bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes of ventricular tachycardia substrate ablation facilitated by preprocedural imaging scar characterization. A prospective multicenter registry
Authors: Penela D , Soto-Iglesias D , Fernandez-Armenta J , Vatasescu R , Zucchelli G , Falasconi G , Marti-Almor J , Franco P , Alderete J , Ordonez A , Viveros D , Bellido A , Francia P , Huguet M , Berruezo A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation is a recommended therapy for patients with ventricular tachycardia (VT). However, recurrences rate in non-ischemic cardiomyopathy (NICM) patients remains high.

Objectives

To analyze outcomes of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization in both, patients with ischemic cardiomyopathy (ICM) cand NICM.

Methods

One hundred and sixty-five consecutive patients with structural heart disease undergoing scar related left-side VT ablation were included in a prospective European multicenter (5 centers) registry. Pixel signal intensity (PSI) maps from the late gadolinium enhancement-CMR (LGE-CMR) and/or the multi-detector cardiac tomography (MDCT) were imported into the navigator system. Ablation approach (e.g. endo vs epicardial; left vs right side) was based in the scar distribution aiming to eliminate the entire arrhythmogenic substrate. Mapping and ablation were focused in the scar areas. In all patients Scar dechanneling was the substrate ablation technique used.

Results

165 [153 (93%) men, 66+12 y.o, 117 (71%) with ischemic heart disease] patients were included. Pre-procedure CMR was performed in 65 (39%), MDCT in 12 (7%) and both in 88 (53%) patients. VT induction protocol was negative after substrate ablation in 121 (73%) patients, completing the procedure in stable sinus rhythm. Procedure related complication rate was 5.5%. Arter a mean follow-up of 18+19 months, overall survival was 91% and 44 (27%) patients had VT recurrences. There was no difference in VT-free survival in ischemic vs non-ischemic patients (Log rank:0.9), as Figure 1 shows.

Conclusions

A strategy of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization with the aim of eliminate the entire arrhythmogenic substrate results in a low recurrence rate. This approach minimizes the gap in VT-free survival after ablation in patients with ICM and NICM.
Outcomes of functional substrate mapping of ventricular tachycardia (Func-VT) - an international propensity-matched prospective registry
Authors: Bangash F A , Zhong C , Collinson J , Farwell D , Calvo J , Dungu J , Silberbauer J , Hunter R , Santangeli P , Vlachos K , Srinivasan N
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Dynamic substrate changes play a key role in facilitating conduction delay and re-entry in ventricular tachycardia (VT) circuits. Extrastimuli pacing can unmask functional channels demonstrated by dynamic delay, which may play a role in the VT circuit. We have previously developed sense protocol mapping, using short coupled single extrastimuli to delineate areas of maladaptive conduction delay, which play an essential part in VT development.

Purpose

We conducted a multicentre prospective propensity-matched registry of functional VT substrate mapping (Func-VT registry) compared with conventional mapping. Procedure times, mortality, and probability of ATP/ICD shocks were compared to the matched institutional cohort.

Methods

Data prospectively analysed from an international registry of patients undergoing ablation for Ventricular tachycardia. Data was gathered from multiple sites evaluating outcomes of VT ablation using sense protocol mapping and comparing the results with institutional cohort using conventional methods of entrainment, activation mapping, late potential and pace mapping. The date was propensity-matched to age and left ventricular ejection fraction.

Results

There were 41 patients (mean age of 60 years, 80% males, mean ejection fraction: 35%) in the func-VT registry. The median procedure time was 161 minutes compared with 305 in the institutional cohort (p=<0.001). 85% of patients were free from symptomatic VT/ anti-tachycardia pacing or ICD shocks at a median follow-up of 340 days. Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same period (p=0.03). Figure 1 shows survival curves demonstrating the probability of death in the Funct-VT registry patients vs institutional cohort (p=0.011).

Conclusions

VT functional mapping registry provides real-world data regarding acute and long-term outcomes and complications. It shows better outcomes and improved survival in patients who underwent ablation using sense protocol mapping.
Utility of cardiac magnetic resonance in assessing arrhythmic risk in patients with non ischemic cardiomyopathy undergoing biventricular pacing
Authors: Sayed M , El Maghawry M , Hassan M , Kandil H , El Damaty A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Non-ischemic cardiomyopathy (NICM) is a common heart muscle disorder, which is responsible for approximately one-third of heart failure and is associated with significant morbidity and mortality. Recent data suggested the lack of mortality reduction from adding a defibrillator to cardiac resynchronization therapy (CRT) in all patients with NICM. Myocardial fibrosis detected by cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) can help risk stratify patients who would benefit from adding a defibrillator to CRT in this patient population.

Purpose

We aim at assessing the relationship between the presence of myocardial fibrosis detected by CMR-LGE and the rate of major arrhythmic events (MAE) that included sustained VT, appropriate CRT-D intervention, VF, and SCD in patients with NICM undergoing (CRT) and to compare all-cause mortality and heart failure improvement between patients who receiving CRT-P vs those who receiving CRT-D based on the presence of myocardial fibrosis.

