Ablation lesions and the long-term effects of energy delivery can be assessed by delayed-enhancement cardiac magnetic resonance (DE-CMR). The aim of the study was to compare the number, extension, and localization of gaps in CB and radiofrequency (RF) techniques in pulmonary vein isolation (PVI). METHODS AND RESULTS: Consecutive patients submitted to PVI with CB in whom DE-CMR images were available (n = 30) were matched (1:1) to patients who underwent PVI with RF (n = 30), considering age, sex, hypertension, and diabetes. Delayed-enhancement cardiac magnetic resonance was obtained at 3 months post-procedure, and images were processed to assess the mean number of gaps around PV ostia, their localization, and the normalized gap length (NGL), calculated as the difference between total gap length and total PV perimeter. Patients were followed up for 12 months. The CB and RF procedures did not differ in the mean number of gaps per patient (4.40 vs. 5.13 gaps, respectively; P = 0.21) nor NGL (0.35 vs. 0.32, P = 0.59). For both techniques, a higher mean number of gaps were detected in right vs. left PVs (3.18 vs. 1.58, respectively; P = 0.01). The incidence of recurrences did not differ between techniques (odds ratio 1.87, 95% confidence interval 0.66-4.97; P = 0.29). CONCLUSION: Location and extension of ablation gaps in PVI did not differ between CB and RF groups in DE-CMR image analysis.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31748945

RESUMO

The use of cardiovascular magnetic resonance imaging left atrial late gadolinium enhancement (LA LGE) is increasing for fibrosis evaluation though the use is still limited to specialized centres due to complex image acquisition and lack of consensus on image analyses. Analysis of LA LGE with image intensity ratio (IIR) (pixel intensity of atrial wall normalized by blood pool intensity) provides an objective method to obtain quantitative data on atrial fibrosis. A threshold between healthy myocardium and fibrosis of 1.2 has previously been established in 3T scans. The aim of the study was to reaffirm this threshold in 1.5T scans. LA LGE was performed using a 1.5T magnetic resonance scanner on: 11 lone-AF patients, 11 age-matched healthy volunteers (aged 27-44) and 11 elderly patients without known history of AF but varying degrees of comorbidities. Mean values of IIR for all healthy volunteers +2SD were set as upper limit of normality and was reproduced to 1.21 and the original IIR-threshold of 1.20 was maintained. The degree of fibrosis in lone-AF patients [median 9.0% (IQR 3.9-12.0)] was higher than in healthy volunteers [2.8% (1.3-8.3)] and even higher in elderly non-AF [20.1% (10.2-35.8), p = 0.001]. The previously established IIR-threshold of 1.2 was reaffirmed in 1.5T LA LGE scans. Patients with lone AF presented with increased degrees of atrial fibrosis compared to healthy volunteers in the same age-range. Elderly patients with no history of AF showed significantly higher degrees of fibrosis compared to both groups with younger individuals.

8.
Phys Rev E ; 99(6-1): 062602, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31330735

RESUMO

Due to the combined effect of anisotropic interactions and activity, Janus swimmers are capable to self-assemble in a wide variety of structures, many more than their equilibrium counterpart. This might lead to the development of novel active materials capable of performing tasks without any central control. Their potential application in designing such materials endows trying to understand the fundamental mechanism in which these swimmers self-assemble. In the present work, we study a quasi-two-dimensional semidilute suspensions of two classes of amphiphilic spherical swimmers whose direction of motion can be tuned: either swimmers propelling in the direction of the hydrophobic patch or swimmers propelling in the opposite direction (toward the hydrophilic side). In both systems we have systematically tuned swimmers' hydrophobic strength and signature and observed that the anisotropic interactions, characterized by the angular attractive potential and its interaction range, in competition with the active stress, pointing toward or against the attractive patch gives rise to a rich aggregation phenomenology.

