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Pacing-induced cardiomyopathy (PICM) consists of heart failure (HF) associated with a drop in the left ventricular ejection fraction (LVEF) in the setting of high-burden right ventricular pacing, with presentation that may range from subclinical to severe. Time to manifestation can go from weeks to years after device implantation. Treatment typically consists in an upgrade to a cardiac resynchronisation therapy (CRT) or His bundle pacing (HisP). Several risk factors for PICM have been described and should be considered before pacemaker (PM) implantation, as thorough patient selection for de novo CRT or HisP, may preclude its manifestation. We present the case of an 82-year-old patient presenting with acute congestive HF and new severely reduced LVEF, 30 days following dual chamber PM implantation for high-grade atrioventricular block. Treatment with HF medication and upgrade to a CRT permitted rapid resolution of the symptoms and normalisation of the LVEF at 1-month follow-up.

A 64-year-old man with diabetes mellitus was diagnosed with a non-ST-segment elevation myocardial infarction and was treated with stent implantation. Four days later, he developed an electrical storm (ES) that persisted despite antiarrhythmic drugs and sedation. External defibrillation was performed more than 100 times over 2 hours. After ruling out the common causes of polymorphic ventricular tachycardia, an ES was considered because of brady-dependent R-on-T phenomenon, presumably precipitated by antiarrhythmic drugs. Temporary transvenous atrial overdrive pacing allowed complete suppression of premature ventricular complexes and ventricular fibrillation.

A 72-year-old man presented for routine dual chamber pacemaker interrogation 13 years following insertion for sick sinus syndrome. Increased noise, impedance and threshold of the right ventricular (RV) lead were identified. RV capture was maintained with an overall RV pacing burden of 47%. A routine generator replacement was scheduled alongside RV lead replacement. Fluoroscopy at the start of the procedure revealed an unexpected striking fracture of the RV pacing lead with complete separation of the proximal and distal portions within the RV. The patient was asymptomatic and described no predisposing factors. He underwent implantation of a new ventricular lead and generator and has remained well. This case demonstrates clear RV lead fracture as a late complication of pacemaker implantation despite maintained capture. This emphasises the need for a chest X-ray when a change in device parameters is noted at device interrogation even in the absence of symptoms.

An 88-year-old woman presented to our hospital due to an 18-hour history of worsening central chest pain. She had a dual-chamber pacemaker due to second-degree Mobitz type II atrioventricular block implanted 10 years ago. Her risk factors included hypertension and hypercholesterolaemia. Her

Objective The leadless cardiac pacemaker is typically implanted percutaneously and has been widely used for patients who have already undergone valve surgery. We sought to determine the feasibility and safety of implanting the leadless pacemaker under direct visualization during valve surgery. Methods We performed a retrospective analysis of consecutive adult patients (n = 15) who underwent implantation of a leadless pacemaker under direct visualization at the time of valve surgery. Indications for single-chamber pacing were sick sinus syndrome with pauses (53.3%), atrial fibrillation with slow ventricular rates (13.3%) or complete heart block (6.6%), and elevated risk for postoperative heart block (26.6%). Leadless pacemaker performance and pacing percentage were assessed. Results Patients' age was 67.5 ± 17 years, 6 patients (40%) were male, and 14 patients (93%) had atrial fibrillation. Isolated tricuspid valve replacement was performed in 5 patients (33.3%), and the remainder underwent multivalve surgery that included concomitant tricuspid valve repair/replacement. In 93% of the patients (n = 14), the immediate post–cardiopulmonary bypass pacing thresholds were normal (≤2.0 V at 0.24 ms) and normalized in the remaining patient by the next morning. The impedance/sensing values were normal and stable through follow-up (151 ± 119 days) in all patients. Reliable leadless pacemaker performance allowed for deferral of temporary epicardial wires in 11 patients (73%). There were no procedural complications or device malfunction. Conclusions Leadless cardiac pacemaker implantation during valve surgery is feasible and safe. This hybrid approach to pacing may simplify the perioperative management of patients undergoing valve surgery who have an indication for single-chamber pacing.

Objectives: To study the safety and feasibility of a restrictive temporary-RV-pacemaker use and to evaluate the need for temporary pacemaker insertion for failed left ventricular (LV) pacing ability (no ventricular capture) or occurrence of high-degree AV-blocks mandating continuous pacing. Background: Ventricular pacing remains an essential part of contemporary transcatheter aortic valve implantation (TAVI). A temporary-right-ventricle (RV)-pacemaker lead is the standard approach for transient pacing during TAVI but requires central venous access. Methods: An observational registry including 672 patients who underwent TAVI between June 2018 and December 2020. Patients received pacing on the wire when necessary, unless there was a high-anticipated risk for conduction disturbances post-TAVI, based on the baseline-ECG. The follow-up period was 30 days. Results: A temporary-RV-pacemaker lead (RVP-cohort) was inserted in 45 patients, pacing on the wire (LVP-cohort) in 488 patients, and no pacing (NoP-cohort) in 139 patients. A bailout temporary pacemaker was implanted in 14 patients (10.1%) in the NoP-cohort and in 24 patients (4.9%) in the LVP-cohort. One patient in the LVP-cohort needed an RV-pacemaker for incomplete ventricular capture. Procedure time was significantly longer in the RVP-cohort (68 min [IQR 52–88.] vs. 55 min [IQR 44–72] in NoP-cohort and 55 min [IQR 43–71] in the LVP-cohort [p < 0.005]). Procedural high-degree AV-block occurred most often in the RVP-cohort (45% vs. 14% in the LVP and 16% in the NoP-cohort [p ≤ 0.001]). Need for new PPI occurred in 47% in the RVP-cohort, versus 20% in the NoP-cohort and 11% in the LVP-cohort (p ≤ 0.001). Conclusion: A restricted RV-pacemaker strategy is safe and shortens procedure time. The majority of TAVI-procedures do not require a temporary-RV-pacemaker.

