bluuebunny/crossref_metadata_2025 huggingface dataset:
TAVI PACER - a contemporary risk score for pacemaker implantation after TAVI
Authors: Lueg J , Janiszewski A , Schulze D , Juri B , Morell L , Hajduczenia M , Hennig P , Erbay A , Niehues S , Landmesser U , Stangl K , Leistner D M , Dreger H , Tscholl V
Published: May 2024

Background

The need for permanent pacemaker implantation (PPM) remains one of the most frequent complications of transcatheter aortic valve implantation (TAVI). The aim of this study was to develop a novel risk score for the prediction of PPM after TAVI using contemporary transcatheter heart valves.

Purpose

The TAVI PACER score is designed to optimize valve selection and implantation technique based on individual patient factors to reduce the need for PPM.

Methods

Between January 2019 and December 2020, 1039 patients underwent TAVI at Charité Universitätsmedizin Berlin. Patients with prior pacemaker implantation or valve-in-valve procedure were excluded. We retrospectively evaluated clinical, electrocardiographic, echocardiographic, computed tomographic, and periprocedural data and applied logistic regression for predicting pacemaker implantation. For variable selection, we ran regression with a Lasso estimator for optimizing the predictive quality of the selected variables. Additionally, we used multiple imputation with 30 imputed sets to deal with missing data.

Results

We included 840 patients (mean age 80.2 ± 9.1 years, 50.5% female), of whom 140 patients (16.6%) needed pacemaker implantation within 30 days post TAVI. We identified 11 relevant risk factors that were included in the final score. In a first step the TAVI PACER score calculates an individual risk for pacemaker implantation using preprocedural characteristics such as grade of mitral insufficiency, nicotine use, preexisting AV Block I° and RBBB, EF, LVEDD and BMI. In a second step the influence of intraprocedural aspects are added to illustrate the extent to which the risk for pacemaker implantation can change, depending on which type of valve, implantation depth and valve perimeter are chosen. Pacemaker implantation can be predicted with a sensitivity of 60% and specificity of 82%.

Conclusion

The TAVI PACER Score is an intuitive and useful tool to predict the risk for pacemaker implantation after TAVI before the intervention and could thus help to reduce the rate of pacemakers implanted.
Procedural heart rate variability and its effect on short-term symptoms after cardioneuromodulation procedure
Authors: Aygun S , Coteli C , Yorgun H , Aytemir K
Published: May 2024

Background

Syncope is a miscellaneous clinical condition that affects a large portion of the population every year all over the world and responsible for a considerable amount of hospital and particularly emergency department admissions (1) The use of a right-sided approach in catheter ablation of ganglion plexi (GP) has been applied to reduce syncope episodes caused by vasovagal syncope (VVS) and decrease the overall burden of syncope (2).

Purpose

Our aim is to show that right-sided GP ablation which is known as cardioneuromodulation (CNM) is a new and promising way to cease recurrent syncope episodes and assess its effects on heart rate (HR), P-P intervals, ventricular depolarisation/repolarization parameters (QRS,QTc,Tpe durations, QTc/Tpe ratio), recurrence of syncope episodes, and patients symptoms such as fatigue, dizziness, etc. We also aimed to identify changes between pre and post procedural heart rates and its effects on short-term symptoms during follow-up.

Methods

A group of 55 patients with positive tilt table response or recurrent vasovagal syncope with pauses >2 sec in holter monitoring was enrolled this study. During the EP study, GPs determined both anatomically and by EP stimulation then autonomic denervation was performed focused by radiofrequency ablation. All patients followed-up for 12 months.

Results

Right-sided ablation was performed during the procedure and HR increased significantly in all patients after the procedure compared to before. Syncope episodes of the patients decreased significantly after the procedure. The patients who did not complain of syncope at the first, second and third appointment, respectively, 76.4% (n:42), 90.9% (n:50) and 92.7% (n:51). Patients had complaints at most within the first 4 months after the procedure (Table-1). At the first appointment, 4 (7.3%) patients had syncope and 9 (16,4%) patients had sinus tachycardia. Patient group with heart rate variability varying more or less than 20% during the procedure were examined, 81% of those with HR variability <20% did not have any symptoms, while 64.7% of the group with HR variability above 20% did not have any symptoms at first appointment (p:0,461) (Table.2). Tachycardia was seen in 23.5% of those with HR variability >20%, while it was determined as 9.5% in those with a HR variability <20 % Although these comparisons do not show a statistically significant difference due to the number of few patients, it is clinically significant. The same relationship was not observed between HR variability and symptoms in the second and third appointments.

Conclusion

Cardioneuromodulation is a remarkable treatment modality and it should be taken into consideration that more symptoms may develop in the early post-procedural period in the group who has post-procedure heart rate variability over 20%, and a cut-off should be determined for the target heart rate during the procedure.Table-1Table-2
Cardiac implantable electronic devices following orthotopic heart transplantation: insights on indications and outcomes from a single centre experience
Authors: Castagno D , Pulvirenti G , Soro P , Ferraris F , Anselmino M , Matta M , Saglietto A , Giustetto C , Dusi V , Pidello S , Raineri C , Simonato E , Rinaldi M , De Ferrari G M , Boffini M
Published: May 2024

Background

Need for cardiac implantable electronic devices (CIED) after orthotopic heart transplantation (OHT) ranges from 7 to 24% of cases depending on several patient and procedural related factors.

Purpose

The aims of this study were to investigate the frequency, indications and the predictors of CIED implantation (especially permanent pacemaker [PPM]) following biatrial anastomosis OHT.

