In patients with permanent pacemaker (PPM) implantation, chronic kidney disease (CKD) milieu increases the risk of pacing-induced cardiomyopathy and worse long-term survival. Conversely, whether high right ventricular (RV) pacing burden in these patients could potentially accelerate renal failure progression and lead to poor outcomes remains unexplored yet.

We analyzed the renal outcomes of advanced CKD (stage 3b-4) patients who received PPM implantation, identified from a multidisciplinary CKD longitudinal management program. RV pacing burden was defined as the average RV pacing percentage (RVP %) from pacemaker insertion to the event or censoring, logarithmically transformed into LogRVP %. RVP % ≥20 % was categorized as a high RV pacing burden group. The primary outcome was a composite of a ≥50 % decline in eGFR from baseline, a sustained eGFR ≤10 mL/min/1.73 m2, initiation of dialysis, and death from renal causes.

A total of 90 patients with mean baseline eGFR 37.8 ± 15.3 mL/min/1.73 m2 and mean averaged RVP % 30.8 % were analyzed over a median follow-up of 3.9 years. Twenty-six patients reached the composite outcome. Higher LogRVP % was significantly associated with the primary composite outcome (hazard ratio [HR]: 1.771, 95 % confidence interval [CI]: 1.096-2.860, p = 0.02), especially those with baseline eGFR <30 mL/min/1.73 m2. Patients with RVP% ≥ 20 % faced a higher risk of primary composite outcome (HR: 2.907, 95 % CI: 1.263-6.687, p = 0.01).

Among advanced CKD patients who underwent PPM implantation, a higher RV pacing burden was significantly associated with an increased risk of poor renal outcomes.

Conduction system pacing (CSP), encompassing His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), revolutionizes cardiac pacing, allowing a more physiological left ventricular activation than conventional right ventricular (RV) pacing through electrode placed in RV apex, interventricular septum or right ventricular outflow tract. Echocardiography plays a pivotal role in patient assessment, primarily by measuring left ventricular ejection fraction (LVEF) to determine the pacing strategy in alignment with current guidelines. Clinical data, simulations and ongoing trials on CSP explore CSP viability across various LVEF conditions. CSP is supposed to defer pacing-induced cardiomyopathy (PiCM) associated with conventional right ventricular pacing (RVP). This paper aims to review the current literature regarding the use of echocardiography in CSP. Images from our experience in the echocardiographic lab were used throughout this document to show our proposals of imaging in CSP. Echocardiography may help to determine lead localization within the interventricular septum (IVS), customizing pacing to individual anatomy and electromechanical indices (like atro-ventricular delay) and evaluates often-overlooked valvular function, a potential PiCM contributor. Three-dimensional (3-D) echocardiography widens the knowledge of lead localization and valvular dysfunction, as well as dyssynchrony assessment. Dyssynchrony, crucial both to resynchronization per se and physiological stimulation is quantified via echocardiography, especially using speckle-tracking imaging. Baseline LVEF and follow-up observation of CSP effects: early in Global Longitudinal Strain (GLS), afterwards in LV volumes and LVEF may improve the future proper qualification of patients. Limited left atrial (LA) and right atrial (RA) strain assessments hold potential in the CSP qualification and response assessment context. Echocardiography complements other imaging modalities for comprehensive patient evaluation. Echocardiography is integral in the CSP clinical use, from patient selection (by showing subtle changes in myocardial function) to post-procedure follow-up (tricuspid regurgitation, LV and RV function, leads and synchrony assessment). GLS, assessed by speckle tracking imaging and profound 2D and 3D (lead placement, septum morphology and global heart function under CSP) analyses show promise in CSP outcome assessment, though standardization is needed.

Conduction disturbances have uncertain implications for long-term left ventricular ejection fraction (LVEF) after transcatheter aortic valve replacement (TAVR). We aimed to examine LVEF changes in patients up to two years post-TAVR.

We examined patients who underwent TAVR between 2012 and 2020 and underwent echocardiography follow-up. Patients were categorized into four groups: 1) Those without a permanent pacemaker (PPM) or left bundle branch block (LBBB) pre- or post-TAVR; 2) Patients with pre- and post-TAVR LBBB; 3) Individuals with preexisting PPM; and 4) Patients requiring new PPM after TAVR. LVEF was assessed at the outset of TAVR, at 30 days, 1-year, and 2-years post-TAVR.