INTRODUCTION During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics confirms LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. METHODS Thirty patients (mean age 76 ± 14 years) were implanted with a stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (comparison-group) conventional implantation with interrupted unipolar pacing was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (uninterrupted-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were evaluated. RESULTS In the comparison-group, LS and CP-pacing impedances were highly correlated (R2 =0.95, p

BACKGROUND Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. OBJECTIVE To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. METHODS Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately one year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold

BACKGROUND The Singapore Cardiac Databank was designed to monitor the performance and outcomes of catheter ablation. We investigated the outcomes of paroxysmal supraventricular tachycardia (PSVT)-ablation in a prospective, nationwide, cohort study. METHODS Atrioventricular nodal re-entrant tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT) or atrial tachycardia (AT)-ablations in Singapore from 2010 to 2018 were studied. Outcomes include acute success, periprocedural-complications, post-operative pacing requirement, arrhythmic recurrence and one-year all-cause mortality. RESULTS Among 2,260 patients (mean age 45±18years, 50% female, 57% AVNRT, 37% AVRT, 6% AT), overall acute success rates of PSVT-ablation was 98.4% and increased in order of AT, AVRT and AVNRT (p

Introduction and objectives This report describes the cardiac pacing activity performed in Spain in 2020, including the number and type of implanted devices, demographic and clinical factors, and data on remote monitoring. Methods Information consisted of the European Pacemaker Patient Card, data submitted to the cardiodispositivos.es online platform, the databases of participating centers, and supplier-reported data. Results A total of 14 662 procedures were registered from 102 hospitals, representing 39.2% of the estimated activity. The implantation rates of conventional and low-energy resynchronization pacemakers were 759 and 31 units per million population, respectively. In all, 520 leadless pacemakers were implanted, 70 with atrioventricular synchrony. The mean age at implantation was high (78.8 years), and the most frequent electrocardiographic change was atrioventricular block. There was a predominance of dual-chamber pacing mode but VVI/R single-chamber pacing was used in 19% of patients in sinus rhythm, depending on age and sex. Remote monitoring capability was present in 18.5% of implanted conventional pacemakers and 45.6% of low-energy resynchronization pacemakers, although registration in this system increased by 53% in 2020. Conclusions In 2020, in the context of the SARS-CoV-2 pandemic, the number of implanted conventional pacemakers decreased by 8% and cardiac resynchronization therapy by 4.6%. The number of leadless pacemakers increased by 16.5%. Sequential pacing was predominant, influenced by age and sex. Home monitoring played a fundamental role as a mode of follow-up in this SARS-CoV-2 pandemic year.

Little is known about the utility of transcatheter aortic valve implantation (TAVI) in patients with cirrhosis of the liver, and their outcomes have not been studied extensively in literature. We performed a retrospective analysis of patients with severe symptomatic aortic stenosis (AS) who underwent transfemoral TAVI with a SAPIEN 3 valve at our institution between April 2015 and December 2018. We identified 32 consecutive patients with evidence of cirrhosis of the liver on imaging (including ultrasound and/or computed tomography) and patients with severe symptomatic AS who underwent transfemoral TAVI with a SAPIEN 3 valve. Among 1,028 patients, 32 had cirrhosis of the liver and 996 constituted the control group without cirrhosis. Mean age in the cirrhosis group was 74.5 years compared with 81.2 years in the control group. Baseline variables were comparable between the groups. Compared with the noncirrhotic group, patients with cirrhosis had a similar 1-year mortality (12% vs 12%, p = 1), a lower 30-day new pacemaker after TAVI rate (6% vs 9%, p = 0.85), a higher 30-day and 1-year readmission rate for heart failure (11% vs 1% and 12% vs 5%, p = 0.12, respectively), and a similar 1-year major adverse cardiac and cerebrovascular event rate (15% vs 14%, p = 0.98). In conclusion, patients with severe AS with concomitant liver cirrhosis who underwent TAVI demonstrated comparable outcomes to their noncirrhotic counterparts.

Right ventricular (RV) pacing-induced cardiomyopathy (PICM) is typically defined as left ventricular systolic dysfunction resulting from electrical and mechanical dyssynchrony caused by RV pacing. RV PICM is common, occurring in 10-20% of individuals exposed to frequent RV pacing. Multiple risk factors for PICM have been identified, including male sex, wider native and paced QRS durations, and higher RV pacing percentage, but the ability to predict which individuals will develop PICM remains modest. Biventricular and conduction system pacing, which better preserve electrical and mechanical synchrony, typically prevent the development of PICM and reverse left ventricular systolic dysfunction after PICM has occurred.

A 43-year-old man with bihemispheric periventricular nodular heterotopia had medically intractable multifocal epilepsy and seizure-related falls. Video-EEG recorded a seizure with ictal asystole, EEG attenuation, and loss of postural tone, reflective of cerebral hypoperfusion (figure 1). After pacemaker implantation, EEG recorded a seizure with ictal cardiac pacing, without EEG attenuation (figure 2). His falls resolved. Antiseizure medications and epilepsy surgery can control seizures and ictal asystole.1 For individuals with intractable epilepsy and ictal asystole who are poor surgical candidates, pacemaker implantation is indicated to prevent injury and any potential contribution of ictal asystole in sudden unexpected death in epilepsy.1,2

OBJECTIVE: Although His bundle pacing (HBP) has shown an improved therapeutic effect than conventional pacing in terms of reducing cardiovascular mortality, the basic characteristics of HBP has not been defined systematically. Therefore, a systematical review and meta-analysis on the HBP characteristics can be timely and favorable. In this study, we aimed to clarify the electrocardiogram and echocardiographic characteristics of the pre- and post-operation of HBP. METHODS: Patients with HBP were exclusively included in this study. By evaluating their electrocardiogram characteristics, echocardiographic parameters, and cardiac function, the therapeutic effect of HBP was assessed. RESULTS: A total of 23 studies were included in the analysis. The overall implant success rate for HBP was 83.64%. After HBP treatment, the paced QRS duration dropped from 147.73±19.46 ms to 116.84±17.32 ms (p

