Clinical value of artificial intelligence 3D echocardiography in evaluating left atrial volume and pulmonary vein structure in patients with atrial fibrillation.

OBJECTIVE: To explore the clinical value of 3D Echocardiography (3DE) in evaluating the changes of left atrial volume and pulmonary vein structure in patients with Atrial Fibrillation (AF). METHODS: Clinical data were collected from 54 AF patients. Left Atrial Anteroposterior Diameter (LADap), Left Atrial left and right Diameter (LADml), and Left Atrial upper and lower Diameter (LADsi) were measured; the maximum Left Atrial Volume (LAVmax), minimum Left Atrial Volume (LAVmin), left atrial presystolic volume (LAVpre), and Cross-Sectional Area (CSA) of each pulmonary vein were analyzed. Passive Ejection Fraction (LAPEF) was calculated. The differences in left atrial volume and pulmonary vein structure between patients with AF and healthy people were compared, and the correlation between the indexes was analyzed. The diagnostic value of the above indicators for AF patients was analyzed. RESULTS: LADap, LADml, LADsi, LAVmax, LAVmin, LAVpre, LAPEF, LSPV CSA, LIPV CSA, RSPV CSA, and RIPV CSA of AF patients were significantly higher. There was a significant positive correlation between left atrial diameter and pulmonary vein structure. There was a significant positive correlation between left atrial volume and pulmonary vein structure. There was a negative correlation between LAPEF and pulmonary vein structure. LADap, LADml, LADsi, LAVmax, LAVmin, LAVpre, LAPEF, LSPV CSA, LIPV CSA, RSPV CSA, and RIPV CSA had a diagnostic value for AF patients. CONCLUSION: 3DE is applicable for evaluating left atrial volume and pulmonary vein structure in patients with AF.

Risk factors of atrial fibrillation complicated with cognitive impairment and the relationship between cardiac function parameters and the degree of cognitive impairment.

OBJECTIVE: To explore the risk factors of Atrial Fibrillation (AF) with Cognitive Impairment (CI) and to analyze the relationship between cardiac function parameters and the degree of CI in patients. METHODS: 120 AF patients were selected, and Montreal Cognitive Assessment (MoCA) was used to distinguish between AF patients with and without CI. Univariate analysis and multivariate Logistic regression analysis were used to evaluate the impact of sociodemographic data, disease-related data, and clinical data on risk factors for AF with CI. Pearson's method was used to analyze the correlation between cardiac function parameters and cognitive function scores in AF patients. RESULTS: There were 89 patients with CI and 31 patients without CI, and the MoCA scores of patients with CI were lower than those in patients without CI. Age, occupational status, educational level, combined smoking history, drinking history, and heart failure, as well as systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, C-reactive protein, free thyroxine, free triiodothyronine, and D-dimer were risk factors for the patient with CI. Left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left atrial maximum volume in patients with CI were higher than those in patients without CI, and left ventricular ejection fraction and peak early diastolic velocity/peak late-diastolic mitral velocity ratio were lower. CONCLUSION: The cardiac function parameters of patients are closely related to attention, orientation, memory, visuospatial, and executive ability. Cardiac function parameters were closely related to cognitive functions.

Randomized Study Comparing Radiofrequency Ablation with the PVAC Gold System vs. Antiarrhythmic Drugs in Elderly Patients with Symptomatic Atrial Fibrillation. / Estudo Randomizado Comparando a Ablação por Cateter com o PVAC Gold vs. Tratamento com Fármacos Antiarrítmicos em Pacientes Idosos com Fibrilação Atrial Sintomática.