Methods

All consecutive patients with NICM satisfying a guideline directed indication for CRT implantation were included in the study after excluding patients who refused to consent, patients with acute decompensated heart failure and those contraindicated for a CMR. Patients were divided into two groups according to presence of fibrosis in cardiac MRI into (CRT-D/LGE) group and CRT-P/No LGE group and followed along for one year.

Results

Sixty patients were enrolled. Sixteen patients (26.6%) developed MAE during the study duration. Seven patients had myocardial fibrosis (receiving CRT-D as per protocol), while only nine patients had no myocardial fibrosis (receiving CRT-P as per protocol), (41.2% vs 20.9%, P=0.045). Presence of CMR-LGE, regardless the extent and distribution, predicted MAE with odd ratio 2.6 (CI=1.78-8.9, P=0.04). The presence of ≥7.5 % of myocardial fibrosis by CMR was associated with 54 % sensitivity and 100% specificity for MAE in the study population (Figure 1). However, All-cause mortality was significantly higher in the (CRT-P/No LGE) group vs (CRT-D/LGE) group [15 (34.9%) vs 2 (11.8%), P=0.076]. Comparison between both groups regarding symptoms of heart failure, QoL and ejection fraction is shown in Table 1.

Conclusion

In patients with NICM candidates for biventricular pacing, the presence of LGE on CMR, irrespective of the extent or segmental pattern, is independently associated with a major arrhythmic event and is associated with worse heart failure outcome. However, the absence of LGE did not rule out MAE and implanting CRT-P based on lack of fibrosis may result in higher all-cause mortality.
Coronary sinus cannulation as real time anatomical landmark to facilitate left bundle branch area pacing
Authors: Tan K , Ng S , Tan L W , Chia P L , Foo D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Left bundle branch area pacing (LBBAP) is an established form of conduction system pacing. Innovative fluoroscopic imaging technique with use of radio-opaque contrast in the right ventricle or using pre-mapped His potential has been advocated as an acquired road map to assist in implantation of LBBAP(1) lead.

Purpose

We aim to explore a different technique by cannulating the coronary sinus (CS) with a sheath and wire to provide real-time anatomical guidance of location of the base of the heart to facilitate more effective LBBAP in a consistent fashion.

Methods

Prior to LBBAP, the body of the CS is cannulated using an AL2 diagnostic angiographic catheter and a 0.035-inch glidewire. The wire is fixated externally, and fluoroscopic image is acquired before proceeding with deployment of the pacing lead onto an optimal ventricular septal position via standard right (RAO 30) and left anterior oblique (LAO 30) views. From August 2021 to October 2022, we enrolled 12 consecutive patients requiring pacemaker for standard indications and explored the CS cannulation method in delivering LBBAP with either steerable catheters or fixed shape sheaths. Thereafter, we analysed and described the success rates, immediate electrical and device parameters, procedural durations, and clinical events.

Results

12 patients were studied. The mean age was 75 ± 13.07 years and 6 (50%) patients were male. 1 (8.3%) was for sinus nodal dysfunction, 10 (83.3%) for atrioventricular block and 1 (8.3%) for atrial fibrillation (AF) control with atrioventricular node ablation. Mean left ventricular ejection fraction was 54.17 ± 8.21 % and baseline QRS was 108.08 ± 23.20ms. LBBAP was successful in all 12 patients based on published criteria with a mean paced QRS duration of 115.25 ± 9.28 ms. The mean total procedure duration was 130.75 +/- 29.84 minutes and mean fluoroscopic duration was 23.17 ± 9.11 minutes. After 1st week post implant, the pacing threshold, sensing, and impedances were stable and acceptable in all the patients. There were no acute complications (e.g. pneumothorax, lead complications, lead dislodgements / perforations) during the periprocedural period.

Conclusion(s)

The CS cannulation method is a feasible, safe, and effective method to to provide real-time anatomical visualisation of the base of the heart. This facilitates the achievement for optimal LBBAP and can be adopted especially in difficult cardiac anatomies or rotated cardiac silhouettes identified on fluoroscopy.
Acute success, stability and safety of left bundle branch area pacing with steerable catheter and stylet-driven leads: A single center experience
Authors: Ng S , Tan K , Chia P L , Foo D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Right ventricular apical pacing is associated with adverse outcomes and there is an increasing preference to perform conduction system pacing as it allows for more physiological left ventricular activation. His-bundle pacing is known to be technically challenging and results in higher pacing thresholds and increased rates of lead dislodgement. Left bundle branch area pacing (LBBAP) is an emerging alternative form of conduction system pacing.

Purpose

We aim to study the acute success rates, short-term stability and safety using steerable catheter and stylet-driven (SD) leads for the purpose of LBBAP.

Methods

40 consecutive patients who underwent LBBAP with steerable catheter and SD leads in our center from August 2021 to November 2022 were included in this series. Patients’ demographics, pacing indications, baseline QRS morphologies and duration and left ventricular ejection fraction (LVEF) were analysed. Acute success was defined as achieving stimulation to LV activation time (Stim-LVAT) ≤75ms or incomplete right bundle branch paced morphology in V1 [1, 2]. We also reported any left bundle branch (LBB) potential (if present) and the V6-V1 interpeak interval. All lead parameters and complications in the immediate (1 day) and short-term (1 week and 3-6 months) timeframe were evaluated.