Aims This study aims to determine procedural characteristics, acute success rates, and medium-term outcomes of consecutive patients undergoing His bundle pacing (HBP); and learning curves of experienced electrophysiologists adopting HBP. Methods and results Consecutive HBP patients at three hospitals were recruited. Clinical characteristics, acute procedural details, and medium-term outcomes were extracted from electronic medical records. Two hundred and thirty-three patients [mean age 74.6 ± 10.1 years, 48% female, 68% narrow QRS, 71% normal left ventricular ejection fraction (LVEF), 55.8% atrioventricular block] underwent HBP. Acute procedural success was 81.1% (mean procedural and fluoroscopic times of 105.5 ± 36.5 and 13.8 ± 9.3 min). Broad QRS was associated with lower HBP success (odds ratio 0.39, P = 0.02). Fluoroscopic and procedural times decreased and plateaued after 30–40 cases per operator. Implant HBP threshold was 1.3 ± 0.7 V at 1.0 ± 0.2 ms and R wave was 5.0 ± 3.9 mV. During follow-up, loss of HBP occurred in a further 12.4% and 11.3% of patients experienced a ≥1 V increase in HBP threshold. Five (2.6%) patients required HBP revision for pacing difficulties. About 8.6% of patients had a >50% decrease in R wave but lead revision for sensing issues was not necessary. On an intention to treat basis, 56.7% of patients in whom HBP was attempted had persisting HBP capture and thresholds of Conclusion Physicians adopting HBP should be cognizant of the learning curve and preferentially select non-dependent patients with normal QRS and LVEF, to minimize risk of lead revision. Further rises in HBP threshold may increase battery drain and need for reoperations, important considerations when choosing HBP for cardiac resynchronization therapy.

Vasovagal syncope (VVS) (or neurocardiogenic syncope) is a common clinical condition that is challenging to both physicians and patients alike. Severe episodes of recurrent syncope can result in physical injury as well as psychological distress. This article provides a brief overview of current management strategies and a detailed overview of therapeutic modalities such as closed loop stimulation (CLS) and cardioneuroablation (CNA).

Left bundle branch pacing (LBBP) is a novel near-physiological pacing method that still lacks quantitative criteria to guide the selection of lead-implanted sites to enhance the success likelihood of lead deployments. This study aimed to quantitatively analyze the relationships of LBBP success likelihood to the distribution of lead-implanted sites and the lead-localization-pacing electrocardiographic (ECG) features. All the lead-implanted sites in patients with finally successful LBBP were enrolled for analysis, including successful and failed sites. A novel coordinate system was invented to describe the sites’ distribution as longitudinal distance (longit-dist) and lateral distance (lat-dist). Corrected distance parameters were generated to eliminate the cardiac dimension variations. The lead-localization-pacing ECG parameters were also collected, such as paced QRS duration (locat-QRSd), left ventricular activation time (locat-LVAT), LVAT/QRSd ratio (locat-LVAT/QRSd), and QRS directions. A total of 94 patients with 105 successful sites and 93 failed sites were enrolled. Longit-dist and corrected longit-dist of successful sites were significantly longer, while locat-QRSd and locat-LVAT were shorter and locat-LVAT/QRSd was lower than failed sites. There was a positive dose–response relationship between LBBP success likelihood and corrected longit-dist with a cut-off of 26.95 mm, whereas there were negative dose–response relationships of LBBP success likelihood to locat-QRSd, locat-LVAT, and locat-LVAT/QRSd with the cut-offs of 142 ms, 92 ms, and 64.7%, respectively. Downward QRS direction in II/III ECG leads was also associated with successful LBBP. Longit-dist, locat-QRSd, locat-LVAT, and locat-LVAT/QRSd were quantitative parameters to guide the selection of lead-implanted sites during LBBP implantation. Quantitative distance and electrocardiographic parameters for lead-implanted site selection to enhance the success likelihood of left bundle branch pacing. LBBP, left bundle branch pacing; Longit-dist, longitudinal distance; CL-apex-dist, distance from contraction line to apex; LBBB, left bundle branch block; IVCD, intraventricular conduction delay; Locat-QRSd, lead-localization-pacing QRS duration; Locat-LVAT, lead-localization-pacing left ventricular activation time; Locat-LVAT/QRSd, lead-localization-pacing LVAT/QRSd ratio.

In certain cardiac conduction system pathologies, like bundle branch block, block may be proximal, allowing for electrical stimulation of the more distal His bundle to most effectively restore activation. While selective stimulation of the His bundle is sought, surrounding myocardium may also be excited, resulting in nonselective pacing. The myocardium and His bundle have distinct capture thresholds, but the factors affecting whether His bundle pacing is selective or nonselective remain unelucidated. Objective: We investigated the properties which affect the capture thresholds in order to improve selective pacing. Methods: We performed biophysically detailed, computer simulations of a His fibre running through a septal wedge preparation to compute capture thresholds under various configurations of electrode polarity and orientation. Results: The myocardial capture threshold was close to that of the His bundle. The His fibre needed to intersect with the electrode tip to favor its activation. Inserting the electrode fully within the septum increased the myocardial capture threshold. Reversing polarity, to rely on anode break excitation, also increased the ease of selective pacing. Conclusion: Model results were consistent with clinical observations. For selective pacing, the tip needs to be in contact with the His fibre and anodal stimulation is preferable. Significance: This study provides insight into helping establish electrode and stimulation parameters for selective His bundle pacing in patients.

Learning objectives The aim of cardiac resynchronisation therapy (CRT) is to improve cardiac function by delivering more physiological cardiac activation to patients with conduction system disease. The most widely investigated method for delivering CRT is biventricular pacing (BiV-CRT). Multiple randomised control trials (RCTs) have found BiV-CRT improves outcomes when it is delivered to patients with heart failure, reduced ejection fraction (EF) and prolonged QRS duration.1–3 The majority of patients included in RCTs assessing BiV-CRT had left bundle branch block (LBBB), were in sinus rhythm, New York Heart Assocation (NYHA) class II or greater and had an EF ≤35%. BiV-CRT is also used as an alternative to right ventricular (RV) pacing in patients who have ventricular impairment and require a high percentage of ventricular pacing.4 Understanding the mechanism through which BiV-CRT delivers its beneficial effects is useful when considering patient selection. ### Improving ventricular electrical dyssynchrony When a patient develops LBBB, this prolongs left ventricular (LV) activation time and produces a non-physiological LV activation pattern. These changes result in less efficient contraction and reduced cardiac output.5 BiV pacing aims to deliver more effective ventricular activation by pacing the left and right ventricles. Ventricular activation occurs via cell-to-cell conduction with activation wavefronts originating from the two pacing sites. The activation time during BiV pacing is typically longer than occurs during activation via the intact conduction system and is relatively constant regardless of intrinsic activation.6 The potential for BiV pacing to deliver improvements in ventricular activation time is dependent on the presenting (intrinsic) conduction delay. A …