BACKGROUND: There are no randomized studies comparing the maintenance of sinus rhythm after catheter ablation (CA) concerning treatment with antiarrhythmic drugs (AA) in elderly patients with paroxysmal atrial fibrillation (AF). OBJECTIVES: To compare the clinical results of pulmonary vein (PV) isolation with the second-generation PVAC Gold catheter against AA treatment in elderly people with recurrent symptomatic paroxysmal AF, refractory to at least one AA, and without structural heart disease. METHODS: Sixty patients with paroxysmal AF ≥ 65 years old were randomized to two forms of treatment: group 1: CA and group 2: AA drugs. The primary outcome was the AF recurrence-free rate after at least one year of follow-up. Secondary outcomes were: progression to persistent forms of AF, impact on quality of life (QOLF), and complications. The significance level adopted in the statistical analysis was 5% (p<0.05). RESULTS: The AF recurrence-free rate was 80% (10% with amiodarone) in the CA group, after 1.3 procedures per patient and 65% in the AA group (60% with amiodarone), (p = 0.119) in an average follow-up of 719 days (Q1: 566; Q3: 730). The persistent AF free rate was 83.4% in the AC group and 67.7% in the AA group (p = 0.073) Both strategies showed an improvement in the AFQoL score during follow-up (p < 0.001), with no difference between the groups. Although without clinical repercussions or impact on the intellectual assessment test, 25% of patients in the CA group showed signs of cerebral embolization on brain MRI. CONCLUSIONS: Both strategies for maintaining sinus rhythm promoted an improvement in the quality of life of elderly patients with symptomatic AF, with no statistical difference in the clinical outcomes. Additional studies using technologies with a better safety profile are needed to evaluate the benefits of CA in elderly patients with AF.

FUNDAMENTO: Não existem estudos randomizados comparando a manutenção do ritmo sinusal após ablação por cateter (AC) em relação ao tratamento com fármacos antiarrítmicos (AA) em pacientes idosos portadores fibrilação atrial (FA) paroxística. OBJETIVOS: Comparar os resultados clínicos do isolamento das veias pulmonares (VPs) com o cateter PVAC Gold de segunda geração com o uso de AA em idosos com FA paroxística sintomática, recorrente, apesar do uso de fármacos AA. MÉTODOS: Sessenta pacientes com FA paroxística ≥ 65 anos e sem cardiopatias estruturais foram randomizados para duas formas de tratamento: grupo 1: AC e grupo 2: AA. O desfecho primário foi a taxa livre de recorrência de FA após pelo menos um ano de seguimento. Os desfechos secundários foram: progressão para formas persistentes de FA, impacto na qualidade de vida (QVFA) e complicações. O nível de significância adotado na análise estatística foi de 5% (p<0,05). RESULTADOS: A taxa livre de recorrência de FA foi de 80% (10% com amiodarona) no grupo AC, após 1,3 procedimentos por paciente e de 65% no grupo AA (60% com amiodarona), (p = 0,119) num seguimento médio de 719 dias (Q1: 566; Q3: 730). A taxa livre de FA persistente foi de 83,4% no grupo AC e de 67,7% no grupo AA (p = 0,073). Ambas as estratégias apresentaram melhora no escore de QVFA durante o seguimento (p < 0,001), sem diferença entre os grupos. Embora sem repercussão clínica ou impacto no teste de avaliação intelectual, 25% dos pacientes do grupo PVAC apresentou sinais de embolização cerebral na RNM cerebral. CONCLUSÕES: Ambas as estratégias para manutenção do ritmo sinusal promoveram melhora na qualidade de vida de pacientes idosos com FA sintomática, sem diferença estatística nos desfechos clínicos preconizados. Estudos adicionais usando tecnologias com melhor perfil de segurança são necessários para avaliar os benefícios da AC em pacientes idosos com FA.

Inflammation Burden and Atrial Fibrillation Burden: A Bidirectional Relationship. / Carga Inflamatória e Carga de Fibrilação Atrial: Uma Relação Bidirecional.

BACKGROUND: Atrial fibrillation (AF) burden is defined as the proportion of time the patient remains in AF over a given period of time; thus, it is theoretically highest in permanent AF and lowest in paroxysmal AF. Inflammation is associated with the initiation and maintenance of AF. However, the relationship between systemic immune-inflammation index (SII) and AF burden is unknown. OBJECTIVE: In the present study, we investigated the relationship between SII and AF burden. METHODS: The present study is a cross-sectional analysis of 453 patients (252 females and 201 males, aged 44 to 94 years) with AF (138 with paroxysmal AF and 315 with permanent AF) who visited the cardiology outpatient clinic between October 2022 and June 2023. SII was calculated as (neutrophils × platelets/lymphocytes). The predictive role of SII and other inflammatory markers in the likelihood of AF pattern was evaluated by logistic regression analyses, and p value < 0.05 was considered statistically significant. RESULTS: Age, diastolic blood pressure, heart rate, diabetes mellitus, neutrophil, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, SII, C-reactive protein, red blood cell distribution width, hemoglobin A1c, and left atrial diameter were significantly higher in the permanent AF group. According to the logistic regression analysis, age (p = 0.038), diabetes mellitus (p = 0.024), red blood cell distribution width (p = 0.023), C-reactive protein (p = 0.010), SII (p = 0.001), and left atrial diameter (p < 0.001) significantly contributed to the prediction of the likelihood of permanent AF. CONCLUSION: SII is independently associated with the AF burden. Prospective studies are needed to determine whether SII may be useful in identifying patients at high risk for AF progression.

