Permanent Cardiac Pacing of the Right Ventricular Outflow Tract Guided by Real-time Assessment of Electromechanical Synchrony.

Permanent right ventricular apical pacing deteriorates cardiac systolic function in some patients. We investigated an alternative site for permanent pacemaker (PPM) lead positioning with the goal of achieving more physiological pacing. A total of 132 patients with bradyarrhythmias underwent PPM implantation at the right ventricular outflow tract (RVOT) with conventional active-fixation leads. A real-time cross-correlation analysis (CCA) was performed using the Synchromax® software (EXO Health, Seattle, WA, USA) to determine the optimal site for ventricular lead implantation based on the cardiac synchrony index. The follow-up period ranged from 6-36 months, and the following parameters were assessed: pacing capture threshold, lead stability, and the need for lead repositioning. Adequate parameters were achieved in 129 patients (98%), and there were no procedure-related complications. At follow-up, no leads were dislodged, pacing thresholds remained stable, and no lead required repositioning. Using real-time CCA as an intraoperative parameter during PPM implantation at the septal RVOT helps to achieve cardiac synchrony in the vast majority of cases. This technique is a simple, effective, and safe way to simplify and standardize PPM implantation at the RVOT.

Factors of mortality in patients with cardiac implantable electronic device: 5-year experience

SUMMARY OBJECTIVE: The use of cardiac implantable electronic devices has increased in recent years. It has also brought some issues. Among these, the complications of cardiac implantable electronic devices infection and pocket hematoma are difficult to manage. It can be fatal with the contribution of patient-related risk factors. In this study, we aimed to find mortality rates in patients who developed cardiac implantable electronic devices infection and pocket hematoma over 5 years. We also investigated the risk factors affecting mortality in patients with cardiac implantable electronic devices. METHODS: A total of 288 cardiac implantable electronic devices patients were evaluated. Demographic details, history, and clinical data of all patients were recorded. Cardiac implantable electronic devices infection was defined according to the modified Duke criteria. The national registry was used to ascertain the mortality status of the patients. The patients were divided into two groups (exitus and survival groups). In addition, the pocket hematoma was defined as significant bleeding at the pocket site after cardiac implantable electronic devices placement. RESULTS: The cardiac implantable electronic devices infection was similar in both groups (p=0.919), and the pocket hematoma was higher in the exitus group (p=0.019). The exitus group had higher usage of P2Y12 inhibitors (p≤0.001) and novel oral anticoagulants (p=0.031). The Cox regression analysis, including mortality-related factors, revealed that renal failure is the most significant risk factor for mortality. Renal failure was linked to a 2.78-fold higher risk of death. CONCLUSION: No correlation was observed between cardiac implantable electronic devices infection and mortality, whereas pocket hematoma was associated with mortality. Furthermore, renal failure was the cause of the highest mortality rate in patients with cardiac implantable electronic devices.

Prognóstico de pacientes chagásicos e não chagásicos submetidos a implante de marcapasso e ressincronizador cardíaco em centro terciário / Prognosis of chagasic and non-chagasic patients undergoing pacemaker and cardiac resynchronizer implantation in a tertiary center

Fundamento: A cardiomiopatia chagásica (CCh) é responsável pelo implante de marcapasso (MP) em muitos pacientes, tendo sido associada a prognóstico adverso. Objetivos: Comparar o prognóstico da população chagásica e não chagásica submetida ao implante de MP e ressincronizador cardíaco. Métodos: Estudo observacional, retrospectivo, que analisou coorte de pacientes submetidos a implante desses dispositivos, em centro terciário, de Outubro 2007 a Dezembro de 2017, comparando o grupo de pacientes chagásicos com os não-chagásicos. O desfecho primário foi a mortalidade por qualquer causa, enquanto os desfechos secundários foram a ocorrência de internação e o desfecho combinado internação e morte. Resultados: Um total de 911 pacientes foram incluídos, sendo que 23,4% apresentavam CCh. Em análise de Cox ajustada por sexo e idade, a doença de Chagas (dCh) não esteve associada ao risco aumentado de morte (HR: 1,14, IC:95%, 0,86-1,51, p=0,365), internação (HR: 0,79, IC:95%, 0,61-1,04, p=0,09) ou desfecho combinado morte e internação (HR: 0,90, IC:95%, 0,72-1,12, p=0,49). Conclusões: A dCh não se associou ao aumento do risco de morte, internação, ou desfecho combinado morte e internação, mesmo após ajuste para sexo e idade. Trabalhos semelhantes ainda não foram publicados na literatura vigente considerando-se especificamente a população chagásica portadora de dispositivos cardíacos, e novos estudos são necessários para se confirmar esses achados