Studies have shown that a permanent left bundle branch pacing (LBBP) is feasible and may be clinically beneficial. The paced QRS morphology in a permanent LBBP typically manifests as a right bundle branch block pattern (RBBB) because the left ventricle is activated earlier than the right ventricle. We present one such case in which a small change in the pacing rate strongly influenced the LBBP QRS morphology. A 71-year-old man diagnosed with sick sinus syndrome had a dual-chamber pacemaker (LBBP) implanted. During the transition from non-selective LBBP to selective LBBP, a shrinking R' wave of the rsR' in V1 was observed. We also observed that the amplitude of the R' wave in lead V1 increased as the pacing rate increased and finally manifested as a complete RBBB. Thus, we demonstrated the impact of retrograde impulse conduction from this pacing site on the QRS complex.

Background Transvenous permanent pacemaker (PPM) implantation is an available option for Fontan patients with sinus node dysfunction. However, the thrombogenic potential of leads within the Fontan baffle is unknown. Objective The purpose of this study was to compare the clot burden in Fontan patients with a transvenous atrial PPM to those without a PPM and those with an epicardial PPM. Methods This was a retrospective cohort study of all transvenous PPM implantations in Fontan patients followed at our institution (2000–2018). We performed frequency matching on Fontan type and age group. Primary outcome was identification of intracardiac clot, pulmonary embolus, or embolic stroke. Results Of 1920 Fontan patients, 58 patients (median age 23 years; interquartile range [25th–75th percentiles] 14–33) at the time of transvenous PPM implantation and 174 matched subjects formed our cohort. The type of Fontan performed in case subjects was right atrium–pulmonary artery or right atrium–right ventricle conduit (54%), lateral tunnel (43%), and extracardiac (3%). The cumulative incidence of clot was highest in patients with transvenous PPM, followed by patients with epicardial PPM and no PPM (1.2 vs 0.87 vs 0.67 per 100 person-years of follow-up, respectively). In multivariable analysis, anticoagulation and/or antiplatelet therapy were protective against clot and resulted in reduction of clot risk by 3-fold (incidence rate ratio 0.33; 95% confidence interval 0.21–0.53; P Conclusion In a large cohort of Fontan patients matched for age and Fontan type, patients with transvenous PPM had a higher but not statistically significant incidence of clot compared to those with no PPM and epicardial PPM. Patients treated with warfarin/aspirin had lower clot risk.

INTRODUCTION His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have emerged as attractive alternatives to traditional biventricular pacing to achieve cardiac resynchronization therapy. Early reported results have been inconsistent, particularly amongst patients in whom initial placement with traditional approaches has been unsuccessful or those with complex anatomy or congenital abnormalities. In this report, we describe the use of three-dimensional electroanatomic mapping (EAM) in five selected cases. METHODS Five patients from multiple clinical sites underwent EAM-guided HBP or LBBAP by highly trained electrophysiologists with significant experience with conduction system pacing. Each patient in this series underwent EAM-guided conduction system pacing due to complex anatomy and/or prior failed lead implantation. RESULTS EAM-guided lead implantation was successful in all five cases. Capture thresholds were relatively low and patients continued to have evidence of successful lead implantation with minimum 1-month follow-up. The fluoroscopy time varied, likely owing to the variable complexity of the cases. CONCLUSIONS The use of EAM, in combination with traditional intracardiac electrograms with or without fluoroscopy, allows more targeted and precise placement of leads for HBP and LBBAP pacing. Further investigation is needed to determine this strategy's long-term performance and to optimize patient selection.

Background His-Purkinje conduction system pacing (HPCSP) has emerged as an effective alternative to overcome the limitations of right ventricular pacing (RVP) via physiological left ventricular activation, but there remains a paucity of comparative information for His bundle pacing (HBP) and left bundle branch pacing (LBBP). Methods A Bayesian random-effects network analysis was conducted to compare the relative effects of HBP, LBBP, and RVP in patients with bradycardia and conduction disorders. PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from database inception until 21 September 2021. Results Twenty-eight studies involving 4,160 patients were included in this meta-analysis. LBBP significantly improved success rate, pacing threshold, pacing impedance, and R-wave amplitude compared with HBP. LBBP also demonstrated a non-significant trend towards superior outcomes of lead complications, heart failure hospitalization, atrial fibrillation, and all-cause death. However, HBP was associated with significantly shorter paced QRS duration relative to LBBP. Despite higher success rate, shorter procedure/fluoroscopy duration, and fewer lead complications, patients receiving RVP were more likely to experience reduced left ventricular ejection fraction, longer paced QRS duration, and higher rates of heart failure hospitalization than those receiving HPCSP. No statistical differences were observed in the remaining outcome measures. Conclusions This network meta-analysis demonstrates the efficacy and safety of HPCSP for the treatment of bradycardia and conduction disorders, with differences in pacing parameters, electrophysiology characteristics, and clinical outcomes between HBP and LBBP. Larger-scale, long-term comparative studies are warranted for further verification. This article is protected by copyright. All rights reserved.

Cardiac amyloidosis (CA) is an increasingly recognized cause of heart failure, characterized by extracellular deposition of insoluble protein fibrils leading to progressive myocardial dysfunction. The most common types of cardiac amyloidosis are immunoglobin light-chain (AL) and transthyretin (ATTR). Conduction abnormalities are commonly encountered among patients with cardiac amyloidosis and are an important cause of morbidity and mortality. Abnormalities range from infra-Hisian intraventricular conduction delay and bundle branch block to complete atrioventricular block. Pacemaker placement in CA patients follows established guidelines, similar to those for patients without CA, with generally good efficacy. The role and appropriate timing of pacemakers for primary prevention of brady-arrhythmias in CA remains uncertain. While biventricular (BiV) pacing has been shown to improve clinical outcomes in patients with systolic heart failure without CA, there are few data examining the utility of BiV pacing in patients with CA. With the advent of effective treatments for AL and ATTR, appropriate application of pacing is important to support patients with CA and conduction disease through therapeutic trials. This systematic review summarizes the current literature examining the utility of pacing in CA. This article is protected by copyright. All rights reserved.