Results

40 patients' age (mean 72.75), gender (male 52.5%), body mass index (mean 24.15) and LVEF (mean 52.75%) were analysed. Pacing indications included sinus nodal dysfunction (25%), atrioventricular block (70%), heart failure with failed cardiac resynchronisation therapy (CRT) (2.5%) and atrial fibrillation (AF) requiring atrioventricular node ablation (2.5%). We achieved an acute success rate of 87.5% (5% with left ventricular septal pacing, 5% converted to conventional right ventricular septal pacing, and 2.5% converted to CRT). Reasons for failure to achieve successful LBBAP include persistent left superior vena cava, high pacing thresholds or inability to burrow lead into the septum for acceptable V1 morphology and Stim-LVAT due to resistance encountered during turning of the lead.

51.43% patients of the successful LBBAP patients had LBB potential present and/or interpeak interval >33ms [3]. Immediate and short-term lead parameters were stable and acceptable in all cases. There were no complications (such as lead dislodgement, rise in lead impedance or threshold) reported during the acute and short-term follow-up.

Conclusion

LBBAP is successful in 87.5% of our cases with use of steerable catheter deploying stylet-driven leads and is proven to be a safe and feasible method for conduction system pacing. Incremental experience with the delivery tools will further improve successful implantation. Longer term follow-up of these patients is needed to determine the long-term safety and stability of LBBAP using steerable catheter and stylet-driven leads.
Physiological stimulation in preserved ejection fraction: A randomized trial
Authors: Rodriguez Queralto O , Gonzalez Matos C , Zaraket F , Jimenez Lopez J , Casteigt B , Rodriguez Gonzalez C , Valles Gras E
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Right ventricular stimulation in the apex (RVAS) produce dysynchrony, leading to left ventricle systolic dysfunction (LVSD) in some cases. Circumstances that can worsen the LVSD are a high burden of RVAS, and the presence of previous LVSD and/or intraventricular conduction disease (IVCD). Direct activation of the specialized conduction system with physiological stimulation (PS) can preserve this physiological pattern and shorten de QRS when the impairment is proximal to the pacing site. Most of the studies with PS has been focused on patients with LVSD, with few and scarce evidences regarding pacients without LVSD.

Objectives and methods

This is a parallel, single blinded, unicentric, randomized trial of patients with preserved of mild reduced left ventricular ejection fraction (LVEF) submitted to a pacemaker implantation due to atrioventricular block (AVB), with previous IVCD (wide QRS) an anticipated high rate of ventricular pacing. Patients were randomized 1:1 to RVAS vs PS and followed for 6 months. Clinical, ECG, echocardiography and analytic parameters were compared. The primary endpoint was the change in the LVEF at 6 months in each group. The secondary endpoints were the changes in the left ventricular end-diastolic diameter (LVEDD), the QRS duration, the pro–B-type natriuretic peptide (NT-proBNP), the NYHA class, and the Minnesota Living with Heart Failure Questionnaire (MLWHFQ) in each group.

Results

The study included 57 patients of 77±9,6 years. Of all patients, 53% were treated with RVAS and 47% with PS. There were 2 patients with crossover to RVAS for technical difficulties and 1 patient with crossover to PS due to apical scar. There were no differences in the basal QRS duration (142.08±20,2 ms), LVEF (58.87±7,2%), NT-proBNP (3336,03±7258,68 pg/ml), or MLWHFQ (22,19±14,68), between both groups (Table 1). Acutely significant differences were observed in the change of QRS duration among groups (+16±29 ms in the RVAS group vs -17±25 ms in the PS group, p<0,001). At 6 months follow-up LVEF showed a non-significant reduction of 0.8±1.1% in the PS group compared to a significant reduction of 5.1±1.7% in the RVAS group (difference 4,26% IC 0,1-8,43 p=0,022). No differences were observed regarding the values of the NT-ProBNP and the MLWHFQ between groups at 6 months (Table 2).

Conclusions

In patients with preserved LVEF requiring pacemaker implantation for AVB, PS shorten the QTS duration and preserves the LVEF compared to RVAS.
Reducing radiation exposure and incision time in pacemakers implantation procedures using direct percutaneous axillary vein puncture
Authors: Vacarescu C , Goanta E V , Cirin L , Lazar M A , Arnautu A , Cozma D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Radiation exposure during device implantation depends overall on the operator experience but also on the type of venous access, type of device and number of leads implanted.

Purpose

to investigate radiation exposure/incision time for uni/bicameral pacemakers (PM) implantation procedures using direct percutaneous axillary vein puncture without primary fluoroscopy guidance and to assess the safety and the efficiency of this procedure strategy.

Methods

single center retrospective cohort study of patients implanted with unicameral and bicameral PM between January 2020 and December 2020 using direct percutaneous axillary vein puncture. All pts were given detailed explanations and informed consent. Procedural steps were: (I) direct percutaneous axillary vein puncture (anatomical landmarks: 1 or 2 cm medial and parallel to the deltopectoral groove at the level of the coracoid process); obtain separate vein access: 1 or 2 punctures; (II) skin incision and subcutaneous pocket dissection; (III) right ventricle (RV) ± right atrium (RA) lead placement and fixation. We analyzed the following data: fluoroscopy/incision time, dose area product (DAP) and the outcome related to procedure difficulties and complications.

