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Advances in cardiac stimulation demonstrate that bradyarrhythmia treatments go beyond heart rate control. The concern with the ventricular stimulation site and, consequently, with the maintenance of intraventricular synchrony has become routine in most services. Techniques of physiological cardiac stimulation, such as stimulation of the bundle of His and the left branch, have been improved. Despite the indisputable benefits of these therapeutic modalities, there are technical difficulties that limit systematic use. In this sense, to make physiological cardiac stimulation more practical and reproducible, the concept of parahissian stimulation was expanded and studied. The technique, simpler and reproducible, contemplates a conventional approach of the right ventricle. The big difference is the use of QRS spatial variance analysis technology (Synchromax®, Exo S.A., Argentina) to confirm the maintenance of ventricular synchrony according to the implanted site.

BackgroundClinical 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.ObjectiveEvaluation of mortality predictors and response to CRT in the Brazilian scenario.MethodsRetrospective 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.ResultsA 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.ConclusionMortality 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.

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Resumo Fundamento A estimulação cardíaca artificial (ECA) por captura direta ou indireta do feixe de His resulta em contração ventricular sincrônica (ECA fisiológica). Objetivos Comparar sincronia cardíaca, características técnicas e resultados de parâmetros eletrônicos entre duas técnicas de ECA indireta do feixe de His: a não seletiva e a parahissiana. Métodos Intervenção experimental (novembro de 2019 a abril de 2020) com implante de marca-passo definitivo (MPd) DDD em pacientes com fração de ejeção ventricular esquerda > 35%. Foram comparadas a sincronia cardíaca resultante mediante algoritmo de análise eletrocardiográfica da variância espacial do QRS e as características técnicas associadas a cada método entre ECA hissiana não seletiva (DDD-His) e parahissiana (DDD-Var). Resultados De 51 pacientes (28 homens), 34 (66,7%) foram alocados no grupo DDD-Var e 17 (33,3%), no grupo DDD-His, com idade média de 74 e 79 anos, respectivamente. No grupo DDD-Var, a análise da variância espacial do QRS (índice de sincronia ventricular) mostrou melhora após o implante de MPd (p < 0,001). Ao ECG pós-implante, 91,2% dos pacientes do grupo DDD-Var mostraram padrão fisiológico de ECA, comprovando ativação similar à do DDD-His (88,2%; p = 0,999). O eixo do QRS estimulado também foi similar (fisiológico) para ambos os grupos. A mediana do tempo de fluoroscopia do implante foi de 7 minutos no grupo DDD-Var e de 21 minutos no DDD-His (p < 0,001), favorecendo a técnica parahissiana. A duração média do QRS aumentou nos pacientes do DDD-Var (114,7 ms pré-MPd e 128,2 ms pós-implante, p = 0,044). A detecção da onda R foi de 11,2 mV no grupo DDD-Var e de 6,0 mV no DDD-His (p = 0,001). Conclusão A ECA parahissiana comprova recrutamento indireto do feixe de His, mostrando-se uma estratégia eficaz e comparável à ECA fisiológica ao resultar em contração ventricular sincrônica similar à obtida por captura hissiana não seletiva.

BackgroundRadiofrequency catheter ablation guided by electroanatomical mapping is currently an important therapeutic option for the treatment of atrial fibrillation. The complexity of the procedure, the several techniques used and the diversity of the patients hinder the reproduction of the results and the indication for the procedure. ObjectiveTo evaluate the efficacy and factors associated with recurrence of atrial fibrillation. MethodsProspective cohort study with consecutive patients submitted to atrial fibrillation ablation treatment guided by electroanatomical mapping. The inclusion criteria were as follows: minimum age of 18 years; presence of paroxysmal, persistent or long-standing persistent AF; AF recording on an electrocardiogram, exercise testing or Holter monitoring (duration longer than 15 minutes); presence of symptoms associated with AF episodes; AF refractoriness to, at least, two antiarrhythmic drugs, one of which being amiodarone, or impossibility to use antiarrhythmic drugs. ResultsThe study included 95 patients (age 55 ± 12 years, 84% men, mean CHADS2 = 0.8) who underwent 102 procedures with a median follow-up of 13.4 months. The recurrence-free rate after the procedure was 75.5% after 12 months. Atrial fibrillation recurred as follows: 26.9% of patients with paroxysmal and persistent atrial fibrillation; 45.8% of patients with long-standing persistent atrial fibrillation (p = 0.04). Of the analyzed variables, the increased size of the left atrium has proven to be an independent predictor of atrial fibrillation recurrence after the procedure (HR = 2.58; 95% CI: 1.26-4.89). Complications occurred in 4.9% of the procedures. ConclusionAtrial fibrillation ablation guided by electroanatomical mapping has shown good efficacy. The increase in left atrium size was associated with atrial fibrillation recurrence.

Introduction: Atrial fibrillation (AF) recurrence occurs in up to 20% of patients after contact force (CF) guided radiofrequency (RF) pulmonary vein isolation (PVI). Discontinuity and non-transmurality are key issue. The 'CLOSE' protocol is a new approach based upon delivery of closely spaced transmural lesions close to the PV ostia. We compared CLOSE-guidance to CF-guidance for ipsilateral PVI (IPVI). Methods: 100 patients with symptomatic paroxysmal AF were enrolled. In the CF group (n ¼ 50), RF was delivered targeting a minimum CF of 10g; in the CLOSE group (n ¼ 50), RF was delivered at the LA-PV junction respecting strict criteria of continuity (inter-lesion distance ,6mm) and transmurality (force-power-time integral .400 at posterior, .550 anterior wall). After IPVI, adenosine test was performed. Recurrence was defined as any atrial tachyarrhythmia lasting more than 30 seconds documented by either ECG or Holter-ECG at 3, 6 and 9 months. Results: Clinical characteristics were similar in both groups. IPVI was obtained in 100% of circles (n ¼ 200). Compared to CF group, CLOSE group was associated with a higher rate of IPVI resistant to adenosine (97% vs 83%, p ,0.01), shorter RF time per circle (18 + 4 min vs 28 + 8 min, p , 0.0001) and shorter procedure time (146 + 27 min vs 193 + 41 min, p , 0.0001). At 9 months, freedom from atrial tachyarrhythmia was 94% in CLOSE compared to 80% in CF group ( p , 0.05). Conclusion: Compared to contact force guided ablation, 'CLOSE' protocol improves outcome in paroxysmal AF patients. A prospective, multi-centre, randomised trial is required.

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.