Permanent pacemaker (PPM) implantation is required in 5% to 10% of patients following transcatheter aortic valve implantation (TAVI). However, there are limited data on the impact of PPM implantation on the incidence of pericardial effusion, cardiac tamponade, and outcomes after TAVI. We identified all hospitalizations in patients ≥18 years of age who underwent TAVI in the years 2016 to 2017 in the Nationwide Readmission Database. The endpoints of the study were pericardial effusion, cardiac tamponade, and percutaneous or surgical drainage of the pericardial cavity in patients that required PPM implantation after TAVI. Multivariable logistic regression determined associations of PPM implantation, pericardial effusion, and tamponade with patient outcomes. A total of 54,317 unweighted hospitalizations for TAVI were identified, of which 5,639 (10.4%) required PPM. The risk of pericardial effusion was significantly greater in patients who required PPM (2.4% vs 1.6%, adjusted odds ratio (aOR) 1.39 (1.15 to 1.70), p

Introducao A pandemia da COVID-19 mudou o panorama da pratica cirurgica das diversas especialidades medicas no mundo inteiro. – Mudancas nas rotinas dos servicos de estimulacao cardiaca artificial foram apoiadas pelas sociedades medicas da especialidade, que estabeleceram recomendacoes para a definicao da gravidade dos casos e da urgencia dos procedimentos cirurgicos. , O objetivo do presente estudo foi avaliar o impacto das medidas implementadas para enfrentamento da pandemia nos procedimentos cirurgicos realizados na area da estimulacao cardiaca artificial, pela comparacao [...]

INTRODUCTION We tested our hypothesis that atrial entrainment pacing (EP) of a) the common-type (com-) fast-slow (F/S-) atypical atrioventricular nodal reentrant tachycardia (AVNRT) using a typical slow pathway (SP), or b) the superior-type (sup-) F/S-AVNRT using a superior SP, both modify the retrograde conduction time across the SP immediately after termination of EP (retro-SP-time). METHODS We measured the difference in the His-atrial interval (HA difference) immediately after cessation of EP, performed at 2 ± 2 rates from the high right atrium (HA[1]-HRA) versus from the proximal coronary sinus (HA[1]-CS) in 17 patients with com-F/S-AVNRT and 11 patients with sup-F/S-AVNRT. We also measured the atrial-His and HA intervals of the first and second cycles immediately after cessation of EP and during stable tachycardia. RESULTS Unequal responses, defined as a ≥ 20-ms HA difference at ≥1 EP rates, were observed in 16 patients (57%), including 7 with com- and 9 with sup-F/S-AVNRT. Irrespective of the EP rate, all unequal responses of com-F/S-AVNRT were due to a shorter HA[1]-CS than HA[1]-HRA, with a mean 34 ± 11 ms HA difference, whereas all unequal responses of sup-F/S-AVNRT were due to a longer HA[1]-CS than HA[1]-HRA, with a mean 49 ± 25 ms HA difference. The unequal responses resolved within two cycles after the cessation of EP. CONCLUSIONS We have identified a little-known pacing site- and pacing rate-dependent shortening of the retro-SP-time.

Background Permanent His-bundle pacing (HBP) is effective and safe; however, the success rate of HBP is low, especially in patients with infranodal block. This study aimed to assess the efficacy and feasibility of HBP implantation using an electrophysiological guided approach targeting a distal His-bundle electrogram (HBE) in patients with atrioventricular block (AVB). Methods Thirty-four consecutive patients with AVB (infranodal block in 28 patients) who underwent HBP were enrolled. During implantation, we attempted to target the distal part of the HBE (distal HBE) beyond the block site based on unipolar mapping. The His-capture threshold was evaluated for 1 year after implantation. Results HBP was achieved in 26 patients and in 21 patients (75%) with infranodal block. Detection of distal HBE was significantly higher in the successful HBP group than in the HBP failure group (65.4% vs. 0%, p = 0.001). Among 15 patients with intra-Hisian block, 14 patients (93%) successfully achieved HBP with distal HBE detection. During the 1-year follow-up period, an increase in His-capture threshold by ≥1.0 V at 1.0 ms occurred in 5 (19.2%) of 26 patients. The increased His-capture threshold group exhibited significantly less detection of distal HBE (20% vs. 76.2%; odds ratio 0.078, 95% confidence interval 0.07-0.87, p = 0.038) and a higher His-capture threshold at implantation (2.0±1.1 V vs. 1.1±0.9 V; odds ratio 1.702, 95% confidence interval 1.025-2.825, p = 0.04) than the non-increased His-capture threshold group. Conclusion HBP implantation guided by distal HBE approach may be feasible with subsequent stable pacing in patients with intra-Hisian and atrioventricular nodal block. This article is protected by copyright. All rights reserved.

Objective: Knowledge of factors causing pacing-induced cardiomyopathy (PICM) is incomplete. We sought to estimate the incidence and predisposing factors for PICM and evaluate if the risk they portend adds up. Methods: Single centre retrospective study where consecutive patients with preserved LVEF undergoing pacemaker (PM) implantation between 2012 and 2018 were analysed. Results: A total of 749 patients (68.4 % male; mean age 59.2 ± 14.08 years) were included in the analysis. PICM developed in 74 (9.9%) patients over a median follow up of 2.2 years (IQR 1.1–3.2). Pre-implant LVEF, paced QRS duration and RV pacing burden were independent predictors of PICM. Using 90 % specificity cut-off values for LVEF and paced QRS, and the value separating lowest tertile of RV pacing from the higher tertiles, three risk factors were identified: (i) baseline LVEF 160 msec, and (iii) RV pacing burden > 33 %. Patients with two or more risk factors were at the highest risk (OR 11.62, 95 % CI 4.62–29.21, p-value