FUNDAMENTO: A carga de fibrilação atrial (FA) é definida como a proporção de tempo que o paciente permanece em FA durante um determinado período de tempo; portanto, é teoricamente mais elevado na FA permanente e mais baixo na FA paroxística. A inflamação está associada ao início e à manutenção da FA. No entanto, a relação entre o índice de inflamação imune sistêmica (SII, do inglês systemic immune-inflammation index) e a carga de FA é desconhecida. OBJETIVO: No presente estudo, investigamos a relação entre o SII e a carga de FA. MÉTODOS: O presente estudo é uma análise transversal de 453 pacientes (252 do sexo feminino e 201 do sexo masculino, com idade entre 44 e 94 anos) com FA (138 com FA paroxística e 315 com FA permanente) atendidos no ambulatório de cardiologia entre outubro de 2022 e junho de 2023. O SII foi calculado como (neutrófilos × plaquetas/linfócitos). O papel preditivo do SII e de outros marcadores inflamatórios na probabilidade do padrão de FA foi avaliado por análises de regressão logística, sendo considerado estatisticamente significativo o valor de p < 0,05. RESULTADOS: Idade, pressão arterial diastólica, frequência cardíaca, diabetes mellitus, neutrófilos, relação plaquetas-linfócitos, relação neutrófilos-linfócitos, SII, proteína C reativa, largura de distribuição de glóbulos vermelhos, hemoglobina A1c e diâmetro do átrio esquerdo foram significativamente maiores no grupo com FA permanente. De acordo com a análise de regressão logística, idade (p = 0,038), diabetes mellitus (p = 0,024), largura de distribuição de glóbulos vermelhos (p = 0,023), proteína C reativa (p = 0,010), SII (p = 0,001) e o diâmetro do átrio esquerdo (p < 0,001) contribuíram significativamente para a predição da probabilidade de FA permanente. CONCLUSÃO: O SII está independentemente associado à carga de FA. Estudos prospectivos são necessários para determinar se o SII pode ser útil na identificação de pacientes com alto risco de progressão da FA.

Differential hemodynamic adaptations to tilt test in patients with idiopathic atrial fibrillation.

The hemodynamic response during the transition from the supine to standing position in idiopathic atrial fibrillation (AF) patients is not completely understood. This study aimed to analyze the hemodynamic changes that occur during the head-up tilt test in idiopathic AF patients. We investigated the hemodynamic changes during the head-up tilt test with impedance cardiography in 40 AF patients (12 with AF rhythm-AFr and 28 with sinus rhythm-AFsr) and 38 non-AF controls. Patients with AFr had attenuated SVI decrease after standing when compared to AFsr and non-AF [ΔSVI in mL/m2: -1.3 (-3.4 to 1.7) vs. -6.4 (-17.3 to -0.1) vs. -11.8 (-18.7 to -8.0), respectively; p < 0.001]. PVRI decreased in AFr but increased in AFsr and non-AF [ΔPVRI in dyne.seg.m2/cm5: -477 (-1148 to 82.5) vs. 131 (-525 to 887) vs. 357 (-29 to 681), respectively; p < 0.01]. Similarly, compared with non-AF patients, AFr patients also had a greater HR and greater CI increase after standing. The haemodynamic response to orthostatic challenge suggests differential adaptations between patients with AF rhythm and those reverted to sinus rhythm or healthy controls. Characterizing the hemodynamic phenotype may be relevant for the individualized treatment of AF patients.