The study included 730 patients: 421 (57.6 %) without conduction abnormalities, 151 (20.7 %) with post-TAVR LBBB (48 pre-existing, 103 new-onset), 63 (8.6 %) with pre-existing PPM, and 95 (13.1 %) requiring new PPM. At discharge, patients without conduction abnormalities exhibited the highest LVEF (57.4 ± 11.5 %), whereas those with pre-existing PPM had the lowest (48.1 ± 15.5 %). Over two years, LVEF remained constant in patients without conduction issues and in those with pre-existing PPM. However, patients with new LBBB experienced a 6.3 % decrease in LVEF, and those requiring new PPM showed a 4.1 % reduction.

New conduction abnormalities, such as LBBB or the need for PPM, induce a decline in LVEF post-TAVR. It is imperative to focus on the long-term monitoring of left ventricular function in patients experiencing new conduction disturbances post-TAVR.

Traditional right ventricular pacing (RVP) can lead to asynchronous cardiac mechanical contractions and increase the risk of atrial fibrillation (AF). This study aimed to compare the occurrence of new-onset AF and the progression of AF between novel physiological pacing-left bundle branch area pacing (LBBAP) and RVP with a long-term follow-up.

Patients with a dual-chamber permanent pacemaker initial implantation, no history of persistent AF, and an expected high proportion of ventricular pacing (VP ≥ 20%) were included in this retrospective cohort study (LBBAP, n = 122; RVP, n = 166). The pacing QRS duration (QRSd) of the LBBAP was significantly shorter than that of the RVP (113 ± 22 vs. 140 ± 27 ms, p < 0.001), while the intrinsic QRSd values from the two groups were comparable. During a mean follow-up of 21.9 ± 9.4 months, the composite outcome of postoperative new-onset AF or AF progression was higher in the RVP group than in the LBBAP group (RVP HR 2.62, 95%CI 1.21-5.67, p = 0.014). Left ventricular end-diastolic diameter (LVEDD) levels decreased in the LBBAP group at 1 year follow-up (50 ± 6 vs. baseline 48 ± 6, p = 0.002).

In a mean follow-up period of 2 years, compared to RVP, LBBAP patients with VP ≥ 20% had a decreased risk of occurrence and progression of AF events.

Right ventricular (RV) pacing, particularly from the RV apex, causes bilateral ventricular dyssynchrony, reducing systolic and diastolic function, by delayed activation of the lateral left ventricle, resulting in a wide QRS with a left bundle branch block (LBBB) morphology. Alternative pacing strategies, such as His-bundle pacing and LBB area pacing, tend to be more physiological, avoiding this problem. The feasibility of attaining a narrow paced QRS from the RV septum has not been methodically examined. This study aimed to test the hypothesis that, through pacing at select RV septal sites by careful mapping, it is possible to achieve a narrow "paced QRS," facilitating physiological pacing. The underlying assumption is that a narrow paced QRS prevents long-term deterioration of cardiac function. During dual-chamber pacemaker implantation with standard active fixation leads, the RV septum was mapped carefully before fixing the lead. A characteristic spike potential was identified at some sites which, on stimulation, yielded a narrow paced QRS. The paced QRS duration was measured at different mapping sites; the narrowest paced complex was chosen for long-term pacing. Sixteen consecutive patients underwent pacemaker implantation using this mapping technique. A narrow paced QRS was achieved in 12 patients, whereas narrow paced complexes could not be achieved in 4 patients. Among the 12 narrow paced QRS patients (mean age, 81.5 ± 8.2 years), the indication for pacing was atrioventricular block in 6 patients and sick sinus syndrome in 6 patients. Two patients showed a negative paced QRS in leads 1 and aVL, suggesting an early left-sided septal activation. In the 12 narrow paced QRS patients, the post-pacing mean QRS duration (121.5 ± 14.9 ms) was not significantly different from the pre-pacing mean QRS duration (118.2 ± 23.5 ms) (P > .5); the QRS morphology was normal in seven patients, while four patients had LBBB and one patient had right bundle branch block. In all 12 patients, the narrowest paced complex was associated with a characteristic potential in the endocardial electrogram. Detailed RV septal mapping can yield a narrow paced QRS associated with a characteristic endocardial potential in the pre-pacing electrogram, suggesting possible direct native conduction system access.