Results

We collected data from 209 consecutive implant procedures; 152 patients (pts) underwent bicameral PM implantation, 57 pts received a unicameral device. All the procedures were done by the same operator (54 yo, 22 years of experience in PM implantation) using axillary access alone (2 years' experience in this technique). In 37 patients (18%) fluoroscopy guided puncture was needed. The mean fluoroscopy time was: bicameral PM 1.2±1.0 min (average incision time: 8.4±5.2 min); unicameral PM 0.4±0.3 min (average incision time: 6.5±4.3 min). The mean DAP was: bicameral PM 0.00358±0.00545 mGy/cm2; unicameral PM 0.00285±0.00449 mGy/cm2. In short term follow-up 1 patient (0.4%) developed pneumothorax and subsequent drainage was needed. Total follow-up period 19.7±4.3 months: at 6 months follow-up 1 patient (0.4%) presented lead fracture; 1 patient with DDD PM (0.4%) presented pocket infection; leads extraction were successful performed and another device was implanted. No other complications were noted.

Conclusion

Single venous access using axillary vein puncture was associated with reduced radiation exposure and decreased incision time. Our data showed a low incidence of complications.
Comparison of 1st and 2nd generation leadless pacemaker in sinus rhythm patients with chronic ventricular pacing for complete atrioventricular block
Authors: Clementy N , Lenormand T , Bodin A , Bisson A , Babuty D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Leadless pacemakers (LPMs) represent a seductive alternative to conventional pacing. First generation of Micra transcatheter pacing system was able to provide single-chamber VVI(R) pacing mode only, with a potential risk of pacemaker syndrome in sinus rhythm patients. A 2nd generation system (AV) now provides atrioventricular synchrony through atrial mechanical sensing capability (VDD mode).

Purpose

We sought to compare VR and AV systems in patients with sinus rhythm and chronic ventricular pacing for complete atrioventricular block.

Methods

All consecutive patients implanted with an LPM in our department for complete atrioventricular block were retrospectively screened. Patients with atrial fibrillation, sinus dysfunction, or ventricular pacing burden <20% at 1-month post-implantation were excluded.

Results

A total of 80 patients – 35 VR (2015-2020) and 45 AV (2020-2021) – were included. VR and AV patients had similar baseline characteristics, except for that VR patients being older (82±8 versus 77±9 years, p=0.01). Mean ventricular pacing burden was 75% in the VR and 79% in the AV group (p=0.63). In AV patients, median atrioventricular synchronous beats rate was 77%, 67% having a >66% rate. An E/A ratio <1 as measured on echocardiography was the only independent predictor of accurate atrial mechanical tracking (adjusted OR=13, p=0.006). One-year survival rate was 86% in the VR group and 95% in the AV group (adjusted p=0.21). Two patients in the VR and 0 in the AV group eventually developed pacemaker syndrome in the 1st year post-implantation (p=0.07).

Conclusion

In sinus rhythm patients with chronic ventricular pacing for complete atrioventricular block implanted with an LPM, atrial mechanical sensing algorithm allowed significant atrioventricular synchrony in most patients, and was associated with no occurrence of – otherwise rare – pacemaker syndrome.
Radiotherapy and cardiac implantable electronic devices: a nurse-based protocol in a single centre experience
Authors: Quintarelli S , Marini M , Agostini R , Demozzi M , Pellizzari S , Guarracini F , Coser A , Vanoni V , Magri E , Lisimberti R , Delana A , Menegotti L , Trianni A , Bonmassari R
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

An increasing number of patients need cardiac implantable electronic devices (CIED) for bradycardia or to prevent sudden cardiac death. At the same time many patients require radiotherapy for oncologic reasons. Interaction between CIEDs and ionizing radiations may cause several dysfunctions: electromagnetic interferences due to oversensing, CIED reset, drainage of the battery, hardware damage to the pulse generator and to the lead-tissue interface.

Purpose

An adequate planning is expected to guarantee the safety of CIED patients, reducing the potential complications. We describe our protocol in use and its application.

Methods

In 2016 an internal protocol was written to standardize the approach to CIED patients undergoing radiotherapy. Cardiology Department, Radiotherapy Unit and Medical Physics were involved in the draft. We stratified patients in high and low risk groups according to the CIED characteristics (ICD vs pacemaker), electro-dependency (yes vs no), and the estimated radiation dose (< 2 Gy: 2-10 Gy, > 10 Gy).

Low risk group:

- Non pacemaker (PM) dependent patients, estimated dose < 10 Gy

- PM dependent patients, estimated dose < 2 Gy

High risk group:

- PM dependent patients, estimated dose > 2 Gy

- Non-PM dependent patients estimated dose >10 Gy

- ICD patients

Two EHRA certificated nurses followed up the patients before, during and after the radiotherapy. Low risk patients received weekly in office evaluation during radiotherapy course. High risk patients were scheduled for daily in office check plus monitoring during each radiotherapy session, ICD therapy was temporarily switched off during each radiotherapy session.

