The progress of percutaneous left atrial appendage occlusion: A bibliometric analysis from 1994 to 2022.

BACKGROUND: Atrial fibrillation is the most common cardiac arrhythmia, affecting 32 million individuals worldwide. Although atrial fibrillation has been studied for decades, a comprehensive analysis using bibliometrics has not been performed for atrial fibrillation-left atrial appendage occlusion (LAAO). Therefore, we analyzed the scientific outputs of global LAAO research and explored the current research status and hotpots from 1994 to 2022. METHODS: We searched the Web of Science core collection for publications related to LAAO that were published between 1994 and 2022. We then performed bibliometric analysis and visualization using Microsoft Excel 2021, Bibliometric (https://bibliometric.com), VOSviewer (version 1.6.19), CiteSpace (version 6.2. R2), and the Bibliometrix 4.0.0 Package (https://www.bibliometrix.org) based on the R language were used to perform the bibliometric analysis, trend and emerging foci of LAAO in the past 29 years, including author, country, institution, journal distribution, article citations, and keywords. In total, we identified 1285 eligible publications in the field of LAAO, with an increasing trend in the annual number of publications. RESULTS: The United States is the country with the most published articles in this field, while the United Kingdom is the country with the most cited literature. Mayo Clinic, from the United States, has the most publications in this area and Horst Sievert from Germany had the highest number of individual publications. The analysis of keywords showed that fibrillation, stroke, safety, oral anticoagulants, and watchman were the main hotpots and frontier directions of LAAO. Surgical treatment of nonvalvular atrial fibrillation, upgrading of related surgical instruments, and anticoagulation regimen after surgical treatment are the major research frontiers. CONCLUSION: We show that the research of percutaneous LAAO has been increasing rapidly over the last decade. Our aim was to overview past studies in the field of LAAO, to grasp the frame of LAAO research, and identify new perspectives for future research.

POPDC1 Variants Cause Atrioventricular Node Dysfunction and Arrhythmogenic Changes in Cardiac Electrophysiology and Intracellular Calcium Handling in Zebrafish.

Popeye domain-containing (POPDC) proteins selectively bind cAMP and mediate cellular responses to sympathetic nervous system (SNS) stimulation. The first discovered human genetic variant (POPDC1S201F) is associated with atrioventricular (AV) block, which is exacerbated by increased SNS activity. Zebrafish carrying the homologous mutation (popdc1S191F) display a similar phenotype to humans. To investigate the impact of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling, homozygous popdc1S191F and popdc1 knock-out (popdc1KO) zebrafish larvae and adult isolated popdc1S191F hearts were studied by functional fluorescent analysis. It was found that in popdc1S191F and popdc1KO larvae, heart rate (HR), AV delay, action potential (AP) and calcium transient (CaT) upstroke speed, and AP duration were less than in wild-type larvae, whereas CaT duration was greater. SNS stress by ß-adrenergic receptor stimulation with isoproterenol increased HR, lengthened AV delay, slowed AP and CaT upstroke speed, and shortened AP and CaT duration, yet did not result in arrhythmias. In adult popdc1S191F zebrafish hearts, there was a higher incidence of AV block, slower AP upstroke speed, and longer AP duration compared to wild-type hearts, with no differences in CaT. SNS stress increased AV delay and led to further AV block in popdc1S191F hearts while decreasing AP and CaT duration. Overall, we have revealed that arrhythmogenic effects of POPDC1 dysfunction on cardiac electrophysiology and intracellular calcium handling in zebrafish are varied, but already present in early development, and that AV node dysfunction may underlie SNS-induced arrhythmogenesis associated with popdc1 mutation in adults.

Connexin43, A Promising Target to Reduce Cardiac Arrhythmia Burden in Pulmonary Arterial Hypertension.

