Indications For Pacing Research Articles

Pacemaker Implantation for Low-Grade Conduction Abnormalities After Balloon-Expandable Transcatheter Aortic Valve Implantation.

A frequent complication after TAVI are postinterventional conduction abnormalities requiring permanent pacemaker implantation. In this study, we analyzed the characteristics of borderline conduction abnormalities leading to pacemaker implantation and the resulting ventricular pacing amounts. All patients who underwent balloon-expandable TAVI between 2014 and 2019 in our tertiary center were analyzed in a retrospective manner. One hundred and sixty-five patients of 1083 TAVI-patients developed postinterventional conduction abnormalities leading to pacemaker implantation. Of these 19 (11.5%) did not represent a clear indication for cardiac pacing according to current European guidelines. Patient characteristics, underlying conduction abnormalities, and the temporal change of ventricular pacing percentages at 24 h and 6 weeks after pacemaker implantation were analyzed. The dominating borderline conduction abnormalities leading to pacemaker implantation were new-onset persisting bundle-branch-blocks and new first-degree AV-blocks with progression of AV-delay. While pacemaker implantation was safe and without severe complications in all cases, only 6 of 19 patients had high pacing amounts (95%-100%) after 24 h while 11 patients had low to no pacing amounts (0%-5%). After 6 weeks, 8 patients showed decreasing pacing amounts, no patient had an increasing amount of ventricular pacing and all patients had an intrinsic ventricular rhythm > 30/min. In our cohort of 1038 TAVI patients, 19 patients underwent PMI for borderline CAs (11.5% of all PMI). Of these, only 2 patients had high pacing amounts after 6 weeks. The risk of complete persisting heart block in these patients is very low. Furthermore, algorithms to reduce ventricular pacing are highly effective to avoid ventricular pacing whenever reasonable.

Equal performance of the subcutaneous and transvenous implantable cardioverter defibrillator across all age groups in the PRAETORIAN trial

Abstract Introduction The subcutaneous ICD (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. In the PRAETORIAN trial the S-ICD proved to be non-inferior to the TV-ICD with regard to inappropriate shocks (IAS) and complications. However, the S-ICD is still mainly the preferred choice in young patients with a long life expectancy and therefore higher risk for lead-related complications. We aimed to evaluate the impact of age on complications and IAS between the S-ICD and TV-ICD. Methods The PRAETORIAN trial is an investigator-initiated, international, multicenter, randomized, two-arm noninferiority trial that was conducted in the United States and Europe. In total 849 patients with a class I or IIa indication for ICD therapy and no pacing indication were randomized to receive an S-ICD (N=426) or TV-ICD (N=423) and followed for a median of 49 months. We compare the occurrence of complications and IAS between increasing quartiles of age. Results Quartile 1 (Q1) consisted of 203 patients aged <55 (109 S-ICD, 94 TV-ICD), Q2 of 199 patients aged 55-62 (100 S-ICD, 99 TV-ICD), Q3 of 232 patients aged 63-69 (111 S-ICD, 121 TV-ICD) and Q4 of 215 patients aged ≥70 (106 S-ICD, 109 TV-ICD). Between the quartiles, there were no significant differences in occurrence of device-related complications (P = 0.32) or IAS (P = 0.66). In Q1, there were 15 (7.4%) complications (5 S-ICD, 10 TV-ICD) and 13 (6.4%) IAS (7 S-ICD, 6 TV-ICD), compared to 20 (10.1%) complications (7 S-ICD, 13 TV-ICD) and 17 (8.5%) IAS (9 S-ICD, 8 TV-ICD) in Q2, 22 (9.5%) complications (12 S-ICD, 10 TV-ICD) and 19 (8.2%) IAS (11 S-ICD, 8 TV-ICD) in Q3 and 18 (8.4%) complications (7 S-ICD, 11 TV-ICD) and 21 (9.8%) IAS (14 S-ICD, 7 TV-ICD) in Q4 (Figure 1.). Figure 2. shows forest plots of the hazard ratios per quartile. Conclusions The S-ICD performed equal to the TV-ICD with regard to IAS and complications between quartiles of age, making the S-ICD a good alternative across all age groups.