An in office evaluation was planned 1, 3, 6 and 12 months after the end of radiotherapy course until 2019, since 2020 all patients were given remote monitoring for accurate follow up.

Results

Between 2016 and November 2022 101 patients with CIED underwent radiotherapy in our facility. Clinical characteristics of the patients are described in Table 1. EHRA certificated nurses managed 1282 radiotherapy sessions without any complication. A transient underestimation of ICD longevity was the only software error occurred.

Conclusions

The reported protocol assured a safe radiotherapy course for all our CIED patients. Given the limited data available about the interaction between the newest CIEDs and radiotherapy, we opted for a high safety profile. The EHRA certified nurse’s involvement allowed to optimize personnel resources.
Feasibility and short-term outcomes of left bundle pacing in paediatric patients: a case series
Authors: Chiramel S , Shenthar J , Reddy S , Banavalikar B , Padmanabhan D , Krishnappa D
Published: May 2023

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Government

Background

Chronic RV apical pacing in pediatric patients can lead to LV dysfunction. Left bundle pacing has been shown to preserve LV function in adults. The feasibility and outcomes of left bundle pacing in pediatric patients are unknown.

Objectives

To study the feasibility, safety, and short-term outcomes of pediatric left bundle branch pacing (LBBp).

Methods

Patients < 18 years with class I or II indication for pacing were the study subjects. All patients had dual-chamber pacemaker implantation from the right or left side.

We did the device implantation either under conscious sedation, or general anesthesia, after 6 hours of fasting and intravenous hydration with normal saline at 1 ml/kg/min. A venogram was performed on the ipsilateral to the implantation site from the cubital venous access with 5-10 ml of non-ionic contrast side to delineate the venous anatomy before the procedure. Venous access was obtained through two separate punctures of the extrathoracic axillary vein using an 18 G puncture needle and a 0.025 glide wire. The vein was sequentially SelectSecure 3830 4F lead, and C315HIS sheath was used for LBBp. An additional loop was added to the ventricular lead to account for the growth of the patient. The primary outcomes were successful, stable LBBp. The secondary outcomes were lead stability over three months with no implant-related complications or death.

Result

This case series has six patients of whom 2 were males and with a mean age of 9.5 years, and a mean body weight of 25.5 Kgs. All patients but one had undergone intracardiac repair (4 VSD, 1 ASD). The pacing indication was symptomatic AV block in five and sick sinus syndrome in one patient. At implant, the mean R wave was 12.83±4.8 mV, mean ventricular threshold was 0.6 ± 0.1 V at 0.5 ms pulse width, mean ventricular impedance of 737.3W ±131.5 ohms. The mean procedure time was 65± 20min, the mean fluoroscopy time was 14.63±13.3 min and the mean contrast volume was 30±20ml and the mean paced QRS duration was 98.5±16.5 ms and V5 LVAT 62.66±22.33ms. During follow follow-up of 4±3 months, the lead parameters were stable with a ventricular threshold of 0.8±0.1V at 0.5ms pulse width impedance of 689±130.2 ohms. There was no lead perforation, dislodgement, or death.

Conclusion

LBBp in the pediatric population is feasible and safe with good -lead stability and no complications in the near term.
Dyssynchrony assessment by ultra-high-frequency electrocardiography: a single numerical parameter to identify the relationship between right and left ventricular depolarization
Authors: Jurak P , Halamek J , Leinveber P , Plesinger F , Smisek R , Viscor I , Vondra V , Nguyen U C , Prinzen F , Curila K
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): grant number NU21-02-00584, the CAS project RVO:68081731, the project National Institute for Research of Metabolic and Cardiovascular Diseases (Programme EXCELES, ID Project No. LX22NPO5104) - Funded by the European Union – Next Generation EU.

Background

The common criterion for assessing synchronous activation during single and biventricular pacing is QRS duration (QRSd). The novel conduction system pacing (CSP) techniques provide more physiological ventricular activation but less clear effects on QRSd. In these circumstances, a more detailed and visual assessment of ventricular synchrony than QRSd alone can be insightful.

Purpose

To investigate whether differences between various modes of CSP can be better differentiated by ultra-high-frequency ECG (UHF-ECG) than by QRSd.

Methods

UHF-ECG recordings were acquired in 199 bradycardia patients with narrow QRS complex during intrinsic rhythm, selective (sHBP) and non-selective His bundle (nHBP), selective (sLBBP) and non-selective left bundle branch (nsLBBP) pacing, and left (LVSP) and right ventricular septal pacing (RVSP). Lead positions were certified using X-ray and QRS morphology. Electrical dyssynchrony (e-DYS) was calculated from UHF-ECG activation times as the maximal time difference between the peaks of ECG leads V1-V6. Positive e-DYS indicates delayed left ventricular (LV) activation, whereas negative e-DYS means delayed right ventricular (RV) activation.