9.
Heart Rhythm ; 16(12): 1849-1854, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31125672

RESUMO

BACKGROUND: The Micra transcatheter pacing system (Micra TPS) is often implanted in patients with atrial fibrillation and thus with increased thromboembolic risk. It is unknown whether the use of anticoagulants, associated with the use of a large venous introducer, implies an increased risk of bleeding in this group of patients. OBJECTIVE: The purpose of this study was to assess the incidence of bleeding and thromboembolic complications after Micra TPS implantation with and without therapeutic anticoagulation. METHODS: This single-center observational study included 107 consecutive patients receiving the Micra TPS from 2014 to 2018. At procedure completion, a figure-of-eight suture was placed at the femoral puncture site after sheath withdrawal and was maintained for 24 hours. In patients receiving enoxaparin or new oral anticoagulants, treatment was discontinued 12 or 24 hours before the procedure, respectively, and was reinitiated 4-6 hours postprocedure. In those receiving vitamin K antagonists (VKAs), dosing was not discontinued and the procedure was performed if the international normalized ratio was less than 3. RESULTS: Sixty-four patients (60%) did not receive anticoagulants. Of the 43 (40%) who did, 29 (67%) received VKAs, 8 (19%) received new oral anticoagulants, and 6 (14%) received enoxaparin. Two patients presented hemorrhagic or thromboembolic complications during short-term follow-up: 1 woman receiving VKAs presented hemorrhagic pericardial effusion without tamponade and 1 woman not receiving anticoagulants presented thrombosis of the ipsilateral saphenous vein. CONCLUSION: Bleeding and thromboembolic complications after receiving Micra TPSs are infrequent. The use of anticoagulant therapy, regardless of the type, does not increase the complications associated with the procedure.

10.
J Cardiovasc Electrophysiol ; 30(9): 1483-1490, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31115940

RESUMO

INTRODUCTION: Recurrences after atrial fibrillation (AF) ablation are still common. Among the reported clinical and imaging predictors of recurrences, diagnosis-to-ablation time (DAT) has been defined as a predictor of ablation outcome in single-center studies. We aimed to validate DAT in a multicenter real-life cohort. METHODS: This was a multicenter study including consecutive patients undergoing first paroxysmal and persistent AF ablation with radiofrequency or cryoballoon catheters during 2013. Cox proportional hazard regression models were performed to identify predictors of recurrence. RESULTS: In total, 309 patients were included across nine centers (71% men, 57 ± 10 years old, 46% with hypertension, and 66% with CHA2 DS2 -VASc ≤ 1). Most patients had paroxysmal AF (67%) and underwent radiofrequency ablation (68%) with a median DAT of 51 (43) months. Patients with DAT ≤ 1 year (16.6%) were less likely to have repeat procedures (4% vs 18%; P = .017). The adjusted proportional hazards Cox model identified hypertension (P = .005), heart failure (P = .011), nonparoxysmal AF (P = .038), DAT > 1 year (P = .007), and LA diameter (P = .026) as independent predictors for AF recurrence. DAT > 1 year was the only modifiable factor independently associated with recurrence (HR 4.2 [95% CI, 1.5-11.9]) CONCLUSION: Diagnosis-to-ablation time is a modifiable factor independently associated with recurrent arrhythmia and repeat ablation after first AF ablation. An early intervention strategy during the first year from AF diagnosis might improve outcomes.

11.
Pacing Clin Electrophysiol ; 42(6): 678-685, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30912154

RESUMO

BACKGROUND: Interlesion distance and ablation index (AI) have been proposed as parameters of radiofrequency (RF) lesion durability. This study analyzes the relationship between RF parameters of automatically acquired lesion tags and late reconnections in repeat pulmonary vein isolation (PVI) procedures. METHODS: One hundred fifty-seven patients underwent contact force (CF)-guided PVI with automatic acquisition of RF lesions. During follow-up, 21 patients underwent a repeat PVI procedure. The relationship between RF parameters (power, CF, impedance drop, and AI) of the initial PVI procedure and reconnections observed at repeat PVI was analyzed. Visual gap was defined as the existence of a discontinuity between two RF lesions automatically acquired in the initial PVI procedure. Regional values of AI associated with lesion durability were identified. RESULTS: Twenty-one patients were included. Three hundred thirty-six segments and 2507 RF lesions were analyzed. The median interval between the initial and repeat PVI procedures was 17 (11-24) months. All patients showed ≥1 reconnected segment. Sixty-three segments (18.7%) were reconnected. Reconnected segments showed visual gaps more frequently than non-reconnected segments (66.6% vs 17.6%; P < .001; negative predictive value 91.4%). The mean distance of visual gaps was 8 ± 2.8 mm. No differences were observed in power (31.4 ± 4.7 W vs 31 ± 4.1 W; P = .573), CF (14.4 ± 5.3 g vs 15.4 ± 5.4 g; P = .315), and impedance drop (6.9 ± 5.2 ohms vs 6.5 ± 3.8 ohms; P = .576) between reconnected and non-reconnected segments. Among segments without visual gap, the minimum AI value was significantly higher in the non-reconnected segments (325 ± 96.1 vs 204.7 ± 78.5; P < .001). No reconnections were observed in segments without visual gap and minimum AI ≥ 330/220 in anterior/posterior wall, respectively. CONCLUSIONS: Contiguity between automatically acquired RF lesions and minimum AI value are the main determinants of long-term PVI durability.

