bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract

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’ &gt; 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&lt;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

Abstract

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

Abstract

Background
Primary prevention implantable cardioverter defibrillator (ICD) therapy is indicated in patients with a LVEF&lt;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 &gt;35% in 44.6%. Myocardial fibrosis was present in 85.1% (LVEF≤35%: 91.1%; LVEF&gt;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

Abstract

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

Abstract

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 &lt;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
Impact of left bundle branch block morphology in predicting response to left bundle branch area pacing for cardiac resynchronization therapy
Authors: Latorre M , Bressi E , Grieco D , Crescenzi C , Golia P , Bruni G , Fagagnini A , Politano A , Panuccio M , De Luca L , Rebecchi M , Calo L , De Ruvo E 
Published: May 2024

Abstract

Background
Left bundle branch area pacing (LBBAP) is a novel pacing technique with an emerging role in resynchronization therapy [1-4]. QRS morphology has shown to significantly influence cardiac resynchronization therapy (CRT) response [5-6].

Purpose
The aim of this study was to assess whether different left bundle branch block (LBBB) definitions are associated with response to LBBAP resynchronization therapy.

Methods
40 consecutive CRT candidates with previously unsuccessful biventricular (BiV) pacing or in which effective CRT could not be achieved with BiV pacing based on anatomical or functional criteria were selected for this study. Both ischemic and non-ischemic heart failure (HF) patients were included. Patients were divided into two groups according to LBBB morphology. Group 1 included 20 patients (45% ischemic HF) with strict LBBB definition according to Strauss criteria [7], while 20 patients in Group 2 (55% ischemic HF) had conventional LBBB morphology. Response to CRT was defined for (1) reduction in QRS duration; (2) increase in left ventricular ejection fraction (LVEF) ≥ 5% and (3) decrease in left ventricular end systolic volume (LVESV) ≥ 15%.

Results
LBBAP was successfully achieved in all patients (mean age: 72.0 years; male: 29). The mean baseline QRS duration before implantation was 178.6±13.8 in the Group 1 and 170.8±29.4 in the Group 2, without a statistically significant difference. Over a mean follow-up of 5.6 months, LBBAP resulted in QRS narrowing in both groups, with a greater reduction in Group 1 (-40.6 ms) compared to Group 2 (-15.1 ms), (p 0.002). Pre-implantation ventricular systolic function did not show significant differences between the two groups, with a mean of 30.1±3.5% in the Strauss LBBB group and 31.0±6.0% in the conventional LBBB group. After implantation LVEF was 42.1±8.5 % in the true LBBB patients and 33.2±7.5 in the conventional LBBB group. Echocardiographic response was observed in 65% of patients with a statistically significant difference between Group 1 (90% of responders) and Group 2 (40% of responders), (p 0,001). HF etiology did not impact the response to LBBAP CRT.

Conclusions
Strict LBBB definition is associated to a greater electrocardiographic and echocardiographic response in patients receiving LBBAP CRT compared to conventional LBBB criteria.\
His bundle pacing implantation in octogenarian patients: a substudy of the PACE-CONDUCT trial
Authors: Stangl D , Buia V , Walascheck J , Bastian D , Rittger H , Vitali-Serdoz L 
Published: May 2024

Abstract

Background
His bundle pacing (HBP) is gaining recognition as a valuable alternative for the management of various cardiac conduction disorders. This substudy, conducted within the framework of the PACE-CONDUCT trial, investigates the outcomes of HBP implantation in patients aged 80 years and older, comparing them with a younger cohort.

Methods
We examined a total of 61 consecutive patients who underwent HBP implantation, utilizing DDD pacemakers, CRT-P, or CRT-D devices, during the years 2021 to 2023. Patients were categorized into two subgroups: those aged younger than 80 years and those aged 80 years or older. The mean age of the entire cohort was 73 years, spanning from 51 to 86 years, with 15 patients (comprising 24.6% of the total) falling into the octogenarian category. His bundle threshold was assessed on the day of implantation, one day post-implantation, and four weeks post-implantation. All HBP implantations were deemed successful, incorporating both selective and non-selective His bundle pacing. Complications were classified as major (necessitating lead or pocket revision) or minor (requiring no revision). Threshold values were converted to volts per milliseconds (volts x milliseconds) for statistical analysis, conducted with IBM SPSS Statistics 29.0.

Results
Initial analysis revealed a consistent success rate of HBP implantation across all patients, with no discernible differences between the two age groups. Threshold measurements at the day of implantation and after one day indicated no differences between the younger and the older group. However, at the four-week mark, a statistically significant lower threshold of His bundle pacing was observed in the octogenarian group (one-sided p-value 0.028), suggesting a faster stabilization to the chronic threshold of the active fixation His Bundle lead. The comparison of major and minor complications between the age groups, conducted using chi-square tests, revealed no age-related discrepancies.