Results

The Figure shows the relationship between QRSd and e-DYS for individual types of stimulation on an intrinsic background (black). All pacing, except sHBP, modes significantly increased QRSd. QRSd was significantly larger during RVSP than all other pacing modes, but QRSd was not able to differentiate between nsHBP, sLBBP, nsLBBP and LVsp. In contrast to QRSd, e-DYS was positive during nsHBP and RVSP and negative during sLBBP, nsLBBP and LVSP (p<0.001).

Conclusion

e-DYS assessed with UHF-ECG provides more detailed information on the ventricular activation and is more superior in differentiating between CSP pacing modes, compared to standard QRSd. sHBP, nsHBP, nsLBBp, and LVSP create activation patterns closest to normal ventricular activation.
Implant failures in conduction system pacing: single centre experience
Authors: Marcantoni L , Deluca F , Pastore G , Baracca E , Marsiglia S , Cappato E , Fornasaro M , Manzato E , Tiribello A , Raffagnato P , Pigaiani C , Zanon F
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Conduction system pacing (CSP) ensures physiological ventricular activation and avoids the dyssynchrony associated with traditional myocardial pacing. New dedicated tools makes it possible to increase procedural success but not yet comparable to myocardial pacing.

Objective

Retrospective analysis of 3-years CSP implants, focusing on implant failures.

Methods

From January 2019 to June 2022, 639 CSP implant were performed (91% PMs and 9% ICDs). Single-chamber ICDs implants and devices replacements were excluded from the analysis because the conduction system pacing could not be an option in those cases. Pacing indications were standard with prevalence of AV block (51%); AF with slow ventricular rate 14.5%; sick sinus syndrome 14.5%; ablate&pace 4%; heart failure or cardiomyopathy 14.5%, re-interventions after malfunction of a previous implant 1.5%. Mean age was 78±9 years; 62% were males.

Results

CSP was successfully achieved in 605 cases (94.6%). In 34 cases lead implant failed. Reasons for failure were "anatomical" in 15 cases (5 due to excessive right atrial enlargement, 5 due to severe pulmonary hypertension; 3 due to scar in the septum and 2 due to stenosis of the venous axis in upgrading procedure) and "technical" in 19 cases (5 due to unacceptable high thresholds, 10 due to uncorrected bundle branch block, 4 due to dislodgment during cutting without reposition). In 52% of the CSP implant failures, an underlying cardiomyopathy or heart failure were documented. Considering CSP failure, the implant was concluded with standard biventricular pacing in 18 cases (in 4 cases the coronary sinus implantation also failed) while 16 implants were concluded with the lead implanted in the septum or apex.

Conclusions

conduction system pacing is feasible in daily clinical practice; available tools allow to achieve high procedural success rate (94.8% implant success rate in our experience). Procedural failures were 5.2% and were caused by anatomical (44%) or technical reason (56%).
Characterization of the effects of right ventricular and left bundle branch area pacing on the QRS complex
Authors: Sales Belles C , Melero Polo J , Cabrera Ramos M , Vadillo Martin P , Mayo Carlos V , Palacios Rosales S , Martinez Cortes J P , Minchole Lapuente A , Pueyo Paules E , Ramos Maqueda J
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): TED2021-130459B-I00 LMP94_21

Introduction

Right ventricular pacing (RVP) has been the treatment of choice for patients with atrioventricular block and sinus node disease for the last decades . It is well known that RVP ventricular may cause ventricular dyssynchrony and could lead to left ventricular dysfunction in 20% of patients, and therefore could increase the risk of heart failure, atrial fibrillation and cardiovascular mortality. Left bundle branch area pacing (LBBAP) has recently emerged as a new physiological pacing modality that can circumvent the limitations of RVP. The purpose of this study was to compare changes induced by RVP and LBBAP in the standard 12-lead ECG by the analysis of QRS complex characteristics in order to asses ventricular dyssynchrony.

Methods

ECG recordings from 134 patients (82 LBBAP, 52 RVP) with indication for anti-bradycardia therapy were acquired before and after pacemaker implantation. Patients were grouped into narrow and wide baseline QRS using a threshold for the QRS duration of 120 ms. Median beats were calculated at baseline and 24 hours post-implantation states for each patient. ECG markers describing ventricular activation were measured, including: 1) QRS duration (QRSd) from QRS onset to QRS end; 2) QRS area (QRSa), computed from the individual areas in orthogonal X, Y and Z leads calculated using the Kors conversion matrix; 3) a new index QRS50 proposed to estimate the ventricular activation time from the first three components of the singular value decomposition of the median QRS complex.

Results

Note that the QRS characteristics showed similar values in baseline for both pacing techniques. In patients with narrow QRS, we found that paced QRS characteristics remained similar from the basal QRS in LBBAP group whereas in RVP group they worsened. The three markers, QRSd, QRSa and QRS50, increased after RVP by 34 ms, 68 uVs and 22 ms, respectively (p<0,001). In patients with wide QRS, LBBAP significantly reduced QRSd, QRSa and QRS50 while RVP increased QRSa and QRS50 and left QRSd unchanged.

