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ABSTRACT Coordinated and harmonic (synchronous) ventricular electrical activation is essential for better left ventricular systolic function. Intraventricular conduction abnormalities, such as left bundle branch block due to artificial cardiac pacing, lead to electromechanical “dyssynchronopathy” with deleterious structural and clinical consequences. The aim of this review was to describe and improve the understanding of all the processes connecting the several mechanisms involved in the development of artificially induced ventricular dyssynchrony by cardiac pacing, most known as pacing-induced cardiomyopathy (PiCM). The chronic effect of abnormal impulse conduction and nonphysiological ectopic activation by artificial cardiac pacing is suspected to affect metabolism and myocardial perfusion, triggering regional differences in the activation/contraction processes that cause electrical and structural remodeling due to damage, inflammation, and fibrosis of the cardiac tissue. The effect of artificial cardiac pacing on ventricular function and structure can be multifactorial, and biological factors underlying PiCM could affect the time and probability of developing the condition. PiCM has not been included in the traditional classification of cardiomyopathies, which can hinder detection. This article reviews the available evidence for pacing-induced cardiovascular disease, the current understanding of its pathophysiology, and reinforces the adverse effects of right ventricular pacing, especially right ventricular pacing burden (commonly measured in percentage) and its repercussion on ventricular contraction (reflected by the impact on left ventricular systolic function). These effects might be the main defining criteria and determining mechanisms of the pathophysiology and the clinical repercussion seen on patients.

Resumo Fundamento A insuficiência cardíaca (IC) com fração de ejeção na faixa média ou intermediária (ICFEI) (em inglês, “mid-range ejection fraction) foi recentemente descrita em diretrizes europeia e brasileira recentes sobre o manejo da insuficiência cardíaca (IC). A fração de ejeção (FE) é um parâmetro importante para direcionar terapia e prognóstico. Estudos têm mostrado resultados conflitantes sem dados representativos de países em desenvolvimento. Objetivo Analisar e comparar a taxa de sobrevida em pacientes com ICFEI com pacientes com IC e FE reduzida (ICFEr), e pacientes com IC e FE preservada, e avaliar as características clínicas desses pacientes. Métodos Estudo coorte que incluiu pacientes com IC aguda admitidos no departamento de emergência de um hospital terciário, referência em cardiologia, localizado no sul do Brasil, entre 2009 e 2011. A amostra foi dividida em três grupos de acordo com a FE: reduzida, intermediária e preservada. Curva de Kaplan-Meier foi analisada de acordo com a FE, e uma análise de regressão logística foi realizada. A significância estatística foi estabelecida em p

Objective: Catheter ablation has been a common procedure used for the management of atrial fibrillation (AF). Atrioesophagel fistula (AEF) is one of the most feared complications of AF ablation. Although it is a rare complication, severe esophageal thermal injury must be avoided. It is important to describe a safe method of preventing esophageal injuries without increasing AF recurrence. Methods: A retrospective cohort study of consecutive patients who underwent radiofrequency AF catheter ablation during 1 year-period wa conducted. One hundred and four patients were enrolled divided in two groups: one with a maximum recorded esophageal temperature (ET) < 38 °C and other with a maximum recorded ET ≥ 38 °C. The primary endpoint was detection of endoscopic esophageal lesions after AF ablation and the secondary endpoint was AF recurrence according to the maximum ET reached during the procedure. Results: The maximum ET was on average 37.3 ± 1.0 °C. Only 4 (3.8%) patients had esophageal lesion diagnosed by upper gastrointestinal endoscopy. There were no cases of esophageal perforation. The AF recurrence rate was 9.6% during the follow-up (10 patients, 3 from the ET max < 38 °C group and 7 from the ET max ≥ 38 °C group; p = 0.181). The maximum ET was not associated with AF recurrence after catheter ablation (OR = 1.65, 95% CI = 0.84-3.24, p = 0.14). Conclusions: A low incidence of esophageal injury after AF ablation with the use of a specific esophageal protection protocol was found. There was no esophageal perforation. The AF recurrence rate was similar to that described in the literature.

OBJECTIVES: To describe the prevalence of the reduced ankle-brachial index (ABI) in patients with heart failure (HF) with preserved ejection fraction (HFpEF) attended at a HF clinic in the metropolitan region of Porto Alegre, and to compar the patients to those with reduced ejection fraction (HFrEF). METHODS: A descriptive observational study, included patients referred to the heart failure clinic in HU-Ulbra with HFpEF or HFrEF and diastolic dysfunction, and measurements of ABIs using vascular Doppler equipment were performed in both groups. RESULTS: The sample consisted of 106 patients with HF, 53.9% of the patients had HFpEF, and 19.4% had a diagnosis of peripheral arterial disease (PAD) (ABI less than 0.9). PAD was identified in 24.1% of the patients with HFpEF, while15.8% of patients in the HFrEF group were diagnosed with PAD. CONCLUSION: Our results did not identify a significantly different prevalence of altered and compatible PAD values in patients with HFpEF. However, we showed a prevalence of 19.4%, a high value if we consider similar populations.