Background The implantation of rapid-deployment aortic valves may interfere with the conduction system of the heart. This study evaluates the occurrence and predictive factors of conduction anomalies in patients undergoing surgical aortic valve replacement (SAVR) with a rapid-deployment balloon-expandable bioprosthesis in a single-center, real-world experience. Methods Between May 2010 and April 2019, 700 consecutive patients were included in a prospective, ongoing database with a longitudinal follow-up preoperatively, at discharge, and at 3 months, 1 year, 3 years, and 5 years postoperatively. Thirty-seven patients (5.3%) had a permanent pacemaker at baseline and were excluded from further analysis, leaving 663 patients for analysis. Assessment of conduction anomalies was performed by electrocardiography (ECG) monitoring and repeated 12-lead ECG during the hospital stay and at postoperative follow-ups. Results Preoperatively, 126 patients (19.0%) presented with different conduction disturbances. New permanent pacemaker implantation (PPI) occurred in 61 patients during the first 14 days (cumulative incidence, 9.4%). The indication for PPI was complete atrioventricular block in 47 cases (77%). Preoperative conduction anomalies, such as right bundle branch block, as well as operative characteristics (concomitant procedures) were found to be independent predictors for new PPI. One-year survival was 98% in patients with new early PPI and 96% in those without new early PPI (P = .60). Conclusions The PPI rate was in the range of previous reports for rapid-deployment prostheses. PPI did not have a significant influence on short- to intermediate-term survival. Case selection with exclusion of patients presenting with baseline conduction disturbances may decrease the rate of new PPIs after SAVR with rapid-deployment balloon-expandable bioprostheses.

Congenital complete heart block and acquired complete heart block are serious conduction abnormalities that may necessitate permanent pacemaker placement. Small patient size and anatomy preclude transvenous pacemaker insertion and risk subcutaneous generator pocket complications. This report describes a case of placement of a pediatric bipolar epicardial pacemaker through a right axillary incision with an intrapleural polytetrafluoroethylene membrane pocket to facilitate future generator exchange.

INTRODUCTION Pacing-induced cardiomyopathy (PICM) is a potential complication of chronic right ventricular (RV) pacing, but its characterization in adult patients is often complicated by pre-existing cardiomyopathy. This study investigated the incidence of PICM in patients with congenital heart block (cHB) who have conduction disease from birth without confounding pre-existing cardiac conditions. METHODS AND RESULTS This retrospective cohort analysis included 42 patients with cHB and baseline left ventricular ejection fraction (LVEF) ≥50%. Kaplan-Meier analysis was used to assess freedom from cardiomyopathy (defined as LVEF

Left bundle branch pacing (LBBP) is a novel conduction system pacing modality, but pacing lead deployment remains challenging.This study aimed to evaluate the feasibility of visualization-enhanced lead deployment for LBBP implantation and to assess LBBP characteristics on the basis of lead tip location.Successful LBBP with a well-defined lead tip location by visualization of the tricuspid value annulus in 20 patients was retrospectively analyzed to develop an image-guided technique to identify the LBBP target site. This technique was then prospectively tested in 60 patients who were randomized into 2 groups, one using the standard approach (the standard group) and the other using the image-guided technique (the visualization group). The procedural details, electrophysiological characteristics, and short-term follow-up were compared between groups.LBBP was successfully achieved in 28 patients in the standard group and in 29 in the visualization group. The procedural and fluoroscopic durations in the visualization group (66.76 ± 14.62 and 7.83 ± 2.05 minutes) were significantly shorter than those in the standard group (85.46 ± 20.19 and 11.11 ± 3.51 minutes) (P.01). The number of lead deployment attempts in the visualization group was lower than that in the standard group (2.03 ± 1.18 vs 2.96 ± 1.17; P.01), and the proportion of left bundle branch potential recorded was higher (79.3% vs 46.4%; P = .01).Using a visualization technique, the procedural and fluoroscopic durations for LBBP implantation were significantly shortened with fewer lead repositioning attempts.

Background The Sars-Cov-2 infection is a multisystem illness that can affect the cardiovascular system. Tachyarrhythmias have been reported but the prevalence of bradyarrhythmia is unclear. Cases have been described of transient high-degree atrioventricular (AV) block in COVID-19 that were managed conservatively. Method A database of all patients requiring temporary or permanent pacing in 2 linked cardiac centres was used to compare the number of procedures required during the first year of the pandemic compared to the corresponding period a year earlier. The database was cross-referenced with a database of all patients testing positive for Sars-Cov-2 infection in both institutions to identify patients who required temporary or permanent pacing during COVID-19. Results The number of novel pacemaker implants was lower during the COVID-19 pandemic than the same period the previous year (540 vs 629, respectively), with a similar proportion of high-degree AV block (38.3% vs 33.2%, respectively, p = 0.069). Four patients with the Sars-Cov-2 infection had a pacemaker implanted for high-degree AV block, 2 for sinus node dysfunction. Of this cohort of six patients, two succumbed to the COVID-19 illness and one from non-COVID sepsis. Device interrogation demonstrated a sustained pacing requirement in all cases. Conclusion High-degree AV block remained unaltered in prevalence during the COVID-19 pandemic. There was no evidence of transient high-degree AV block in patients with the Sars-Cov-2 infection. Our experience suggests that all clinically significant bradyarrhythmia should be treated by pacing according to usual protocols regardless of the COVID status. This article is protected by copyright. All rights reserved.

OBJECTIVES To evaluate the safety and feasibility of left bundle branch area pacing (LBBAP) in patients with valvular interventions. METHODS Eighty-four patients were included in this study. All patients underwent recent surgical or percutaneous valvular interventions. LBBAP was attempted in all patients. Implant success rates, peri- and postprocedure electrocardiogram, pacing parameters, and complications were assessed at implant, and during follow-up. RESULTS LBBAP implantation was successful in 80/84 (95%) patients. Mean age was 74.1 ± 13.8 years and 56% patients were male. Prior valvular replacements included: percutaneous aortic (26), surgical aortic (36), combined surgical aortic plus mitral (6), MVR (10), tricuspid (1), and pulmonic (1). Average LVEF was 52.6 ± 11%. Majority of patients underwent LBBAP due to atrioventricular block (76%) and sinus node disease (13%). Total procedure duration was 74.1 ± 12.5 min and fluoroscopic duration was 9.7 ± 6.8 min. Pacing parameters were stable during follow-up period of 10.0 ± 6.3 months. Pacing QRS duration was significantly narrower than baseline QRS duration (131.5 ± 31.4 ms vs. 114.3 ± 13.7 ms, p