Methods

A retrospective, single centre, observational study was conducted, including all the patients who underwent OHT between May 1990 and October 2023 at our Institution. For each patient clinical and procedural information were collected and a long-term active follow-up was performed. The primary endpoint of the study was PPM or implantable cardioverter defibrillator (ICD) implantation while all-cause mortality or de novo OHT was a secondary endpoint. Uni- and multivariable logistic regression analyses were performed to identify factors associated with PPM implantation.

Results

Overall, 546 patients were included and followed-up for a median of 8 years [IQR 1.2-14.3]. During this time frame, 89 (16.3%) patients required PPM implantation (only one patient [0.2%] underwent ICD implantation) at median time of 110 days [IQR 25-2230] after OHT. The main indication for PPM implantation was the development of sinus node dysfunction in 60 patients (67.4%) whereas 29 (32.6%) patients with atrioventricular block required PPM implantation. During follow-up, 265 deaths (48.5%) occurred but no significant differences in long-term prognosis were observed between patients requiring CIED implantation and those who did not (45.5% vs. 49.1%, p-value=0.53, figure). At multivariable analysis, impaired renal function (i.e. low eGFR), cardiac allograft vasculopathy, the occurrence of severe heart transplant rejection and a higher BMI were factors associated with PPM implantation (table).

Conclusions

Among patients undergoing OHT with biatrial anastomosis technique, PPM implantation is not uncommon but it does not negatively impact on prognosis. Several factors, especially severe heart transplant rejection, cardiac allograft vasculopathy and impaired renal function can help identifying patients at higher risk of PPM.TableFigure
Sinus nodal denervation by targeting the superior paraseptal ganglionated plexus: randomized comparison of right-atrial and bi-atrial cardioneuroablation guided by ablation index
Authors: Wichterle D , Stiavnicky P , Jansova H , Peichl P , Stojadinovic P , Borisincova E , Haskova J , Cihak R , Kautzner J
Published: May 2024

Background

Radiofrequency (RF) catheter ablation of superior paraseptal ganglionic plexus (SPSGP) that significantly suppresses the vagal modulation of the sinus node is used for the treatment of functional bradyarrhythmias. A reasonable effect can be achieved by targeting this plexus from the endocardial aspect of both the right and left atria.

Purpose

The study aimed to compare the acute efficacy of unifocal right-atrial (RA) and comparably extensive bi-atrial (BA) ablation of SPSGP for sinus nodal denervation as assessed by intraprocedural extracardiac vagus nerve stimulation (ECVS).

Methods

A population of 22 patients (age: 43±9 years, 55% males) undergoing cardioneuroablation (CAN) for functional bradyarrhythmias were randomized 1:1 to two ablation strategies that included: [1] single RF lesion at the very posterior site of the junction between right atrium and superior vena cava with ablation index (AI) = 800 (RA group) and [2] the same but twice smaller RF lesion (AI = 400) complemented with strictly contralateral left-atrial lesion (AI = 400) at the anterior vestibulum of right superior pulmonary vein (BA group). The effect of ablation was investigated by the post-ablation change in sinus rate and the attenuation of the response of the sinus node to ECVS (frequency: 50 Hz, pulse width: 0.05 ms, output: 1 V/kg [<70V], duration: 5 s) via the right internal jugular vein.

Results

Per-protocol ablation resulted in sinus acceleration by 9±15 bpm vs. 15±16 bpm (P=0.40) in RA vs. BA groups, respectively. Inducible sinus arrests were shortened by 4.7±4.2 s vs. 6.2±1.5 s (P=0.27) and reached the post-ablation level of 3.0±3.7 s vs. 1.0±0.3 s (P=0.08) in RA vs. BA groups, respectively. The results are also displayed in the Figure as medians, interquartile range (boxes) and total range (whiskers). Complete sinus nodal denervation was achieved in 8/11=73% vs. 11/11=100% patients (Fisher exact test P=0.21) in RA vs. BA groups, respectively. Practically 100% denervation efficacy in the BA group contrasted with 3 patients in the RA group in whom ablation had virtually no effect on ECVS-based indices (duration of post-ablation sinus arrests: 11.2, 8.7, and 5.2 s). Acute effects did not change substantially during the waiting period of 20±5 min.

Conclusions

In this small study with acute procedural endpoints, unifocal RA ablation of SPSGP appeared numerically less effective for sinus nodal denervation than comparably extensive BA ablation although the difference was formally non-significant. The ECVS-based outcome measure was valuable in detecting the differences between study groups. Change in sinus rate was not a reliable marker of sinus nodal denervation.
In-hospital outcomes of anterior versus non-anterior st elevation myocardial infarction complicated with complete atrioventricular block
Authors: Margolis G , Levi Y , Abu Fanne R , Saada M , Kobo O , Kazatsker M , Roguin A , Leshem E
Published: May 2024

Background

Complete atrioventricular block (CAVB) is an infrequent complication of acute ST-elevation myocardial infarction (STEMI), and information on its outcomes is scarce. We aimed to address the characteristics and in-hospital outcomes of patients with anterior versus non-anterior STEMI complicated with CAVB in a contemporary, nationwide, all-comer registry, in the U.S.

Methods

Using the National Inpatient Sample (NIS) database, we identified patients who were hospitalized with STEMI, complicated with CAVB between 2016- 2019. Patients with any cardiac implantable electronic device (CIED) in-situ were excluded. Baseline characteristics, in-hospital procedures and outcomes including time to temporary or permanent pacemaker (PPM)/implantable cardioverter defibrillator (ICD) implantation, length of stay and mortality were collected.