Catheter ablation for atrial fibrillation in heart failure with reduced ejection fraction patients: A meta-analysis.

BACKGROUND: The optimal treatment of atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (HFrEF) remains unsettled. OBJECTIVE: The purpose of this study was to assess the efficacy of catheter ablation (CA) and medical therapy compared to medical therapy alone in patients with AF and HFrEF. METHODS: We performed a systematic review of randomized controlled trials (RCTs) comparing CA with guideline-directed medical therapy for AF in patients with HFrEF (left ventricular ejection fraction [LVEF] ≤ 40%). We systematically searched PubMed, Embase, and Cochrane for eligible trials. A random effects model was used to calculate the risk ratios (RRs) and mean differences (MDs), with 95% confidence intervals (CIs). RESULTS: Six RCTs comprising 1055 patients were included, of whom 530 (50.2%) were randomized to CA. Compared with medical therapy, CA was associated with a significant reduction in heart failure (HF) hospitalization (RR 0.57; 95% CI 0.45-0.72; P < .01), cardiovascular mortality (RR 0.46; 95% CI 0.31-0.70; P < .01), all-cause mortality (RR 0.53; 95% CI 0.36-0.78; P < .01), and AF burden (MD -29.8%; 95% CI -43.73% to -15.90%; P < .01). Also, there was a significant improvement in LVEF (MD 3.8%; 95% CI 1.6%-6.0%; P < .01) and quality of life (Minnesota Living with Heart Failure Questionnaire; MD -4.92 points; 95% CI -8.61 to -1.22 points; P < .01) in the ablation group. CONCLUSION: In this meta-analysis of RCTs of patients with AF and HFrEF, CA was associated with a reduction in HF hospitalization, cardiovascular mortality, and all-cause mortality as well as a significant improvement in LVEF and quality of life.

Catheter ablation versus medical therapy for atrial fibrillation in patients with heart failure with preserved ejection fraction: A systematic review and meta-analysis.

BACKGROUND: The benefit of catheter ablation for atrial fibrillation (AF) in patients with heart failure with preserved ejection fraction (HFpEF) remains uncertain. OBJECTIVE: We performed a systematic review and meta-analysis to compare catheter ablation and medical therapy (antiarrhythmics for rhythm or rate control) in patients with AF and HFpEF. METHODS: We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials. Outcomes were the composite end points of death or heart failure (HF) hospitalization, all-cause death, cardiovascular death, all-cause rehospitalization, and HF hospitalization. Statistical analysis was performed using R statistical software, version 4.3.2 (R Foundation for Statistical Computing). Heterogeneity was assessed with I2 statistics. RESULTS: We included 20,257 patients from 8 studies. Of those, 3 were derived from RCTs, either through post hoc analysis or subgroup analysis, and 5 were observational studies. The median follow-up ranged from 24.6 to 61.2 months. Compared with medical therapy, catheter ablation was associated with a statistically significant lower risk of death or HF hospitalization (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.47-0.83; P = .001; I2 = 66%), all-cause death (HR 0.68; 95% CI 0.46-0.99; P = .047; I2 = 61%), cardiovascular death (HR 0.42; 95% CI 0.21-0.84; P = .014; I2 = 22%), and HF hospitalization (HR 0.43; 95% CI 0.23-0.82; P = .011; I2 = 87%). CONCLUSION: In this meta-analysis, catheter ablation was associated with a lower risk of all-cause death, cardiovascular death, HF hospitalization, and all-cause rehospitalization in comparison to medical therapy in patients with AF and HFpEF.

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.

Impact of weight adjusted high frequency low tidal volume ventilation and atrial pacing in lesion metrics in high-power short-duration ablation: Results of a pilot study.