Traditional right ventricular pacing (RVP) can lead to asynchronous cardiac mechanical contractions and increase the risk of adverse cardiac events. This study aimed to compare the clinical complications between left bundle branch area pacing (LBBAP), which is both novel and physiological, and RVP in a cohort requiring ventricular pacing.

A retrospective study was conducted on patients with initial implantation of a dual-chamber, permanent pacemaker and with ventricular pacing proportion more than 20 % from January 2019 to December 2020. Patients were divided into the LBBAP or RVP group and follow-up was conducted routinely. The primary outcome was ventricular lead complications, including an increase in the ventricular lead threshold or a decrease in R-wave amplitude. Overall complications were defined as ventricular lead complications, ventricular lead dislocation, ventricular lead perforation, adverse cardiovascular events and cardiovascular death.

A total of 248 patients were included in the analysis (LBBAP, n=98; RVP, n=150). The pacing QRS duration in LBBAP patients was significantly shorter than in RVP patients (110.3±22.7 vs 140.0±29.3 ms, p<0.01). For a mean follow-up duration of 13 mos, the risk of ventricular lead complications was higher in the LBBAP group than in the RVP group (62.0 % vs. 36.5 %, p=0.03). LBBAP was comparable to RVP within one year follow-up when considering overall complications. At the one year follow-up ultrasound examinations, the LA in LBBAP group was decreased (p=0.04). Considering the larger initial left ventricular end-diastolic diameter (LVEDD) in the LBBAP group, the similarity of LVEDD values in both groups at follow-up suggested that LVEDD was reduced in patients treated with LBBAP. There was no difference in left ventricular ejection fraction (LBBAP LVEF, baseline = 61.2±8.6 %) between the two groups at baseline or follow-up.

LBBAP patients were more prone to ventricular lead threshold increase and amplitude decrease than RVP patients. The risk of overall complications in the two pacing modalities were equal in one year follow-up duration. LBBAP is safe and effective in patients with VP>20 % and without seriously depressed LVEF.

The relationship between conduction system pacing (CSP) and the incidence of atrial fibrillation (AF) in patients with heart failure and preserved ejection fraction (HFpEF) remains uncertain. This study aims to investigate the occurrence of atrial high-rate episodes (AHREs) following CSP in patients with HFpEF, in comparison to right ventricular pacing (RVP).

Patients with HFpEF who received dual-chamber pacemakers for atrioventricular block were retrospectively enrolled from January 2018 to January 2023. Both new-onset and progressive AHREs were recorded, along with other clinical data, including cardiac performance and lead outcomes.

A total of 498 patients were enrolled, comprising 387 patients with RVP and 111 patients with CSP, with a follow-up duration of 44.42 ± 10.41 months. In patients without a prior history of AF, CSP was associated with a significantly lower incidence of new-onset AHREs when the percentage of ventricular pacing was ≥20% (9.52% vs. 29.70%, P = 0.001). After adjusting for confounding factors, CSP exhibited a lower hazard ratio for new-onset AHREs compared to RVP (HR 0.336; [95% CI: 0.142-0.795]; P = 0.013), alongside left atrial diameter (LAD) (HR 1.109; [95% CI: 1.048-1.173]; P < 0.001). In patients with a history of AF, the progression of AHREs in CSP and RVP did not differ significantly (32.35% vs. 34.75%, P = 0.791). Cardiac performance metrics, including left ventricular end-diastolic diameter (LVEDD) (49.09 ± 4.28 mm vs. 48.08 ± 4.72 mm; P = 0.015), LAD (40.68 ± 5.49 mm vs. 39.47 ± 5.24 mm; P = 0.001), and NYHA class (2.31 ± 0.46 vs. 1.59 ± 0.73; P < 0.001), improved obviously following CSP, while LVEDD (48.37 ± 4.57 mm vs. 49.30 ± 5.32 mm; P < 0.001), LAD (39.77 ± 4.58 mm vs. 40.83 ± 4.80 mm; P < 0.001), NYHA class (2.24 ± 0.43 vs. 2.35 ± 0.83; P = 0.018), and left ventricular ejection fraction (LVEF) (57.41 ± 2.42 vs. 54.24 ± 6.65; P < 0.001) deteriorated after RVP.

Our findings suggest that CSP may be associated with improvements in cardiac performance and a reduction in new-onset AHREs compared to RVP in patients with HFpEF. However, prospective randomized trials are anticipated to confirm these potential benefits.