Conclusion

In patients receiving a pacemaker for anti-bradycardia therapy, LBBAP led to more synchronized ventricular activation than RVP measured from QRS duration- and area-related characteristics.
Screw-in attempts and success rates in left bundle branch area pacing lead implantation
Authors: Haeberlin A , Seiler J , Kozhuharov N , Baldinger S H , Servatius H , Madaffari A , Thalmann G , Kueffer T , Muehl A , Tanner H , Roten L , Reichlin T , Noti F
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Left bundle branch area pacing (LBBAP) represents a novel cardiac pacing approach that overcomes limitations of conventional right ventricular (septo-) apical pacing. Feasibility and early safety have been shown previously. However, technical limitations (non-dedicated leads, limited availability of suitable implantation sheats) still may preclude successful conduction system pacing (CSP) lead implantation. So-called drilling and entanglement effects can prevent lead implantation at a suitable site and multiple screw-in attempts may be required. However, lead implantation may ultimately still be unsuccessful.

Purpose

To evaluate the number of total screw-in attempts until abandonment of LBBAP lead implantation during the procedure.

Methods

We prospectively assessed 170 consecutive LBBAP lead implantation attempts at our center from 09/2021 to 11/2022. All implanters had previous experience with His-bundle pacing lead implantation. Successful conduction system pacing was established according to standard criteria (R-wave peak time in V6, V1-V6-interpeak interval, programmed stimulation or visibility of a left bundle potential) and pacing thresholds <2V/0.5ms. The number of screw-in attempts and decision of LBBAP lead implantation abandonment was at the operator’s discretion.

Results

Patient baseline characteristics and procedural outcomes are shown in the table (percentages and median values with interquartile range in brackets). Overall CSP lead implantation success rate was 91%. Two patients (1%) experienced complications (one atrial lead dislodgement, one pneumothorax). Median number of screw-in attempts in all interventions was 2 (interquartile range [IQR] 1-4, maximum 12). If implantation was successful, a maximum of four attempts provided already 90% of the overall chance of success (figure). Additional lead implantation attempts rarely provided an additional benefit but prolonged overall implantation duration.

Conclusion

To balance implantation success rates with procedure duration, the number of screw-in attempts during LBBAP lead implantation may be limited to 4-5 attempts. Bail-out strategies (implantation of a cardiac resynchronization pacemaker or a conventional pacemaker) may be considered if CSP lead implantation is unsuccessful after 4-5 attempts.
Isolated PR prolongation in patients undergoing transcatheter aortic valve implantation
Authors: Perel N , Tovia-Brodie O , Schnur A , Glikson M , Michowitz Y
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

New conduction disturbances are common complications following transcatheter aortic valve implantation (TAVI). The last ESC guidelines recommended electrophysiological study (EPS) or long-term monitoring for patients with new LBBB above 150 ms or one that is associated with PR prolongation (IIa indication). For patients with preexisting conduction abnormality and further PR or QRS prolongation EPS or long-term monitoring are also recommended but with a IIb recommendation. The data regarding the prognosis and management of patients with isolated PR prolongation is limited.

Purpose

Evaluate the need for permanant pacmaker implantation, occurance of syncope and mortality during the 1st year following Transcatheter aortic valve implantation

Methods

All patients undergoing TAVI at Shaare Zedek Medical Center were retrospectively reviewed. All patients underwent at least 1 ECG prior and daily post the procedure. Patients with isolated PR prolongation > 20 ms compared to baseline ECG were included. While patients with preexisting permanent pacemaker (PPM), complete AV block or any peri or post procedural QRS widening > 20 ms were excluded. Patient were followed for 1 year for the occurrence of syncope, PPM or death.

Results

Excluding patients with preprocedural PPM, 1028 patients were reviewed. Compared to baseline ECG, 124 (12%) patients had isolated PR prolongation, of whom 88 (71%) and 36 (29%) had baseline narrow and wide QRS respectively. During follow-up none of these 88 patients with baseline narrow QRS required in hospital PPM, while only 2 patients with baseline wide QRS required in hospital PPM. During 1 year follow-up, 6 patients (4.8%) died and no one had syncopal episode or need for PPM.

Conclusion

Post TAVI, isolated new PR prolongation is not associated with an adverse outcome including syncope or progression to complete heart block and need for PPM at 1 year post the procedure. These finding may be considered when evaluating these patients post the procedure.
Learning curve for left bundle branch area pacing with standard stylet-driven pacing leads
Authors: Yu G , Kim H T , Yu H T , Joung B Y , Pak H N , Lee M H
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

His bundle pacing (HBP) was developed as a physiological conduction system pacing to complement the problem of conventional right ventricular pacing (RVP) related to dyssynchrony. Recently, left bundle branch area pacing (LBBAP), which overcomes the shortcomings of HBP, has been implemented. Most studies on initial experiences with LBBAP have reported that it was achieved through a lumen-less pacing lead (LLL) with a fixed helix design; however, there are situations in which LLL cannot be used. This study aimed to evaluate the initial experience and learning curve of LBBAP using a standard stylet-driven lead with an extendable helix design.

Methods

The study included 265 patients who underwent LBBAP or conventional RVP performed by operators without previous LBBAP experience at our hospital in Korea between December 2020 and October 2021. LBBAP was performed using a stylet-driven pacing lead with an extendable helix. The learning curve was evaluated by analyzing fluoroscopy and procedure times.