Background: Inflammation process is an important determinant for subsequent changes in cardiac function and remodeling after acute myocardial infarction (MI). Recent studies have implicated that ALK4 haplodeficiency improves cardiac function after MI. However, it remains unknown if the beneficial effects are partly attributed to ALK4 haplodeficiency-induced modulation on inflammatory response in the inflammatory phase of MI. In this research, we aimed to explore the mechanism of ALK4 haplodeficiency in the inflammatory stage of MI. Methods: ALK4, CD16, and CD14 were detected in peripheral blood mononuclear cells (PBMCs) isolated from MI patients and healthy volunteers. ALK4 haplodeficiency (ALK4+/-) mice and wild-type (WT) littermates were randomly divided into the sham group and the MI group. Inflammation cytokines and chemokines were measured. Echocardiography and intracardiac electrophysiological recordings were performed on the 3rd day and the 7th day after MI operation. ALK4 expression and inflammation cytokines were also detected in LPS- or IL-4-stimulated bone marrow-derived macrophages (BMDM) from the ALK4+/- mice and WT littermates. Results: ALK4 gene expression in circulating monocytes of MI patients was higher than that in those of healthy volunteers. Cardiac inflammation and vulnerability of ventricular arrhythmia after acute myocardial injury are significantly alleviated in ALK4+/- mice as compared to WT littermates. On the 3rd day post-MI, the level of M1 macrophages were decreased in ALK4+/- mice as compared to WT littermates, while the level of M2 macrophages were increased on the 7th day post-MI. BMDM isolated from ALK4+/- mice displayed reduced secretion of pro-inflammation cytokines after stimulation by LPS in hypoxic condition and increased secretion of anti-inflammation cytokines after stimulation by IL-4. As a result, the haplodeficiency of ALK4 might be responsible for reduced inflammation response in the post-MI stage. Conclusions: ALK4 haplodeficiency reduces cardiac inflammation, improves cardiac function, and finally reduces the vulnerability of ventricular arrhythmia in the inflammatory stage after MI.

Parallel connection of an electrophysiology recording system (EP system) to equipment for conduction system pacing (CSP) has been widely used for fine monitoring of intracardiac electrograms and pacing evaluation. We experienced a case showing unexpected pacing threshold exacerbation under specific conditions when the EP system was connected in parallel. We evaluated the underlying mechanism using an ex vivo model. An ex vivo pacing and intracardiac electrogram monitoring model was generated using an oscilloscope, pacing system analyzer (PSA), EP system, and simulated heart. The discrepancy between expected output at the PSA and the actual measured output value at the simulated heart was measured under various conditions and using various combinations of pacing equipment. Parallel connection of the EP system was associated with reduced electrical output from the PSA as recorded at the simulated heart. The unexpected adverse effects were particularly noticeable when using an RMC-5000 EP system with the pacing function on. The trouble is completely resolved by simply turning off the pacing function of the system. There is a possibility that the EP system might increase the pacing threshold in CSP when the PSA and EP system is are deployed in parallel. The issue may provoke pseudo failure of CSP due to the high pacing threshold. When the RMC-5000 is used for conduction system pacing in parallel with a PSA for the pacing test, the pacing function of RMC-5000 should be turned off.

The efficacy and safety of his-purkinje system pacing (HPSP) upgrades in patients with pacing-induced cardiomyopathy (PICM) and atrial fibrillation (AF) are still unknown.Patients with PICM were continuously enrolled from January 2018 to March 2020. All patients were further divided into AF subgroup and sinus rhythm subgroup. Clinical data including echocardiographic examination parameters, electrocardiogram (ECG) measurements, and New York Heart Association (NYHA) classification, were assessed before and after the procedure. The HPSP upgrades, including his bundle pacing (HBP) and left bundle branch pacing (LBBP) were completed in 34 of 36 (94%) patients, Complications including electrode dislodged, perforation, infection or thrombosis were not observed in the perioperative period. During a mean of 11.52 ± 5.40 months of follow-up. The left ventricular ejection fraction (LVEF) increased significantly (33.76 ± 7.54 vs 40.41 ± 9.06, P0.001), and the QRS duration decreased (184.22 ± 23.76 ms vs 120.52 ± 16.67 ms, P0.001) after the upgrades. LVEDD reversed from 59.29 ± 7.74 mm to 53.91 ± 5.92 mm (P0.001), and the NYHA functional class also improved to 2.00 ± 0.76 from 2.55 ± 0.91 at the first follow-up (P0.001). The left atrium (LA) size also slightly decreased compared to the initial state (47.44 ± 7.14 mm VS 45.56 ± 7.78, P = 0.010). BNP significantly decreased from a median value of 458.06(256.35-755.10) to 172.31(92.69-552.14) (P = 0.004). The threshold did not increase significantly (1.18 ± 0.76 mv@0.4 ms vs 1.26 ± 0.91mv @ 0.4 ms, P = 0.581). These improvements in patients with AF were similar with those in patients without AF (P0.05).HPSP upgrades improved the heart performance and reversed the left ventricular remodeling in patients suffering from PICM with or without AF, and it should be a promising choice in these patients.

Introduction Pediatric patients who receive pacemakers may have a lifetime of repeat exposure to fluoroscopy. His bundle pacing may provide better long-term pacing for these patients. To minimize fluoroscopy and for improved localization of the His bundle, we utilized three-dimensional mapping to guide His bundle pacing and we follow-up short-term results. Methods An Octapolar Livewire catheter (Abbott, Minneapolis, USA) was used for mapping and location of the His bundle while 3-dimensional mapping via the EnSite Precision system (Abbott Medical, Abbott Park, IL) was utilized to create a 3-dimensional geometry. The EnSite Precision system also mapped and recorded His bundle signal strengths and earliest ventricular activation or retrograde His bundle activation. Results Three patients are presented and followed for 4–5 months. The ages ranged from 10 to 15 years with 1 male patient. Diagnoses including progressive atrioventricular block, alternating bundle branch block and atrioventricular canal defect with complete heart block. All patients received selective His-bundle pacing systems. The range in fluoroscopy time was 6.4 to 9.9 min with 5.64 mGy to 10.18 mGy. Stable lead thresholds, impedances and sensing were present at last follow-up. Conclusions His bundle pacing in our 3 pediatric patients including one with altered His-bundle physiology (case 3 with atrioventricular canal defect) was successful with good short-term follow-up results.