While essential hypertension (HTN) is very prevalent, pulmonary arterial hypertension (PAH) is very rare in the general population. However, due to progressive heart failure, prognoses and survival rates are much worse in PAH. Patients with PAH are at a higher risk of developing supraventricular arrhythmias and malignant ventricular arrhythmias. The latter underlie sudden cardiac death regardless of the mechanical cardiac dysfunction. Systemic chronic inflammation and oxidative stress are causal factors that increase the risk of the occurrence of cardiac arrhythmias in hypertension. These stressful factors contribute to endothelial dysfunction and arterial pressure overload, resulting in the development of cardiac pro-arrhythmic conditions, including myocardial structural, ion channel and connexin43 (Cx43) channel remodeling and their dysfunction. Myocardial fibrosis appears to be a crucial proarrhythmic substrate linked with myocardial electrical instability due to the downregulation and abnormal topology of electrical coupling protein Cx43. Furthermore, these conditions promote ventricular mechanical dysfunction and heart failure. The treatment algorithm in HTN is superior to PAH, likely due to the paucity of comprehensive pathomechanisms and causal factors for a multitargeted approach in PAH. The intention of this review is to provide information regarding the role of Cx43 in the development of cardiac arrhythmias in hypertensive heart disease. Furthermore, information on the progress of therapy in terms of its cardioprotective and potentially antiarrhythmic effects is included. Specifically, the benefits of sodium glucose co-transporter inhibitors (SGLT2i), as well as sotatercept, pirfenidone, ranolazine, nintedanib, mirabegron and melatonin are discussed. Discovering novel therapeutic and antiarrhythmic strategies may be challenging for further research. Undoubtedly, such research should include protection of the heart from inflammation and oxidative stress, as these are primary pro-arrhythmic factors that jeopardize cardiac Cx43 homeostasis, the integrity of intercalated disk and extracellular matrix, and, thereby, heart function.

Incidence and prognosis of cardiac conduction system diseases in hypertension: the STEP trial.

Patients with cardiac conduction system diseases (CSD) may have increased incidence and mortality of cardiovascular events. Here we report a post hoc analysis of the Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) randomized clinical trial (ClinicalTrials.gov number, NCT03015311) concerning the effect of intensive blood pressure (BP) control on the incidence of new-onset CSD and the prognostic implications of preexisting or new-onset CSD. The incidence of new-onset CSD was similar in the intensive (n = 205, 6.42%) and standard (n = 188, 5.94%) treatment arms. Participants with preexisting CSD had a higher risk for acute decompensated heart failure. Increased age, male sex and increased body mass index were independently associated with increased risk for new-onset CSD. Our results suggest that intensive BP control may not reduce the incidence of new-onset CSD compared with standard BP control.

Extracellular Kir2.1C122Y Mutant Upsets Kir2.1-PIP2 Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome.

BACKGROUND: Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys (cysteine)122-to-Cys154 disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane. We evaluated whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing its open state. METHODS: We identified a Kir2.1 loss-of-function mutation (c.366 A>T; p.Cys122Tyr) in an ATS1 family. To investigate its pathophysiological implications, we generated an AAV9-mediated cardiac-specific mouse model expressing the Kir2.1C122Y variant. We employed a multidisciplinary approach, integrating patch clamping and intracardiac stimulation, molecular biology techniques, molecular dynamics, and bioluminescence resonance energy transfer experiments. RESULTS: Kir2.1C122Y mice recapitulated the ECG features of ATS1 independently of sex, including corrected QT prolongation, conduction defects, and increased arrhythmia susceptibility. Isolated Kir2.1C122Y cardiomyocytes showed significantly reduced inwardly rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking. Molecular dynamics predicted that the C122Y mutation provoked a conformational change over the 2000-ns simulation, characterized by a greater loss of hydrogen bonds between Kir2.1 and phosphatidylinositol 4,5-bisphosphate than wild type (WT). Therefore, the phosphatidylinositol 4,5-bisphosphate-binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch clamping, the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing phosphatidylinositol 4,5-bisphosphate concentrations. In addition, the Kir2.1C122Y mutation resulted in channelosome degradation, demonstrating temporal instability of both Kir2.1 and NaV1.5 proteins. CONCLUSIONS: The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential for the channel function. We demonstrate that breaking disulfide bonds in the extracellular domain disrupts phosphatidylinositol 4,5-bisphosphate-dependent regulation, leading to channel dysfunction and defects in Kir2.1 energetic stability. The mutation also alters functional expression of the NaV1.5 channel and ultimately leads to conduction disturbances and life-threatening arrhythmia characteristic of Andersen-Tawil syndrome type 1.