Leadless pacemaker - lead parameters stability and battery longevity in the mid-term follow-up

Abstract Background A leadless pacemaker (L-PM) has been designed to avoid the need for a pacemaker pocket and transvenous lead. Long-term safety will largely depend on the need for replacements, mainly due to battery depletion (end-of-life). While the mean L-PM battery longevity predicted by the manufacturer is 12 years, real-world longevity data are still scarce. We aimed to describe L-PM parameters’ stability and battery longevity during the mid-term follow-up. Methods Single-center registry of consecutive patients undergoing L-PM implantation from May 2015 to November 2023. Procedural characteristics, lead parameters and battery longevity were collected immediately after implantation and during the most recent follow-up visit. Results Overall, 261 consecutive patients had a transcatheter L-PM implanted through a femoral vein (mean age 78±10 years; 66% male). Mean procedural duration was 44±28min and fluoroscopy time was 4,4±3,9min. The device was successfully implanted in all but one patient. The main indications for permanent pacing were high-degree atrioventricular block [N=130 (50%)], atrial fibrillation with pauses [N=78 (30%)], and sinus node disease [N=28 (11%)]. Immediately after implantation, three cases (1,2%) of pericardial effusion (one with tamponade) were reported. In one case (0,4%), a conventional pacemaker was implanted due to L-PM acute dysfunction. No other procedure-related complications, including dislodgment, were reported at discharge. After a mean follow-up of 2,8±1,7years, the pacing threshold and R-wave amplitude remained stable [0,67mV vs. 0,62mV (p=0,9); and 10,3mV vs. 16,1mV (p<0,001), respectively] and mean ventricular pacing was 54±38%. Expected battery longevity was >8 years (maximum value) in 84% of the patients. In the subgroup of patients with >5 years of follow-up (N=20; mean follow up of 6,3±1,8years), the expected battery longevity was >8 years in 85% (N=17) of the patients. In three cases, the L-PM was upgraded to cardiac resynchronization therapy or left bundle branch area pacing due to pacing-induced left ventricular dysfunction. There was one case of L-PM end-of-life 6 years after implant (pacing threshold 0,5mV; ventricular pacing 100%), in which a second L-PM was successfully implanted. Overall, 78 (31%) patients died, a mean of 2,2±1,9 years after L-PM implantation, none related to the device. Conclusion In this real-world cohort, L-PM maintained stable pacing parameters and, in the mid-term follow-up, only one battery depletion was observed while expected longevity remained above 8 years in the large majority of patients. Longer follow up will allow better understanding of both technical and clinical aspects relevant to manage end-of-life devices.Table 1Figure 1

Conduction system versus right ventricular pacing for atrioventricular block: a reconstructed individual participant data meta-analysis