Background: Chagas cardiomyopathy (ChCC) is responsible for the implantation of pacemaker (PM) in many patients and has been associated with an adverse prognosis. Objectives: To compare the prognosis of the chagasic and non-chagasic population undergoing PM and cardiac resynchronizer implantation. Methods: Observational, retrospective study, which analyzed a cohort of patients who underwent implantation of these devices, in a tertiary center, from October 2007 to December 2017, comparing the group of chagasic with non-chagasic patients. The primary outcome was mortality from any cause, while the secondary outcomes were the occurrence of hospitalization and the combined outcome of hospitalization and death. Results: A total of 911 patients were included, of which 23.4% had ChCC. In a Cox analysis adjusted for sex and age, Chagas disease (ChD) was not associated with an increased risk of death (HR: 1.14, CI:95%, 0.86-1.51, p=0.365), hospitalization (HR: 0.79, CI:95%, 0.61-1.04, p=0.09) or combined outcome of death and hospitalization (HR: 0.90, CI:95%, 0.72-1 .12, p=0.49). Conclusions: ChD was not associated with an increased risk of death, hospitalization, or combined outcome of death and hospitalization, even after adjustment for sex and age. Similar studies have not yet been published in the current literature specifically considering the chagasic population with cardiac devices, and new studies are needed to confirm these findings.

Estimulación temporal mediante cable de fijación activa / Temporal stimulation by active fixation lead

Resumen Objetivo: Determinar seguridad y eficacia del marcapasos temporal mediante cable de fijación activa vía yugular y/o subclavia. Métodos: Se analizaron pacientes desde 2017 a 2021 postextracción de marcapasos dependientes de estimulación. Resultados: Se colocó estimulación temporal en 25 pacientes con una edad media de 68 ± 16 años. La media de duración de la estimulación temporal fue cinco días. No se registró mortalidad asociada a la estimulación temporal, sin embargo en un paciente se presentó desplazamiento de cable y falla de captura a los cuatro días de la colocación. Conclusiones: La estimulación temporal mediante cable de fijación activa es segura y eficaz.

Abstract Objective: To determine the efficacy and safety of temporary pacing with an active fixation lead placed trough the internal jugular vein and/or subclavian vein. Methods: We analyzed a consecutive series of 25 out of 73 patients that had a pacemaker extraction and were pacing dependent requiring temporary pacing with an active fixation lead until the new pacemaker implant, from 2017 to 2021. Results: After extraction 25 patients age 68 years ±16 years, required temporary pacing, the media for temporary pacing was 5 days. There were no mortality associated to temporary stimulation. Only one patient (4%) had a complication 4 days after the implant with capture fail due to a microdislogement requiring reintervention. Conclusion: Temporary stimulation through active fixation pacemaker lead it is safe and effective.

Eficácia da estimulação hissiana e septal profunda comparada à estimulação cardíaca convencional: revisão de literatura / Efficacy of hissian and deep septal stimulation compared to conventional cardiac stimulation: literature review