12.
Sensors (Basel) ; 19(4)2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30791638

RESUMO

This article presents a precise landing system that allows rotary-wing UAVs to approach and land safely on moving platforms, without using GNSS at any stage of the landing maneuver, and with a centimeter level accuracy and high level of robustness. This system implements a novel concept where the relative position and velocity between the aerial vehicle and the landing platform are calculated from the angles of a cable that physically connects the UAV and the landing platform. The use of a cable also incorporates a number of extra benefits, such as increasing the precision in the control of the UAV altitude. It also facilitates centering the UAV right on top of the expected landing position, and increases the stability of the UAV just after contacting the landing platform. The system was implemented in an unmanned helicopter and many tests were carried out under different conditions for measuring the accuracy and the robustness of the proposed solution. Results show that the developed system allowed landing with centimeter accuracy by using only local sensors and that the helicopter could follow the landing platform in multiple trajectories at different velocities.

13.
Europace ; 21(5): 724-731, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649273

RESUMO

AIMS: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) may define left atrial (LA) anatomy and structural remodelling, and facilitate atrial fibrillation (AF) ablation. We aimed to assess the intra- and inter-observer reproducibility and agreement of LGE-CMR parameters with direct application to AF ablation techniques. METHODS AND RESULTS: One experienced and one non-experienced observer performed complete LGE-CMR data analysis twice, on different days, in 40 randomly selected LGE-CMR examinations [20 performed before ablation (pre-ablation) and 20 performed 3 months after ablation (post-ablation)]. Four additional observers (two experienced and two non-experienced) performed complete LGE-CMR data analysis in a subgroup of 30 patients (15 pre-ablation and 15 post-ablation). All LGE-CMR were performed in sinus rhythm. Intra- and inter-observer reproducibility of LA volume, LA area, and sphericity index (SI) was high: coefficient of variation <10% and intraclass correlation coefficient >0.71. Geometric congruency of repeated reconstruction of LA shape was high: maximal error <5 mm for intra-observer and <8 mm for inter-observer. The precision of scar location increased with extent of scar, and was high (Dice coefficient >0.75) when the scar area was >5 cm2 for a single observer and >15 cm2 for multiple observers. Non-experienced observers performed equally well to experienced observers. CONCLUSION: Late gadolinium enhancement cardiac magnetic resonance measurements of LA area, volume, and SI were reproducible, and geometric congruency of LA shape was high. Location of scar was precise for scar areas >5 cm2 for single observers and >15 cm2 for multiple observers, regardless of the observers' experience. These results may serve as a reference for future studies on the role for substrate-based AF ablation procedures.