Spatially Conserved Spiral Wave Activity During Human Atrial Fibrillation.

BACKGROUND: Atrial fibrillation is the most common cardiac arrhythmia in the world and increases the risk for stroke and morbidity. During atrial fibrillation, the electric activation fronts are no longer coherently propagating through the tissue and, instead, show rotational activity, consistent with spiral wave activation, focal activity, collision, or partial versions of these spatial patterns. An unexplained phenomenon is that although simulations of cardiac models abundantly demonstrate spiral waves, clinical recordings often show only intermittent spiral wave activity. METHODS: In silico data were generated using simulations in which spiral waves were continuously created and annihilated and in simulations in which a spiral wave was intermittently trapped at a heterogeneity. Clinically, spatio-temporal activation maps were constructed using 60 s recordings from a 64 electrode catheter within the atrium of N=34 patients (n=24 persistent atrial fibrillation). The location of clockwise and counterclockwise rotating spiral waves was quantified and all intervals during which these spiral waves were present were determined. For each interval, the angle of rotation as a function of time was computed and used to determine whether the spiral wave returned in step or changed phase at the start of each interval. RESULTS: In both simulations, spiral waves did not come back in phase and were out of step." In contrast, spiral waves returned in step in the majority (68%; P=0.05) of patients. Thus, the intermittently observed rotational activity in these patients is due to a temporally and spatially conserved spiral wave and not due to ones that are newly created at the onset of each interval. CONCLUSIONS: Intermittency of spiral wave activity represents conserved spiral wave activity of long, but interrupted duration or transient spiral activity, in the majority of patients. This finding could have important ramifications for identifying clinically important forms of atrial fibrillation and in guiding treatment.

Prognostic benefits of His-Purkinje capture in physiological pacemakers for bradycardia.

INTRODUCTION: Clinical outcomes of long-term ventricular septal pacing (VSP) without His-Purkinje capture remain unknown. This study evaluated the differences in clinical outcomes between conduction system pacing (CSP), VSP, and right ventricular pacing (RVP). METHODS: Consecutive patients with bradycardia indicated for pacing from 2016 to 2022 were prospectively followed for the clinical endpoints of heart failure (HF)-hospitalizations and all-cause mortality at 2 years. VSP was defined as septal pacing due to unsuccessful CSP implant or successful CSP followed by loss of His-Purkinje capture within 90 days. RESULTS: Among 1016 patients (age 73.9 ± 11.2 years, 47% female, 48% atrioventricular block), 612 received RVP, 335 received CSP and 69 received VSP. Paced QRS duration was similar between VSP and RVP, but both significantly longer than CSP (p < .05). HF-hospitalizations occurred in 130 (13%) patients (CSP 7% vs. RVP 16% vs. VSP 13%, p = .001), and all-cause mortality in 143 (14%) patients (CSP 7% vs. RVP 19% vs. VSP 9%, p < .001). The association of pacing modality with clinical events was limited to those with ventricular pacing (Vp) > 20% (pinteraction < .05). Adjusting for clinical risk factors among patients with Vp > 20%, VSP (adjusted hazard ratio [AHR]: 4.74, 95% confidence interval [CI]: 1.57-14.36) and RVP (AHR: 3.08, 95% CI: 1.44-6.60) were associated with increased hazard of HF-hospitalizations, and RVP (2.52, 95% CI: 1.19-5.35) with increased mortality, compared to CSP. Clinical endpoints did not differ between VSP and RVP with Vp > 20%, or amongst groups with Vp < 20%. CONCLUSION: Conduction system capture is associated with improved clinical outcomes. CSP should be preferred over VSP or RVP during pacing for bradycardia.

Risk of cardiac conduction disorders, and pacemaker implantations among individuals tested for serum Borrelia burgdorferi antibodies, a nationwide, matched, population-based cohort study.