Introdução: Pacientes com insuficiência cardíaca e doenças do sistema de condução necessitam de dispositivos para monitoramento dos batimentos cardíacos, como marcapassos permanentes, dispositivos de ressincronização cardíaca ou cardiodesfibriladores implantáveis. A estimulação ventricular direita (EVD) é tradicionalmente o tratamento de escolha. No entanto, estudos demonstraram evidências de dissincronia ventricular, redução da função cardíaca, recorrência de fibrilação atrial e aumento da mortalidade associadas a esta abordagem. O conhecimento dos efeitos adversos das técnicas convencionais justifica a realização de pesquisas para determinar se a estimulação hissiana (EH) é uma técnica que produz maior ativação fisiológica e ventricular mais sincronizada. Objetivo: Avaliar a eficácia da estimulação hissiana comparada à EVD em relação aos parâmetros eletrocardiográficos, ecocardiográficos e clínicos.Material e Métodos: Os critérios de elegibilidade seguiram a estratégia PICOS: P ­ pacientes com indicação de dispositivos cardíacos eletrônicos implantáveis; I ­ estimulação hissiana; C ­ estimulação ventricular direita; O ­ duração do complexo QRS, fração de ejeção, diâmetro ventricular ou classe funcional da New York Heart Association (NYHA); S ­ ensaios clínicos controlados randomizados (ECR) e não randomizados. As buscas foram realizadas nas bases Medline via PubMed, Embase, LILACS e Cochrane Library, realizadas em março de 2023 por três revisores independentes. Resultados: Foram incluídos sete ensaios clínicos comparando as técnicas EH versus EVD quanto aos desfechos investigados. Para a duração do complexo QRS, três estudos encontraram resultado significativamente melhor no grupo intervenção. Para fração de ejeção e classe funcional da NYHA, dois estudos apresentaram resultados significativamente melhores no grupo EH. Quanto ao risco de viés, apenas dois apresentaram risco baixo e médio, quatro apresentaram risco alto em um, dois ou três dos itens avaliados. Conclusões: A técnica EH demonstrou superioridade à técnica convencional, entretanto são necessários ECR de maior qualidade metodológica e meta-análises para verificar a eficácia clínica da técnica, envolvendo maior número de pacientes e tempo de seguimento.

Introduction: Patients with heart failure and cardiac conditions require devices for monitoring the heartbeat, such as permanent pacemakers, cardiac resynchronization devices, or implantable cardioverter defibrillators. Right ventricular stimulation (RVP) has traditionally been the treatment of choice. However, studies have shown evidence of ventricular dyssynchrony, reduced cardiac function, recurrence of atrial fibrillation, and increased mortality associated with this approach. Recognizing the adverse effects of conventional techniques justifies conducting research to determine whether Hissian or His bundle pacing (HPB) stimulation can provide more physiologically synchronized ventricular activation. Objective: The aim is to assess the efficacy of Hissian stimulation compared to right ventricular pacing (RVP) in relation to electrocardiographic, echocardiographic and clinical parameters. Material and Methods: The eligibility criteria will follow the PICOS strategy: P ­ Patients with indication for implantable electronic cardiac devices; I ­ Hissan Stimulation; C ­ Right Ventricular Stimulation; O ­ QRS complex duration, ejection fraction, ventricular diameter and New York Heart Association (NYHA) functional class; S ­ Controlled Trials. Searches were conducted on the Medline via PubMed, Embase, Latin America and Caribbean Health Science Literature Database (LILACS) and Cochrane Library platforms. The searches were performed in March 2023 by three independent reviewers. Results: Seven clinical trials were included, comparing HPB versus RVP techniques regarding the investigated outcomes. For the QRS complex duration, three studies found a significantly better result in the intervention group. For ejection fraction and NYHA functional class, two studies had significantly better results in the HPB group too. Concerning the risk of bias, out of the seven studies included, only two presented low and medium risk, four presented high risk in one, two or three of the items evaluated. Conclusions: The HPB technique has demonstrated superiority to the conventional technique, however, RCT of higher methodological quality and meta-analysis are needed to verify the clinical effectiveness of the technique, involving more patients and longer follow-up time.

[Temporal stimulation by active fixation lead.] / Estimulación temporal mediante cable de fijación activa.

Objective: To determine the efficacy and safety of temporary pacing with an active fixation lead placed trough the internal jugular vein and/or subclavian vein. Methods: We analyzed a consecutive series of 25 out of 73 patients that had a pacemaker extraction and were pacing dependent requiring temporary pacing with an active fixation lead until the new pacemaker implant, from 2017 to 2021. Results: After extraction 25 patients age 68 years ±16 years, required temporary pacing, the media for temporary pacing was 5 days. There were no mortality associated to temporary stimulation. Only one patient (4%) had a complication 4 days after the implant with capture fail due to a microdislogement requiring reintervention. Conclusion. Conclusion: Temporary stimulation through active fixation pacemaker lead it is safe and effective.