Abstract Background Right ventricular pacing (RVP) is typically offered to patients with established or impending atrioventricular block (AVB) in the absence of left ventricular systolic dysfunction. Direct stimulation of His-Purkinje fibres via conduction system pacing (CSP) is an emerging alternative to RVP to prevent pacing-induced cardiomyopathy. Purpose To perform a systematic review and meta-analysis testing CSP versus RVP in patients with AVB and a left ventricular ejection fraction ≥35%. Methods Observational studies comparing CSP with RVP that reported clinical outcomes were systematically identified. The primary outcome was time-to-first all-cause mortality, heart failure hospitalisation (HFH) or upgrade to biventricular pacing. Secondary endpoints included the individual components of the primary endpoint. Individual participant time-to-event data (IPD) was obtained through data-sharing agreements or reconstructed from digitisation of Kaplan-Meier curves where available. Mixed-effects Cox proportional hazards regression that modelled between-study heterogeneity as a random intercept to account for differing baseline hazards between distinct study populations was performed on these data. Conventional pairwise random effects meta-analyses were also performed. This analysis was prospectively registered. Results 12 eligible studies enrolling 4627 patients were included. In reconstructed IPD pooled survival analyses, CSP associated with a 38% reduced hazard of the primary endpoint compared with RVP [hazard ratio 0.62, 95% CI 0.51 to 0.76, p<0.001] (Figure 1). In pairwise meta-analyses, CSP associated with a 46% risk reduction in the primary endpoint [relative risk (RR) 0.54, 95% CI 0.41 to 0.71, p<0.001] (Figure 2A). CSP also associated with reductions in risk of all-cause mortality [RR 0.60, 95% CI 0.45 to 0.80, p<0.001], HFH [RR 0.39, 95% CI 0.28 to 0.55, p<0.001] and upgrade to biventricular pacing [RR 0.19, 95% CI 0.07 to 0.52, p=0.001] compared with RVP (Figure 2B-D). Conclusions In reconstructed IPD pooled survival analyses, CSP associated with reductions in the primary composite endpoint of all-cause mortality, heart failure hospitalisation or upgrade to biventricular pacing compared with RVP, independent of ventricular pacing burden. This was mirrored in conventional meta-analyses of the primary composite endpoint, and when individual components of the composite were analysed. It may not be necessary to predict which patients will have an elevated pacing burden when applying this therapy. Until randomised data from the PROTECT-HF trial becomes available, this analysis offers the most precise summary estimate of the comparative effects of CSP versus RVP in patients with an AVB indication for pacing, but no evidence of heart failure.Kaplan-Meier plot comparing CSP vs RVPForest plots for major endpoints

Left fascicular pacing is not inferior to left bundle branch pacing in preserving ventricular mechanical synchrony and cardiac function

Abstract Background Left bundle branch pacing (LBBP) has emerged as a more physiological alternative to right ventricular pacing.However, capturing the pre-divisional LBB is not easy to accomplish. This study investigates if left fascicular pacing(LFP), defined as the capture of one of the LBB fascicles, could achieve comparable left ventricular (LV) mechanical synchronicity and cardiac function compared to LBBP. Methods Thirty-one patients with pacing indication for bradycardia were retrospectively collected: LBBP was successfully performed in 13 patients and 18 achieved LFP. All patients underwent echocardiography before and after implantation and at one-year follow-up. Left ventricular (LV) volumes, ejection fraction (EF) and global longitudinal strain (GLS) were measured. The lateral-septal (LW-SW) work difference was used as a measure of mechanical dyssynchrony. Septal flash, apical rocking and septal strain patterns were also assessed. Results Although LW-SW work difference were significantly higher in the LBBP groups than that in the LFP group at baseline(272±269 mmHg*% vs 25±279mmHg*%,p=0.02), a similar increase in LW-SW work difference was observed during follow-up(199±342 mmHg*% vs 371±384mmHg*%,p=0.21). In addition, both LFP and LBBP induced septal flash or apical rocking in some patients, and resulted in subtle changes in strain patterns, which were not significantly different between groups. At one year follow-up, LV ejection fraction (EF) remained almost unchanged in both LBBP and LFP patients(ΔLVEF: 1.1+3.1% vs -0.3±4.8%,p=0.35) , and global longitudinal strain (GLS) was slightly and equally decreased in LFP compared to LBBP (ΔLVGLS: -1.6±2.3% vs -1.2±2.7%,p=0.69). Conclusion LFP and LBBP did not differ in mechanical dyssynchrony or LV remodelling.

Safety profile, electrical performances and clinical outcomes of a novel leadless pacemaker; first results from real-world clinical practice in Saudi Arabia