OBJECTIVES: To investigate the short- and long-term risks of atrioventricular block and other cardiac conduction disorders associated with being tested for Borrelia burgdorferi (Bb) antibodies or Bb seropositivity as measures of confounding by indication and Bb infection, respectively. METHODS: We performed a nationwide population-based matched cohort study (Denmark, 1993-2021). We included 52 200 Bb-seropositive individuals (stratified as only Bb-IgM-seropositive [n = 26 103], only Bb-IgG-seropositive [n = 18 698], and Bb-IgM-and-IgG-seropositive [n = 7399]) and two age- and sex-matched comparison cohorts: 104 400 Bb-seronegative individuals and 261 000 population controls. We investigated the risk associated with being tested for serum Bb antibodies and being Bb seropositive. Outcomes were atrioventricular block and other conduction disorders. We calculated short-term odds ratios (aOR) (within 1 month), and long-term hazard ratios (aHR) (after 1 month) adjusted for age, sex, diabetes, chronic heart failure, and kidney disease with 95% CI. RESULTS: Compared with population controls, individuals tested for Bb antibodies had increased short- and long-term risks of atrioventricular block (aOR 47.9, 95% CI: 30.0-76.7, aHR 1.3, 95% CI:1.2-1.3), and other conduction disorders (aOR 18.2, 95% CI: 10.1-32.8, aHR 1.2, 95% CI: 1.1-1.4). Compared with Bb-seronegative individuals, only Bb-IgM-and-IgG-seropositive individuals had increased short-term risk of atrioventricular block (aOR: 2.1, 95% CI: 1.5-3.1). DISCUSSION: The results suggest that Bb antibody testing is included in the diagnostic work-up of conduction disorders. Finally, that Bb seropositivity is not associated with other conduction disorders than atrioventricular block or with increased long-term risk of conduction disorders.

Atrioventricular block secondary to transient causes and long-term recurrence after an index event.

BACKGROUND: Atrioventricular block (AVB) secondary to transient causes can recover with its correction. However, studies assessing predictors of recovery and long-term recurrence are lacking. METHODS: Patients with advanced or complete AVB who had a reversible cause admitted in a single expert center were retrospectively studied. Patients with AVB secondary to acute coronary syndromes were excluded from analysis. RESULTS: In a population of 162 patients, the main factors associated with recovery of rhythm without a permanent pacemaker (PPM) implantation were the presence of chronic kidney disease (CKD) on dialysis (OR 7.6; CI 95% 1.2-47.5 (p = .03)); greater serum potassium levels (OR 2.3; CI 95% 1.28-4.0 (p < .01)), higher dosage of bradycardic drugs (OR 2.2; CI 95% 1.13-4.4 (p = .02)), the association between different bradycardic drugs (OR 9.0; CI 95% 2.02-40.3 (p < .01)) and between drug therapy and hyperkaliemia (OR 5.2; CI 95% 1.8-15.1 (p < .01)). There was an overall high burden of conductions abnormalities which did not correlate with recovery of rhythm (OR 0.5; CI 95% 0.19-1.5 (p = .23)). In 29 patients (17.9%) there was a correction of the AVB. During a maximum follow-up of 130 months, 24 patients (82.8%) had a recurrence which warranted a PPM. In the overall cohort only five patients (3%) had sustained recovery of rhythm. CONCLUSIONS: Recovery of AVB was mainly observed with higher doses of drug therapy, higher serum potassium levels or a combination of factors and regardless of baseline conduction abnormalities. The high rate of recurrence during follow-up warrants a close follow-up or PPM implantation at index admission.

Cardiac arrhythmia in COVID-19 patients.

The coronavirus disease 2019 (COVID-19) was first introduced in December 2019, which is known as severe acute respiratory syndrome caused by coronavirus-2 (SARS-CoV-2) that is a serious and life-threatening disease. Although pneumonia is the most common manifestation of COVID-19 and was initially introduced as a respiratory infection, in fact, the infection of COVID-19 is a subset of complications and damage to various organs. There are several reports of cardiac involvement with COVID-19. A wide range of cardiac complications may occur following COVID-19 infection, including systolic heart failure, myocarditis, pericarditis, atrial and ventricular arrhythmias, and thromboembolic events. There are various hypotheses about the pathophysiology of cardiovascular involvement by this virus. At the top of these hypotheses is the release of cytokines to the heart. Although there are other assumptions, considering that one of the causes of death in patients with COVID-19 is arrhythmia. It is necessary to know correctly about its pathophysiology and etiology. Therefore, in this study, we have reviewed the articles of recent years in the field of pathophysiology and etiology of arrhythmia in patients with COVID-19 infection. The purpose of this study was to provide a basis for a correct and more comprehensive understanding of the pathogenesis of arrhythmia in patients with COVID-19 infection.