Objetivo: Determinar seguridad y eficacia del marcapasos temporal mediante cable de fijación activa vía yugular y/o subclavia. Métodos: Se analizaron pacientes desde 2017 a 2021 postextracción de marcapasos dependientes de estimulación. Resultados: Se colocó estimulación temporal en 25 pacientes con una edad media de 68 ± 16 años. La media de duración de la estimulación temporal fue cinco días. No se registró mortalidad asociada a la estimulación temporal, sin embargo en un paciente se presentó desplazamiento de cable y falla de captura a los cuatro días de la colocación. Conclusiones: La estimulación temporal mediante cable de fijación activa es segura y eficaz.

Cardiomyopathy Induced by Artificial Cardiac Pacing: To Whom, When, Why, and How? Insights on Heart Failure Development.

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.

Reprocessamento de Marca-Passos em Países de Língua Portuguesa: Uma Reflexão Clínica / Pacemaker Reuse in Portuguese Speaking Countries: A Clinical Reflection

Resumo Há uma enorme disparidade entre os países de alta renda e outros em termos de acesso a dispositivos médicos cardíacos, como marca-passos e desfibriladores implantáveis. Os custos são uma das principais barreiras ao uso de dispositivos cardíacos nesses países. Existem iniciativas internacionais que visam reduzir essa disparidade, e o reuso de marca-passos tem sido discutido como uma possível alternativa. O conceito de reutilização de marca-passos não é novo; entretanto, estudos recentes têm se mostrado seguros, éticos e eficazes para aqueles que precisam de dispositivos eletrônicos cardíacos implantáveis e não tem como adquiri-los. Parte dos países de língua portuguesa, especialmente na África, precisam de uma resposta imediata que beneficie seus inúmeros pacientes que sofrem de arritmias tratáveis.

Abstract There is a gap between high-income countries and others in terms of access to medical cardiac devices, such as pacemakers and implantable cardioverter defibrillators. Costs are one of the main barriers to the use of cardiac devices in these countries. There are international initiatives that aim to reduce the gap. The reuse of pacemakers has been discussed as a possible alternative to this problem. The concept of reusing pacemakers is not new; however, recent studies have proven to be safe, ethical, and effective for those who need cardiac implantable electronic devices and cannot afford them. Part of the Portuguese-speaking countries, especially in Africa, need an immediate response that benefits their countless patients who suffer from treatable arrhythmias.

Cardiomyopathy Induced by Artificial Cardiac Pacing: To Whom, When, Why, and How? Insights on Heart Failure Development

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.

[Left bundle branch stimulation in diffuse electrical heart disease in a pediatric patient]. / Estimulación de rama izquierda en enfermedad eléctrica difusa cardiaca en una paciente pediátrica.

Left bundle branch stimulation is a second-line strategy in patients where His bundle stimulation is not optimal. Currently, no cases of left bundle branch stimulation have been reported in patients with diffuse electrical cardiac disease or in the pediatric population.

Estimulação do Ramo Esquerdo do Sistema His-Purkinje: Experiência Inicial / Left Bundle Branch Pacing of His-Purkinje Conduction System: Initial Experience

Resumo Fundamento A estimulação ventricular direita convencional aumenta o risco de fibrilação atrial e insuficiência cardíaca em portadores de marca-passo. A estimulação do ramo esquerdo (RE) do sistema His-Purkinje pode evitar os desfechos indesejados da estimulação ventricular direita. Objetivo Analisar retrospectivamente os desfechos intraoperatórios, eletrocardiográficos e os dados clínicos do seguimento inicial de pacientes submetidos à estimulação do RE. Métodos Foram avaliados os parâmetros eletrônicos do implante e eventuais complicações precoces de 52 pacientes consecutivos submetidos à estimulação do sistema de condução. O nível de significância alfa adotado foi igual a 0,05. Resultados 52 pacientes foram submetidos a estimulação do RE do sistema His-Purkinje, obtendo sucesso em 50 procedimentos. 69,2% dos pacientes eram do sexo masculino e a mediana e intervalo interquatil da idade no momento do implante foi de 73,5 (65,0-80,0) anos. A duração do QRS pré-implante foi de 146 (104-175) ms e de 120 (112-130) ms após o procedimento. O tempo de ativação do ventrículo esquerdo foi de 78 (70-84) ms. A amplitude da onda R foi de 12,00 (7,95-15,30) mV, com limiar de estimulação de 0,5 (0,4-0,7) V × 0,4 ms e impedância de 676 (534-780) ohms. O tempo de procedimento foi de 116 (90-130) min e o tempo de fluoroscopia foi de 14,2 (10,0-21,6) min. Conclusão A estimulação cardíaca do sistema de condução His-Purkinje por meio da estimulação do ramo esquerdo é uma técnica segura e factível. Nesta casuística, apresentou alta taxa de sucesso, foi realizada com tempo de procedimento e fluoroscopia baixos e obteve medidas eletrônicas adequadas.