Abstract Introduction Leadless pacemakers (LP) are emerging as an effective and safe alternative to transvenous pacemakers to reduce lead-related and pocket-related complications and to improve patient experience. A new LP system, the Aveir VR, has been approved in 2022 for US and other countries, and in 2023 for Europe, and features innovative characteristics such as the active fixation helix mechanism and the possibility to measure sensing/pacing parameters before LP deployment. Purpose Evaluate safety, electrical performances and clinical outcomes associated with the first Aveir VR LP implants in 2 Hospitals in Saudi Arabia. Methods We performed a prospective evaluation of all-comer patients who received Aveir VR LP. Decision for LP implant was based on conditions such as cardiac pacing indication, lack of upper extremity venous access, risk of device infection, and life expectancy, and using shared decision-making. Clinical and electrical data were collected at implant and at 1st and 6th month visits. Results A total of 54 patients (25 female, mean age 69 years) were included between December 2022 and October 2023. Pacemaker implant indication was AV block in 25 (46%) patients, sinus node disease in 19 (35%) patients, atrial fibrillation and slow ventricular response in 9 (17%) patients and left bundle branch block in 1 (2%) patient. Implant was successful in all attempted cases. Final device position was lower septum in 51/54 (94.4%) patients and mid-septum in 3/54 (5.6%) patients. Mean procedure time was 48±22 minutes and showed a decreasing trend as a function of operator experience with a mean of 55, 50 and 36 minutes in the first, second and third group of consecutive implants, respectively. Mean fluoroscopic time was 11±8 minutes and showed a decreasing trend as a function of operator experience with a mean of 13, 13 and 6 minutes in the first, second and third group of consecutive implants, respectively. Final device position was achieved at first attempt in 42/54 (77.8%) cases and at first or second attempt in 51/54 (94.4%) cases. At implant mean R wave sensing was 7.6±3.7 mV, mean impedance was 724±335 Ohm, mean threshold was 1.0±0.6 V at 0.4 ms. During implant there was one patient with pericardial effusion treated with pericardiocentesis. In a mean follow-up of 73 days there were no procedure-related or device-related complications, electrical parameters showed acceptable values, and all implanted devices performed as expected. Median longevity, estimated at last follow-up visit, was 19 years (interquartile range: 12-20 years). Conclusion First real-world cases of use of a novel leadless pacemaker in Saudi Arabia show optimal feasibility and good safety profile and electrical performances. Procedure and fluoroscopic times were acceptable and decreased as a function of operator experience. Longevity estimations predict very long service life-times.

The influence of prolonged antibiotic treatment before lead extraction procedures on the outcomes of device reimplantation in cardiac implantable electronic device infections

Abstract Background Cardiac implantable electronic devices (CIED) related infections have a considerable clinical and economic burden in the cohort of CIED-implanted patients and require a complex and thoughtful approach of the "heart team". Complete CIED removal is recommended for all patients with confirmed CIED infection, but the optimal duration of antibiotic therapy (AT) before lead extraction (LE) and its impact on the time of reimplantation are still debatable [1-2]. This study was aimed to evaluate the impact of prolonged AT before LE on the outcomes of device reimplantation. Methods Consecutive cases of LE due to CIED infection at our centre from 2013 to 2022 were reviewed. Our approach assumed the duration of AT for a minimum of 2 weeks for patients with pocket infection (PI), and at least 4 weeks for endocarditis with the exception of non-response to the AT. The target time for reimplantation was 2-3 days after LE with the exception of uncontrolled infection, positive blood culture, logistical reasons or reevaluation of pacing indications during follow-up. Results From a total of 256 LE, 202 (in 198 patients) were due to CIED infection (pacemaker-67,8%, CRT-19,8%, ICD-12,4%). In 62,4% of the cases there was only PI, in 24,7% only endocarditis and in 12,9% it was concomitant. Systemic infection was found in 43,1% of the cases. The mean dwell time of the leads was 92.2±5.0 months (n=201, median 84, IQR 29.0-132.0). In cases of PI, the mean time of AT before LE was 21,7±1,0 days (n=124, median 21, IQR 14.0-28.0), whereas it was 31,6±1,7 days (n=76, median 28, IQR 21.0-42.0) in cases of endocarditis (p<0.05). The duration of AT after LE was 17.7±0.8 days (n=121, median 14, IQR 14.0-21.0) in cases of PI and 22.7±1.4 days (n=76, median 21, IQR 14.0-28.0) in cases of endocarditis (p<0.05). Procedural success was achieved in 98,5% and the procedural failure rate was 1,5%. Major complication rate was 2,5% and minor complication rate was 8,9%. There was no intraprocedural death. Device reimplantation after LE was performed in 68,8% (139) of all patients. The majority of reimplantations (57,6%) occurred within 7 days after LE (figure 1). The mean reimplantation time was 43.6±12.1 days (n=135, median 6, IQR 4.0-15.0), without statistically significant difference in time to reimplantation between PI and endocarditis (p=0.78). 9 patients were reimplanted with epicardial ventricular lead and 1 with leadless pacemaker. Total reinfection rate was 2% (4), all the cases were due to contralateral PI with reimplantation after LE in 11, 12, 38 and 596 days, respectively. One of the patients was also diagnosed with an allergy to silicone, nickel and palladium. Mortality rate during the first 30 days was 5%. Uneventful 12-month follow-up was achieved by 80,2%. Conclusions Appropriate prolonged AT before LE led to feasibility of early device reimplantation with a low rate of reinfection.Time to preimplantation