The deleterious effects of long term right ventricular pacing are increasingly being recognized today. Current clinical practice favors the implantation of dual-chamber permanent pacemaker which maintains atrioventricular synchrony and is associated with better quality of life. However, despite the popular belief and common sense surrounding the superiority of dual-chamber pacing over single chamber pacing, the same has never been conclusively verified in clinical trials. Some observational evidence however, does exists which supports the improved cardiac hemodynamics, lower the rate of atrial fibrillation, heart failure and stroke in dual-chamber pacing compared to single-chamber pacing. In the index study by Haque et al, right ventricular pacing, particularly in ventricular paced, ventricular sensed, inhibited response and rate responsive pacemaker adversely impacted the left ventricular functions over 9-months compared to dual pacing, dual sensing, dual responsive and rate responsive pacemaker. Although there are key limitations of this study, these findings does support a growing body of evidence reinstating the superiority of dual chamber pacing compared to single chamber pacing.

For patients with left ventricular systolic dysfunction and prolonged QRS duration, cardiac resynchronization therapy (CRT) can improve cardiac electromechanical synchrony and prevent adverse clinical outcomes.

This study sought to investigate the role of delta QRS duration (ΔQRSd) in predicting clinical response to CRT.

The RAFT (Resynchronization-Defibrillation for Ambulatory Heart Failure Trial) study randomized 1798 patients to CRT with defibrillator or implantable cardioverter-defibrillator alone. Those who received CRT and had electrocardiograms available at baseline and after CRT implantation were included in this analysis. ΔQRSd was calculated as the absolute difference between QRS duration at baseline and with CRT pacing. The primary outcome was the composite of death and heart failure hospitalization.

There were 813 patients included in this analysis. The median age was 67 years, and 125 patients (15.2%) were female. The median ΔQRSd was -2 ms (-20 to 18 ms), and 447 (55%) patients had a ΔQRSd ≤0 after implantation. ΔQRSd was an independent predictor of the composite outcome for patients with CRT (hazard ratio, 1.012; 95% confidence interval, 1.008-1.017). CRT recipients with ΔQRSd >0 had higher rates of the composite outcome than patients randomized to implantable cardioverter-defibrillator alone.

For patients receiving CRT for heart failure with left ventricular systolic dysfunction and QRS prolongation, ΔQRSd was an independent predictor of long-term mortality and heart failure hospitalization.

Although left bundle branch area pacing (LBBAP) has been shown to be a feasible option for delivering physiological pacing, data are largely limited to single-center reports. The aim of this analysis was to systematically assess the safety and efficacy of LBBAP with the Model 3830 lead among primarily bradycardia patients.

PubMed, Embase, Cochrane Library, and Google Scholar were searched for full-text articles on LBBAP using the SelectSecure Model 3830 lumenless lead. Rates and means were estimated using random- and mixed-effects models. Of 3395 articles, 53 met inclusion criteria, representing 6061 patients undergoing an implant attempt. Average patient age was 68.1 years (95% CI: 66.6, 69.6) and 53.1% were male (95% CI: 50.5%, 55.7%). The average implant success rate among bradycardia-indicated patients was 92.7% (95% CI: 89.5%, 94.9%). The overall estimated procedural adverse event rate was 2.5% (95% CI: 1.1%, 5.4%). The estimated septal perforation rate at implant was 1.6% (95% CI: 1.0%, 2.6%) with no adverse clinical sequelae reported. Pacing thresholds were low at implant (0.67 V [95% CI: 0.64, 0.70]) and remained stable through 12 months (0.76 V [95% CI: 0.72, 0.80]). Among bradycardia-indicated patients, LVEF remained stable from baseline to post-implant (59.5% [95% CI: 57.9%, 61.1%] vs. 60.1% [95% CI: 58.5%, 61.7%]).

This meta-analysis including 6061 patients implanted with a Model 3830 lead for LBBAP found an average implant success rate of 92.7% and a procedural adverse event rate of 2.5% with stable electrical parameters and LVEF post-implant.