Abstract Background Conventional right ventricular pacing increases the risk of atrial fibrillation and heart failure in pacemaker patients. Stimulation of the left bundle branch (LBB) of the His-Purkinje system can prevent the unwanted outcomes of right ventricular pacing. Objective To retrospectively analyze the intraoperative outcomes, electrocardiographic and clinical data from the initial follow-up of patients submitted to stimulation of the LBB. Methods The electronic parameters of the implant and of possible early complications of 52 consecutive patients submitted to stimulation of the conduction system were evaluated. The adopted significance level was 0.05. Results Fifty-two patients underwent left bundle branch stimulation, with 50 successful procedures; 69.2% of the patients were male, and the median and interquartile range of age at the time of implantation was 73.5 (65.0-80.0) years. The pre-implant QRS duration was 146 (104-175) ms and 120 (112-130) ms after the procedure. The left ventricle activation time was 78 (70-84) ms. The R-wave amplitude was 12.00 (7.95-15.30) mV, with a stimulation threshold of 0.5 (0.4-0.7) V x 0.4 ms and impedance of 676 (534-780) ohms. The procedure duration was 116 (90-130) min, and the fluoroscopy time was 14.2 (10.0-21.6) min. Conclusion Cardiac stimulation of the His-Purkinje conduction system through the stimulation of the left bundle branch is a safe and feasible technique. In this study, it showed a high success rate, with low procedure and fluoroscopy periods, achieving adequate electronic measurements.

Sincronia Ventricular na Estimulação Cardíaca Parahissiana: Alternativa por Ativação Cardíaca Fisiológica (Estimulação Indireta do Feixe de His)? / Ventricular Synchrony in Para-Hisian Cardiac Pacing as an Alternative for Physiological Cardiac Activation (Indirect Recruitment of the His Bundle?)

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.

Abstract Background Artificial cardiac pacing by direct or indirect His bundle capture results in synchronous ventricular contraction (physiological pacing). Objectives To compare cardiac synchronization, technical characteristics, and electronic parameters between two techniques of indirect His-bundle pacing: non-selective (NS-HBP) vs para-Hisian pacing (PHP). Methods The experimental intervention (between November 2019 and April 2020) consisted of implanting a DDD pacemaker in patients who had left ventricular ejection fraction (LVEF) > 35%. The resulting cardiac synchronization was compared using an electrocardiographic algorithm that analyzed QRS variation and the technical characteristics of non-selective Hisian pacing (DDD-His) and para-Hisian pacing (DDD-Var). Results Of 51 total patients (men: 28), 66.7% (34) were allocated to the DDD-Var group and 33.3% (17) to the DDD-His group. The mean ages in each group were 74 and 79 years, respectively. In the DDD-Var group, QRS variation (ventricular synchrony) improved after implantation (p < 0.001). In post-implantation ECG, 91.2% of the DDD-Var group presented a physiological pacing pattern, which was similar to the DDD-His group (88.2%; p = 0.999). The paced QRS axis was also similar (physiological) for both groups. Intraoperative fluoroscopy time (XRay) during implantation was lower for the para-Hisian technique (median 7 min in the DDD-Var group vs 21 min in the DDD-His group, p < 0.001). The mean QRS duration increased in the DDD-Var group (114.7 ms pre-implantation vs 128.2 ms post-implantation, p = 0.044). The mean post-implantation R-wave amplitude was 11.2 mV in the DDD-Var group vs 6.0 mV in the DDD-His group, p = 0.001. Conclusion Para-Hisian pacing appears to indirectly recruit the His bundle, which would make this an effective and comparable strategy for physiological pacing, resulting in synchronous ventricular contraction similar to that of non-selective Hisian pacing.

Increased QRS duration and dispersion are associated with mechanical dyssynchrony in patients with permanent right ventricular apical pacing.

