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.

Taquicardia ventricular polimórfica tipo torsadess de pointes secundaria a estimulación por marcapasos / Polymorphic ventricular taquicardia "torsades de pointes" associated to abnormal pacemaker stimulation

La taquicardia ventricular polimórfica se origina en los ventrículos, cuyos complejos QRS son de morfología, amplitud y dirección variable, con frecuencias que oscilan entre 200 y 250 lpm, pudiendo ser autolimitadas o degenerar en una fibrilación ventricular. La TdP es un tipo de taquicardia ventricular polimórfica caracterizada por complejos con un eje eléctrico que gira alrededor de la línea isoeléctrica y que está asociada a QT largo. Se presenta el caso de una paciente portadora de marcapaso que presenta episodios de taquicardia ventricular polimórfica, con una morfología típica de TdP, sin documentación de QT prolongado previo ni actual, generada por la estimulación ventricular sobre onda T, de forma accidental por desplazamiento del electrodo auricular a Ventrículo Derecho (VD).

Polymorphic ventricular tachycardia is a tachycardia originating in the ventricles, where the QRS complexes have variable morphology, amplitude, and direction, with frequencies ranging between 200 and 250 bpm; it may be self-limited or degenerate into ventricular fibrillation. Torsades de Pointes (TdP) is a type of polymorphic ventricular tachycardia characterized by complexes with an electrical axis that rotates around the isoelectric line and that is associated with long QT interval. We present the case of a patient with a pacemaker who presents episodes of polymorphic ventricular tachycardia, with a typical morphology of TdP, without documentation of previous or current prolonged QT, generated by ventricular stimulation on the T wave, accidentally due to displacement of the atrial electrode to the Right Ventricle (RV).

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.

Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing / 中华心血管病杂志

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing / 中华心血管病杂志

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

A single-centre experience of His bundle pacing without electrophysiological mapping system: implant success rate, safety, pacing characteristics and one-year follow up

INTRODUCTION@#Despite the challenges related to His bundle pacing (HBP), recent data suggest an improved success rate with experience. As a non-university, non-electrophysiology specialised centre in Singapore, we report our experiences in HBP using pacing system analyser alone.@*METHODS@#Data of 28 consecutive patients who underwent HBP from August 2018 to February 2019 was retrospectively obtained. The clinical and technical outcomes of these patients were compared between two timeframes of three months each. Patients were followed up for 12 months.@*RESULTS@#Immediate technical success was achieved in 21 (75.0%) patients (mean age 73.3 ± 10.7 years, 47.6% female). The mean left ventricular ejection fraction was 53.9% ± 12.1%. The indications for HBP were atrioventricular block (n = 13, 61.9%), sinus node dysfunction (n = 7, 33.3%) and upgrade from implantable cardioverter-defibrillator to His-cardiac resynchronisation therapy (n = 1, 4.8%). No significant difference was observed in baseline characteristics between Timeframe 1 and Timeframe 2. Improvements pertaining to mean fluoroscopy time were achieved between the two timeframes. There was one HBP-related complication of lead displacement during Timeframe 1. All patients with successful HBP achieved non-selective His bundle (NSHB) capture, whereas only eight patients had selective His bundle (SHB) capture. NSHB and SHB capture thresholds remained stable at the 12-month follow-up.@*CONCLUSION@#Permanent HBP is feasible and safe, even without the use of an electrophysiology recording system. This was successfully achieved in 75% of patients, with no adverse clinical outcomes during the follow-up period.

Chinese emergency expert consensus on bedside temporary cardiac pacing (2023) / 中华危重病急救医学