14.
Circ Arrhythm Electrophysiol ; 11(12): e006659, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30562102

RESUMO

BACKGROUND: There is limited knowledge about the impact of anatomic gaps as assessed by delayed gadolinium enhancement cardiac magnetic resonance on atrial fibrillation (AF) recurrence after first pulmonary vein (PV) isolation. METHODS: Consecutive patients underwent delayed gadolinium enhancement cardiac magnetic resonance 3 months after radiofrequency circumferential PV isolation. Delayed gadolinium enhancement cardiac magnetic resonance images were assessed from 360 PV resulting in 2880 segments in the 2×8-segment model from 94 patients (52±11 years, 62% paroxysmal AF). Left atria were segmented using dedicated software. Anatomic gap was defined as discontinuation of the ablation line by ≥3 mm. Relative gap length was calculated as absolute gap length divided by the total length of the ablation line. AF recurrence was assessed after a mean follow-up duration of 15±10 months Results: Mean number of anatomic gaps was 5.4 per patient. Recurrence within the first year of ablation was observed in 21 patients with paroxysmal AF (36%) and 19 patients with persistent AF (53%). In the univariate analysis, CHA2DS2-VASc score, AF type, and relative gap length were predictive of recurrence. In the multivariate analysis, only relative gap length was significantly associated with recurrence (hazard ratio, 1.16 [1.02-1.31] per each 10% of gap). CONCLUSIONS: The total relative gap length but not the number of anatomic gaps in the PV ablation line as assessed by delayed gadolinium enhancement cardiac magnetic resonance was associated with AF recurrence 1 year after first PV isolation. An increase of 10% relative gap length increased the likelihood of AF recurrence by 16%.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Gadolínio , Interpretação de Imagem Assistida por Computador/métodos , Imagem Cinética por Ressonância Magnética/métodos , Veias Pulmonares/cirurgia , Adulto , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/mortalidade , Ablação por Cateter/mortalidade , Estudos de Coortes , Meios de Contraste , Feminino , Humanos , Aumento da Imagem/métodos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Espanha , Estatísticas não Paramétricas , Análise de Sobrevida
15.
Gac. sanit. (Barc., Ed. impr.) ; 32(5): 492-495, sept.-oct. 2018. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-174200

RESUMO

La supervivencia relativa se ha utilizado habitualmente como medida de la evolución temporal del exceso de riesgo de mortalidad en cohortes de pacientes diagnosticados de cáncer, teniendo en cuenta la mortalidad de una población de referencia. Una vez estimado el exceso de riesgo de mortalidad pueden calcularse tres probabilidades acumuladas a un tiempo T: 1) la probabilidad de fallecer asociada a la causa de diagnóstico inicial (enfermedad en estudio), 2) la probabilidad de fallecer asociada a otras causas, y 3) la probabilidad de supervivencia absoluta en la cohorte a un tiempo T. Este trabajo presenta la aplicación WebSurvCa (https://shiny.snpstats.net/WebSurvCa/), mediante la cual los registros de cáncer de base hospitalaria y poblacional, y los registros de otras enfermedades, estiman dichas probabilidades en sus cohortes seleccionando como población de referencia la mortalidad de la comunidad autónoma que consideren


Relative survival has been used as a measure of the temporal evolution of the excess risk of death of a cohort of patients diagnosed with cancer, taking into account the mortality of a reference population. Once the excess risk of death has been estimated, three probabilities can be computed at time T: 1) the crude probability of death associated with the cause of initial diagnosis (disease under study), 2) the crude probability of death associated with other causes, and 3) the probability of absolute survival in the cohort at time T. This paper presents the WebSurvCa application (https://shiny.snpstats.net/WebSurvCa/), whereby hospital-based and population-based cancer registries and registries of other diseases can estimate such probabilities in their cohorts by selecting the mortality of the relevant region (reference population)


Assuntos
Humanos , Neoplasias/mortalidade , Neoplasias da Mama/mortalidade , Mortalidade/tendências , Taxa de Sobrevida/tendências , Modelos Estatísticos , Aplicações da Informática Médica , Estudos de Coortes , Fatores de Risco
16.
Eur Phys J E Soft Matter ; 41(8): 91, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30112662

RESUMO

In our work we have studied a two-dimensional suspension of finite-size Vicsek hard disks, whose time evolution follows an event-driven dynamics between subsequent time steps. Having compared its collective behaviour with the one expected for a system of scalar Vicsek point-like particles, we have analysed the effect of considering two possible bouncing rules between the disks: a Vicsek-like rule and a pseudo-elastic one, focusing on the order-disorder transition. Next, we have added to the two-dimensional suspension of hard-disk Vicsek particles disk-like passive obstacles of two types: either fixed in space or moving according to the same event-driven dynamics. We have performed a detailed analysis of the particles' collective behaviour observed for both fixed and moving obstacles. In the fixed obstacles case, we have observed formation of clusters at low noise, in agreement with previous studies. When using moving passive obstacles, we found that that order of active particles is better destroyed as the drag of obstacles increases. In the no drag limit an interesting result was found: introduction of low drag passive particles can lead in some cases to a more ordered state of active flocking particles than what they show in bulk.

