Research Progress in the Effect of His-Purkinje Conduction System Pacing on Cardiac Function / 中山大学学报(医学科学版)

Cardiac pacing is an effective treatment for cardiac pacing and conduction dysfunction and severe heart failure. However， the conventional right ventricular pacing may increase the incidences of heart failure and atrial fibrillation， and biventricular pacing has a relatively high non-response rate. As a new technique of physiological pacing， a number of studies in recent years have been conducted to show the stability of pacing parameters and good cardiac synchronization of his-purkinje system pacing. This article reviews the current status of research and progress in the effects of his-purkinje conduction system pacing on cardiac function， so as to provide a theoretical basis for promoting the development of this technology.

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.

Manejo de la insuficiencia cardiaca con estimulación hisiana en bloqueo de rama derecha: reporte de caso / Management of heart failure with His bundle pacing in right bundle branch block: case report

Resumen La terapia de resincronización cardiaca mediante estimulación hisiana ha demostrado ser efectiva en pacientes con bloqueo de rama izquierda del haz de His e insuficiencia cardiaca. Paciente masculino, con 47 años de edad, con insuficiencia cardiaca, fracción de expulsión del 17% y miocardio dilatada idiopática, electrocardiograma en ritmo sinusal, bloqueo auriculoventricular de 1.er grado, intervalo PR 400 ms, bloqueo completo de rama derecha del haz de His, bloqueo del fascículo anterior de la rama izquierda del haz de His, duración del QRS 200 ms. Se decidió realizar estimulación selectiva del haz de His. La resincronización cardiaca biventricular convencional en pacientes con presencia de bloqueo completo de la rama derecha del haz de His no está indicada debido a la pobre respuesta al tratamiento. La estimulación hisiana permite reclutar la rama bloqueada y reestablecer la conducción a través de ella, de tal forma que, en ausencia de necrosis, se logre sincronía biventricular. En el caso presentado el reclutamiento de la rama derecha mediante estimulación hisiana se reflejó en el restablecimiento de la sincronía biventricular, medida por rastreo de marcas (speckle tracking) e incremento significativo de la fracción de expulsión del ventrículo izquierdo del 17 al 36.6%, con un incremento absoluto del 19.6%.

Abstract Cardiac resynchronization therapy has proven to be an effective therapy in patients with left bundle branch block and heart failure. Male, 47 years old, heart failure with a left ventricle ejection fraction of 17%, idiopathic heart failure. ECG with sinus rhythm, 1st degree AV block, PR 400 ms, complete right bundle branch block, anterior hemi-fascicle of the left bundle of His, and QRS duration 200 ms. We decided to perform a selective His bundle pacing. In patients with right bundle branch block the biventricular cardiac resynchronization is not indicated due to low treatment response. His bundle pacing allows recruiting the blocked branch and restoring conduction throughout it, therefore, in the absence of necrosis the biventricular synchrony is achieved. We presented a case of His bundle pacing with recruitment of the right bundle branch, which reestablish biventricular synchrony measured by speckle tracking, and with a significant increase of the left ventricle ejection fraction from 17 to 36.6%, with an absolute increase of 19.6%.

Permanent HIS bundle Pacing Feasibility in Routine Clinical Practice: Experience from an Indian Center

There is a paucity of experience regarding His bundle pacing (HBP) at laboratories initially attempting the procedure, especially in the Indian scenario. Patient who underwent HBP were selected for pacing therapy or in lieu of cardiac resynchronization therapy (CRT) at a single center. Among 22 patients attempted, 19 patients underwent successful implant, achieving selective HBP in 14 patients. There was a significant improvement in left ventricular ejection fraction (LVEF) (49.3 ± 9.3 vs. 36.7 ± 9.2) in the LV dysfunction subgroup (n = 6). Over a follow-up of 15 ± 6.5 months, thresholds were stable in all except one patient, and there was no requirement of lead revision. In summary, we found that HBP is a feasible option for achieving physiological pacing.

Nursing care of 5 patients with atrial fibrillation treated with left atrial appendage occlusion combined with his bundle up pacing / 中国实用护理杂志

Objective To summarize the nursing experience of left atrial appendage occlusion combined with his bundle lifting pacing in the treatment of atrial fibrillation. Methods The heart center of our hospital was first created with left atrial appendage combined with hirson bundle pacing, and 5 cases were completed from January 1, 2017 to January 1, 2018, and the nursing points were summed up in combination with the perioperative and postoperative follow-up nursing. Results All 5 patients were successfully performed with combined operation, and no serious complications occurred during the perioperative period and follow-up period. Conclusions Because the process of innovation is more complicated, it is necessary for the nursing team to carry out strict auxiliary nursing and monitoring of the disease in different stages so as to ensure the operation safety and improve the quality of life of the patients.