Results

A total of 17470 patients, were hospitalized with a primary diagnosis of STEMI and concomitant diagnosis of CAVB, 2755(15.8%) with Anterior and 14715(84.2%) with non-anterior STEMI. Non-anterior STEMI patients included more women, had higher prevalence of hypertension, dyslipidemia, smoking history and chronic pulmonary disease, while anterior STEMI patients had higher prevalence of chronic kidney disease and ischemic cardiomyopathy. Anterior STEMI patient had significantly higher rate of in hospital death [955 (35%) vs 2220 (15%), p<0.001], CPR, VT/VF, cardiac arrest, acute heart failure, respiratory failure, mechanical ventilation >96 hours and acute kidney injury. In both groups 40% received temporary pacemaker, but mean time to implantation was longer in anterior STEMI patients [1.1±3.3 vs 0.3±1.2 days, p<0.001]. Rate of any permanent CIED implantation was also significantly higher in the anterior STEMI patients with longer time to PPM implantation, [3.3±3.5 vs 2.8±2.8 days, p<0.001]. Use of mechanical circulatory support devices was significantly higher in anterior STEMI patients.

Conclusion

In STEMI patients complicated with CAVB, in-hospital outcomes of anterior STEMI were worse comparing to non-anterior STEMI, with significantly higher rates of in-hospital death, in-hospital complications and CIED implantations.
In-vivo mapping of human polymorphic ventricular tachycardia in Brugada syndrome
Authors: Pannone L , Della Rocca D G , Vergara P , Sorgente A , Overeinder I , Bala G , Almorad A , Stroker E , Pappaert G , Sieira J , La Meir M , Brugada P , Chierchia G B , Sarkozy A , De Asmundis C
Published: May 2024

Background/introduction

Brugada syndrome (BrS) is associated with ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Different mechanisms have been described for human PMVT, including epicardial drifting of rotational activity before stabilization on the apex.

Purpose

The aim of this study is mapping human PMVT mechanisms in BrS with ECG imaging (ECGI) in-vivo.

Methods

All BrS patients, were prospectively enrolled between 1992 and 2022. Inclusion criteria for the study were: 1) BrS diagnosis; 2) PMVT mapped with ECGI during thoracoscopic epicardial right ventricle outflow tract ablation. PMVT was adjudicated if a changing QRS pattern was present. Phase mapping was performed for each PMVT. All maps were imported on a dedicated software and analyzed offline. Left anterior descending coronary artery was added, based on CT scan reconstruction as a reference for the interventricular septum (in grey in Figure 1). Phase maps were performed using the Hilbert transform on detrended signals and the phases of wavefront propagation were color-coded. Rotational activity was defined as a continuous progression of phase from -π to +π around a phase singularity point. Focal activity was defined as a wavefront that appears de novo, without arising from another wavefront and spreading from its origin.

Results

A total of 21 BrS patients with VF were analyzed and 2 patients (9.5%) were found with PMVT. A total of 2 episodes of PMVT were mapped (one for each BrS patient) with a duration of 2.9 s and 1.3 s, respectively. Both PMVT had spontaneous initiation and termination. The mean number of rotational activities was 2.45 ± 0.07, with a mean of 2.9 ± 0.71 rotations on the apex and 0.8 ± 1.13 rotations on the septum. No other rotational activity was observed. There were 2 and 1 focal activities on the septum, respectively. No other focal activity was observed. The phase mapping of both PMVT episodes was consistent with the mechanism shown in Figure 1. In the first phase of PMVT (negative QRS) a stable rotor (white arrow) is found over ventricular apex (Figure 1, Panels A-D). In Figure 1, Panel E a septal activity appears (yellow arrow). The reduction of QRS voltage is secondary to a fusion between septal (yellow arrow) and apical (white arrow) rotational activities (Figure 1, Panels F-G). In the second phase of PMVT (positive QRS) a stable focal activity (yellow arrow) is found over the ventricular septum (Figure 1, Panels H-J).

Conclusion

In patients with BrS, change in the QRS pattern during PMVT is secondary to a fusion between rotational septal and apical activities.Figure 1
Automated template matching versus conventional pace-mapping during pvc ablation: results from a randomized controlled trial
Authors: Schulz N , Steven D , Sultan A , Van Den Bruck J H , Woermann J , Schipper J , Scheurlen C , Dittrich S , Filipovic D , Erlhoefer S , Lueker J
Published: May 2024

Background

Pace-mapping has an important role in the ablation of idiopathic premature ventricular contractions (PVC). There is a software with an automated algorithm annotating and visualizing template matching points. Automated template matching (ATM) facilitates the matching process and may thus shorten the procedure duration and potentially increase ablation success.

In this randomized study we evaluate whether the use of the automated template matching (ATM) software compared to conventional pace-mapping (PM) influences outcomes and periprocedural parameters in patients undergoing PVC ablation.

Methods

The study was performed as a prospective randomized controlled single-center clinical trial. Patients scheduled for de-novo PVC ablation were included and randomly assigned to either PVC ablation using the ATM algorithm (ATM) or conventional pace-mapping (PM).

The primary endpoint was the procedural outcome represented by the PVC burden after three and twelve months. Secondary endpoints were periprocedural parameters including procedure duration, number, and duration of radiofrequency application (RFA), fluoroscopy (FS) dose, and duration.

An interim analysis was predetermined after 72 patients had completed their three-month follow-up.

Results

After the interim analysis, the study was prematurely ended for futility.