Background: When compared to biventricular pacing, fusion CRT pacing was linked to a decreased incidence of atrial fibrillation (AF). There is a gap in the knowledge regarding exclusive fusion CRT without interference with RV pacing, and all the current data are based on populations of patients with intermittent fusion pacing. Purpose: To assess left atrium remodeling and AF incidence in a real-life population of permanent fusion CRT-P. Methods: Retrospective data were analyzed from a cohort of patients with exclusive fusion CRT-P. Device interrogation, exercise testing, transthoracic echocardiography (TE), and customized medication optimization were all part of the six-monthly individual follow-up. Results: Study population: 73 patients (38 males) with non-ischemic dilated cardiomyopathy aged 63.7 ± 9.3 y.o. Baseline characteristic: QRS 159.8 ± 18.2 ms; EF 27.9 ± 5.1%; mitral regurgitation was severe in 38% of patients, moderate in 47% of patients, and mild in 15% of patients; 43% had type III diastolic dysfunction (DD), 49% had type II DD, 8% had type I DD. Average follow-up was 6.4 years ± 27 months: 93% of patients were responders (including 31% super-responders); EF increased to 40.4 ± 8.5%; mitral regurgitation decreased in 69% of patients; diastolic profile improved in 64% of patients. Paroxysmal and persistent AF incidence was 11%, with only 2% of patients developing permanent AF. Regarding LA volume, statistically significant LA reverse remodeling was observed. Conclusions: Exclusive fusion CRT-P was associated with important LA reverse remodeling and a low incidence of AF.

Background: Conduction abnormality post-transcatheter aortic valve implantation (TAVI) remains clinically significant and usually requires chronic pacing. The effect of right ventricular (RV) pacing post-TAVI on clinical outcomes warrants further studies. Methods: We identified 147 consecutive patients who required chronic RV pacing after a successful TAVI procedure and propensity-matched these patients according to the Society of Thoracic Surgeons (STS) risk score to a control group of patients that did not require RV pacing post-TAVI. We evaluated routine echocardiographic measurements and performed offline speckle-tracking strain analysis for the purpose of this study on transthoracic echocardiographic (TTE) images performed at 9 to 18 months post-TAVI. Results: The final study population comprised 294 patients (pacing group n = 147 and non-pacing group n = 147), with a mean age of 81 ± 7 years, 59% male; median follow-up was 354 days. There were more baseline conduction abnormalities in the pacing group compared to the non-pacing group (56.5% vs. 41.5%. p = 0.01). Eighty-eight patients (61.6%) in the pacing group required RV pacing due to atrioventricular (AV) conduction block post-TAVI. The mean RV pacing burden was 44% in the pacing group. Left ventricular ejection fraction (LVEF) was similar at follow-up in the pacing vs. non-pacing groups (57 ± 13.0%, 59 ± 11% p = 0.31); however, LV global longitudinal strain (-12.7 ± 3.5% vs. -18.8 ± 2.7%, p < 0.0001), LV apical strain (-12.9 ± 5.5% vs. 23.2 ± 9.2%, p < 0.0001), and mid-LV strain (-12.7 ± 4.6% vs. -18.7 ± 3.4%, p < 0.0001) were significantly worse in the pacing vs. non-pacing groups. Conclusions: Chronic RV pacing after the TAVI procedure is associated with subclinical LV systolic dysfunction within 1.5 years of follow-up.

Cardiac pacing has evolved in recent years currently culminating in the specific stimulation of the cardiac conduction system (conduction system pacing, CSP). This review aims to provide a comprehensive overview of the available literature on CSP, focusing on a critical classification of studies comparing CSP with standard treatment in the two fields of pacing for bradycardia and cardiac resynchronization therapy in patients with heart failure. The article will also elaborate specific benefits and limitations associated with CSP modalities of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP).

Based on a growing number of observational studies for different indications of pacing therapy, both CSP modalities investigated are advantageous over standard treatment in terms of narrowing the paced QRS complex and preserving or improving left ventricular systolic function. Less consistent evidence exists with regard to the improvement of heart failure-related rehospitalization rates or mortality, and effect sizes vary between HBP and LBBAP. LBBAP is superior over HBP in terms of lead measurements and procedural duration. With regard to all reported outcomes, evidence from large scale randomized controlled clinical trials (RCT) is still scarce. CSP has the potential to sustainably improve patient care in cardiac pacing therapy if patients are appropriately selected and limitations are considered. With this review, we offer not only a summary of existing data, but also an outlook on probable future developments in the field, as well as a detailed summary of upcoming RCTs that provide insights into how the journey of CSP continues.