Perioperative bundle of cares for patients receiving His bundle pacing or para-His bundle pacing / 介入放射学杂志

Objective To explore the optimal perioperative nursing program for patients receiving cardiac pacemaker by His bundle pacing or by para-His bundle pacing.Methods A total of 26 patients,who were receiving cardiac pacemaker by His bundle pacing or by para-His bundle pacing,were enrolled in this study.The bundle of cares,used as the nursing intervention measures,was executed in all patients,which included strengthening the professional training for specialist team members,improvement of preoperative intervention,careful intraoperative cooperation,postoperative observation of patient's condition and complications,prevention and health guidance,etc.Results Through the strict implementation of the special bundle of nursing cares,all the 26 patients could well cooperated with surgical procedure,and after the treatment the patients recovered smoothly and achieved the desired results with no occurrence of complications.Conclusion The intervention measures of the bundle of cares are scientific and reasonable.The implementation of the special bundle of nursing cares can promote the professional nursing ability of nurses and ensure the quality of nursing service.

Cardiac atrioventricular conduction improved by autologous transplantation of mesenchymal stem cells in canine atrioventricular block models / 老年心脏病学杂志（英文版）

Objective Atrioventricular block (AVB) is a common and serious arrhythmia. At present, there is no perfect method of treatment for this kind of arrhythmia. The purpose of this study was to regenerate cardiac atrioventricular conduction by autologous transplantation of bone marrow mesenchymal stem cells (MSCs), and explore new methods for therapy of atrioventricular block. Methods Eleven Mongrel canines were randomized to MSCs transplantation (n=6) or control (n=5) group. The models of permanent and complete AVB in 11 canines were established by ablating His bundle with radiofrequency technique. At 4 weeks after AVB, bone marrow was aspirated from the iliac crest. MSCs were isolated and culture-expanded by means of gradient centrifugal and adherence to growth technique, and differentiated by 5-azacytidine in vitro. Differentiated MSCs (1ml, 1.5×107cells) labeled with BrdU were autotransplanted into His bundle area of canines by direct injection in the experimental group, and 1ml DMEM in the control group. At 1-12 weeks after operation,the effects of autologous MSCs transplantation on AVB models were evaluated by electrocardiogram, pathologic and immunohistochemical staining technique. Results Compared with the control group, there was a distinct improvement in atrioventricular conduction function in the experimental group. MSCs transplanted in His bundle were differentiated into analogous conduction system cells and endothelial cells in vivo, and established gap junction with host cardiomyocytes. Conclusions The committed-induced MSCs transplanted into His bundle area could differentiate into analogous conduction system cells and improve His conduction function in canine AVB models.

Anti-bradyarrhythmia Efficacy of Cilostazol:An Experimental Study / 中国药房

OBJECTIVE:To study the effect and mechanism of cilostazol in experimental anti-bradyarrhythmia.MET-HODS:Bradyarrhythmia model of mice was induced using verapamil hydrochloride and nicotine,respectively.The electrocardiograms at different time and the heart rates of the model mice after intragastric administration of different dosages of cilostazol were recorded.The in vivo His' bundle electrogram(HBE)recordings in rabbits were obtained after intragastric administration of different dosage of cilostazol for detection of A-H interval and H-V interval,which were compared with control group(normal saline group).RESULTS:Verapamil hydrochloride and nicotine markedly slowed down the heart rates of mice,but cilostazol significantly sped up the heart rates in mice(P

STUDY OF BEAT TO BEAT SURFACE RECORDING OF HIS BUNDLE ACTIVITY WITHOUT AVERAGING IN MAN / 解放军医学杂志

Objective To investigate the application of open beat to beat techniques recording His bundle activity without digital averaging. Methods Recording was performed with very low noise, high gain amplifiers and by analog filtering. 3 brigade amplifiers and 16 bite A/D were connected to a microcomputer by USB. The signal was processed by A pattern recognition plus digital filtering software. The subjects were in a supine position during the recording. Results A prominent waveform was observed between the atrial and ventricular complexes and corresponded to His bundle activity in 46 volunteers. Recordings in 8 patients were compared with records obtained by intracardiac electrode, and a good conformation was seen. Conclusion The noninvasive method of beat to beat surface recording of His bundle activity has broad clinical applicability and high utility for the patients with latent A-V block and eletrophysiologic study.