Abstract Background: Clinical studies demonstrate that up to 40% of patients do not respond to cardiac resynchronization therapy (CRT), thus, appropriate patient selection is critical to the success of CRT in heart failure. Objective: Evaluation of mortality predictors and response to CRT in the Brazilian scenario. Methods: Retrospective cohort study including patients submitted to CRT in a tertiary hospital in southern Brazil from 2008 to 2014. Survival was assessed through a database of the State Department of Health (RS). Predictors of echocardiographic response were evaluated using Poisson regression. Survival analysis was performed by Cox regression and Kaplan Meyer curves. A two-tailed p value less than 0.05 was considered statistically significant. Results: A total of 170 patients with an average follow-up of 1011 ± 632 days were included. The total mortality was 30%. The independent predictors of mortality were age (hazard ratio [HR] of 1.05, p = 0.027), previous acute myocardial infarction (AMI) (HR of 2.17, p = 0.049) and chronic obstructive pulmonary disease (COPD) (HR of 3.13, p = 0.015). The percentage of biventricular stimulation at 6 months was identified as protective factor of mortality ([HR] 0.97, p = 0.048). The independent predictors associated with the echocardiographic response were absence of mitral insufficiency, presence of left bundle branch block and percentage of biventricular stimulation. Conclusion: Mortality in patients submitted to CRT in a tertiary hospital was independently associated with age, presence of COPD and previous AMI. The percentage of biventricular pacing evaluated 6 months after resynchronizer implantation was independently associated with improved survival and echocardiographic response.

OBJECTIVES: Atrial fibrillation is the most common sustained arrhythmia and is associated with poor outcomes, including stroke. The ability of anticoagulation therapy to reduce the risk of stroke has been well established; however, the prevalence of anticoagulation therapy use in the Public Health System is unknown. The aim of this study is to evaluate both the prevalence of anticoagulation therapy among patients with atrial fibrillation and the indications for the treatment. METHODS: In this cross-sectional study, we included consecutive patients who had atrial fibrillation documented by an electrocardiogram performed between September 2011 and March 2012 at a university hospital of the Public Health System. The variables analyzed included the risk of a thromboembolic event and/or bleeding, the use of antiplatelet or anticoagulation therapy, the location where the electrocardiogram report was initially reviewed and the specialty of the physician who initially reviewed it. RESULTS: We included 162 patients (mean age 68.9 years, 56% men). Hypertension (90.1%), heart failure (53.4%) and stroke (38.9%) were the most prevalent diseases found. Only 50.6% of the patients knew that they had atrial fibrillation. Regarding the use of therapy, only 37.6% of patients classified as high risk according to the CHADS2 scores and 35.5% according to the CHA2DS2VASc used oral anticoagulation. A presumptive diagnosis of heart failure and the fact that the electrocardiogram was evaluated by a cardiologist were the only independent predictors of the use of anticoagulants. CONCLUSIONS: Our study found a low prevalence of oral anticoagulation therapy among patients with atrial fibrillation and an indication for stroke prophylaxis for the use of this therapy, including among those with high CHADS2 and CHA2DS2VASc scores.

Fundamento: A ablação por cateter de radiofrequência guiada por mapeamento eletroanatômico é, atualmente, uma importante opção terapêutica para o tratamento da fibrilação atrial. A complexidade do procedimento, as diferentes técnicas e a diversidade de pacientes dificultam a reprodução dos resultados bem como a indicação do procedimento. Objetivo: Avaliar a eficácia e os fatores relacionados à recorrência de fibrilação atrial. Métodos: Estudo de coorte prospectivo com pacientes consecutivos submetidos ao tratamento de fibrilação atrial por ablação e mapeamento eletroanatômico. Foram incluídos os seguintes pacientes: idade acima de 18 anos; portadores de fibrilação atrial paroxística, persistente ou persistente de longa duração; com registro de fibrilação atrial em eletrocardiograma, Holter ou ergometria (duração > 15 minutos); com sintomas associados aos episódios de fibrilação atrial; e apresentando refratariedade a, pelo menos, duas drogas antiarrítmicas (entre elas amiodarona) ou impossibilidade do uso de drogas antiarrítmicas. Resultados: Foram incluídos 95 pacientes (idade 55 ± 12 anos, 84% homens, CHADS2 médio = 0,8) que realizaram 102 procedimentos com seguimento mediano de 13,4 meses. A taxa livre de recorrência após o procedimento foi de 75,5% após 12 meses. Os pacientes portadores de fibrilação atrial paroxística e fibrilação atrial persistente apresentaram recorrência de 26,9% versus 45,8% dos pacientes portadores de fibrilação atrial persistente de longa duração (p = 0,04). Das variáveis analisadas, o tamanho do átrio esquerdo demonstrou ser preditor independente de recorrência de fibrilação atrial após o procedimento (HR = 2,58, IC95% = 1,36-4,89). Houve complicações em 4,9% dos procedimentos. Conclusão: A ablação de fibrilação atrial guiada por mapeamento eletroanatômico demonstrou ser um procedimento com boa eficácia. O aumento do tamanho do átrio esquerdo foi associado à recorrência de fibrilação atrial.