Chronic wireless communication between dual-chamber leadless pacemaker devices

BackgroundAveir DR (Abbott, Abbott Park, IL) is a dual-chamber leadless pacemaker (LP) system with distinct atrial and ventricular LPs (ALP, VLP) that communicate wirelessly to deliver atrioventricular synchronous pacing. Success rates of these implant-to-implant (i2i) transmissions have not been systematically evaluated. ObjectiveThis study aims to evaluate chronic i2i success rates in a clinical setting. MethodsPatients meeting standard dual-chamber pacing indications were enrolled and implanted with dual-chamber LP systems as part of a prospective international clinical trial (Aveir DR i2i Study). The percent of successful i2i transmissions from ALP-to-VLP (A-to-V) and VLP-to-ALP (V-to-A) were interrogated from LPs in de novo patients using the device programmer at implant, discharge, and at 1, 3, and 6 months postimplant (1M, 3M, 6M). ResultsA total of 399 patients completed device implant and i2i diagnostic interrogation (62% male; age 69 years; 65% sinus node dysfunction, 32% atrioventricular [AV] block). Median A-to-V and V-to-A i2i success rates exceeded 90% of beats at all time-points from implant to 6M. The minority of patients with A-to-V or V-to-A i2i success in <70% of beats at implant (A-to-V: 19% of patients, V-to-A: 31% of patients) showed roughly 40% improvement by 1M, with this minority dropping to roughly 5% of patients by 6M. Improvement in i2i communication success may be attributed to reprogramming of i2i setting levels, natural changes in dominant posture, and device stabilization. ConclusionWireless implant-to-implant communication in the new dual-chamber leadless pacemaker system demonstrated successful transmissions in >90% of beats throughout the 6-month evaluation period. Communication success improved significantly over time postimplant for specific subgroups. Clinical Trial RegistrationAveir DR i2i Study, ClinicalTrials.gov ID NCT05252702.

Left ventricular volumes and function in successful and failed His-BundLe Pacing. A comparative prospective study.

Initial data suggest that His Bundle Pacing (HBP) could preserve long-term cardiac structure and function better than Right Ventricular Pacing (RVP), but evidence is limited. We studied consecutive patients with baseline ejection fraction (EF) ≥ 50% who underwent HBP attempt, either successful (HBP group) or failed (RVP group). Two-dimensional (2D) and three-dimensional (3D) echocardiography were carried out at baseline and after 6 months of ventricular pacing burden > 20%. Among 68 patients, 40 underwent successful HBP, and 28 RVP. The HBP and RVP groups did not differ for age, sex and pacing indication. At baseline, the HBP and RVP groups did not differ for 2D EF (62% vs. 62%), 3D EF (60% vs. 63%), 2D (-19% vs. -19%) and 3D global longitudinal strain (GLS) (-15% vs. -16%). After 6 months, 2D EF (-3.86%) and 3D EF (-5.71%) significantly decreased in the RVP group and did not change in the HBP group (p for interaction .006 and <.001, respectively). 2D GLS (3.08%) and 3D GLS (2.22%) significantly increased in the RVP group, but did not change in the HBP group (p for interaction .013 and <.016, respectively). Pacing induced cardiomyopathy (PICM) (EF drop ≥ 10% and EF < 50%) occurred in 14% (RVP) versus 0% (HBP) of patients (p = .025). Successful HBP was superior to RVP in preserving LV systolic function despite a high ventricular pacing burden, and was less frequently associated with PICM.