Results

LBBAP was successful in 65 of 69 (94.2%) patients during the observation period. In 65 patients who underwent LBBAP, mean fluoroscopy and procedural times were 17.1 ± 17.2 minutes and 64.2 ± 33.5 minutes, respectively. The learning curve for achieving LBBAP plateaued after the 24th case, with a gradually shortening procedure time.

Conclusion

During the initial experience with LBBAP, fluoroscopy and procedural times improved with increasing operator experience. For operators who were experienced in cardiac pacemaker implantation, the steepest part of the learning curve was over the first 20-25 cases. It is shorter than the previously reported learning curves of HBP.
Preliminary results from a single-center registry of left bundle branch area pacing with the use of classic, non-dedicated electrodes, without the use of additional sheaths
Authors: Ludwik B , Labus M , Spikowski J , Roleder T
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

In recent years, interest in left bundle branch area pacing (LBBAP) has been growing. The vast majority of reports concern procedures performed with the use of a dedicated set of equipment - a sheath and an electrode.

Purpose

The aim of the study was to assess the possibility of using classical electrodes with active fixation, used for years, for stimulation of the left bundle branch, without the use of dedicated sheaths, which could allow the routine introduction of LBBAP in each patient without the need for preliminary qualification before the procedure.

Methods

These are preliminary results from a single-center, prospective registry of pacemaker, cardioverter-defibrillator and CRT-D implantation procedures from February to November 2022. Routine patients were enrolled in the registry. Abbott's Tendril STS electrodes were used for successful LBBAP. In all procedures only suitably shaped mandrills were used without any additional sheaths.

Results

113 people (age 72.6 ± 13.8, 44 women) were included in the registry in the given period. Successful LBBAP was achieved in 107 (94,7%) patients, including 15 patients initially qualified for CRT-D. LBBAP was abandoned in 6 patients mainly due to problems with finding the optimal implantation site. The average time of mapping and effective fixation of the electrode was 21.7±14.7 minutes, x-ray time (whole procedure): 10:08±5:36 minutes, procedure time: 62,9±21,2 minutes, pacing threshold: 0.57±0.34V/0.4ms, sense: 9.5±4.5mV, resistance: 485±130 Ohms, RWPT: 74±12ms, interpeak (time between peak V6 and V1): 47±15ms. No important adverse events have been observed, nor problems with stimulation in follow-up.

Conclusions

Preliminary results of LBBAP using classic electrodes without the use of dedicated equipment show results comparable to those achieved with dedicated electrodes and sheaths, which may facilitate the use of LBBAP as a routine stimulation method in most patients.
Long-term safety and efficacy of leadless pacemakers in the Dutch cohort
Authors: Breeman K T N , Oosterwerff E F J , De Graaf M A , Juffer A , Saleem-Talib S , Maass A H , Wilde A A M , Boersma L V A , Remanna H , Van Dijk V F , Van Erven L , Delnoy P P H M , Tjong F V Y , Knops R E
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Leadless pacemakers (LPs) were designed to circumvent pocket- and lead-related pacemaker complications. Up to two years after implantation, adequate real-world safety and efficacy have been demonstrated. Because the duration of pacemaker therapy is well over two years, longer-term data is warranted for the net clinical benefit of leadless pacing.

Objective

Our aim was to evaluate the safety and efficacy of LP therapy on the long-term in a real-world cohort.

Methods

In this retrospective cohort study, all consecutive patients were included with a first LP implantation (Nanostim LP or Micra VR LP) from December 21, 2012 to December 13, 2016 in 6 Dutch high-volume centers. The primary safety endpoint was the rate of procedure- or device-related major complications at 5-year follow-up. Analyses were performed with and without the Nanostim battery advisory-related complications. The efficacy is described as pacing threshold, impedance and R-wave amplitude over time; changes in these parameters were assessed using mixed models.

Results

179 patients were included (117 [65%] male, mean age 79±9 years), of whom 93 (52%) with a Nanostim and 86 (48%) with a Micra LP. Mean follow-up duration was 45±25 months. A total of 46 major complications occurred, of which 8 not advisory-related. The 5-year major complication rate without advisory-related complications was 4.5% (Figure, A). Including advisory-related complications, the 5-year major complication rate was 30.5%. Not advisory-related complications included dislocations (n=3, of which 2 periprocedurally), pericardial effusion (n=1), groin bleeding (n=1), loss-of-capture (n=2) and pacemaker syndrome (n=1). Reinterventions were required in 7/8 (88%), only prolonged hospitalization in 1 (12%; the groin bleeding), and surgery in none. All 8 occurred within 90 days after implantation. Pacing threshold was stable over time (p=0.53), R-wave amplitude increased (p=0.002), and impedance decreased (p<0.001) (Figure, B).

Conclusion

The long-term major complication rate excluding advisory-related complications was low. Especially few complications occurred after the acute phase, which may be a specific benefit of LP therapy. The performance was adequate with a stable pacing threshold over time, whereas in transvenous pacemakers usually a gradually increasing threshold is seen. These findings confirm previous safety and efficacy results and are promising for longer-term data on leadless pacing.