OBJETIVO: A insuficiência renal crônica (IRC), presente em metade dos portadores de insuficiência cardíaca (IC), está associada ao aumento de mortalidade nessa populaçao. A terapia de ressincronizaçao cardíaca (TRC), que traz benefícios aos pacientes com IC, também pode melhorar a IRC. O objetivo deste estudo foi avaliar a funçao renal após a TRC. MÉTODO: Estudo de coorte, retrospectivo, de pacientes que se submeteram a TRC de julho de 2004 a maio de 2010, para analisar a taxa de filtraçao glomerular (TFG) pré-operatória e seis meses após a TRC. RESULTADOS: Foram incluídos 67 pacientes, com idade média de 68 anos, 70% dos quais eram renais crônicos nao dialíticos. A média da creatinina prévia à TRC foi de 1,47 mg/dl e seu valor após a TRC foi de 1,35 mg/dl (p2) e após a TRC (54,3 ml/min/1,73 m2), com valor de p=0,144. Entretanto, quando analisadas as TFG nos subgrupos, verificou-se melhora importante da funçao renal nos pacientes que apresentavam TFG menor antes da TRC. Naqueles em estágio 3 da funçao renal, observou-se acréscimo de 7,2 ml/min/1,73 m2 após a TRC; o que representa uma melhora da funçao renal de 15,45%. Nos que estavam em estágio 4, o ganho foi de 11,7 ml/min/1,73 m2 após a TRC, um incremento de 48,34%. CONCLUSAO: A TRC proporcionou melhora da TFG nos pacientes com IRC moderada a severa, porém nao apresentou impacto na funçao renal dos pacientes com TFG inicial >60 ml/min/1,73 m2.

Abstract Objective: Rhythm abnormalities following transcatheter aortic valve implantation (TAVI) and indications for permanent pacemaker implantation (PPI) were reviewed, which aren't well established in the current guidelines. New left bundle branch block and atrioventricular block are the most common electrocardiographic changes after TAVI. PPI incidence ranges from 9-42% for self-expandable and 2.5-11.5% for balloon expandable devices. Not only anatomical variations in conduction system have an important role in conduction disorders, but different valve characteristics and their relationship with cardiac structures as well. Previous right bundle branch block has been confirmed as one of the most significant predictors for PPI.

Coordinated and harmonic (synchronous) ventricular electrical activation is essential for better left ventricular systolic function. Intraventricular conduction abnormalities, such as left bundle branch block due to artificial cardiac pacing, lead to electromechanical "dyssynchronopathy" with deleterious structural and clinical consequences. The aim of this review was to describe and improve the understanding of all the processes connecting the several mechanisms involved in the development of artificially induced ventricular dyssynchrony by cardiac pacing, most known as pacing-induced cardiomyopathy (PiCM). The chronic effect of abnormal impulse conduction and nonphysiological ectopic activation by artificial cardiac pacing is suspected to affect metabolism and myocardial perfusion, triggering regional differences in the activation/contraction processes that cause electrical and structural remodeling due to damage, inflammation, and fibrosis of the cardiac tissue. The effect of artificial cardiac pacing on ventricular function and structure can be multifactorial, and biological factors underlying PiCM could affect the time and probability of developing the condition. PiCM has not been included in the traditional classification of cardiomyopathies, which can hinder detection. This article reviews the available evidence for pacing-induced cardiovascular disease, the current understanding of its pathophysiology, and reinforces the adverse effects of right ventricular pacing, especially right ventricular pacing burden (commonly measured in percentage) and its repercussion on ventricular contraction (reflected by the impact on left ventricular systolic function). These effects might be the main defining criteria and determining mechanisms of the pathophysiology and the clinical repercussion seen on patients. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary vein (PV) stenosis is an important complication of the AF ablation and could be underestimated if their assessment is not systematically done. Selective Segmental Ostial Ablation (SSOA) and Circunferential Pulmonary Veins Ablation (CPVA) have demonstrated efficacy in atrial fibrillation (AF) treatment. In this study the real incidence of PV stenosis in patients (pts) submitted to both SSOA and CPVA was compared. [ABSTRACT FROM AUTHOR]