Conduction system pacing versus biventricular pacing in heart failure with reduced ejection fraction: a systematic review and meta-analysis of randomized controlled trials

Conduction system pacing (CSP) has emerged as a promising alternative to biventricular pacing (BVP) heart failure patients with reduced ejection fraction (HFrEF) and ventricular dyssynchrony, but its benefits are still uncertain. In this study, we aim to evaluate clinical outcomes of CSP versus BVP for cardiac resynchronization in patients with HFrEF. PubMed, Scopus, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing CSP to BVP for resynchronization therapy in patients with HFrEF. Heterogeneity was examined with I2 statistics. A random-effects model was used for all outcomes. We included 7 RCTs with 408 patients, of whom 200 (49%) underwent CSP. Compared to biventricular pacing, CSP resulted in a significantly greater reduction in QRS duration (MD -13.34 ms; 95% CI -24.32 to -2.36, p=0.02; I2=91%) and NYHA functional class (SMD -0.37; 95% CI -0.69 to -0.05;p=0.02; I2=41%), and a significant increase in left ventricular ejection fraction (LVEF) (MD 2.06%; 95% CI 0.16 to 3.97; p=0.03; I2=0%). No statistical difference was noted for LVESV (SMD -0.51 mL; 95% CI -1.26 to 0.24; p=0.18; I2=83%), lead capture threshold (MD -0.08 V; 95% CI -0.42 to 0.27; p=0.66; I2=66%), and procedure time (MD 5.99 min; 95% CI -15.91 to 27.89; p=0.59; I2=79%). These findings suggest that CSP may have electrocardiographic, echocardiographic, and symptomatic benefits over biventricular pacing for patients with HFrEF requiring cardiac resynchronization.

Conduction System Stimulation to Avoid Left Ventricle Dysfunction.

BACKGROUND: Right ventricular apical pacing (RVAP) can produce left ventricle dysfunction. Conduction system pacing (CSP) has been used successfully to reverse left ventricle dysfunction in patients with left bundle branch block. To date, data about CSP prevention of left ventricle dysfunction in patients with preserved left ventricular ejection fraction (LVEF) are scarce and limited mostly to nonrandomized studies. Our aim is to demonstrate that CSP can preserve normal ventricular function compared with RVAP in the setting of a high burden of ventricular pacing. METHODS: Consecutive patients with a high-degree atrioventricular block and preserved or mildly deteriorated LVEF (>40%) were included in this prospective, randomized, parallel, controlled study, comparing conventional RVAP versus CSP. RESULTS: Seventy-five patients were randomized, with no differences between basal characteristics in both groups. The stimulated QRS duration was significantly longer in the RVAP group compared with the CSP group (160.4±18.1 versus 124.2±20.2 ms; p<0.01). Seventy patients were included in the intention-to-treat analyses. LVEF showed a significant decrease in the RVAP group at 6 months compared with the CSP group (mean difference, -5.8% [95% CI, -9.6% to -2%]; P<0.01). Left ventricular end-diastolic diameter showed an increase in the RVAP group compared with the CSP group (mean difference, 3.2 [95% CI, 0.1-6.2] mm; P=0.04). Heart failure-related admissions were higher in the RVAP group (22.6% versus 5.1%; P=0.03). CONCLUSIONS: Conduction system stimulation prevents LVEF deterioration and heart failure-related admissions in patients with normal or mildly deteriorated LVEF requiring a high burden of ventricular pacing. These results are only short term and need to be confirmed by further larger studies. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06026683.

Utilization of and perceived need for simulators in clinical electrophysiology: results from an EHRA physician survey.

