The First Brazilian Cardiovascular Registry of Atrial Fibrillation: Primary Results of the RECALL Study.

BACKGROUND: It is estimated that atrial fibrillation (AF) affects approximately 1.5 million people in Brazil; however, epidemiological data are limited. We sought to evaluate the characteristics, treatment patterns, and clinical outcomes in patients with AF in Brazil by creating the first nationwide prospective registry. METHODS: RECALL was a multicenter, prospective registry that included and followed for 1 year 4,585 patients with AF at 89 sites across Brazil from April 2012 to August 2019. Patient characteristics, concomitant medication use, and clinical outcomes were analyzed using descriptive statistics and multivariable models. RESULTS: Of 4,585 patients enrolled, the median age was 70 (61, 78) years, 46% were women, and 53.8% had permanent AF. Only 4.4% of patients had a history of previous AF ablation and 25.2% had a previous cardioversion. The mean (SD) CHA2DS2-VASc score was 3.2 (1.6); median HAS-BLED score was 2 (2, 3). At baseline, 22% were not on anticoagulants. Of those taking anticoagulants, 62.6% were taking vitamin K antagonists and 37.4% were taking direct oral anticoagulants. The primary reasons for not using an oral anticoagulant were physician judgment (24.6%) and difficulty in controlling (14.7%) or performing (9.9%) INR. Mean (SD) TTR for the study period was 49.5% (27.5). During follow-up, the use of anticoagulants and INR in the therapeutic range increased to 87.1% and 59.1%, respectively. The rates/100 patient-years of death, hospitalization due to AF, AF ablation, cardioversion, stroke, systemic embolism, and major bleeding were 5.76 (5.12-6.47), 15.8 (14.6-17.0), 5.0 (4.4-5.7), 1.8 (1.4-2.2), 2.77 (2.32-3.32), 1.01 (0.75-1.36), and 2.21 (1.81-2.70). Older age, permanent AF, New York Heart Association class III/IV, chronic kidney disease, peripheral arterial disease, stroke, chronic obstructive pulmonary disease, and dementia were independently associated with increased mortality while the use of anticoagulant was associated with lower risk of death. CONCLUSIONS: RECALL represents the largest prospective registry of patients with AF in Latin America. Our findings highlight important gaps in treatment, which can inform clinical practice and guide future interventions to improve the care of these patients.

Vasoactive Biomarkers in Patients With Vasovagal Syncope During Head-Up Tilt Test: A Case-Control Study.

Background: Vasovagal syncope (VVS) is the most common cause of syncope. Some stages of its pathophysiological mechanisms remain unclear. Vasoactive substances such as nitric oxide metabolites (NOx) and endothelin (ET) may be involved during acute orthostatic stress. Objective: To analyze plasma changes in NOx and ET and heart rate variability (HRV) in the supine positions (T1) and during the head-up tilt test (HUTT) (T2), in patients with VVS (case group) and control group. Methods: Thirty-seven patients (17 in the case group and 20 in the control group), matched for age and sex (mean aged 31.8 years) underwent HUTT with simultaneous HRV recording and venipuncture. Blood samples were collected during phases T1 and T2 and the analysis was performed without knowledge of the HUTT result. Results: In the total sample, there was an increase in NOx values (P = .014), however there was no increase in ET values from phase T1 to phase T2. Patients with VVS tended to increase plasma NOx values (P = .057) and had significantly higher plasma values compared to ET (P = .033) between phases T1 to T2. In the control group, there was no significant change in the values of these vasoactive substances. Regarding HRV, there were a decrease in the component HF (high frequency) and increased of the LF (low frequency)/HF ratio during HUTT. Conclusions: There was an increase in ET during HUTT occurred only in the case group. These patients are more likely to have an imbalance between antagonistic vasoactive biomarkers during orthostatic stress.

Atrial Fibrillation and Risk of Dementia: Epidemiology, Mechanisms, and Effect of Anticoagulation.

