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.

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.

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.

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.

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.

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)

Unusual ventricular activation produced by temporary transvenous cardiac pacing: electrovectorcardiographic findings / Activación ventricular inusual producida por estimulación cardíaca transvenosa temporal: hallazgos electrovectorcardiográficos

Abstract Complete heart block (CHB) results from dysfunction of the cardiac conduction system, which results in complete electrical dissociation. The ventricular escape rhythm can have its origin anywhere from the atrioventricular node to the bundle branch-Purkinje system. CHB typically results in bradycardia, hypotension, fatigue, hemodynamic instability, syncope, or even Stokes-Adams syndrome. Escape rhythm originating above the bifurcation of the His bundle (HB) produces narrow QRSs with relatively rapid heart rate (HR) (except in cases of His system disease). We present a middle-aged man with an HR of 34 bpm, progressive fatigue, in whom a temporary pacemaker was implanted in the subtricuspid region. The post-intervention electrocardiogram had unusual features.

Resumen El bloqueo cardíaco completo (BCC) resulta de la disfunción del sistema de conducción cardíaco, lo que ocasiona una disociación eléctrica completa entre aurículas y ventrículos. El ritmo de escape resultante puede tener su origen en cualquier lugar desde el nodo auriculoventricular hasta el sistema His Purkinje. El BCC generalmente produce bradicardia, hipotensión, fatiga, inestabilidad hemodinámica, síncope o incluso el síndrome de Stokes-Adams. El ritmo de escape que se origina por encima de la bifurcación del haz de His produce intervalos QRS estrechos con frecuencia cardíaca no muy lenta (excepto en casos de enfermedad del sistema Hisiano). Presentamos a un hombre de mediana edad con una frecuencia cardíaca de 34 lpm, fatiga progresiva, en el que se implantó un marcapasos temporario en la región subtricuspídea. El electrocardiograma resultante a la intervención presentó características inusuales.

Long-Term Mortality in Cardioinhibitory Carotid Sinus Hypersensitivity Patient Cohort / Mortalidade de uma Coorte de Portadores da Resposta Cardioinibitória à Massagem do Seio Carotídeo - Estudo Longitudinal com 11 Anos de Seguimento

Abstract Background: Cardioinhibitory carotid sinus hypersensitivity (CICSH) is defined as ventricular asystole ≥ 3 seconds in response to 5-10 seconds of carotid sinus massage (CSM). There is a common concern that a prolonged asystole episode could lead to death directly from bradycardia or as a consequence of serious trauma, brain injury or pause-dependent ventricular arrhythmias. Objective: To describe total mortality, cardiovascular mortality and trauma-related mortality of a cohort of CICSH patients, and to compare those mortalities with those found in a non-CICSH patient cohort. Methods: In 2006, 502 patients ≥ 50 years of age were submitted to CSM. Fifty-two patients (10,4%) were identified with CICSH. Survival of this cohort was compared with that of another cohort of 408 non-CICSH patients using Kaplan-Meier curves. Cox regression was used to examine the relation between CICSH and mortality. The level of statistical significance was set at 0.05. Results: After a maximum follow-up of 11.6 years, 29 of the 52 CICSH patients (55.8%) were dead. Cardiovascular mortality, trauma-related mortality and the total mortality rate of this population were not statistically different from that found in 408 patients without CICSH. (Total mortality of CICSH patients 55.8% vs. 49,3% of non-CICSH patients; p: 0.38). Conclusion: At the end of follow-up, the 52 CICSH patient cohort had total mortality, cardiovascular mortality and trauma-related mortality similar to that found in 408 patients without CICSH.

