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.

Mejoría clínica, hemodinámica y de marcadores bioquímicos tras estimulación ventricular desde el área de la rama izquierda / Clinical, hemodynamic and biochemical improvement related to left bundle branch area pacing

Resumen Introducción: La estimulación ventricular derecha puede provocar insuficiencia cardiaca y disfunción ventricular. La estimulación en el área de la rama izquierda (ERI) permite capturar el sistema His-Purkinje. La ERI se ha estudiado en la estimulación ventricular y en la terapia de resincronización cardiaca. La evolución de los péptidos natriuréticos (NT-proBNP) asociada a la ERI no ha sido estudiada hasta el momento. Métodos: Se incluyeron pacientes consecutivos remitidos para implante de marcapasos o terapia de resincronización cardiaca. El implante del electrodo de ERI se realizó siguiendo la técnica descrita por Huang et al. Los pacientes eran sometidos a ecocardiograma y determinación de NT-proBNP antes y cuatro semanas después del procedimiento. Resultados: Se analizaron 50 pacientes con implante exitoso y seguimiento completo. No hubo diferencias significativas entre los umbrales medidos durante el procedimiento y los obtenidos al cabo de 12 semanas. La ERI logró una reducción significativa de la anchura del complejo QRS (148 ± 21 vs. 107 ± 11 ms; p = 0.029). La ERI logró una reducción significativa de la clasificación funcional en el conjunto de la muestra y una reducción significativa de NT-proBNP (2,888.2 ± 510 vs. 1,181 ± 130 pg/ml; p = 0.04). En pacientes con fracción de eyección del ventrículo izquierdo (FEVI) < 50% y asincronía se logró un incremento significativo de la FEVI con la ERI (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). Conclusiones: La ERI es factible en la mayoría de pacientes y se asocia con una reducción de la duración del complejo QRS. La ERI no condiciona un efecto deletéreo sobre la FEVI a corto-medio plazo; además, en aquellos pacientes con FEVI deprimida y asincronía ventricular permite incrementar la FEVI.

Abstract Background: Right ventricular pacing is associated with risk of heart failure and left ventricular dysfunction. Left bundle branch area pacing (LBBP) has emerged as an alternative method for delivering physiological pacing. The effect of LBBP on N-terminal pro-brain natriuretic peptide (NT-proBNP) has not been investigated. Method: Finally, 50 patients referred for pacemaker implantation were included. LBBP was performed as described previously by Huang et al. Transthoracic echocardiogram and NT-proBNP were performed before and four weeks after the procedure. Results: 50 patients were analyzed. There were not differences between ventricular thresholds during the procedure and 3 months later, LBBP significantly reduced QRS complex duration (148 ± 21 vs. 107 ± 11 ms; p = 0.029). LBBP significantly improved NYHA functional class and reduced NT-proBNP concentration (2888.2 ± 510 vs. 1181 ± 130 pg/ml; p = 0.04). In patients showing left ventricular ejection fraction (LVEF) < 50% and ventricular desynchrony LBBP showed a significant LVEF increase (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). Conclusions: LBBP was feasible and safe in most of patients. LBBP was associated with reduction in QRS width and with increase in LVEF in patients with ventricular desynchrony, while in patients with normal LVEF it remained unchanged during follow-up.

Strain echocardiography in predicting LV dysfunction in RV apical pacing

Right ventricular (RV) pacing is associated with a reduction in left ventricular (LV) systolic function, thought to be mediated by pacing-induced ventricular dyssynchrony. The prevalence of heart failure after RV pacing is reported to range from 31±3%. We studied 60 subjects with high-grade atrioventricular block and Complete Heart Block (CHB) scheduled to undergo right ventricular apical pacing. 2D echocardiography was done at baseline, 1 month and 12 months. Pacing-induced cardiomyopathy was defined as a reduction in LVEF to <45%. Strain was evaluated off-line from digitally stored images using all advanced software package (cardiac wall motion quantification (CMQ); Toshiba Medical Systems). Longitudinal strain for individual myocardial segments was measured from the apical four-chamber, two-chamber and long axis views (16 segment AHA/ASE model). None had LV dysfunction at baseline based on 2D and strain echo imaging. Subsequently 18 patients were detected to develop low GLS score (less than -14.5) at 1 month. On subsequent follow up at 1 year, all 18 patients developed LV dysfunction on 2D Echocardiography. Thus Strain imaging with GLS score helped in early detection of LV dysfunction in RV apical pacing subjects. Pacing-induced cardiomyopathy had significant association with high grade AV block with pacemaker dependency. It had no significant associations with other comorbidities like diabetes, hypertension, ischemic heart disease or with the type of medication intake. However there was a statistically significant association with heart failure

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.