Effects of heart ischemia-reperfusion on atrioventricular node conduction in rabbits / 第三军医大学学报

Objective To study the effects of heart ischemia reperfusion on conductive function of atrioventricular node (AVN) in rabbits. Methods Animal models of ischemia reperfusion of AVN were established by ligating and reopening the right coronary artery of rabbits. A total of 60 adult rabbits were divided into control groups ( n =10), right coronary artery occlusion group ( n =10), and ischemia reperfusion groups with ligation of the right artery occlusion for 10, 30, 60 and 120 min respectively ( n =10 for every subgroup). The hemodynamics, His bundle electrography and epicardial electography were carried out and recorded. Results After occlusion of right coronary artery, 94.8% animals in experimental groups were found to have prolonged atrial His interval (AH) ( P

The effect of imidazoline receptor agonist-moxonidine on the His bundle electrogram in vivo / 西安交通大学学报(医学版)

Objective To study the effect of moxonidine (Mox) on the His bundle electrogram (HBE) of normal rabbits. Methods A total of 24 healthy rabbits were randomly divided into four groups: control group, small dose of Mox (0.1 mg?kg -1), medium dose of Mox (0.3 mg?kg -1) and large dose of Mox (0.9 mg?kg -1). The electrode catheter was inserted from the right carotid artery to record the HBE. The HBE and the synchronism surface ECG were recorded before and after intravenous injection. Results In normal rabbits, the R-R interphase, P-R interphase of the ECG and the H-V interphase of the HBE were prolonged in a dose-dependent manner after intravenous injection of Mox. Mox exerted no significant influence on the A-H interphase. Conclusion ① Mox decreases the heart rate of rabbits in a dose-dependent manner in vivo. ② Mox dose-dependently prolongs the P-R interphase of the surface ECG and the H-V interphase of HBE. This indicates that Mox mainly acts on the intraventricular conducting system.

New breakthrough in beat to beat surface recording of his bundle potential / 解放军医学杂志

Objective To evaluate a noninvasive method which has been applied on human subjects to observe beat to beat activity of the His bundle potential. Methods Recording was performed with very low noise, high gain amplifiers and by analog filtering. 3-brigade amplifiers and 16-bite A/D were connected to a microcomputer by USB. The signal was processed by a combined pattern recognition and digital filtering software. Results The results of surface monitoring were compared with intracardiac method in 30 patients. The results of non-invasive method were consistent with that interventional method. A prominent waveform was observed between the atrial and ventricular complexes (A, H, V waves), and corresponded to His bundle activity in all patients. Conclusion The noninvasive method of beat to beat surface recording of His bundle activity has broad clinical applicability and high utility for the patients with latent A-V block and eletrophysiologic study.

ARCHITECTURE OF THE SPECIALIZED MYOCARDIAL FIBERS OF THE ATRIOVENTRICULAR JUNCTION AREA / 解剖学报

The architecture of the specialized myocardial fibers of the atrioventricular junction area(AVJ) were observed under microscope on serial sections. It was found that the human A-V node extend backward divergently to form two posterior extensions (left and right, LPE, RPE). The A-V node can be divided into a superficial layer and a deep layer, and the deep layer further divided into a upper part and a lower part. The fibers in the superficial layer are vertical, and join with the lower part of the deep layer at the anterior extremity of the node. The lower part of the deep layer is the main axis of the node. The fibers in the lower part of the deep layer are longitudinal, and join with the RPE at the posterior extremity of the node. The fibers in the upper part of the deep layer are oblique and join with the LPE at the posterior extremity of the node, and mix with the lower part at the anterior extremity. The longitudinal dissociation of the anterior part of the His bundle is more distinct than that of the posterior part. The lower-left part of the bifurcating part of the bundle extend to form the posterior left branch, the upper-left and upper-middle parts of the bifurcating part extend to form the anterior left branch, and the right part and lower-middle part of the bifurcating part extend to form the right bundle branch. The morphological evidence of the dual or multiple conducting pathways, the longitudinal dissociation and the reentry pathways in the AVJ were discussed.