AIMS: Simulator training has been recently introduced in electrophysiology (EP) programmes in order to improve catheter manipulation skills without complication risks. The aim of this study is to survey the current use of EP simulators and the perceived need for these tools in clinical training and practice. METHODS AND RESULTS: A 20-item online questionnaire developed by the Scientific Initiatives Committee of the European Heart Rhythm Association (EHRA) in collaboration with EHRA Digital Committee was disseminated through the EHRA Scientific Research Network members, national EP groups, and social media platforms. Seventy-four respondents from 22 countries (73% males; 50% under 40 years old) completed the survey. Despite being perceived as useful among EP professionals (81%), EP simulators are rarely a part of the institutional cardiology training programme (20%) and only 18% of the respondents have an EP simulator at their institution. When available, simulators are mainly used in EP to train transseptal puncture, ablation, and mapping, followed by device implantation (cardiac resynchronization therapy [CRT], leadless, and conduction system pacing [CSP]). Almost all respondents (96%) believe that simulator programmes should be a part of the routine institutional EP training, hopefully developed by EHRA, in order to improve the efficacy and safety of EP procedures and in particular CSP 58%, CRT 42%, leadless pacing 38%, or complex arrhythmia ablations (VT 58%, PVI 45%, and PVC 42%). CONCLUSION: This current EHRA survey identified a perceived need but a lack of institutional simulator programme access for electrophysiologists who could benefit from it in order to speed up the learning curve process and reduce complications of complex EP procedures.

Single operator experience, learning curve, outcomes, and insights gained with conduction system pacing.

BACKGROUND: Conduction system pacing (CSP) is increasingly utilized to prevent and correct dyssynchrony. Barriers to CSP adoption include limited training, methodologic variability, laboratory slot allocation, and few data on learning curves. We report learning curves/clinical outcomes from a single experienced electrophysiologist who was new to CSP, and share gained insights. METHODS: Retrospective analysis of all patients who underwent attempted CSP implantation (2016-2023). Patient characteristics, ECGs, echocardiograms, fluoroscopy/procedure times, lead data were recorded at implant and follow-up. RESULTS: CSP leads were implanted successfully in 167/191(87.4%) patients with a follow-up of 278 ± 378 days. His-bundle pacing (HBP = 59) and left-bundle-area pacing (LBAP = 108) had similar procedure/fluoroscopy times, QRS duration decreases, and ejection fraction improvements (all p > NS). Eight HBP lead revisions were required for high capture thresholds LBAP demonstrated lower pacing thresholds, higher lead impedances, and greater R-wave amplitudes at implant and follow-up. After 25 HBP cases, implant pacing thresholds, fluoroscopy, procedural times did not decrease. After 25 LBAP cases, there were significant decreases in all these parameters (p < 0.05). A separate analysis in LBAP patients with recorded Purkinje signals showed no differences in paced ECG characteristics between patients with pre- QRS Purkinje signals versus patients with Purkinje signals post-QRS onset. CONCLUSIONS: Experienced implanters who are new to CSP can achieve steady-state procedural/fluoroscopy times after a learning curve of 25 implants. LBAP showed lower capture thresholds and higher success rates. Adequate depth of lead deployment (as determined by published parameters) does not require Purkinje potential to be pre-QRS. Operators new to CSP.can forego HBP and directly implement LBAP.

Holt-Oram syndrome.

BACKGROUND: Holt-Oram syndrome (HOS) is a rare genetic illness, which concerns disturbances in the appearance of the upper limbs, congenital heart malformations, and cardiac conduction diseases. HOS usually requires the implantation of a pacemaker, because of cardiac conduction disturbances. CASE REPORT: We present the case of a patient with HOS qualified for pacemaker implantation due to overt bradycardia. To prevent the development of heart failure in the future, the His-bundle pacing technique was used. The implantation was successful. In the control, after one year, the man remains in good condition. The pacing was over 90%, and the left ventricular ejection fraction (LVEF) was stable (60%). CONCLUSIONS: So far, there are no reports on which methods of stimulation are required when it comes to patients with HOS. His-bundle pacing technique is a new type of physiological pacing, which can avoid heart failure.