INTRODUCTION: Lesion size index (LSI) was introduced with the use of Tacticath™ and as a surrogate of lesion quality. The metric used to achieve the predetermined values involves combined information of contact force (CF), power and radiofrequency time. Rapid atrial pacing (RAP) and high-frequency low-tidal volume ventilation (HFLTV) independently or in combination improve catheter stability and CF and quality of lesions. Data of the impact of body weight adjusted HFLTV ventilation strategy associated with RAP in the lesion metrics still lacking. The study aimed to compare the results of high-power short-duration (HPSD) atrial fibrillation ablation using simultaneous weight adjusted HFLTV and RAP and standard ventilation (SV) protocol. METHODS: Prospective, nonrandomized study with 136 patients undergoing de novo ablation divided into two groups; 70 in RAP (100 ppm) + HFLTV with 4 mL/kg of tidal volume and 25 breaths/min (group A) and 66 patients with SV in intrinsic sinus rhythm (group B). Ablation using 50 W, CF of 5-10 g/10-20 g and 40 mL/minute flow rate on the posterior and anterior left atrial wall, respectively. RESULTS: No procedure-related complications. Group A: Mean LSI points 70 ± 16.5, mean total lower LSI 3.4 ± 0.5, mean total higher LSI 8.2 ± 0.4 and mean total LSI 5.6 ± 0.6. Anterior and posterior wall mean total LSI was 6.0 ± 0.4 and 4.2 ± 0.3, respectively. Mean local impedance drop (LID) points were 118.8 ± 28.4, mean LID index (%) 12.9 ± 1.5, and mean LID < 12% points 55.9 ± 23.8. Anterior and posterior wall mean total LID index were 13.6 ± 2.0 and 11.9 ± 1.7, respectively. Recurrence in 11 (15.7%) patients. Group B: Mean LSI points 56 ± 2.7, mean total lower LSI 2.9 ± 0.7, mean total higher LSI 6.9 ± 0.9, and mean total LSI 4.8 ± 0.8. Anterior and posterior wall mean total LSI was 5.1 ± 0.3 and 3.5 ± 0.5, respectively. Mean LID points were 111.4 ± 21.5, mean LID index (%) 11.4 ± 1.2, and mean LID < 12% points 54.9 ± 25.2. Anterior and posterior wall mean total LID index were 11.8 ± 1.9 and 10.3 ± 1.7, respectively. Recurrence in 14 (21.2%) patients. Mean follow up was 15.2 ± 4.4 months. CONCLUSION: Weight adjusted HFLTV ventilation with RAP HPSD ablation produced lower recurrence rate and better LSI and LID parameters in comparison to SV and intrinsic sinus rhythm.

Rivaroxabana para prevenção de eventos tromboembólicos em pacientes com fibrilação atrial não-valvular / Rivaroxaban for event prevention thromboembolic events in patients with atrial fibrillation non-valvular

INTRODUÇÃO: A fibrilação atrial não-valvular (FANV) é um tipo comum de arritmia cardíaca que afeta cerca de 1 em cada 20 pessoas com idade maior que 65 anos e 1 em cada dez indivíduos com mais de 75 anos (1). A FANV é um importante fator de risco para ocorrência de acidente vascular cerebral (AVC) isquêmico e está implicada em cerca de 15% de todos os casos. Diferentes diretrizes recomendam o uso de antocoagulante oral (ACO) em pacientes com FANV com o objetivo de reduzir o risco da ocorrência do AVC(3). Durante décadas, o antocoagulante oral mais amplamente empregado foi a varfarina. Evidências mostram que a anticoagulação com a varfarina, um antagonista da vitamina K, reduz o risco de AVC em até 64% quando comparada ao placebo. A redução absoluta de risco atribuivel à varfarina ressalta a efetividade da terapia de anticoagulação nestes pacientes, embora o risco ainda permaneneça elevado. No entanto, existem barreiras para a utilização da varfarina na prática clínica. Iniciar e manter o tratamento dos pa

Fibrilación auricular recurrente posterior a ablación de venas pulmonares: serie de casos / Recurrent atrial fibrillation after ablation of pulmonary veins: case series / Fibrilação atrial recorrentes pós ablação das veias pulmonares: série de casos