Atrial fibrillation (AF) is one of the cardiovascular risk factors for dementia. Several longitudinal studies have reported an association between AF and dementia independently of stroke history. Although the mechanisms underlying this association are not fully understood, proposed mechanisms include cerebral hypoperfusion, inflammation, genetic factors, cerebral microbleeds, and recurrent silent cerebral ischemia. Oral anticoagulation can be used to minimize risk of cognitive decline and dementia, given that brain insults can be caused by chronic microemboli or microbleeds. However, controversy on the effects of warfarin and direct oral anticoagulants on this risk exists. This article will address these aspects, with data on the studies already published and a critical view on this subject.

Analysis of Heart Rate Variability Before and During Tilt Test in Patients with Cardioinhibitory Vasovagal Syncope / Análise da Variabilidade de Frequência Cardíaca antes e durante o Teste de Inclinação em Pacientes com Síncope Vasovagal Tipo Cardioinibitória

Abstract Background: Cardioinhibitory vasovagal response is uncommon during the tilt test (TT). Heart rate variability (HRV) by use of spectral analysis can distinguish patients with that response. Objective: To compare the HRV in patients with cardioinhibitory vasovagal syncope (case group - G1) with that in patients without syncope and with negative response to TT (control group - G2). Methods: 64 patients were evaluated (mean age, 36.2 years; 35 men) and submitted to TT at 70 degrees, under digital Holter monitoring. The groups were paired for age and sex (G1, 40 patients; G2, 24). Results: In G1, 21 patients had a type 2A response and 19 had type 2B, with mean TT duration of 20.4 minutes. There was a greater low frequency (LF) component (11,6 versus 4,5 ms2, p=0.001) and a lower low/high frequency ratio in the supine position (3,9 versus 4,5 ms2, p=0.008) in G1, with no difference during TT between the groups. Applying the receiver operating characteristic curve for cardioinhibitory response, the area under the curve was 0.74 for the LF component in the supine position (p = 0.001). The following were observed for the cutoff point of 0.35 ms(2) for the LF component: sensitivity, 97.4%; specificity, 83.3%; positive predictive value, 85.3%; negative predictive value, 96.9%; and positive likelihood ratio, 5.8. Conclusion: HRV in the supine position allowed identifying patients with syncope and cardioinhibitory response with a high negative predictive value and likelihood ratio of 5.8.

Resumo Fundamento: A resposta cardioinibitória vasovagal ao teste de inclinação (TI) é pouco frequente. A variabilidade da frequência cardíaca (VFC) por meio da análise espectral pode discernir os pacientes (pts) com aquela resposta. Objetivo: Avaliar a VFC em pts com síncope vasovagal cardioinibitória (grupo caso - G1), comparando-a com a VFC de pts sem síncope e com resposta negativa ao TI (grupo controle - G2). Métodos: foram avaliados 64 pts, média de idade 36,2 anos, 35 homens, submetidos ao TI a 70º, sob monitoramento pelo Holter digital. Os grupos foram pareados por idade e sexo, sendo 40 pts do G1 e 24 do G2. Resultados: No G1, 21 pts apresentaram resposta tipo 2A e 19, tipo 2B, com média do TI de 20,4 min. Houve maior valor do componente de baixa frequência (BF) (11,6 versus 4,5 ms2, p=0,001) e menor relação baixa/alta frequência na posição supina (3,9 versus 4,5 ms2, p=0,008) no G1, sem diferença durante o TI. Aplicando-se a curva de operação característica para resposta cardioinibitória, foi obtida a área abaixo da curva de 0,74 para o componente BF na posição supina (p=0,001). Para o ponto de corte de 0,35 ms2 para BF observaram-se: sensibilidade, 97,4%; especificidade, 83,3%; valor preditivo positivo, 85,3%; valor preditivo negativo, 96,9%; e razão de probabilidade positiva, 5,8. Conclusão: A VFC na posição supina permitiu identificar os pts com síncope e com resposta cardioinibitória, com um alto valor preditivo negativo e uma razão de probabilidade de 5,8.

Analysis of Heart Rate Variability Before and During Tilt Test in Patients with Cardioinhibitory Vasovagal Syncope.