Temporary cardiac pacing is an essential technique in the diagnosis and treatment of arrhythmias. Due to its urgency, complexity, and uncertainty, it is necessary to develop an evidence-based emergency operation norms. Currently, there is no specific consensus guidelines at home or abroad. The Emergency Branch of Chinese Medical Association organized relevant experts to draft the Chinese emergency expert consensus on bedside temporary cardiac pacing (2023) to guide the operation and application of bedside cardiac pacing. The formulation of the consensus adopts the consensus meeting method and the evidentiary basis and recommendation grading of the Oxford Center for Evidence-based Medicine in the United States. A total of 13 recommendations were extracted from the discussion on the methods of bedside temporary cardiac pacing, the puncture site of transvenous temporary cardiac pacing, the selection of leads, the placement and placement of leads, pacemaker parameter settings, indications, complications and postoperative management. The recommended consensus includes the choice between transcutaneous and transvenous pacing, preferred venous access for temporary transvenous pacing, the target and best guidance method for implantation of bedside pacing electrodes, recommended default pacemaker settings, recommended indications for sinoatrial node dysfunction, atrioventricular block, acute myocardial infarction, cardiac arrest, ventricular and supraventricular arrhythmias. They also recommended ultrasound guidance and a shortened temporary pacing support time to reduce complications of temporary transvenous cardiac pacing, recommended bedrest, and anticoagulation after temporary transvenous pacing. Bedside temporary cardiac pacing is generally safe and effective. Accurate assessment, correct selection of the pacing mode, and timely performance of bedside temporary cardiac pacing can further improve the survival rate and prognosis of related emergency patients.

Estimulación cardíaca temporal de larga duración con cable activo y marcapaso permanente externo / Long-term temporary cardiac pacing with active lead and external permanent pacemaker

INTRODUCCIÓN. La estimulación cardíaca temporal de larga duración con cable activo y marcapaso permanente externo es una técnica recientemente incluida en las guías de manejo de bradicardias sintomáticas. CASOS CLÍNICOS. Se describen 4 casos de pacientes sometidos a estimulación cardíaca temporal de larga duración con cable activo y marcapaso permanente externo de la unidad de Hemodinámica del Hospital de Especialidades Carlos Andrade Marín, con indicaciones diversas. DISCUSIÓN. El tiempo medio de permanencia con el cable activo y el marcapaso externalizado fue 23 días. No hubo complicaciones del procedimiento. Un paciente falleció por causas no relacionadas con la estimulación y 2 se recuperaron en sus domicilios. CONCLUSIÓN. La técnica de estimulación temporal utilizando marcapasos permanentes recuperados se muestra extremadamente útil para mantener un marcapaso cardíaco seguro, incluso ambulatorio y por largo tiempo, hasta el implante de dispositivos definitivos. Su limitación es la factibilidad de hacerlo solo en centros de tercer nivel.

INTRODUCTION. Long-duration temporary cardiac pacing with active lead and permanent external pacemaker is a technique recently included in the guidelines for the management of symptomatic bradycardias. CLINICAL CASES. We describe 4 cases of patients who underwent long-duration temporary cardiac pacing with active lead and external permanent pacemaker at the Hemodynamics Unit of the Hospital de Especialidades Carlos Andrade Marín, with different indications. DISCUSSION. The mean length of stay with the active lead and externalized pacemaker was 23 days. There were no procedural complications. One patient died of causes unrelated to pacing and 2 recovered at home. CONCLUSIONS. The technique of temporary pacing using retrieved permanent pacemakers is extremely useful for maintaining safe cardiac pacing, even on an outpatient basis and for a long period of time, until implantation of definitive devices. Its limitation is the feasibility of doing it only in third level centers.

Study on Impedance of Implantable Cardiac Pacemaker in Unipolar/Bipolar Pacing Mode by in Vitro Experiment / 中国医疗器械杂志

The unipolar/bipolar pacing mode of pacemaker is related to its circuit impedance, which affects the battery life. In this study, the in vitro experiment scheme of pacemaker circuit impedance test was constructed. The human blood environment was simulated by NaCl solution, and the experimental environment temperature was controlled by water bath. The results of in vitro experiments showed that under the experimental conditions similar to clinical human parameters, the difference between the circuit impedance of bipolar mode and unipolar mode is 120~200 Ω. The results of the in vitro experiment confirmed that the circuit impedance of bipolar circuit was larger than that of unipolar mode, which was found in clinical practice. The results of this study have reference value to the optimization of pacing mode and the reduction of pacemaker power consumption.