Background: His bundle pacing (HBP) is a physiological alternative to biventricular (BiV) pacing. We compared short-term results of both pacing approaches in symptomatic atrial fibrillation (AF) patients with moderately reduced left ventricular (LV) ejection fraction (EF ≥35% and

Leadless pacemakers (LLPMs) have become a major breakthrough in the management of bradyarrhythmia as an attractive alternative to the standard transvenous pacemakers (TV-PMs). Recently, the introduction of a second-generation LLPMs (Micra AV-MC1AVR1) has expanded pacing modes to obtain atrioventricular (AV) synchronous pacing, providing an interesting alternative in the actual scenario of leadless pacing. Nevertheless, actual reports have highlighted some concerns regarding those devices. In this review, we sought to provide an overview of this technology based on its approval studies and major reports.

Background The need for new permanent pacemaker implantation (PPI) after Transcatheter Aortic Valve Implantation (TAVI) remains a critical issue. Membranous Septum (MS) length is associated with PPI after TAVI. The aim of this study was to identify different MS thresholds for the contemporary THV-platforms. Methods This retrospective, case-control study enrolled all patients who underwent a successful TAVI procedure with contemporary THV-platforms in the Erasmus University Medical Center between January 2016 and March 2020. The follow-up period for new PPI was 30 days. MS-length was determined by Computed Tomography. Results The study consisted 653 TAVI patients with median age 80.6 years (IQR 74.7–84.8). New PPI occurred in 120 patients (18.4%). Patients with new PPI had a shorter MS-length (2.9 mm (IQR 2.3–4.3) vs. 4.2 mm (IQR 2.9–5.7), p < 0.001). MS-length < 3 mm identified a high-risk phenotype with 30.3% PPI-rate (OR 6.5 [95%CI 2.9–14.9]), MS-length 3–6 mm an intermediate-risk phenotype with 15.4% PPI-rate (OR 2.7 [95%CI 1.2–6.2]) and MS > 6 mm a low-risk phenotype with a 6.3% PPI-rate (reference). For the Lotus valve, there was no significant difference in PPI-rates between the high-risk (45.8%, OR 3.5 [95%CI 0.8–15.1]) and low-risk group (20%). By multivariate analysis MS-length, Agatston-score, use of Lotus valve, and ECG with first-degree AV block, RBBB or bifascular block were independent predictors for new PPI. Conclusion MS-length was an independent predictor for new PPI post-TAVI. Three phenotypes were found based on MS-length. MS < 3 mm was universally associated with a high risk for new PPI (>30%). MS > 6 mm represented a low-risk phenotype with PPI-rate < 10%. PPI-rate varied per THV type in the intermediate phenotype. PPI-rate with Lotus was high regardless of MS-length.

Clinical outcomes of transcatheter aortic valve implantation (TAVI) have significantly improved with the accumulation of operator and institution experience as well as the wide use of newer generation devices. There is limited data on TAVI outcomes compared with surgical aortic valve replacement (SAVR) in contemporary practice in the United States. We queried the 2018 Nationwide Readmission Database of the United States. International Classification Diagnosis code 10 was used to extract TAVI and SAVR admissions. A propensity-matched cohort was created to compare TAVI and SAVR outcomes. A weighted 48,349 TAVI and 24,896 SAVR for aortic stenosis were included and 4.9% of TAVI were performed with an embolic protection device. In propensity-matched cohort (12,708 TAVI and 12,708 SAVR), TAVI conferred lower in-hospital mortality (1.7% vs 3.8%), acute kidney injury (11.3% vs 22.9%), and transfusion rate (5.9% vs. 20.6%) whereas new pacemaker rate was higher in TAVI compared with SAVR (10.5% vs. 7.0%) (all p values0.001). Stroke rate was similar between TAVI and SAVR (1.5% vs. 1.5%) (p value = 0.79). The routine discharge was more frequent (66.9% vs 25.8%) and length of stay was shorter (4.8 vs. 9.8 days) in TAVI than SAVR. Hospitalization cost was higher in SAVR than TAVI (51,962 vs 57,754 U.S. dollars) (all p values0.001). In-hospital mortality was also lower in TAVI compared with isolated SAVR. TAVI was performed more frequently than SAVR in 2018 in the United States with lower in-hospital mortality of TAVI compared with both SAVR and isolated SAVR.

Recent studies have demonstrated that right ventricular pacing (RVP) has deleterious effects on non-synchronized ventricular contraction, while His-bundle pacing (HBP) or left bundle branch area pacing (LBBaP) contribute to improvements in patients’ mid- and long-term outcomes. This meta-analysis aimed to compare the safety and efficacy of physiologic pacing (HBP/LBBaP) versus those of RVP. A systematic search of PubMed, Cochrane Library, and Embase was conducted for studies that compared the effects of physiologic pacing and RVP. All eligible studies were published before January 1, 2021 and were conducted in humans. STATA software version 15.0 was used for all the data analyses. Twenty articles (n = 2787 patients) were included in this meta-analysis. Compared to RVP, physiologic pacing was associated with a significantly shorter QRS duration and better cardiac function. Physiologic pacing was also correlated with lower rates of mitral regurgitation, pacing-induced cardiomyopathy, death, heart failure hospitalization, and atrial fibrillation, although the above results were not statistically significant. In addition, RVP led to the achievement of higher success rates than physiologic pacing, a shorter fluoroscopic time and mean procedure duration, a lower pacing threshold: the results were statistically significant. Compared with HBP, LBBaP appeared to have some advantages in R wave amplitudes, pacing threshold, fluoroscopic time, procedure time, and success rate, with statistically significant differences. Whereas HBP was associated with fewer surgical complications and shorter QRS duration, the results were not statistically significant. Physiologic pacing (HBP/LBBaP) might be a better strategy than RVP and improve long-term clinical outcomes like cardiac function. Although LBBaP appears to have some advantages over HBP, the long-term benefits are still controversial. More large-scale randomized clinical trials are needed for further verification.