17.
Artigo em Inglês | MEDLINE | ID: mdl-30103925

RESUMO

In this study, we hypothesized that terrestrial plant oils, rich in alpha linolenic acid (ALA) and stearidonic acid (SDA) relative to fish oil, rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), prevent negative effects on cardiovascular and neurological function using a rat model fed a hypercaloric diet. Results showed effects on the FA profile, namely, eicosapentaenoic, EPA, and docosahexaenoic, DHA, levels. There were also effects on neural aspects (cAMP response element-binding protein, CREB, gene expression, at least, doubled) and the pro-inflammatory/anti-inflammatory balance (TNF-α, tumor necrosis factor alpha reduced by 30-50%). The most positive impact of ALA and SDA was the beneficial reduction of total lipids (from 395 ±â€¯3 to 352-361 mg/dL), VLDL-cholesterol (from 21.8 ±â€¯0.2 to 14.1-17.8 mg/dL), and triacylglycerols (from 109 ±â€¯1 to 71-89 mg/dL) in both LIN (diet enriched in linseed oil) and BUG (diet enriched in Buglossoides oil) groups. Overall, data indicate that ALA- and SDA-rich lipid sources may counteract the undesirable cardiovascular effects of a hypercaloric diet based on milk fat.


Assuntos
Dieta Ocidental/efeitos adversos , Ácidos Graxos Ômega-3/administração & dosagem , Metabolismo dos Lipídeos/efeitos dos fármacos , Ácido alfa-Linoleico/administração & dosagem , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Quimioterapia Combinada , Ácidos Graxos/análise , Ácidos Graxos Ômega-3/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Óleos Vegetais/administração & dosagem , Óleos Vegetais/farmacologia , Ratos , Fator de Necrose Tumoral alfa/metabolismo , Ácido alfa-Linoleico/farmacologia
18.
Europace ; 20(12): 1959-1965, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29860416

RESUMO

Aims: Left atrial (LA) fibrosis can be identified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) in patients with atrial fibrillation (AF). However, there is limited information about anatomical fibrosis distribution in the left atrium. The aim is to determine whether there is a preferential spatial distribution of fibrosis in the left atrium in patients with AF. Methods and results: A 3-Tesla LGE-CMR was performed in 113 consecutive patients referred for AF ablation. Images were post-processed and analysed using ADAS-AF software (Galgo Medical), which allows fibrosis identification in 3D colour-coded shells. A regional semiautomatic LA parcellation software was used to divide the atrial wall into 12 segments: 1-4, posterior wall; 5-6, floor; 7, septal wall; 8-11, anterior wall; 12, lateral wall. The presence and amount of fibrosis in each segment was obtained for analysis. After exclusions for artefacts and insufficient image quality, 76 LGE-MRI images (68%) were suitable for fibrosis analysis. Segments 3 and 5, closest to the left inferior pulmonary vein, had significantly higher fibrosis (40.42% ± 23.96 and 25.82% ± 21.24, respectively; P < 0.001), compared with other segments. Segments 8 and 10 in the anterior wall contained the lowest fibrosis (2.54% ± 5.78 and 3.82% ± 11.59, respectively; P < 0.001). Age >60 years was significantly associated with increased LA fibrosis [95% confidence interval (CI) 0.19-8.39, P = 0.04] and persistent AF approached significance (95% CI -0.19% to 7.83%, P = 0.08). Conclusion: In patients with AF, the fibrotic area is preferentially located at the posterior wall and floor around the antrum of the left inferior pulmonary vein. Age >60 years was associated with increased fibrosis.


Assuntos
Fibrilação Atrial/diagnóstico por imagem , Função do Átrio Esquerdo , Remodelamento Atrial , Meios de Contraste/administração & dosagem , Átrios do Coração/diagnóstico por imagem , Imagem por Ressonância Magnética , Compostos Organometálicos/administração & dosagem , Veias Pulmonares/diagnóstico por imagem , Fatores Etários , Idoso , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Feminino , Fibrose , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Veias Pulmonares/patologia , Veias Pulmonares/fisiopatologia , Fatores de Risco
19.
J Cardiovasc Electrophysiol ; 29(8): 1065-1072, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29722466