Initial clinical experience of left bundle branch pacing after transcatheter aortic valve implantation / 中华心血管病杂志

Objective: To investigate the efficacy and safety of left bundle branch pacing(LBBP) in patients after transcatheter aortic valve implantation (TAVI). Methods: This is a retrospective study. A total of 35 patients underwent TAVI and received pacemaker implantation from January 2018 to December 2020 in Beijing Fuwai Hospital were enrolled. Patients were divided into LBBP group (n=12) and right ventricular apex pacing (RVAP) group (n=23) according to the pacing position. The success rate of operation in LBBP group was calculated, and the occurrence of complications were observed, and the parameters of pacemaker were measured on the 3rd day and 1, 3 and 6 months after operation. The N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiographic and ECG indexes were compared between the two groups on the 3rd day and 1, 3, and 6 months after pacemaker implantation. Result: A total of 35 patients were included, The age was (76.4±7.7) years, including 19 males (54.3%). The procedure time ((86.58±17.10)min vs. (68.74±9.18)min, P<0.001) and fluoroscopy duration ((20.08±4.44)min vs. (17.00±2.26)min, P<0.001) were significantly longer in LBBP group compared with RVAP group. The operation success rate of LBBP group was 11/12. There was no serious operation related complications such as pneumothorax, hemothorax, electrode dislocation, infection, and lower limb bleeding. The patients were followed up for 7.43 (5.21, 9.84) months. The programmed parameters of pacemaker were in the ideal range and stable during follow-up. At 3 and 6 months after operation, the left ventricular ejection fraction in LBBP group was higher than that in RVAP Group (at 3 months: (60.75±2.89)% vs. (57.35±3.33)%, P=0.004; at 6 months: (63.17±3.33)% vs. (56.17±3.97)%, P<0.001), NT-proBNP values was lower in LBBP group than that in RVAP Group (at 3 months: 822 (607, 1 150)ng/L vs. 1 052 (902, 1 536)ng/L, P=0.006; at 6 months: 440 (330,679)ng/L vs. 783 (588, 1 023)ng/L, P=0.001). At 1, 3 and 6 months after operation, the QRS duration was shorter in LBBP group than that in RVAP group (1 month: 99 (97, 107)ms vs. 126(124, 130)ms, P<0.001; 3 months: 98(96, 105)ms vs. 129(128, 133)ms, P<0.001; 6 months: 96(94, 104)ms vs. 130(128, 132)ms, P<0.001). Conclusions: For patients with permanent pacemaker indications after TAVI, LBBP is feasible, safe and reliable. It could improve the cardiac function in the short term, the long-term effect of LBBP needs to be further observed.

Predictive value of impedance of leadless pacemaker during implantation on trend changes of pacing threshold / 中华心血管病杂志

Objective: To explore the predictive value of the impedance measured during leadless pacemaker Micra implantation on the trend of changes of pacing threshold post implantation. Methods: This is a retrospective cross-sectional study. Patients who received implantation of leadless pacemaker Micra at the Second Xiangya Hospital of Central South University from December 2019 to August 2020 were enrolled. The clinical data and the intraoperative electrical parameters during leadless pacemaker implantation were collected. The impedance and pacing threshold data were analyzed at three time points: immediate release, 5-10 min after release, and after traction test. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to analyze the value of the impedance at immediate release on predicting the trend of changes of pacing threshold post implantation. Results: A total of 21 patients (mean age: (72.2±12.5) years, 12 males) were included. The impedance of 21 patients was (798.1±35.3) Ω immediately after implantation, (800.9±35.6) Ω after 5-10 minutes of release, and (883.6±31.7) Ω after traction test. Impedance was similar between the three time points (P>0.05). The threshold was (0.97±0.11) V/0.24 ms immediately after implantation, (0.95±0.12) V/0.24 ms at 5-10 min after the release, and (0.59±0.06) V/0.24 ms after the traction test. The threshold was significantly lower after the traction test than that immediately after release (P=0.003) and than that at 5-10 minutes after release (P=0.008), suggesting a decreased tendency of the threshold over time. According to the analysis of the ROC curve, the immediate impedance after the release ≥680 Ω could predict the ideal pacing threshold after the traction test (AUC=0.989, 95%CI 0.702-0.964, P<0.001), the prediction sensitivity was 87%, and the specificity was 100%. The pacing threshold would be not ideal with the immediate impedance ≤ 520 Ω (95%CI 0.893-1.000, P<0.001), the sensitivity was 100%, and the specificity was 80%. Conclusions: The impedance immediately after the release has predictive value for the changing trend of threshold post leadless pacemaker Micra implantation. Impedance ≥680 Ω immediately after release is often related with ideal pacing threshold after the traction test. In contrast, the impedance ≤ 520 Ω pacing is often related with unsatisfactory threshold after the traction test, therefore, it is recommended to find a new pacing site to achieve the impedance ≥680 Ω immediately after release during leadless pacemaker Micra implantation.