BACKGROUND: Cardioinhibitory vasovagal response is uncommon during the tilt test (TT). Heart rate variability (HRV) by use of spectral analysis can distinguish patients with that response. OBJECTIVE: To compare the HRV in patients with cardioinhibitory vasovagal syncope (case group - G1) with that in patients without syncope and with negative response to TT (control group - G2). METHODS: 64 patients were evaluated (mean age, 36.2 years; 35 men) and submitted to TT at 70 degrees, under digital Holter monitoring. The groups were paired for age and sex (G1, 40 patients; G2, 24). RESULTS: In G1, 21 patients had a type 2A response and 19 had type 2B, with mean TT duration of 20.4 minutes. There was a greater low frequency (LF) component (11,6 versus 4,5 ms2, p=0.001) and a lower low/high frequency ratio in the supine position (3,9 versus 4,5 ms2, p=0.008) in G1, with no difference during TT between the groups. Applying the receiver operating characteristic curve for cardioinhibitory response, the area under the curve was 0.74 for the LF component in the supine position (p = 0.001). The following were observed for the cutoff point of 0.35 ms(2) for the LF component: sensitivity, 97.4%; specificity, 83.3%; positive predictive value, 85.3%; negative predictive value, 96.9%; and positive likelihood ratio, 5.8. CONCLUSION: HRV in the supine position allowed identifying patients with syncope and cardioinhibitory response with a high negative predictive value and likelihood ratio of 5.8.

Experiência inicial da estimulaçäo cardíaca artificial com marcapasso VDD de eletrodo único / Initial experience of a single lead VDD pacing system

Objetivo: O objetivo deste estudo é avaliar o desempenho do marcapasso VDD com eletrodo único Dromos-Biotronic. Casuística e Métodos: Num período de 12 meses foram realizados 21 implantes de sistemas VDD com eletrodo único, no Instituto do Coraçao do Hospital Madre Teresa. Onze pacientes eram do sexo feminino, a média de idades foi de 59,8 anos (16 a 77). Todos os pacientes apresentavam bloqueio atrioventricular (BAV) avançado (BAV total e BAV segundo grau). A miocardiopatia chagásica foi a etiologia de maior prevalência (76,1 por cento), seguido de pós-cirúrgico (14,3 por cento), miocardioesclerose (4,7 por cento) e de etiologia desconhecida (4,7 por cento). Os pacientes utilizaram eletrodo SL 60-/13-UP Biotronic. A técnica de implante foi a tradicional para implantes VVI endocavitários, apenas com o cuidado de posicionar os anéis de "sensing" atrial em posiçao alta ou médio-alta no átrio e medir os potenciais desta cavidade. A avaliaçao pós-operatória foi realizada a nível ambulatorial, no terceiro mês de pós-operatório, constando de análise telemétrica, ecocardiográfica e teste de esforço em esteira, para avaliaçao da funçao ventricular, tolerância ao exercício e manutençao do sincronismo AV no repouso e durante movimento. Resultados: A análise telemétrica demonstrou boa captura atrial no repouso em todos os pacientes (100 por cento). O teste de limiar de sensibilidade atrial revelou onda "P" média de 1,27 mV, sendo que apenas um paciente tinha sensibilidade atrial reprogramada para 0,1 mV devido a perda de captura dependente de posiçao; os demais pacientes foram mantidos com programaçao à nominal deste parâmetro (0,2 mV). A ecocardiografia revelou melhora da fraçao de ejeçao em 71,4 por cento dos pacientes e 90,47 por cento relataram melhora funcional (NYHA). Ao teste de esforço 95,23 por cento dos pacientes mantiveram o sincronismo AV no pico do esforço. Conclusao: A estimulaçao cardíaca artificial em VDD com eletrodo único demonstrou excelente alternativa à estimulaçao em DDD, porque manteve o sincronismo AV em repouso e no exercício, melhorou o desempenho hemodinâmico e, conseqüentemente, a classe funcional da maioria dos pacientes, sem a necessidade de se utilizar um segundo eletrodo, evitando, assim, as complicaçoes de implante e seu acompanhamento deste. Desta forma, o sistema VDD com eletrodo único reúne as facilidades de implante dos sistemas VVI, com os benefícios hemodinâmicos dos sistemas DDD...