BACKGROUND: Permanent right ventricular apical pacing may have negative effects on ventricular function and contribute to development of heart failure. We aimed to assess intra- and interventricular mechanical dyssynchrony in patients with permanent right ventricular apical pacing, and to establish electrocardiographic markers of dyssynchrony. METHODS: 84 patients (46:38 male:female) who required permanent pacing were studied. Pacing was done from right ventricular apex in all patients. We measured QRS duration and dispersion on standard 12-lead ECG. Intra- and interventricular mechanical dyssynchrony and left ventricular ejection fraction were assessed by transthoracic echocardiography. Patients were followed-up for 24 months.  Results: Six months after implantation, QRS duration increased from 128.02 ms to 132.40 ms, p≤0.05. At 24 months, QRS dispersion increased from 43.26 ms to 46.13 ms, p≤0.05. Intra- and interventricular dyssynchrony increased and left ventricular ejection fraction decreased during follow-up. A QRS dispersion of 47 ms predicted left ventricular dysfunction and long-term electromechanical dyssynchrony with a sensitivity of 80% and a specificity of 76%.  Conclusion: In patients with permanent right ventricular apical pacing there is an increased duration and dispersion of QRS related to dyssynchrony and decreased left ventricular ejection fraction. This study shows that QRS dispersion could be a better predictive variable than QRS duration for identifying left ventricular ejection fraction worsening in patients with permanent right ventricular apical pacing. The electrocardiogram is a simple tool for predicting systolic function worsening in these patients and can be used at the bedside for early diagnosis in the absence of clinical symptoms, allowing adjustments of medical treatment to prevent progression of heart failure and improve the patient's quality of life.

Implante de marcapasos permanente. Acceso al ápex del ventrículo derecho usando radioscopia solo en el último momento

RESUMEN En Cuba, el primer implante de marcapasos se realizó el 6 de julio de 1964, mientras que en Cienfuegos se inicia esta actividad en 1979, por un grupo de profesionales liderados por el Dr. Francisco Riverón Mena, quien se mantuvo durante más de diez años al frente de la estimulación cardíaca, en el Hospital Dr. Gustavo Aldereguía Lima. El presente trabajo se propone describir el método para el implante de marcapasos permanente aplicado en dicha institución, introducido por el Dr. Riverón, como alternativa al modo convencional. Esta técnica requiere muy poca utilización de radiaciones ionizantes; resulta eficaz y más segura, tanto para el paciente como para el personal de salud, pues se emplea radioscopia solo en el último momento del procedimiento, lo cual la diferencia del método convencional. Aunque en la actualidad no se practica, durante la etapa que se aplicó en el hospital, brindó seguridad a pacientes y personal de salud, por lo que debería retomarse su uso.

ABSTRACT In Cuba, the first pacemaker implant was carried out on July 6, 1964, while in Cienfuegos this activity began in 1979, by a group of professionals led by Dr. Francisco Riverón Mena, who stayed for more than ten years in charge of cardiac stimulation, at the Dr. Gustavo Aldereguía Lima Hospital. The present work aims to describe the method for permanent pacemaker implantation applied in said institution, introduced by Dr. Riverón, as an alternative to the conventional mode. This technique requires very little use of ionizing radiation; It is effective and safer, both for the patient and for the health personnel, since fluoroscopy is used only at the last moment of the procedure, which differentiates it from the conventional method. Although it is not currently practiced, during the stage that it was applied in the hospital, it provided security to patients and health personnel, so its use should be resumed.

[Different phenotypes of mitral regurgitation in patients with right apical ventricular pacing: an echocardiographic approach in a heterogeneity of clinical scenarios]. / Distintos fenotipos de insuficiencia mitral en pacientes con estimulación apical del ventrículo derecho: un abordaje ecocardiográfico en una heterogeneidad de escenarios clínicos.

The presence of mitral regurgitation (MR) in patients with right ventricular apical pacing can be the result of multiple phenomena. On the one hand, this stimulation causes an asynchronous activation of the left ventricle (LV) and the papillary muscles, leading to a deterioration of the LV ejection fraction and causing an inadequate closure of the valve apparatus. However, there is a wide heterogeneity of ischemic and non-ischemic myocardial conditions that can coexist with mechanical alteration of the LV and the mitral valve leading to or worsening MR in these patients, which can make the etiological determination of valvular regurgitation difficult. Transthoracic echocardiography study allows comprehensive evaluation of mitral valve regurgitation and ventricular function parameters and mechanical asynchrony as a result of artificial pacing. The comprehensive study of these phenomena is relevant in clinical decision-making to define those patients who benefit from cardiac resynchronization therapy to alleviate symptomatic MR.