The success rate of His-Purkinje system pacing in patients with various sites of atrioventricular block / 中华心血管病杂志

Objective: To evaluate the success rate of His-Purkinje system pacing (HPSP) in patients with various sites of atrioventricular block (AVB) and provide clinical evidence for the selection of HPSP in patients with AVB. Methods: This is a retrospective case analysis. 637 patients with AVB who underwent permanent cardiac pacemaker implantation and requiring high proportion of ventricular pacing from March 2016 to September 2021 in the Department of Cardiology, General Hospital of Northern Theater Command were enrolled. The site of AVB was determined by electrophysiological examination. His bundle pacing (HBP) was performed in the first 130 patients (20.4%) who were classified as the HBP group and HPSP included HBP and/or left bundle branch pacing (LBBP) was performed in later 507 patients (79.6%) and these patients were classified as the HPSP group. The basic clinical information such as age and sex of the two groups was compared, and the success rates of HBP or HPSP in patients with different sites of AVB and QRS intervals were analyzed. Results: The age of HBP group was (66.4±15.9) years with 75 males (57.7%). The age of HPSP group was (66.8±13.6) years with 288 (56.8%) males. Among 637 patients, 63.0% (401/637) had atrioventricular node block; 22.9% (146/637) had intra-His block; 14.1% (90/637) had distal or inferior His bundle block. Totally, the success rate of HPSP was higher than that of HBP [93.9% (476/507) vs. 86.9% (113/130), P<0.05]. In each group of patients with various AVB sites, the success rate of HPSP was higher than that of HBP respectively and both success rates of HBP and HPSP showed a declining trend with the distant AVB site. The success rate of HBP in patients with atrioventricular node block and intra-His block was higher than that in patients with distal or inferior His bundle block [95.2% (79/83) vs. 47.1% (8/17), P<0.001; 86.7% (26/30) vs. 47.1% (8/17), P=0.010]. The success rate of HPSP was higher than that of HBP in patients with distal or inferior His bundle block [87.7% (64/73) vs 47.1% (8/17), P=0.001]. In patients with QRS<120 ms, 94.9% (520/548) of AVB sites were in atrioventricular node or intra-His, and HBP had a similar high success rate with HPSP [95.6% (109/114) vs. 96.3% (418/434), P=0.943] in these patients. In patients with QRS ≥ 120 ms, 69.7% (62/89) of AVB sites were at distal or inferior His bundle, and the success rate of HBP was only 25.0% (4/16), while the success rate of HPSP was as high as 79.5% (58/73), P<0.001. Conclusions: In patients with QRS<120 ms and atrioventricular node block or intra-His block, success rates of HBP and HPSP are similarly high and HBP might be considered as the first choice. In patients with QRS ≥ 120 ms and AVB site at distal or inferior His bundle, the success rate of HPSP is higher than that of HBP, suggesting LBBP should be considered as the first-line treatment option.

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.

Patient with an implantable cardiac electrical stimulation device. What should the anesthesiologist know? / Paciente con dispositivo de estimulación eléctrica cardiaca implantable. ¿Qué debe saber el anestesiólogo?

Abstract Patients with implantable electric stimulation devices are challenging to the anesthesiologist since these cases demand a comprehensive knowledge about how the device operates, the indications for the implant and the implications that must be addressed during the perioperative period. This article is intended to provide the reader with clear and structured information so that the anesthesiologist will be able to safely deal with the situation of a patient with an implantable cardiac stimulation device, who has been programmed for emergent surgery. A search for the scientific evidence available was conducted in Pubmed / Medline, ScienceDirect, OVID, SciELO), for a non-systematic review. The incidence of the use of cardiac electric stimulation devices has been growing. Their operation is increasingly complex, and demands being constantly updated on the knowledge in the area.