At termination of the trial 108 patients had been included. 18 patients dropped out of the study. Out of the remaining 90 patients, 88 patients (97%) have completed the three-month follow-up, and 73 patients (81%) the twelve-month follow-up. The mean age at the time of procedure was 57.3 years [18-82] without significant differences between both groups.

Before ablation, the mean PVC burden was 20.8% [0.1-55.0] (ATM: 20.8% [3.0-55.9]; PM: 20.7% [0.1-44.0]; p=0.959). At 3-month follow-up, the mean PVC burden in both groups (ATM: 4.7% [0-29.4]; PM: 3.6% [0-45.7]; p=0.512) showed no significant difference between the groups. At 12-month follow-up the mean PVC burden in both groups (ATM: 3.8% [0-31]; PM: 2.2% [0-25.6]; p=0.282) also resulted in a non-significant difference between the groups.

Furthermore, the procedural parameters (table) did not differ significantly between both groups.

Conclusion

In this randomized trial, the use of the automated template matching software did not result in improved outcomes or procedure-related parameters. Conventional pace-mapping appeared to be equally effective compared to the automated template matching software as used in this study.Table secondary endpoints
Bipolar catheter ablation of left ventricular summit PVC
Authors: Woermann J , Van Den Bruck J , Schipper J , Filipovic K , Ackmann J , Erlhoefer S , Pavel F , Scheurlen C , Dittrich S , Sultan A , Steven D , Lueker J
Published: May 2024

Background

Premature ventricular contractions (PVC) arising from the left ventricular summit are a challenging arrhythmia to manage, often refractory to conventional radiofrequency ablation. This study aimed to investigate the effectiveness of bipolar ablation as a therapeutic option for PVCs originating from this anatomically complex region.

Methods

We conducted a retrospective analysis of a prospective ablation registry to identify patients with recurrent, symptomatic PVCs originating from the left ventricular (LV) summit who underwent bipolar ablation. Bipolar ablation involved the use of two ablation catheters, delivering radiofrequency energy from opposite sides of the summit. The catheters were connected by a dedicated adapter, allowing to connect one ablation catheter in position of a return electrode. Procedural success was defined as the elimination of PVCs during the procedure and freedom from PVCs on follow-up monitoring. Results were compared to a similar patient group who had received unipolar ablation of summit-PVCs.

Results

A total of 12 pts received bipolar ablation between July 2022 and October 2023. Three pts underwent ablation for VT and were excluded. A total of 9 pts (mean age 57±18 years, n=7 [78%] male, BMI 28±5kg/m2) were included in the analysis. All but one had a history of a previous unsuccessful ablation attempt (median 1 [1-2]). In a group of 33 patients undergoing unipolar ablation 8 (32%) had received ≥ 1 previous ablation and were included in the analysis. Baseline parameters did not differ between groups. The acute procedural success rate for bipolar ablation was 89% in bipolar pts and 75% in unipolar pts, with a mean procedural time of 173±33 min, a mean fluoroscopy time of 14±9 min (158±55 min [p=0.478] and 14±12 min [p=0.995] for unipolar pts). Bipolar ablation was performed between the LVOT and RVOT in 6, and between LVOT and the distal CS in 6 pts with 25-35 W. No major complications were detected in bipolar pts while one non-fatal tamponade occurred in the unipolar pts group. Follow-up data at 97 [93-269] days revealed a sustained reduction in PVC burden in bipolar pts (from 18±13% to 7±9%; p=0.026) while unipolar ablation did not show a significant burden reduction (15±6% to 11±10%; p=0.382). The success rate of a relative burden reduction >50% did not differ significantly between the groups (bipolar: 6 pts [67%] 3 pts [38%]; p=0.347).

Conclusion

Bipolar ablation offers an effective and safe therapeutic approach for PVCs originating from the LV summit. It significantly reduced PVC burden in this analysis. The data suggest that a repeat procedure after a failed summit PVC ablation should only be performed if bipolar ablation is available during the second procedure. Larger studies are warranted to confirm efficacy and safety of this ablation method.
The evaluation of the efficacy of automated peak frequency annotation algorithm for the identification of critical isthmus of ventricular tachycardia and deceleration zones
Authors: Zekeriyeyev S , Coteli C E M , Yorgun H I K M E T , Aytemir K U D R E T
Published: May 2024

Background

Substrate modification techniques have widely been adopted due to hemodynamic instability and non-inducibility of clinical ventricular tachycardia (VT). Accurate annotation of local near field EGMs is paramount to better evaluate the ventricular substrate. Furthermore, annotation of late potentials (LP) necessitates substantial manual input and isochronal late activation mapping (ILAM) involves constant sensitivity adjustments, potentially affecting the accuracy of local ventricular signal representation.

Objective

This study aims to assess the utility of novel automated peak frequency (PF), which aims to determine near field local activity in low voltage regions in the prediction of the CI of scar related reentrant VTs. Furthermore, the effectiveness of automated PF annotation of near field EGMs to identify deceleration zone (DZ) during ILAM was also evaluated.

Methods

A total of 18 patients with scar-related VT were analyzed. In all patients, VT isthmuses were identified based on activation maps and acute termination achieved during radiofrequency ablation. Automated PF annotation using Ensite X system (Abbott) was retrospectively performed in all cases specifically in areas of low voltage with fractioned signals. The accuracy of applying the PF value and automated ILAM map for detecting VT isthmus was also assessed.