Changes of ventricular septal myocardial injury current in left bundle branch area pacing / 中国综合临床

Objective:Explore the characteristics of injury current changes in ventricular septal myocardium during left bundle branch area pacing (LBBAP) surgery.Methods:Retrospective analysis of clinical data of patients who underwent permanent pacemaker implantation at The Second People's Hospital of Wuxi in Jiangsu Province from January 2020 to November 2022. Among them, 42 patients were treated with LBBAP (LBBAP group) and 56 patients with Right ventricle septum pacing (RVSP group). Compare the conventional parameters such as threshold, perception, impedance during electrode implantation, damage current values at 0, 5, and 10 minutes before and after electrode rotation, and the correlation between damage current and conventional parameters. The measurement data is represented by xˉ± s, analysis of variance is used for comparison between multiple groups, t-test is used for comparison between two groups, and repeated measurement analysis of variance is used for comparison between two groups at multiple time points; Counting data is represented as an example (%), and inter group comparisons are made using χ 2 Inspection; Pearson correlation analysis was used to analyze the correlation between the two variables. Results:There was no statistically significant difference in pacing threshold, perception, and impedance between the two groups of electrode implantation surgery (all P>0.05). The damage current values at 0, 5, and 10 minutes before and after electrode rotation in the LBBAP group were higher than those in the RVSP group [(7.19±1.26) mV compared to (5.33±0.79) mV, (22.50±3.06) mV compared to (10.85±1.70) mV, (15.75±2.63) mV compared to (8.01±1.09) mV, (9.24±2.00) mV compared to (5.51±0.98) mV]. The damage current values at 0 minutes after electrode rotation in both groups were higher than before electrode rotation, and gradually decreased thereafter, After 10 minutes of electrode placement, the damage current value of the LBBAP group was still higher than the level before electrode rotation (all P<0.05), while there was no statistically significant difference between the RVSP group and the level before electrode rotation ( P>0.05). The damage current value at 0 minutes after the LBBAP group electrode was in place was positively correlated with ventricular septal thickness and left ventricular posterior wall thickness ( r values 0.45 and 0.46, P values 0.003 and 0.002, respectively), and negatively correlated with conventional pacing parameter impedance ( r=-0.32, P=0.037). There was no correlation with threshold and perception ( r values 0.08 and 0.01, P values 0.604 and 0.968, respectively). The damage current value at 0 minutes after the RVSP group electrode was in place was negatively correlated with the threshold ( r=-0.28, P=0.036). Conclusions:The COI value of LBBAP interventricular septum myocardium increased significantly after the electrode was rotated out. The COI value at 0 min after the electrode put in place was positively correlated with the interventricular septum thickness and left ventricular posterior wall thickness, and negatively correlated with the electrode impedance, but there was no correlation with threshold and perception.

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.

Effect of external diaphragm pacing therapy combined with abdominal functional electrical stimulation on respiratory function for stroke patients / 中国康复理论与实践

ObjectiveTo explore the effect of external diaphragm pacing therapy combined with abdominal functional electrical stimulation on respiratory function for stroke patients. MethodsFrom October, 2020 to September, 2022, 54 stroke patients were randomly divided into control group (n = 18), external diaphragm pacing group (n = 18) and combined treatment group (n = 18). All the groups received breathing training, while the external diaphragm pacing group received external diaphragm pacing therapy, and the combined treatment group received external diaphragm pacing and abdominal functional electrical stimulation therapy, for two weeks. They were measured forced vital capacity (FVC), forced expiratory volume in first second (FEV1), ratio of forced expiratory volume in first second in forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) with pulmonary function instrument; measured diaphragmatic excursion (DE) and diaphragmatic thickness (DT) with ultrasound, before and after treatment. ResultsThree cases in the control group, two cases in the external diaphragm pacing group and one case in the combined treatment group dropped off. The FVC, FEV1, PEF, MIP, MEP and DE improved in all the groups (|t| > 3.366, P < 0.01) after treatment; and the FVC, FEV1, MIP and DE increased more in the combined treatment group and the external diaphragm pacing group than in the control group (P < 0.05); the FVC and FEV1 increased more in the combined treatment group than in the external diaphragm pacing group (P < 0.05). ConclusionExternal diaphragm pacing therapy may improve ventilation and inspiratory muscle strength, and increase diaphragm movement for stroke patients; while the ventilation improved more after combining with abdominal functional electrical stimulation.