Resumo Fundamento: A resposta cardioinibitória (RCI) à massagem do seio carotídeo (MSC) caracteriza-se por assistolia ≥ 3 segundos provocada por 5 a 10 segundos de MSC. Existe uma preocupação de que pacientes com RCI e episódios prolongados de assistolia possam falecer em consequência direta de bradiarritmia, ou em decorrência de lesão cerebral, trauma grave ou arritmia ventricular pausa dependente. Objetivos: Determinar a mortalidade total, a mortalidade cardiovascular e a mortalidade relacionada ao trauma de uma coorte de pacientes com RCI à MSC e comparar essas mortalidades com as de uma coorte de pacientes sem RCI à MSC. Métodos: Em 2006, 502 pacientes com idade igual ou superior a 50 anos foram submetidos à MSC. Destes, 52 pacientes (10,4%) foram identificados com RCI. A sobrevida desta coorte foi comparada àquela observada em uma coorte de 408 pacientes sem RCI por meio de curvas de Kaplan-Meier. A regressão de Cox foi utilizada para avaliação da relação entre a RCI à MSC e a mortalidade. Variáveis com p < 0,05 foram consideradas estatisticamente significativas. Resultados: Após seguimento máximo de 11,6 anos, 29 dos 52 portadores de RCI (55,8%) faleceram. A mortalidade total, a mortalidade cardiovascular e a mortalidade relacionada ao trauma desta coorte de pacientes não foram significativamente diferentes daquelas encontradas nos 408 pacientes sem RCI (mortalidade total com RCI: 55,8% versus 49,3% sem RCI; p: 0,38). Conclusões: No fim do seguimento, a mortalidade dos 52 portadores de RCI foi semelhante à observada em uma coorte de pacientes sem RCI. A mortalidade cardiovascular e a relacionada ao trauma também foi semelhante nas duas coortes.

Application and efficacy of the adjustment on left ventricular electrical delay and the distance between right and left ventricular pacing polar in optimizing the left ventricular pacing polar / 中华心血管病杂志

Objective: To investigate the application and efficacy of left ventricular (LV) electrical delay (LVED) and the distance of right ventricular(RV) pacing polar to LV(DRLV) in optimizing LV pacing polar. Methods: Heart failure (HF) patients who implanted cardiac resynchronization therapy (CRT) device with a LV quadripolar lead from January 2014 to January 2018 at General Hospital of Northern Theater Command were enrolled in the study. Measurements of LVED and DRLV of each polar of the lead were performed in patients with HF who underwent CRT with LV quadripolar lead. The principle in turn for polar selecting used for clinical LV pacing was the pacing polar: (1)without phrenic nerve stimulation(PNS); (2)with appropriate capture threshold; (3)not located in apical; (4)with maximal LVED; (5)with maximal DRLV. The LV pacing polar was selected for CRT according to the procedure. The distribution of target veins implanted with LV quadripolar lead were calculated. The percentage of biventricular pacing at 6-month follow-up was recorded. The following indexes were compared before and 6-month after surgery, including QRS duration, LV end-systolic volume(LVESV), LV ejection fraction(LVEF), LV end-diastolic dimension(LVEDD), 6 minute walking distance(6MWD), New York Heart Association(NYHA) class. The efficacy and echocardiographic efficacy of CRT was evaluated. Results: There were twenty-nine HF patients enrolled. The mean age of enrolled patients was(61.7±7.6)years old, nineteen (66%)of them were male. There were seventeen(59%) patients diagnosed as dilated cardiomyopathy and twelve(41%) patients as ischemic cardiomyopathy. All patients were successfully implanted with LV quadripolar lead into target veins, and all four pacing sites were also in target veins. Target veins were located in lateral veins in 15 patients (52%), anterior veins in 2 patients (7%), posterior veins in 11 patients (38%), and lateral branches of great cardiac veins in 1 patient (3%). After 6-month of follow-up, the percentage of biventricular pacing was greater than 95%.There were nineteen(66%) patients optimized LV pacing polar by the largest LVED and four (14%) patients by the DRLV. Of the 29 patients, 5(17%) patients used D1 as the pacing polar, 5(17%) patients used M2 as the pacing polar, 7(24%) patients used M3 as the pacing polar, and 12(41%) patients used P4 as the pacing polar. The pacing polars (D1, M2) of traditional bipolar lead were used in 10(34%) patients, and the LV quadripolar lead specific pacing polars (M3, P4) were used in 19(66%) patients.Compared to a LV quadripolar lead, the LV pacing polar (M3, P4) selected in 19(66%) patients were not achievable with the traditional LV bipolar lead (D1, M2). Preoperative QRS duration, LVESV, LVEF, LVEDD, 6MWD and NYHA class were (171±24)ms, (231±79)ml, (28±5)%, (74±11)mm, (294±103)m, (3.2±1.0)class and the postoperative 6-month were (130±12)ms, (158±73)ml, (36±10)%, (66±12)mm, (371±86)m, (1.9±0.5)class. These indexes were significantly improved after 6 months operation(P<0.001). 97% and 83% patients were responders of CRT as assessed by 6-month efficacy and echocardiographic efficacy. Conclusion: The maximal LVED and DRLV can be used to select LV pacing polar with a high rate of CRT response rate.