Results

Among the study group, 12 (66.7%) had ischemic cardiomyopathy, while 6 (33.3%) had nonischemic cardiomyopathy [3 (16.7%) with arrhythmogenic right ventricular cardiomyopathy, 2 (11.1%) with idiopathic dilated cardiomyopathy, and 1 (5.6%) with hypertrophic cardiomyopathy]. All identified isthmuses were located in areas exhibiting bipolar voltage below 0.5 mV and a PF of 250 Hz with fractionated EGMs Automated NF DZ annotation predicted the VT isthmus in 16/18 (88.9%) of the cases similar to the conventional ILAM with manual adjustment (88.9%).

Conclusion

Using high-density electroanatomical mapping with near field algorithm, a PF cutoff of 250 Hz accurately identified the low voltage regions to predict the CI of VT. In addition, automated annotation of EGMs during ILAM similarly identified the DZs compared with conventional last deflection algorithm with manual adjustments, which were colocalized with CI of VTs.
Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: data from a multicenter experience
Authors: Migliore F , Schiavone M , Pittorru R , Forleo G B , Mitacchione G , Biffi M , Gulletta S , Kuschyk J , Rovaris G , Tilz R , Tondo C , Di Biase L , Gasperetti A , Tarzia V , Gerosa G
Published: May 2024

Background

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF).Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs, with a lower risk of short- and long-term of device-related complications and infections. Purpose:The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation. Methods:The study population included patients with an S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy. Results:The study population included 30 patients (25 male;median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population.Electromagnetic interference (EMI) occurred in 21 (70%) patients.The primary sensing vector was the one most significantly involved in determining EMI.Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector.The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks due to EMI. Six patients (20%) experienced appropriate shocks.No S-ICD extraction because of need for antitachycardia pacing,ineffective therapy or infection was reported. Conclusions: Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS,and undersensing in the post-operative period following LVAD implantation should be considered.Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.
AV synchrony maintained by a dual-chamber leadless pacemaker in real-world conditions
Authors: Defaye P , Reddy V Y , Ip J E , Doshi R , Exner D V , Canby R , Bongiorni M G , Shoda M , Hindricks G , Neuzil P , Rashtian M , Nevo J , Knops R E
Published: May 2024

Background/Introduction

A dual-chamber leadless pacemaker system has been developed to provide atrial and ventricular pacing and maintain atrioventricular (AV) synchrony. The device demonstrated an ability to maintain consistent AV synchrony in an in-clinic setting when tested through a series of postures and gaits under some programming restrictions. Assessing AV synchrony within real-world conditions is needed to understand the device’s performance under wider variations in activity and over a longer period.

Purpose

Assess a dual-chamber leadless pacemaker’s ability to maintain AV synchrony in an ambulatory environment of daily living under clinically driven programmed settings.

Methods

Implanted de novo subjects, who had at least 25% atrial pacing after 3-months post-implant, wore a 12-lead Holter monitor for a minimum of 24 hours during normal daily activities and completed a symptom diary. Devices were programmed to a dual chamber pacing mode and clinically appropriate settings then interrogated pre- and post-assessment. An independent Core Laboratory evaluated AV Synchrony, based on a configurable sampling window approach at repeated intervals, and defined synchronous cycles based on whether PR intervals fell within a 50 ms margin of the programmed Paced AV Delay.

Results

Among the 50 subjects who were administered the assessment, 48 of their Holters were analyzable (mean age 71.4 ± 10.9 years; 66.7% male), and 47 subjects had paired device interrogation data available. The analyzable population was predominantly indicated for sinus node dysfunction (83.3%) with a minority indicated for AV block (16.7%). The mean ± standard deviation of the programmed paced AV delay was 260.0 ± 47.6 ms, and mean PR interval was 241.4 ± 35.1 ms. An atrial paced beat and ventricular paced beat were each present in 69.5% and 22.5% of the evaluable cardiac cycles in the population, respectively. Mean AV Synchrony was maintained above 97% (95% CI: 95.5, 98.8) in the entire cohort and was sustained at high rates within each sub-population. Device metrics that diagnose the rate of directional implant-to-implant (i2i) communication also confirmed device data average throughput rates above 90% (Picture 1). There were no reported episodes of oversensing, undersensing, loss of capture, or pauses.

Conclusion

Among subjects with standard pacemaker indications, the dual-chamber leadless pacemaker system maintains very high rates of AV synchrony, exceeding i2i throughput, within real-world conditions utilizing clinically appropriate programmed settings.AV Synchrony and i2i by Indication
Feasibility and safety of physiologic pacing post-TAVR
Authors: Pajaro Merino P A , Del Valle Montero J A , Moraleda Salas M T , Luque Perez M , Arce Leon A , Esteve Ruiz I , Carreno Lineros J M , Gomez Menchero A E , Morina Vazquez P
Published: May 2024

Introduction

His-Purkinje conduction system pacing (HPCSP) is an increasingly used technique due to its benefits. The transcatheter aortic valve replacement (TAVR) has in turn been growing and surpasses the number of procedures than surgical aortic valve replacement, however, the main disadvantage with respect to the surgical technique is a greater risk of atrioventricular block and the need for permanent pacing.

Purpose

Assess the feasibility of HPCSP in patients after TAVR, the success rates and the pacing thresholds.

Methods

We present a series of consecutive patients (undergoing TAVI in a single center with need for subsequent ventricular stimulation (n=58), from March 2019 to July 2023, performing HPCSP as the first stimulation option.