Conclusions
This substudy of the PACE-CONDUCT trial underscores the feasibility and safety of His bundle pacing implantation in octogenarian patients, comparable to their younger counterparts. While no initial threshold variations are observed, the octogenarian group demonstrated improved His bundle pacing thresholds approximately four weeks post-implantation. Importantly, the study revealed no heightened complication risk associated with advanced age, affirming that very old patients aged 80 or older can derive the benefits of His bundle pacing without increased complication rates. Given the relatively modest patient cohort in this study, further investigations are warranted to validate and extend these findings.T-tests and Chi square tests
The pursuit of gender equality: a substudy of the PACE-CONDUCT trial on gender differences in His bundle pacing implantation
Authors: Stangl D , Buia V , Walascheck J , Rittger H , Bastian D , Vitali-Serdoz L 
Published: May 2024

Abstract

Background
His bundle pacing (HBP) is an effective alternative to traditional right ventricular pacing, providing physiological pacing. The impact of gender on the success of HBP implantation has not been extensively explored. We conducted a substudy of the PACE-CONDUCT registry to investigate gender differences in HBP implantation success.

Methods
We analyzed successful HBP implantations performed from 2021 to 2023. A total of 61 patients were included, comprising 22 females (36%) and 39 males (64%) . The mean age of the entire cohort was 73 years, with ages ranging from 51 to 86 years. His bundle thresholds were assessed at implantation, the day following implantation, and four weeks post-implantation. All data were analyzed using IBM SPSS Statistics 29.0, and thresholds were converted into volts × milliseconds for statistical analysis.

Results
The minimal HBP threshold across all measurements was 0.10 volts × milliseconds, equivalent to a standard threshold of 0.25 volts by 0.4 milliseconds, while the maximal threshold was 7.13 volts × milliseconds, corresponding to a standard threshold of 4.75 volts by 1.5 milliseconds. Gender differences were examined, dividing the patient cohort into male and female groups, and an independent-samples t-test was conducted. The results did not reveal any statistically significant differences in HBP threshold between the two groups at the time of implantation, one day post-implantation, or one month post-implantation. Chi square tests were conducted to determine if there could be any gender differences analyzing the complication rates, also finding negative results.

Conclusion
This substudy of the PACE-CONDUCT trial found no significant gender-based differences in the success of His bundle pacing implantations, taking the threshold at implantation, one day after and four weeks after implantation as a surrogate of goodness of the HBP implantation itself. Although the cohort size was limited, our findings provide initial insights, suggesting that gender is not a decisive factor in HBP threshold outcomes or in complication rates. Further investigations with larger sample sizes are warranted to explore this topic in greater depth.statistics output
Right ventricular systolic pressure is an independent risk factor of all-cause death and inappropriate therapies in patients with implanted CRT-D
Authors: Machowicz J , Dyrbus M , Pyka Ł , Kurek A , Niedziela J , Adamowicz-Czoch E , Ostrega M , Sokola K , Pres D , Skrzypek M , Tajstra M , Gasior M 
Published: May 2024

Abstract

Introduction
Cardiac resynchronization therapy-defibrillators (CRT-D) are implanted mostly in patients with low left ventricular ejection fraction (LVEF) and wide QRS. In such subjects, there is often a concomitant right ventricular (RV) dysfunction, which has been associated with higher long-term mortality. However, data on the association between RV dysfunction and arrhythmic outcomes in patients with CRT-D are scarce.

Purpose
To define whether there is any association between right ventricular dysfunction and antiarrhythmic therapies or all-cause mortality in patients with HF and CRT-D.

Methods
The clinical and demographic data of patients enrolled in this study were obtained from the single-centre COMMIT-HF registry. The parameters regarding right ventricular function, such as right ventricle dimension (RVD), tricuspid annular systolic plane systolic excursion (TAPSE) and right ventricular systolic pressure (RVSP) were obtained from electronic patients’ records. The data on the long-term hard endpoints were obtained from the national healthcare provider, while the data on the risk of arrhythmic events, CRT-D shocks and antitachycardia pacing (ATP) were obtained from investigator-initiated and -adjudicated single-centre remote monitoring database updated annually. Multivariable stepwise logistic regression was used to determine independent predictors of the study outcomes, being all-cause death, and the occurrence of appropriate and inappropriate CRT-D therapies.

Results
During the period between July, 2009 and November, 2019, 335 patients were enrolled at the RM programme after implantation of CRT-D. Of them, during the median (Q1-Q3) follow-up period of 5.3 (2.8-6.6) years, (113 (33.7%) died, 111 (33.1%) received appropriate and 37 (11%) inappropriate therapies. In the multivariable analysis, the independent predictors of all-cause death were reduction in LVEF and increase in RVSP. Lower age and increased LVEDD were independent predictors of appropriate therapies, while lower age and increased RVSP were independent predictors of inappropriate therapies. No association between TAPSE and RVD and outcomes was found.

Conclusions
Among right ventricular dysfunction parameters, RVSP is an independent predictor of inappropriate therapies and all-cause death, but not of appropriate therapies in patients with HF and CRT-D.