Clinical observation on six children of left bundle branch area pacing / 中华儿科杂志

Objective@#To explore the safety and effectiveness of left bundle branch area pacing (LBBAP) in children.@*Methods@#Clinical data, pacing electrocardiogram and parameters of 6 patients (5 females and 1 male) who underwent permanent pacemaker implantation and LBBAP from January to June 2019 in the Department of Pediatric Cardiology of Anzhen Hospital were retrospectively analyzed.@*Results@#The weight of the 6 patients aged between 9 and 14 years ranged from 26 to 48 kg. Five patients were diagnosed with third degree atrioventricular block, and 1 patient was diagnosed with cardiac dysfunction after right ventricular apical pacing. Cardiac function decreased in one patient and remained normal in the other five patients. Left ventricular end diastolic diameter (LVEDD) Z score was 1.85±0.65. V1 lead showed changes like right bundle branch block in pacing electrocardiogram. No significant difference was found regarding QRS wave duration ((95±13) ms vs. (111±20) ms, t=-1.610, P>0.05) between preoperation and postoperation. Pacing threshold was (0.85±0.26) V. The sensing threshold was (15.0±4.3) mV and the impedance was (717±72) Ω. P potential was recorded in 3 cases. The earliest left ventricular local activation time was (56±5) ms and remained stable at different output voltages. Postoperative echocardiography revealed that the electrodes were located near the endocardium of the left ventricular septum. No complications such as myocardial perforation and electrode dislocation occurred during follow-up. The pacing threshold, sensing threshold and impedance were (0.60±0.09)V, (16.1±3.9)mV, (662±78)Ω respectively at 3 months after operation. The patient with low left ventricular ejection fraction (LVEF) recovered to normal on the 3 rd day after LBBAP (45% vs. 57%). The LVEDD Z score decreased to (1.1±0.3) at 3 months after operation and was significantly lower than that before operation (t=2.38, P<0.05).@*Conclusions@#LBBAP in children can achieve narrow QRS pacing andphysiological pacing with stablepacing parameters. It can improve left ventricular enlargement caused by long-term bradycardia, and cardiac dysfunction and cardiac enlargement caused by long-term right ventricular apical pacing quickly and effectively.LBBAP is safe and feasible for older children in the near future. However, the long term potential risks of LBBAP need further observation and study.

Catéter de Swan Ganz con marcapasos en la cirugía mini-invasiva mitral / Pacing Swan-Ganz Catheter in Minimally Invasive Mitral Valve Surgery

RESUMEN Introducción: La cirugía mediante mini-toracotomía lateral presenta ventajas comparativas sobre el acceso convencional como menor trauma quirúrgico, reducida morbimortalidad y un resultado estético superior, pero plantea dificultades en caso de necesitar estimulación eléctrica temporal. Objetivo: Valorar el empleo terapéutico del catéter de Swan-Ganz con marcapasos incorporado como solución a dicho problema y analizar sus complicaciones. Material y métodos: Se incluyeron pacientes programados para cirugía mini-invasiva mitral mediante mini-toracotomía lateral. Se definió empleo terapéutico del catéter al uso debido a bradiarritmias o trastornos de conducción o necesidad de incrementar la frecuencia cardíaca con fines hemodinámicos. Pacientes intervenidos de urgencia o emergencia, fueron excluidos del estudio. Resultados: Fueron incluidos 517 pacientes (289 de sexo masculino, con edad promedio de 68,3 ± 10,4 años); se efectuaron 115 (22,2%) reemplazos y 402 (77,7%) plásticas mitrales. Simultáneamente, se realizaron 294 (56,9%) procedimientos de Maze, 182 (35,2%) cierres de orejuela izquierda, 9 (1,7%) cierres de defectos septales y 14 (2,7%) plásticas tricuspídeas. Ciento sesenta y dos (313%) pacientes necesitaron ser marcapaseados; debido a bradiarritmias, 85 (52,47%) pacientes; por trastornos de conducción, 50 (30,86%) pacientes; mientras que otros 27 (16,66%) requirieron incrementar su frecuencia debido a bajo volumen minuto. La mortalidad resultó de 12 (2,32%) casos. Catorce (2,7%) pacientes presentaron pérdida de captura y se resolvieron con el reposicionamiento del catéter, mientras que 2 (0,6%) pacientes presentaron atrapamiento y requirieron reintervención. Conclusiones: Casi un tercio de los pacientes intervenidos mediante mini-toracotomía lateral requirieron del empleo terapéutico del catéter de Swan-Ganz con marcapasos. Dos pacientes presentaron atrapamiento y requirieron resolución quirúrgica.