RESUMO

INTRODUCTION: The purpose of this study was to compare the anatomical characteristics of scar formation achieved by visual-guided laser balloon (Laser) and radiofrequency (RF) pulmonary vein isolation (PVI), using late-gadolinium-enhanced cardiac magnetic resonance imaging (LGE-CMR). METHODS AND RESULTS: We included 17 patients with paroxysmal or early persistent drug resistant AF who underwent Laser ablation; 2 were excluded due to procedure-related complications. The sample was matched with a historical group of 15 patients who underwent PVI using RF. LGE-CMR sequences were acquired before and 3 months post-PVI. Ablation gaps were defined as pulmonary vein (PV) perimeter sections showing no gadolinium enhancement. The number of ablation gaps was lower in Laser versus RF ablations (median 7 vs. 14, P  =  0.015). Complete anatomical PVI (circumferential scar around PV, without gaps) was more frequently achieved with Laser than with RF (39% vs. 19% of PVs, P  =  0.025). Fewer gaps were present at the superior and anterior left PV and posterior right PV antral regions in the Laser group, compared to RF. Scar extension into the PVs was similar in both groups, although RF produced more extensive ablation scar toward the LA body. AF recurrences at 1 year were similar in both groups (Laser 36% vs. RF 27%, P  =  1.00). CONCLUSIONS: Compared to RF, Laser ablation achieved more complete anatomical PVI, with less LA scar extension. However, AF recurrence appears to be similar after Laser compared to RF ablation. Further studies are needed to assess whether the anatomical advantages of Laser ablation translate into clinical benefit in patients with AF.


Assuntos
Gadolínio , Imagem Cinética por Ressonância Magnética/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Veias Pulmonares/diagnóstico por imagem , Ablação por Radiofrequência/tendências , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Terapia a Laser/efeitos adversos , Terapia a Laser/tendências , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Veias Pulmonares/cirurgia , Ablação por Radiofrequência/efeitos adversos
20.
Eur Heart J Cardiovasc Imaging ; 19(9): 1002-1009, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659784

RESUMO

Aims: Left atrial (LA) remodelling is a key determinant of atrial fibrillation (AF) ablation outcome. Optimal methods to assess this process are scarce. LA sphericity is a shape-based parameter shown to be independently associated to procedural success. In a multicentre study, we aimed to test the feasibility of assessing LA sphericity and evaluate its capability to predict procedural outcomes. Methods and results: This study included consecutive patients undergoing first AF ablation during 2013. A 3D model of the LA chamber, excluding pulmonary veins and LA appendage, was used to quantify LA volume (LAV) and LA sphericity (≥82.1% was considered spherical LA). In total, 243 patients were included across 9 centres (71% men, aged 56 ± 10 years, 44% with hypertension and 76% CHA2DS2-VASc ≤ 1). Most patients had paroxysmal AF (66%) and underwent radiofrequency ablation (60%). Mean LA diameter (LAD), LAV, and LA sphericity were 42 ± 6 mm, 100 ± 33 mL, and 82.6 ± 3.5%, respectively. Adjusted Cox models identified paroxysmal AF [hazard ratio (HR 0.54, P = 0.032)] and LA sphericity (HR 1.87, P = 0.035) as independent predictors for AF recurrence. A combined clinical-imaging score [Left Atrial Geometry and Outcome (LAGO)] including five items (AF phenotype, structural heart disease, CHA2DS2-VASc ≤ 1, LAD, and LA sphericity) classified patients at low (≤2 points) and high risk (≥3 points) of procedural failure (35% vs. 82% recurrence at 3-year follow-up, respectively; HR 3.10, P < 0.001). Conclusion: In this multicentre, real-life cohort, LA sphericity and AF phenotype were the strongest predictors of AF ablation outcome after adjustment for covariates. The LAGO score was easy to implement, identified high risk of procedural failure, and could help select optimal candidates. Clinical Trial Registration Information: NCT02373982 (http://clinicaltrials.gov/ct2/show/NCT02373982).


Assuntos
Fibrilação Atrial/cirurgia , Remodelamento Atrial/fisiologia , Ablação por Cateter/métodos , Imagem Tridimensional , Imagem Cinética por Ressonância Magnética/métodos , Fatores Etários , Idoso , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/fisiopatologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Cuidados Pós-Operatórios , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Recidiva , Medição de Risco , Fatores Sexuais , Análise de Sobrevida , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
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