Pacemaker implantation combined with atrioventricular node ablation (AVNA) is a well-established strategy for uncontrolled atrial arrhythmias. Limited data are available regarding His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in this setting.

To compare the outcomes of HBP and LBBAP in patients undergoing pacemaker implantation combined with AVN in routine clinical practice.

We prospectively included all patients who underwent AVNA after successful conduction system pacing (CSP) in two hospitals between September 2017 and May 2023. The primary outcome was the 1-year composite of first episode of heart failure hospitalization, symptomatic atrioventricular node reconduction requiring a second AVNA procedure, lead revision or death from any cause.

A total of 164 patients underwent AVNA following successful CSP (68 HBP and 96 LBBAP). Mean pacemaker implantation and AVNA procedure times were shorter in the LBBAP group than the HBP group (46±18 vs 59±23min; P<0.001 and 31±12 vs 43±22min, respectively; P<0.001). Complete atrioventricular block was more frequently obtained in the LBBAP group (88/96 patients [92%] vs 54/68 patients [79%]; P=0.04). One-year freedom from the composite outcome was more frequent in the LBBAP group (89.7% vs 72.9%; hazard ratio 0.32, 95% confidence interval 0.14-0.72; P=0.01). The strategy was similarly effective in both groups with a significant improvement in NYHA class and left ventricular ejection fraction. A secondary pacing threshold elevation >1V occurred only in the HBP group (11%).

In this prospective, comparative study, LBBAP provided better 1-year outcomes than HBP.

Heart failure (HF) is a complex and progressive disease marked by substantial morbidity and mortality rates, frequent episodes of decompensation, and a reduced quality of life (QoL), with severe financial burden on healthcare systems. In recent years, several large-scale randomized clinical trials (RCTs) have widely expanded the therapeutic armamentarium, underlining additional benefits and the feasibility of rapid titration regimens. This notwithstanding, mortality is not declining, and hospitalizations are constantly increasing. It is widely acknowledged that even with guideline-directed medical therapy (GDMT) on board, HF patients have a prohibitive residual risk, which highlights the need for innovative treatment options. In this scenario, groundbreaking devices targeting valvular, structural, and autonomic abnormalities have become crucial tools in HF management. This has led to a full-fledged translational boost with several novel devices in development. Thus, the aim of this review is to provide an update on both approved and investigated devices.

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacing-induced cardiomyopathy. Until recently, biventricular pacing (BiVP) was the only modality which could mitigate or prevent pacing induced dysfunction. Further, BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes. However, the high non-response rate of around 20%-30% remains a major limitation. This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system. To overcome this limitation, the concept of conduction system pacing (CSP) came up. Despite initial success of the first CSP via His bundle pacing (HBP), certain drawbacks including lead instability and dislodgements, steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy (CRT). Subsequently, CSP via left bundle branch-area pacing (LBBP) was developed in 2018, which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies. Further, its safety has also been well established and is largely free of the pitfalls of the HBP-CRT. In the recent metanalysis by Yasmin et al, comprising of 6 studies with 389 participants, LBBP-CRT was superior to BiVP-CRT in terms of QRS duration, left ventricular ejection fraction, cardiac chamber dimensions, lead thresholds, and functional status amongst heart failure patients with left bundle branch block. However, there are important limitations of the study including the small overall numbers, inclusion of only a single small randomized controlled trial (RCT) and a small follow-up duration. Further, the entire study population analyzed was from China which makes generalizability a concern. Despite the concerns, the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT. At this stage, one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBP-CRT in management of heart failure patients with left bundle branch block.

We present a case of a man with ischemic cardiomyopathy and single chamber implantable cardioverter-defibrillator who developed sinus arrest creating sudden dependence on right ventricular (RV) pacing. He presented with cardiogenic shock secondary to abrupt onset ventricular dyssynchrony from RV pacing, which required emergent stabilization and completely resolved with atrial pacing.

To establish a basic understanding of cardiogenic shock management. To reinforce the adverse effects associated with right ventricular pacing.