La ablación de las venas pulmonares se ha convertido en un tratamiento clave para fibrilación auricular (FA). Sin embargo, pueden ocurrir recurrencias. La estrategia disponible para la ablación después de una recurrencia de FA es controvertida, compleja y desafiante, y la información es limitada. Mediante la presentación de una serie de casos se resumen y discuten elementos clave en la comprensión y tratamiento del paciente con FA recurrente sintomática después de un procedimiento inicial de ablación de venas pulmonares que requiere un nuevo procedimiento de ablación. En las últimas décadas se ha obtenido una mejor comprensión de los mecanismos fisiopatológicos implicados en la FA recurrente posterior a ablación de venas pulmonares, lo que permite identificar factores asociados, crear scores predictores e implementar técnicas de optimización o estrategias adicionales para mejorar la durabilidad y la eficacia del aislamiento de venas pulmonares. Debido a que la reconexión de venas pulmonares es un hallazgo típico durante los procedimientos repetidos, ésta debe ser considerada el objetivo principal de una nueva ablación. Las estrategias de ablación adicional (desencadenantes extrapulmonares o sustratos arritmogénicos) son controvertidas y requieren investigaciones futuras.

Pulmonary vein ablation has become a key treatment for atrial fibrillation (AF). However, recurrences can occur. The ideal strategy for ablation after AF recurrence is controversial, complex, and challenging, with limited data available. By presenting a series of cases, we summarize and discuss key elements in the understanding and treatment of patients with symptomatic recurrent AF after an initial pulmonary vein ablation procedure who are subjected to a new ablation procedure. In recent decades, there has been a better understanding of the pathophysiological mechanisms involved in recurrent AF after pulmonary vein ablation, making it possible to identify associated factors, create predictive scores and implement optimization techniques or additional strategies to improve the durability and efficacy of pulmonary veins isolation. Because pulmonary vein reconnection is a typical finding during repeat procedures, it should be considered the primary goal for a repeat ablation procedure. Additional ablation strategies (extrapulmonary triggers or arrhythmogenic substrates) are controversial and require further investigation.

A ablação das veias pulmonares tornou-se um tratamento chave para fibrilação atrial (FA). No entanto, podem ocorrer recorrências. A estratégia ideal para a ablação após uma recorrência da FA é controversa, complexa e desafiadora e existem dados limitados. Através da apresentação de uma série de casos resumimos e discutimos elementos chave no entendimento e tratamento do paciente com FA recorrente sintomática após um procedimento inicial de ablação de veias pulmonares, que são submetidos a um novo procedimento de ablação. Nas últimas décadas obteve-se uma melhor compressão dos mecanismos fisiopatológicos envolvidos na FA recorrente pós-ablação de veias pulmonares, isso permite identificar fatores associados, criar scores preditores, implementar técnicas de otimização ou estratégias adicionais para melhorar a durabilidade e eficácia do isolamento de veias pulmonares. Dado que a reconexão de veias pulmonares é um achado típico durante os procedimentos repetidos deve ser considerado o objetivo principal para uma nova ablação. As estratégias de ablação adicional (desencadeadores extrapulmonares ou substratos arritmogénicos) são controversas e requerem investigação futura.

Epicardial Fat Tissue Thickness and Omentin in Patients with Atrial Fibrillation

Abstract Background: Although electrical and structural remodeling has been recognized to be important in the pathophysiology of atrial fibrillation, the mechanisms underlying remodeling process are unknown. There has been increasing interest in the involvement of inflammatory molecules and adipokines released from the epicardial fat tissue in the pathophysiology of atrial fibrillation. Objectives: In our study, we aimed to investigate the relationship of atrial fibrillation with increased epicardial adipose tissue, inflammatory molecules released from this tissue and omentin. Methods: Thirty-six patients who were followed up with a diagnosis of permanent AF at the cardiology outpatient clinic 33 individuals without atrial fibrillation (controls) were included in the study. Epicardial adipose tissue thickness of patients was measured by echocardiography. Serum omentin, IL 6, IL 1 beta, TNF alpha and CRP levels were measured. Man-Whitney U test was performed for comparisons and significance was established at 5% (p<0.05). Results: Epicardial adipose tissue thickness was significantly greater in the patient group (6mm [4-5.5]) than controls (4mm [3-5.5]) (p <0.001). No significant difference was found in the concentrations of omentin or inflammatory molecules between the groups. Conclusion: No relationship was found between atrial fibrillation and serum levels or omentin or inflammatory markers. A relationship between epicardial adipose tissue thickness measured by echocardiography and atrial fibrillation was determined.

Strain Echocardiography to Predict Postoperative Atrial Fibrillation.