Incidence of atrial high rate episodes after dual-chamber permanent pacemaker implantation and its clinical predictors

Atrial high rate episodes (AHRE) confers increased morbidity and mortality amongst patients with permanent pacemaker implantation (PPI). The incidence of AHREs and it's clinical predictors in Indian patients without prior history of atrial fibrillation (AF) are not well understood. A total of 100 dualchamber PPI patients, who had no prior history of AF, underwent pacemaker interrogation starting from a minimum of 1 month after implantation to detect any AHREs. The incidence of AHREs was 17% at a mean follow up 15.2 ± 7.5 months. Only right ventricular apical lead position was found to have an independent association with AHREs (OR: 3.50, 95% CI: 1.02e12.03; p ¼ 0.04).

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.

Cardiac Tamponade during Transcatheter Aortic Valve Implantation (TAVI)

Transcatheter aortic valve implantation (TAVI) is a new minimally invasive procedure for symptomatic patients with severe aortic stenosis and surgical high-risk. Numerous technical improvements have been developed to simplify the procedure and reduce the incidence of complications. Temporary pacing of the right ventricle remains mandatory to ensure transient hypotension and low cardiac output while performing predilation of the aortic annulus and accurately position and deploy the valve. Temporary pacing is also crucial as a backup pacing device if complete atrioventricular block develops after TAVI. Implanting a temporary pacing wire requires additional venous vascular access and a pacing lead, both of which may generate complications. Cardiac tamponade during TAVI is a rare complication. We present the case of a cardiac tamponade during TAVI probably due to right ventricular perforation associated with pacing. We report some measures to avoid such complications and improve the TAVI procedure

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.

Pressure-strain loops technique detects the effects of different pacing modes of left bundle branch on left ventricular myocardial work / 中华超声影像学杂志

Objective:To evaluate the effects of different pacing modes (unipolar/bipolar) under left bundle branch pacing(LBBP) on ventricular mechanical synchrony and myocardial work using the pressure-strain loop technique.Methods:Twenty-nine patients with LBBP due to symptomatic bradycardia were collected as LBBP group in Sun Yat-sen Memorial Hospital of Sun Yat-sen University from December 2018 to July 2020. Another 29 matched patients with right ventricular pacing (RVP) during the same period were also included as a RVP group. Each LBBP patient was programmed to different pacing modes (uni-/bio-polar) within 1 week after the operation.Under each pacing mode, the inter- and intra-ventricular mechanical synchronization were evaluated. Meanwhile, the global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) were obtained by the left ventricular pressure-strain loops technique.Results:Compared with the RVP group, the mechanical synchrony in the LBBP group was significantly improved (all P<0.05). GWI, GCW, and GWE increased, while GWW decreased, and the differences were statistically significant (all P<0.05), there were no significant differences in ventricular mechanical synchronization, GWI, GCW, GWE, and GWW between unipolar and bipolar pacing in the LBBP group (all P>0.05), there were no significant differences in these parameters when increasing output voltage (all P>0.05). Conclusions:LBBP induces better mechanical synchronization and higher myocardial work efficiency than RVP. Different LBBP pacing modes do not affect ventricular mechanical synchronization and myocardial work efficiency.

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.

Effect of early external diaphragm pacing on patients with mechanical ventilation / 中华急诊医学杂志

Objective:To investigate the effect of early external diaphragm pacing on the diaphragm function and prognosis of patients with mechanical ventilation.Methods:A total of 47 patients receiving invasive mechanical ventilation in the Emergency Intensive Care Unit of Hunan Provincial People's Hospital (The First Affiliated Hospital of Hunan Normal University) from October 2019 to July 2021 were selected and randomly divided into the treatment group ( n=23) and control group ( n=24). The patients in the control group received routine clinical treatment. On this basis, the treatment group received external diaphragm pacing treatment every day from the third day of mechanical ventilation until weaning, and was followed up to 30 days after discharge. The diaphragm thickness, diaphragm excursion, diaphragm thickening fraction, mechanical ventilation time, number of weaning failures, length of hospital stay and death toll were compared between the two groups. Results:Compared with the control group, the diaphragm thickness [(0.21±0.05) cm vs. (0.16±0.05) cm], diaphragm excursion [(1.38±0.37) cm vs. (1.11±0.48) cm], and diaphragm thickening fraction [26% (19%, 32%) vs. 18.5% (10.25%, 20%)] in the treatment group increased significantly (all P<0.05). The mechanical ventilation time was shorter in the treatment group [10 (7, 15) d vs. 13 (10.25, 19) d], and the difference was statistically significant ( P<0.05). There were no significant differences in the number of weaning failures (7 vs. 9), length of hospital stay [22 (15 , 30) d vs.. 24 (17.25, 34.25) d] and deaths (8 vs. 8) (all P>0.05). Conclusions:Early application of external diaphragm pacing can improve the diaphragm function of patients with mechanical ventilation, delay the decline in diaphragm function, increase diaphragm excursion and diaphragm thickening fraction, and shorten the mechanical ventilation time.

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.