Resumen El paciente portador de un dispositivo de estimulación eléctrica cardiaca implantable se convierte en un reto para el anestesiólogo debido a que implica un conocimiento integral que abarca su funcionamiento, las indicaciones que llevaron a su implante y las implicaciones que se deben abordar en el perioperatorio. Este artículo busca proporcionar al lector información clara y estructurada que le permita al anestesiólogo enfrentarse de forma segura al escenario de un paciente con un dispositivo de estimulación eléctrica cardiaca implantable programado para cirugía emergente. Se realizó una búsqueda de la evidencia científica disponible en bases de datos (Pubmed / Medline, ScienceDirect, OVID, SciELO), para una revisión no sistemática. La incidencia en el uso de dispositivos de estimulación eléctrica cardiaca viene en aumento. Su funcionamiento es cada vez más complejo lo cual implica una actualización permanente del conocimiento en esta área.

Association between fragmented QRS and postprocedural rhythm disturbances in patients who underwent transcatheter aortic valve implantation

SUMMARY INTRODUCTION: According to recent studies, the rate of atrioventricular block requiring permanent pacing in patients following transcatheter aortic valve implantation varied between 5.7% and 42.5%. Fragmented QRS is a useful marker of myocardial scar and can predict adverse cardiac events. In this study, we examined association between f ragmented QRS and postprocedural rhythm disturbances and the need for permanent pacing in patients who underwent transcatheter aortic valve implantation. OBJECTIVE: In this study, we examined association between fragmented QRS and postprocedural rhythm disturbances and the need for permanent pacing in patients who underwent transcatheter aortic valve implantation' sentence is enough for it. METHODS: We retrospectively analyzed standard 12-lead electrocardiographic recordings of 124 consecutive patients in whom a CoreValve prosthesis was implanted. We examined 12-lead electrocardiogram before and after procedure along with one- and six-month follow-up. We documented QRS fragmentation and postprocedural rhythm disturbances. RESULTS: There was a significant increase in the frequency of left bundle branch block, (21.1 versus 0%, p<0.05) and the incidence of atrioventricular blocks requiring permanent pacing (21.1 versus 0%, p<0.05) following transcatheter aortic valve implantation in patients whose preprocedural electrocardiogram recordings revealed fragmented QRS compared to those without fragmented QRS. Based our collected data, the presence of QRS fragmentation in anterior derivations was the only independent factor associated with postprocedural rhythm disturbances (B-value 0.217; OR 0.805; 95%CI 0.136-4.78; p=0.004). CONCLUSION: Our data showed an increased risk for the development of new-onset left bundle branch block and atrioventricular blocks following transcatheter aortic valve implantation in patients whose baseline electrocardiogram recordings demonstrated QRS fragmentation.

Left ventricular systolic function between left bundle branch pacing and right ventricular septum pacing in patients with pacemaker dependence by three-dimensional speckle tracking imaging / 中南大学学报(医学版)

OBJECTIVES@#To compare the left ventricular systolic function between the 1eft bundle branch pacing (LBBP) and right ventricular septum pacing (RVSP) in patients with pacemaker dependence by three-dimensional speckle tracking imaging (3D-STI).@*METHODS@#A total of 65 patients with atrioventricular block (AVB) (Mobitz type II second-degree AVB, high-degree AVB, or third-degree AVB), who underwent permanent cardiac pacing implantation including 32 patients receiving LBBP (LBBP group) and 33 patients receiving RVSP (RVSP group) from June 2018 to June 2019,were enrolled in this study. These patients met the following inclusion criterion: pre-operative left ventricular ejection fraction (LVEF)>50% and ventricular pacing rate>40% at 6-month programming follow-up; and the patients underwent echocardiography at pre-operation and 6 months after operation. The 3D-STI was used to obtain global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS).@*RESULTS@#All the patients in the LBBP group and the RVSP group had normal LVEF, there was no significant difference between the 2 group (@*CONCLUSIONS@#For patients with pacemaker dependence and normal LVEF at pre-operation, the cardiac function in the LBBP group is not significantly better than that in the RVSP group in short term follow-up. But in terms of physiologic pacing and long-term cardiac function protection, the 1eft bundle branch pacing is an optimal pacing mode.