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Atrial fibrillation (AF) is currently defined as symptomatic by asking patients if they are aware of when they are in AF and if they feel better in sinus rhythm. However, this approach of defining AF as symptomatic and asymptomatic fails to adequately consider the adverse effects of AF in patients who are unaware of their rhythm including progression from paroxysmal to persistent AF, and the development of dementia, stroke, sinus node dysfunction, valvular regurgitation, ventricular dysfunction, and heart failure. Labeling these patients as asymptomatic falsely suggests that their AF requires less intense therapy and puts into question the notion of truly asymptomatic AF. Because focusing on patient awareness ignores other important consequences of AF, clinical endpoints that are independent of symptoms are being developed. The concept of AF burden has more recently been used as a clinical endpoint in clinical trials as a more clinically relevant endpoint compared to AF-related symptoms or time to first recurrence, but its correlation with symptoms and other clinical outcomes remains unclear. This review will explore the impact of AF on apparently asymptomatic patients, the use of AF burden as an endpoint for AF management, and potential refinements to the AF burden metric. The review is based on a presentation by the senior author during the 2023 16th annual European Cardiac Arrhythmia Society (ECAS) congress in Paris, France.

Transcatheter aortic valve replacement (TAVR) has emerged as a formidable treatment option for severe symptomatic aortic stenosis ahead of surgical aortic valve replacement. The encouraging results from large randomized controlled trials has resulted in an exponential rise in the use of TAVR even in the low-risk patients. However, this is not without challenges. Need for permanent pacemaker (PPM) post-TAVR remains the most frequent and clinically relevant challenge. Naturally, identifying risk factors which predispose an individual to develop high grade conduction block post-TAVR is important. Various demographic factors, electrocardiographic features, anatomic factors and procedural characteristics have all been linked to the development of advanced conduction block and need for PPM following TAVR. Amongst these electrophysiological variables, most notably a prolonged QRS > 120 ms regardless of the type of conduction block seems to be one of the strongest predictors on logistic regression models. The index study by Nwaedozie et al highlights that patients requiring PPM post-TAVR had higher odds of having a baseline QRS > 120 ms and were more likely to be having diabetes mellitus that those who did not require PPM.

Cardiac implantable electronic devices (CIEDs) improve quality of life and prolong survival, but there are additional considerations for cardiovascular imaging after implantation-both for standard indications and for diagnosing and guiding management of device-related complications. This clinical consensus statement (part 2) from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists, cardiac imagers, and pacing specialists regarding the use of imaging in patients after implantation of conventional pacemakers, cardioverter defibrillators, and cardiac resynchronization therapy (CRT) devices. The document summarizes the existing evidence regarding the role and optimal use of various cardiac imaging modalities in patients with suspected CIED-related complications and also discusses CRT optimization, the safety of magnetic resonance imaging in CIED carriers, and describes the role of chest radiography in assessing CIED type, position, and complications. The role of imaging before and during CIED implantation is discussed in a companion document (part 1).

His bundle pacing (HBP) is the most physiological form of ventricular pacing. Few prospective studies have analyzed lead localization using imaging techniques and its relationship with electrical parameters and capture patterns. The objective of this study is to examine the correlation between electrical parameters and lead localization using three-dimensional transthoracic echocardiography (3D TTE).

This single-center, prospective, nonrandomized clinical research study (January 2018 to June 2020) included patients with an indication of permanent pacing, in whom 3D TTE was performed to define lead localization as supravalvular or subvalvular.

A total of 92 patients were included: 56.5% of leads were supravalvular, and 43.5% were subvalvular, which resembles previous anatomic descriptions of autopsied hearts of His bundle localization within the triangle of Koch (ToK). R-wave sensing was higher when the His lead was localized subvalvular instead of supravalvular. His lead localization was not associated with HBP threshold or impedance differences, nor with the two different HBP patterns of capture, or with the ability of HBP to correct baseline BBB. The thresholds remained stable during follow-up visits, regardless of His lead localization. Higher R-wave sensing was observed during follow-up than at baseline, mainly in the subvalvular His leads. However, lead impedances in both positions decreased during follow-up.

Lead localization in relation to the tricuspid valve did not influence the electrical performance of HBPs. Wide anatomical variations of the His bundle within the ToK explain our findings, reinforcing the idea that the technique for HBP should be fundamentally guided by electrophysiological and not anatomical parameters.

The prognostic value of preimplantation nutritional status is not yet known for older diabetic patients that received right ventricular pacing (RVP). The study aimed to investigate the clinical value of the four malnutrition screening tools for the prediction of heart failure hospitalization (HFH) in older diabetic patients that received RVP.

Retrospective observational cohort study.