ABSTRACT Background: The use of a lateral mini-thoracotomy presents several advantages over the standard access, such as less surgical trauma, reduced morbidity and mortality, shorter recovery time and better cosmetic results, but presents difficulties if temporary pacing is required. Objective: The aim of this study was to evaluate the therapeutic use of a Swan-Ganz catheter with pacing capabilities and analyze its complications. Methods: Patients undergoing scheduled minimally invasive mitral valve surgery through lateral mini-thoracotomy were included in the study. Therapeutic use of the pacing catheter was defined as the need for pacing due to bradyarrhythmias or conduction disorders or need of increasing heart rate in case of hemodynamic instability. Patients undergoing urgent or emergency surgery were excluded from the study. Results: A total of 517 patients were included in the study; mean age was 68.3 ± 10.4 years and 289 (55.9%) were men; 115 patients (22.2%) underwent mitral valve replacement and 402 (77.7%) mitral valve repair. The following concomitant procedures were carried out: 294 (56.9%) Maze procedures, 182 (35.2%) left atrial appendage closures, 9 (1.7%) atrial septal defect closures and 14 (2.7%) tricuspid valve repair surgeries. In the postoperative period 162 (31.3%) patients required pacing due to bradyarrhythmias in 85 cases (52.47%), conduction disorders in 50 (30.86%), and need to increase heart rate in 27 (16.66%) patients with low cardiac output syndrome. Postoperative mortality was 2.32% (n=12). Fourteen (2.7%) patients presented loss of capture that was resolved with catheter repositioning, while 2 (0.6%) patients presented catheter entrapment requiring reintervention. Conclusion: Almost one-third of the patients undergoing lateral mini-thoracotomy required therapeutic use of the pacing Swan-Ganz catheter. Two patients presented catheter entrapment and required surgical reintervention.

Efficacy, Safety, and Performance of Isolated Left vs. Right Ventricular Pacing in Patients with Bradyarrhythmias: A Randomized Controlled Trial / Eficácia, Segurança e Desempenho da Estimulação Ventricular Esquerda versus Direita em Pacientes com Bradiarritmias: Ensaio Clínico Randomizado

Abstract Background: Considering the potential deleterious effects of right ventricular (RV) pacing, the hypothesis of this study is that isolated left ventricular (LV) pacing through the coronary sinus is safe and may provide better clinical and echocardiographic benefits to patients with bradyarrhythmias and normal ventricular function requiring heart rate correction alone. Objective: To assess the safety, efficacy, and effects of LV pacing using an active-fixation coronary sinus lead in comparison with RV pacing, in patients eligible for conventional pacemaker (PM) implantation. Methods: Randomized, controlled, and single-blinded clinical trial in adult patients submitted to PM implantation due to bradyarrhythmias and systolic ventricular function ≥ 0.40. Randomization (RV vs. LV) occurred before PM implantation. The main results of the study were procedural success, safety, and efficacy. Secondary results were clinical and echocardiographic changes. Chi-squared test, Fisher's exact test and Student's t-test were used, considering a significance level of 5%. Results: From June 2012 to January 2014, 91 patients were included, 36 in the RV Group and 55 in the LV Group. Baseline characteristics of patients in both groups were similar. PM implantation was performed successfully and without any complications in all patients in the RV group. Of the 55 patients initially allocated into the LV group, active-fixation coronary sinus lead implantation was not possible in 20 (36.4%) patients. The most frequent complication was phrenic nerve stimulation, detected in 9 (25.7%) patients in the LV group. During the follow-up period, there were no hospitalizations due to heart failure. Reductions of more than 10% in left ventricular ejection fraction were observed in 23.5% of patients in the RV group and 20.6% of those in the LV group (p = 0.767). Tissue Doppler analysis showed that 91.2% of subjects in the RV group and 68.8% of those in the LV group had interventricular dyssynchrony (p = 0.022). Conclusion: The procedural success rate of LV implant was low, and the safety of the procedure was influenced mainly by the high rate of phrenic nerve stimulation in the postoperative period.