Efetividade e Segurança da Remoção de Cabos-Eletrodos Transvenosos de Marca-Passos e Desfibriladores Implantáveis no Cenário da Prática Clínica Real / Effectiveness and Safety of Transvenous Removal of Cardiac Pacing and Implantable Cardioverter-defibrillator Leads in the Real Clinical Scenario

Resumo Fundamento Remoção de cabos-eletrodos de dispositivos cardíacos eletrônicos implantáveis (DCEI) é procedimento pouco frequente e sua realização exige longo treinamento profissional e infraestrutura adequada. Objetivos Avaliar a efetividade e a segurança da remoção de cabos-eletrodos de DCEI e determinar fatores de risco para complicações cirúrgicas e mortalidade em 30 dias. Métodos Estudo prospectivo com dados derivados da prática clínica. De janeiro/2014 a abril/2020, foram incluídos, consecutivamente, 365 pacientes submetidos à remoção de cabos-eletrodos, independentemente da indicação e técnica cirúrgica utilizada. Os desfechos primários foram: taxa de sucesso do procedimento, taxa combinada de complicações maiores e morte intraoperatória. Os desfechos secundários foram: fatores de risco para complicações intraoperatórias maiores e morte em 30 dias. Empregou-se análise univariada e multivariada, com nível de significância de 5%. Resultados A taxa de sucesso do procedimento foi de 96,7%, sendo 90,1% de sucesso completo e 6,6% de sucesso clínico. Complicações maiores intraoperatórias ocorreram em 15 (4,1%) pacientes. Fatores preditores de complicações maiores foram: tempo de implante dos cabos-eletrodos ≥ 7 anos (OR= 3,78, p= 0,046) e mudança de estratégia cirúrgica (OR= 5,30, p= 0,023). Classe funcional III-IV (OR= 6,98, p<0,001), insuficiência renal (OR= 5,75, p=0,001), infecção no DCEI (OR= 13,30, p<0,001), número de procedimentos realizados (OR= 77,32, p<0,001) e complicações maiores intraoperatórias (OR= 38,84, p<0,001) foram fatores preditores para mortalidade em 30 dias. Conclusões Os resultados desse estudo, que é o maior registro prospectivo de remoção de cabos-eletrodos da América Latina, confirmam a segurança e a efetividade desse procedimento no cenário da prática clínica real. (Arq Bras Cardiol. 2020; 115(6):1114-1124)

Abstract Background Transvenous lead extraction (TLE) of cardiac implantable electronic devices (CIED) is an uncommon procedure and requires specialized personnel and adequate facilities. Objectives To evaluate the effectiveness and safety of the removal of CIED leads and to determine risk factors for surgical complications and mortality in 30 days. Methods Prospective study with data derived from clinical practice. From January 2014 to April 2020, we included 365 consecutive patients who underwent TLE, regardless of the indication and surgical technique used. The primary outcomes were: success rate of the procedure, combined rate of major complications and intraoperative death. Secondary outcomes were: risk factors for major intraoperative complications and death within 30 days. Univariate and multivariate analysis were used, with a significance level of 5%. Results Procedure success rate was 96.7%, with 90.1% of complete success and 6.6% of clinical success. Major intraoperative complications occurred in 15 (4.1%) patients. Predictors of major complications were: lead dwelling time ≥ 7 years (OR = 3.78, p = 0.046) and change in surgical strategy (OR = 5.30, p = 0.023). Functional class III-IV (OR = 6.98, p <0.001), renal failure (OR = 5.75, p = 0.001), CIED infection (OR = 13.30, p <0.001), number of procedures performed (OR = 77.32, p <0.001) and major intraoperative complications (OR = 38.84, p <0.001) were predictors of 30-day mortality. Conclusions The results of this study, which is the largest prospective registry of consecutive TLE procedures in Latin America, confirm the safety and effectiveness of this procedure in the context of real clinical practice. (Arq Bras Cardiol. 2020; 115(6):1114-1124)