Results

We achieved HPCSP in 49 of 58 patients (84.5%). Patients had a mean age of 81.5 years, 60.3% men, mean LVEF 53.82 ± 12.4%. His bundle pacing (HBP) was successful as first option in 41.4% of cases, and left bundle branch area (LBBAP) in 43,1 % of cases (73.5% of the remaining 58.6%) , while the other 9 patients (15.5%) were pace conventionally at right ventricle, septal or wireless. HBP thresholds and R-wave amplitudes at implantation were 0.99 ± 0.72 at 0.5 ms, 4.59 ± 3.67 mV), remaining stable at follow-up at 1 month (1.16 ± 0.92 at 0.5 ms, 4.17 ± 3.97 mV),. Average QRS width was40.8 ± 21.3 ms pre and 122.43 ± 15.2 ms post). LBBAP pacing thresholds and R-wave amplitudes were(0.89 ± 0.45 at 0.5 ms, 6.145 ± 5.3 mV)at implant, and were stable at follow-up at 1 month (0.75 ± 0.3 at 0.5 ms, 8.41 ± 5.8 mV), with no improvements on QRS (129.75 ± 21.01 ms pre, 134.13 ± 17.34 ms post).

During a mean follow-up of 23 months. There has been no acute elevation of thresholds or need for reintervention. Only 6 patients have died (10.3%), 2 of them (33%) from cardiovascular causes.

Conclusions

HPCSP is feasible as a routine techniquein patients after TAVR who need a pacemaker implantation, with low pacing thresholds, which remained stable on the follow-up.
Single-center experience with His bundle lead implantation: success rate, implantation method optimization, and lessons learned in 426 patients
Authors: Foeldvary M , Grigoryan A , Tribunyan S , Bachour C , Feldmann T , Israel C
Published: May 2024

Background

Conduction system pacing (CSP) is increasingly used to avoid the development of pacing-induced cardiomyopathy in patients who require a high amount of ventricular pacing. His bundle pacing (HBP) is considered as ideal to achieve the narrowest paced QRS and optimal synchronization in patients with intrinsic narrow QRS or right bundle branch block but also as difficult at implantation.

Purpose

We analyzed our experience with HBP in terms of time and effort, pacing and sensing results, success rate, and lessons learned for optimization over a time period of 7 years.

Methods

All consecutive patients in whom HBP was attempted between 6/2016 and 11/2023 were included in this analysis. Implantations were performed using a pacing system analyzer (PSA) with high-resolution electrograms (EGMs). Data on implantation success [selective or non-selective HBP, left bundle branch area pacing (LBBAP)], sensing and pacing parameters, achievement of His bundle current of injury (coi), duration of implantation and fluoroscopy were collected prospectively. These results were compared for the 1st, 2nd, 3rd and 4th quartile of implantations and reasons for improvement or deterioration were analyzed.

Results

HBP was attempted in 426 patients (78±11 years, 38% female, 90% AV block, left ventricular ejection fraction 54±10 %, 81 single-, 286 dual-, 46 triple-chamber pacemakers, 2 dual- and 11 triple-chamber ICDs) and was successful in 404 patients (95%): 182 non-selective HBP, 206 selective HBP, and 16 LBBAP. R wave amplitude was 4.5±3.5 mV, pacing threshold 1.1 ± 0.6V/1.0 ms. In 16% of patients, a ventricular back-up lead was implanted. A His bundle coi was achieved in 61% of patients. The implantation duration was 92±43 min, fluoroscopy duration 10±8 min. Success rate increased from 89% in the 1st to 99% in the 4th quartile. Improved implantation success was associated with using a stiff 3D steerable sheath, implantation site at the distal His bundle, and an increased number of screw-in turns until a His bundle coi was visible.

Conclusions

Establishing an implantation routine with 1) a PSA and high-resolution EGMs, 2) use of a stiff 3D steerable sheath, 3) implantation at the distal His bundle with myocardial capture (non-selective HBP) as a back-up, and 4) an increased number of screw-in turns of the lead tip until a His bundle coi is achieved, HBP implantation can be facilitated and results optimized to a highly acceptable implantation effort and a success rate >95%.
The effect of bachmann bundle pacing on diastolic function in patients with non-obstructive HCM
Authors: Singh J , Subramanian M , Saggu D , Yalagudri S , Sridevi C , Narasimhan C , Korabathina R
Published: May 2024

Background and Objective

Patients with non-obstructive HCM (nHCM) have advanced diastolic dysfunction and atrial remodeling, leading to increased heart failure hospitalisations. The objective of this study was to evaluate the role of Bachmann bundle pacing (BBP) in diastolic filling compared to right atrial appendage pacing (RAAP).

Methods

Forty patients with symptomatic nHCM and normal LV function were prospectively enrolled from January 2021 to June 2023. Inclusion criteria included electrocardiographic evidence of inter-atrial delay, E/e’ > 15, and an indication for ICD implantation. BBP was attempted in twenty patients, others underwent RAAP. A Biotronik Selectra 3D 40-S sheath was used for BBP in patients in whom initial lead implantation was unsuccessful. BBP was defined based on P-wave morphology and fluoroscopic lead position. The RV lead was implanted in the RV apex in all patients and the AV delay was optimized based on diastolic filling period and E/e’. Devices were programmed in DDD mode. During follow up, diastolic function, functional capacity, atrial fibrillation, and heart failure hospitalisations were assessed in both groups.