Resumo Fundamento: Considerando-se os potenciais efeitos deletérios da estimulação do ventrículo direito (VD), a hipótese desse estudo é que a estimulação unifocal ventricular esquerda pelo seio coronário é segura e pode proporcionar melhores benefícios clínicos e ecocardiográficos aos pacientes com bradiarritmias que apresentam função ventricular normal, necessitando apenas da correção da frequência cardíaca. Objetivos: Avaliar a segurança, a eficácia e os efeitos da estimulação do ventrículo esquerdo (VE), utilizando um cabo-eletrodo com fixação ativa, em comparação à estimulação do VD. Métodos: Estudo clínico, randomizado, simples-cego em pacientes adultos com indicação de marca-passo (MP) devido a bradiarritmias e função ventricular sistólica ≥ 0,40. A randomização aleatória (VD vs VE) ocorreu antes do procedimento. Os desfechos primários do estudo foram: o sucesso, a segurança e a eficácia do procedimento proposto. Os desfechos secundários foram: a evolução clínica e alterações ecocardiográficas. Empregou-se os testes Qui-quadrado, Exato de Fisher e t de Student, com nível de significância de 5%. Resultados: De junho de 2012 a janeiro de 2014 foram incluídos 91 pacientes, sendo 36 no grupo VD e 55 no grupo VE. As características basais dos pacientes dos dois grupos foram similares. O implante de MP foi realizado com sucesso e sem nenhuma intercorrência em todos os pacientes do grupo VD. Dos 55 pacientes inicialmente alocados para o grupo VE, o implante do cabo-eletrodo em veias coronárias não foi possível em 20 (36,4%) pacientes. Dentre os 35 pacientes que permaneceram com o cabo-eletrodo no VE, a estimulação frênica foi a complicação mais frequente e foi detectada em 9 (25,7%) pacientes. Na fase de seguimento clínico, não houve hospitalizações por insuficiência cardíaca. Reduções superiores a 10% na fração de ejeção do VE foram observadas em 23,5% dos pacientes do grupo VD e em 20,6% dos pacientes do grupo VE (p = 0,767). A análise feita pelo Doppler tecidual mostrou que 91,2% dos indivíduos do grupo VD e 68,8% dos do grupo VE apresentaram dissincronia interventricular (p = 0,022). Conclusões: A taxa de sucesso do implante no VE foi baixa e a segurança do procedimento foi influenciada, principalmente, pela alta taxa de estimulação frênica no pós-operatório.

Importancia de la sincronía aurículo-ventricular para el gasto cardíaco en un paciente con insuficiencia cardíaca y fracción de eyección reducida / Importance of atrioventricular synchrony for cardiac output in a patient with heart failure and reduced ejection fraction

RESUMEN Hombre de 80 años de edad, con antecedentes de miocardiopatía dilatada de origen isquémico, con disfunción sisto-diastólica del ventrículo izquierdo, que inicialmente presentó flutter auricular con inestabilidad hemodinámica y se realizó cardioversión eléctrica, luego de la cual se obtuvo un ritmo no precedido de onda P a 40 latidos por minuto, que fue interpretado como fibrilación auricular bloqueada; razón por la que se le colocó un marcapasos externo. Durante su evolución se realizó electrocardiograma de 12 derivaciones, donde se evidenció estimulación ventricular permanente con conducción retrógrada (ventrículo-auricular). Se disminuyó la frecuencia de estimulación para priorizar el ritmo espontáneo del paciente y se obtuvo marcada mejoría de la curva de presión arterial.

ABSTRACT An 80-year-old male patient is presented, with previous dilated cardiomyopathy of ischemic etiology, with systo-diastolic left ventricular dysfunction, who initially presented atrial flutter and hemodynamic instability, thus, an electrical cardioversion was performed. After this procedure, a blocked atrial fibrillation was observed. Thus, an external pacemaker was placed. During the evolution, a 12 lead electrocardiogram was performed, showing permanent ventricular stimulation with retrograde conduction (ventriculo-atrial). The pacing rate was diminished for prioritizing the patient's spontaneous rhythm resulting in an improvement of the blood pressure curve.