Postoperative atrial fibrillation (POAF) complicates 15% to 40% of cardiovascular surgeries. Its incidence progressively increases with aging, reaching 50% in octogenarians. This arrhythmia is usually transient but it increases the risk of embolic stroke, prolonged hospital stay, and cardiovascular mortality. Though many pathophysiological mechanisms are known, POAF prediction is still a hot topic of discussion. Doppler echocardiogram and, lately, strain echocardiography have shown significant capacity to predict POAF. Alterations in oxidative stress, calcium handling, mitochondrial dysfunction, inflammation, fibrosis, and tissue aging are among the mechanisms that predispose patients to the perfect "atrial storm". Manifestations of these mechanisms have been related to enlarged atria and impaired function, which can be detected prior to surgery. Specific alterations in the atrial reservoir and pump function, as well as atrial dyssynchrony determined by echocardiographic atrial strain, can predict POAF and help to shed light on which patients could benefit from preventive therapy.

The Effects of Fibrotic Cell Type and Its Density on Atrial Fibrillation Dynamics: An In Silico Study.

Remodeling in atrial fibrillation (AF) underlines the electrical and structural changes in the atria, where fibrosis is a hallmark of arrhythmogenic structural alterations. Fibrosis is an important feature of the AF substrate and can lead to abnormal conduction and, consequently, mechanical dysfunction. The fibrotic process comprises the presence of fibrotic cells, including fibroblasts, myofibroblasts and fibrocytes, which play an important role during fibrillatory dynamics. This work assesses the effect of the diffuse fibrosis density and the intermingled presence of the three types of fibrotic cells on the dynamics of persistent AF. For this purpose, the three fibrotic cells were electrically coupled to cardiomyocytes in a 3D realistic model of human atria. Low (6.25%) and high (25%) fibrosis densities were implemented in the left atrium according to a diffuse fibrosis representation. We analyze the action potential duration, conduction velocity and fibrillatory conduction patterns. Additionally, frequency analysis was performed in 50 virtual electrograms. The tested fibrosis configurations generated a significant conduction velocity reduction, where the larger effect was observed at high fibrosis density (up to 82% reduction in the fibrocytes configuration). Increasing the fibrosis density intensifies the vulnerability to multiple re-entries, zigzag propagation, and chaotic activity in the fibrillatory conduction. The most complex propagation patterns were observed at high fibrosis densities and the fibrocytes are the cells with the largest proarrhythmic effect. Left-to-right dominant frequency gradients can be observed for all fibrosis configurations, where the fibrocytes configuration at high density generates the most significant gradients (up to 4.5 Hz). These results suggest the important role of different fibrotic cell types and their density in diffuse fibrosis on the chaotic propagation patterns during persistent AF.

Cerebral Structure and Function in Stroke-free Patients with Atrial Fibrillation.

OBJECTIVES: Atrial fibrillation (AF) is associated with high risk of dementia and brain atrophy in stroke-free patients, but the mechanisms underlying this association remain unclear. We aimed to examine the brain volume and connectivity of paramount cognitive brain networks in stroke-free patients with AF without dementia. MATERIALS AND METHODS: Twenty-six stroke-free patients with AF and 26 age and sex-matched subjects without AF were submitted to a 3-tesla brain structural and functional MRI. An extensive clinical evaluation excluded stroke, dementia, low cardiac output, carotid stenosis and metabolic diseases without optimal therapy. We used CHA2DS2-VASc score to classify the cardiovascular risk factor burden and a broad neuropsychological battery to assess the cognitive performance. Voxel based morphometry analysis of. structural MRI defined whole-brain gray and white matter volumes. Finally, we used eco-plannar MRI images to compare the differences of functional connectivity of 7 large-scale resting-state networks between AF patients and controls. RESULTS: Taking into account the history of hypertension and heart failure, AF was associated to volume decrease of the right basal frontal lobe and right inferior cerebellum. Decreased connectivity of the ventral Default Mode Network (vDMN) was observed in the AF group. No disruption of connectivity was observed in the executive, visuospatial and salience networks. CONCLUSION: Individuals with AF without stroke or dementia have subtle reduction of gray and white matter, restricted to frontal areas and cerebellum. These patients show decreased vDMN connectivity, without other large-scale brain network disruption.