Results

Among the forty patients (age 48.2+7.8 yrs, males 75%, ESC-SCD Risk 4.3+0.6%), the baseline P wave duration, E/A, E/e’ were 138.4+16.4 ms, 2.5+0.5, and 17.5+2.4, respectively. Six patients (15%) had a history of paroxysmal AF (3 each in BBP and RAAP groups). Of the 16 patients (80%) who underwent successful BBP, the Selectra 3D 40-S sheath was used in 8 patients (Figure 1, Panel A). During BBP, a bachmann bundle potential was recorded in 7 of 16 patients (43.8%) (Figure 1, Panel C). The pacing threshold (1.5+0.5@0.4ms vs. 0.9+0.3@0.4ms, p=0.026) was higher and the atrial sensing (1.8+0.4 vs. 3.3+0.6, p=0.002) was lower in the BBP group compared to the RAAP group at 4 weeks and 6 months of follow up. There was an acute rise in threshold (2.1@0.4 ms) in 1 BBP patient at 4 weeks of follow up. Patients in the BBP group had a reduction in P wave duration compared to the patients in the RAAP group (-22.5 + 5.4 vs. +5.6 + 3.2 ms, p<0.001). During follow up (11.4 + 3.4 months), there was a significant improvement in diastolic function (E/e’), functional capacity (NYHA Class) and reduction in NT-proBNP in the BBB group compared to the RAAP group (Figure 1). The percentage of atrial pacing was similar in both groups (BBP 73.2 + 7.8 vs. RAAP 78.5 + 9.1 %, p=0.219). The risk of atrial fibrillation/tachycardia (12.5% vs. 35.0%, p=0.022) and heart failure hospitalisations (6.3% vs. 20%, p=0.042) was lower in the BBP group compared with RAAP during follow up.

Conclusions

BBP is safe and effective in improving diastolic function, functional capacity and heart failure hospitalizations in patients with nHCM.BBP Pacing using Selectra 3D 40-S SheathChange in E/e', NYHA, and NT-pro BNP
Development of chronic thresholds in His bundle pacing: single-center experience over 7 years in 426 patients
Authors: Grigoryan A , Foeldvary M , Tribunyan S , Bachour C , Feldmann T , Israel C
Published: May 2024

Background

Conduction system pacing (CSP), e. g. by His bundle pacing (HBP) has the potential to perform highly synchronized ventricular pacing in patients with AV block and narrow QRS complex or right bundle branch block. Therefore, CSP is recommended in these patients to prevent pacing-induced cardioomyopathy. However, there have been reports about an acute and chronic threshold increase in HBP that may cause asystole in pacemaker-dependent patients.

Purpose

We checked the development of chronic pacing thresholds, the incidence of dislodgements and of consecutive asystole in patients with HBP.

Methods

All consecutive patients with HBP attempted in our center between 6/2016 and 11/2023 were enrolled. Pacing and sensing parameters over 36 months together with the follwing events were collected and analyzed: His bundle lead dislodgement, loss of capture, threshold increase to ≥3.0V/1.0 ms, emergency admission due to syncope with loss of HBP and asystole.

Results

In 426 patients (78±11 years, 38% female, 90% AV block, left ventricular ejection fraction 54±10%), HBP was attempted and in 388 patients successful (47% non-selective, 53% selective HBP), 16 patients were converted to left bundle branch area pacing, 22 implantations attemps were unsuccessful. Pacing and sensing performance during follow-up are listed in the Fig.

There were 3 lead dislodgements (2 patients with Twiddler syndrome), 1 loss of capture (patient with sinus node disease), and 13 increases of pacing thresholds to ≥3.0V/1.0 ms, summing up to 17 events over 3 years (4.3%). No patient had a clinical event due to threshold increase or loss of HBP capture. All His bundle threshold increases were clinically silent because patients were not pacemaker-dependent, had non-selective HBP with myocardial capture serving as a "back-up" or due to a previously implanted right ventricular back-up lead.

Conclusions

There is a modest pacing threshold increase in His bundle thresholds from 1.1 to 1.8V@1.0 ms over a period of 3 years. However, this did not cause clinically relevant events in our patient cohort.Chronic pacing and sensing parameters
Left ventricular ejection fraction and myocardial fibrosis in survivors of ventricular fibrillation and ventricular tachycardia
Authors: Leyva F , Zegard A , Okafor O , Debono J , Lencioni M , Griffith M , Marshall H , Qiu T
Published: May 2024

Background

Primary prevention implantable cardioverter defibrillator (ICD) therapy is indicated in patients with a LVEF<35%. Increasing evidence suggests that LVEF is a poor predictor or ventricular arrhythmias, such as ventricular tachycardia (VT) or fibrillation (VF).

Methods

Patients hospitalized for VF (55.4%) or VT with hemodynamic compromise underwent late gadolinium enhancement cardiovascular magnetic resonance (CMR). Patients with congenital heart disease, channelopathies, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and chemotherapy-induced cardiomyopathy were excluded.

Results

Among patients (n=111, aged 62.1 ± 14.6 years [mean ± SD]) hospitalized for VF (55.4%) or VT with hemodynamic compromise (44.5%) only 29/111 (43.6%) had a history of cardiac disease. At the index hospitalization, an ischemic cause was identified in 69.3%, a non-ischemic cause in 24.8% and no cause emerged in 5.9%. The LVEF (39.1 ± 17.2%) was ≤35% in 55.4% and >35% in 44.6%. Myocardial fibrosis was present in 85.1% (LVEF≤35%: 91.1%; LVEF>35%: 77.8%; p = 0.0619).