This study was conducted between January 2017 and January 2018 at the Fuwai Hospital, Beijing, China, and included older (age ≥ 65 years) diabetic patients that received RVP for the first time Measurements: The Prognostic Nutritional Index (PNI), Geriatric Nutritional Risk Index (GNRI), Naples Prognostic Score (NPS), and the Controlling Nutritional Status (CONUT) score were used to estimate the preimplantation nutritional status of the patients. Univariate and multivariate Cox proportional hazard regression analyses were performed to investigate the association between preimplantation malnutrition and HFH.

Overall, 231 older diabetic patients receiving RVP were included. The median follow-up period after RVP was 53 months. HFH was reported for 19.9% of the included patients. Our results showed preimplantation malnutrition for 18.2%, 15.2%, 86.6% and 66.2% of the included patients based on the PNI, GNRI, NPS, and CONUT score, respectively. The cumulative rate of HFH during follow-up period was significantly higher for patients in the preimplantation malnutrition group based on the PNI (log-rank = 13.0, P = 0.001), GNRI (log-rank = 8.5, P = 0.01), and NPS (log-rank = 15.7, P < 0.001) compared to the normal nutrition group, but was not statistically significant for those in the preimplantation malnutrition group based on the CONUT score (log-rank = 2.7, P = 0.3). As continuous variables, all the nutritional indices showed significant correlation with HFH (all P < 0.05). However, multivariate analysis showed that only GNRI was independently associated with HFH (HR = 0.97, 95% CI: 0.937-0.997, P = 0.032). As categorical variables, PNI, GNRI, and NPS showed significant correlation with HFH. After adjustment of confounding factors, moderate-to-severe degree of malnutrition was an independent predictor of HFH based on the PNI (HR = 4.66, 95% CI: 1.03-21.00, P = 0.045) and GNRI (HR = 3.02, 95% CI: 1.02-9.00, P = 0.047).

Preimplantation malnutrition was highly prevalent in older diabetic patients that received RVP. The malnutrition prediction tools, PNI and GNRI, showed significant prognostic value in accurately predicting HFH in older diabetic patients with RVP.

Heart failure (HF) is a leading health burden around the world. Although pharmacological development has dramatically advanced medication therapy in the field, hemodynamic disorders or mechanical desynchrony deteriorated by intra or interventricular conduction abnormalities remains a critical target beyond the scope of pharmacotherapy. In the past 2 decades, nonpharmacologic treatment for heart failure, such as cardiac resynchronization therapy (CRT) via biventricular pacing (BVP), has been playing an important role in improving the prognosis of heart failure. However, the response rate of BVP-CRT is variable, leaving one-third of patients not benefiting from the therapy as expected. Considering the non-physiological activation pattern of BVP-CRT, more efforts have been made to optimize resynchronization. The most extensively investigated approach is by stimulating the native conduction system, e.g., His-Purkinje conduction system pacing (CSP), including His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). These emerging CRT approaches provide an alternative to traditional BVP-CRT, with multiple proof-of-concept studies indicating the safety and efficacy of its utilization in dyssynchronous heart failure. In this review, we summarize the mechanisms of dyssynchronous HF mediated by conduction disturbance, the rationale and acute effect of CSP for CRT, the recent advancement in clinical research, and possible future directions of CSP.

Temporary epicardial pacing frequently is employed after cardiac surgery, and can have a significant impact on a patient's hemodynamics, arrhythmias, and valvulopathies. Given that anesthesiologists often are involved intimately in the initial programming and subsequent management of epicardial pacing in the operating room and intensive care unit, it is important for practitioners to have a detailed understanding of the modes, modifiable intervals, and potential complications that can occur after cardiac surgery. Because this topic has not been reviewed recently in anesthesia literature, the authors attempted to review relevant epicardial pacemaker specifics, discuss modes and parameters that apply to the perioperative period, present an algorithm for mode selection, describe the potential effects of epicardial pacing on valvulopathies and hemodynamics, and, finally, discuss some postoperative considerations.

Temporary right ventricular pacing in unstable bradycardia and cardiovascular interventions is associated with atrioventricular dyssynchrony and reduced cardiac output. Currently, sequential atrioventricular pacing options are limited andnot routinely used. Herein, we discuss a novel, first in-human technique of temporary atrioventricular sequential pacing and how it compares to existing modalities of atrioventricular pacing.