Conclusions

A large proportion of sustained VT or VF survivors would not have previously met LVEF primary prevention criteria for ICD therapy. In this 'ICD treatment gap', myocardial fibrosis was more prevalent than a LVEF≤35%. Further studies are needed to determine whether myocardial scar rather than LVEF≤35% should be used as an indication for primary prevention ICD therapy.
Outcomes of subcutaneous implantable cardioverter defibrillators: UK tertiary centre experience
Authors: Toon L T , Elrefai M , Bates A , Patil R , Hudson J , Zubair Z , Roberts P R
Published: May 2024

Introduction

Subcutaneous implantable cardioverter–defibrillators (S-ICDs) were introduced to address limitations associated with the transvenous ICDs (TVICDs). The programming features of the S-ICDs is however restricted compared to TVICDs. Our investigation aims to assess the outcomes of S-ICDs that have been implanted at our institution.

Purpose

To assess the outcomes of S-ICDs implanted at a tertiary healthcare centre in the United Kingdom.

Methods

A retrospective analysis was conducted, encompassing data from all individuals who underwent S-ICD implantation at our institution between January 2011 to April 2023 (n=240). Complications were categorized as device-related complications or inappropriate shock (IAS). All occurrences of IAS; lead revisions; infection; pocket hematoma requiring drainage, blood transfusion, or prolongation of hospitalization; and other complications prompting medical or surgical intervention were documented. The underlying causes and outcomes of IAS were reviewed. If S-ICD was either deactivated or explanted, the reasons for such actions were documented.

Results

Among the 240 patients included in the study, the average age is 46 years, with 66% being male. The average body mass index (BMI) is 27.8 and the ejection fraction (EF) is 43.3%. Comprehensive baseline characteristics are outlined in Table 1.

Defibrillation testing (DFT) is a standard practice in our institution to ensure the integrity of S-ICDs and was conducted in all patients unless contraindicated. The success rate of DFT among attempted patients was 73%.

The cumulative incidence of device-related complications over the study period was 15%. Eleven patients (4.6%) experienced IAS with T-wave oversensing as the leading cause. Patients undergoing S-ICD implantation for secondary prevention were found to be more susceptible to experiencing IAS (8 Vs 3, p=0.005) but no other baseline characteristics exhibited an association with any complications. The administration of beta-blockers and device reprogramming prevented further IAS in five patients. The remaining patients necessitated interventions such as lead revision, ablation therapy, switching to TVICD, or upgrading to cardiac resynchronisation therapy (CRT).

A total of 38 patients required device explant or deactivation. The primary cause for such actions was due to patient mortality. The other notable causes included S-ICD infection, premature battery depletion, and IAS (Table 2).

Conclusion

Based on our findings, S-ICD emerges as a useful option for the prevention of sudden cardiac death in many patients. The decision regarding the selection of the appropriate ICD for individual patients warrants comprehensive discussion, encompassing a thorough discussion of advantages and disadvantages with the patients. We anticipate that the data elucidated in this study will be valuable in informing future patient care considerations.Table 1Baseline CharacteristicsTable 2Reasons
Impact of myocardial phenotype on atrioventricular delay optimization at rest and during exercise: insights from a virtual patient study
Authors: Manetti C A , Van Osta N , Prinzen F W , Herbots L , Delhaas T , Lumens J
Published: May 2024

Background

The usefulness of atrioventricular delay (AVD) optimization in cardiac resynchronization therapy (CRT) for heart failure (HF) patients with left bundle branch block (LBBB) and reduced left ventricular ejection fraction (LVEF) is still debated. Yet, studies have not explored the role of non-electrical myocardial disease substrates in determining optimal AVD settings among patients.

Purpose

We first hypothesized that acute response to AVD optimization might be modulated by various myocardial disease substrates. Furthermore, we hypothesized that cardiac function is more sensitive to changes in AV coupling during exercise and that this sensitivity is also modulated by underlying myocardial disease substrates.

Methods

We used the CircAdapt model of the human heart and circulation to simulate different types of LV remodeling that can be found in CRT candidates. First, an LBBB-like pattern of mechanical activation was imposed by delaying LV free wall (LVFW) and interventricular septal (IVS) activation relative to right ventricular free wall activation. Then, two types of LV remodeling were simulated by LV dilation with preserved or impaired myocardial contractility, resulting in LVEF <35%. To investigate the effect of diastolic dysfunction, we increased passive myocardial stiffness of the IVS and LVFW on both substrates with LV remodeling until a mean left atrial pressure (mLAP) of 14 mmHg was reached. CRT was simulated by resynchronizing IVS and LVFW. AVD optimization was conducted by gradually reducing the paced AVD from 220 ms to 40 ms in steps of 20 ms. In each simulation, the optimal paced AVD at rest (cardiac output (CO) and heart rate (HR) of 4.2 L/min and 80 bpm, respectively) was assessed using stroke volume (SV) and mLAP which is used as a measure of LV filling pressure. To investigate the relative effect of these myocardial phenotypes during AVD optimization under exercise, CO and HR were increased step-wise.

Results

The gain in SV by AVD optimization was larger in the simulations with healthy myocardium than in those with hypo-contractile and stiff myocardium (Figure 1: top-row). However, mLAP was comparably decreased by AVD optimization in healthy and diseased myocardium (Figure 1: bottom row). During exercise, the optimum AVD shifted to shorter values (Figure 2: top-row), and mLAP was much more sensitive to AVD, particularly in the presence of hypo-contractile and stiff myocardium (Figure 2: bottom row).

Conclusion

Virtual patient simulations show that both myocardial hypocontractility and stiffness dampen the effect of AVD optimization on SV. Furthermore, simulations suggest that patients benefit more from AVD optimization during exercise than during resting conditions. These mechanistic insights may help to gain more benefit from AVD optimization for patients undergoing CRT.AVD optimization at restAVD optimization during exercise