Rates and predictors for sustained ventricular tachycardia in patients with cardiac sarcoidosis and AV block as first cardiac presentation: Implications for device implantation

BackgroundAtrioventricular block (AVB) is a frequent initial presentation of cardiac sarcoidosis (CS), but dangerous ventricular arrhythmias (VA) can occur. Despite the scarcity of data, guidelines recommend implantable cardioverter-defibrillator (ICD) rather than a pacemaker implantation whenever a device is needed. ObjectiveIn this study, we aimed to establish predictors for sustained VA in patients with CS presenting with pacing indication because of an AVB. MethodsWe prospectively enrolled 112 patients with CS. Excluding those with VA, 82 patients remained and were divided into 2 groups: 34 individuals with AVB as initial presentation and 48 with other symptoms as first presentation (OSF). Both groups were compared for clinical characteristics, rates of VA, left ventricular assist device (LVAD) implantation, heart transplantation, and mortality. ResultsDuring follow-up, VA was detected in 50% in the AVB and 10.4% in the OSF group (P = .001). Death, LVAD implantation, and heart transplantation occurred in 11.8% in AVB group vs 10.4% in the OSF group (P = .847). Late gadolinium enhancement (LGE) was equally observed in both groups: 70% vs 70.5% (P = .966), whereas more patients in the AVB group exhibited abnormal positron emission tomography (PET) uptake: 86.2% vs 54.3% (P = .007). In multivariate analysis, AVB (hazard ratio [HR], 25.15), right ventricular (RV) LGE in cardiovascular magnetic resonance (CMR) (HR, 7.39) were predictors for VA occurrence, whereas the use of immunosuppressive therapy was associated with less VA (HR, 0.26). ConclusionsPatients with CS presenting with AVB have a high risk of sustained VA. Although immunosuppressive drugs may reduce the occurrence of VA, ICD implantation is reasonable, especially in case of RV LGE.

Conduction system pacing compared with biventricular pacing for cardiac resynchronization therapy in patients with heart failure and mildly reduced left ventricular ejection fraction: Results from International Collaborative LBBAP Study (I-CLAS) Group

BackgroundCardiac resynchronization therapy (CRT) is a guideline-recommended therapy in patients with heart failure with mildly reduced ejection fraction (HFmrEF, 36%–50%) and left bundle branch block or indication for ventricular pacing. Conduction system pacing (CSP) using left bundle branch area pacing or His bundle pacing has been shown to be a safe and physiologic alternative to biventricular pacing (BVP). ObjectiveThe aim of this study was to compare the clinical outcomes between BVP and CSP for patients with HFmrEF undergoing CRT. MethodsConsecutive patients who underwent BVP or CSP with HFmrEF between January 2018 and June 2023 at 16 international centers were included. The primary outcome was the composite end point of time to death or heart failure hospitalization (HFH). Secondary end points included change in left ventricular ejection fraction (LVEF) and individual end points of death and HFH. ResultsA total of 1004 patients met inclusion criteria: BVP, 178; CSP, 826 (His bundle pacing, 154; left bundle branch area pacing, 672). Mean age was 73 ± 13 years; female, 34%; and LVEF, 42% ± 5%. Paced QRS duration in CSP was significantly narrower compared with BVP (129 ± 21 ms vs 144 ± 19 ms; P < .001). LVEF improved during follow-up in both groups (49% ± 10% vs 48% ± 10%; P = .32). CSP was independently associated with significant reduction in the primary end point of time to death or HFH compared with BVP (22% vs 34%; hazard ratio, 0.64; 95% confidence interval, 0.43–0.94; P = .025). ConclusionCSP was associated with improved clinical outcomes compared with BVP in this large cohort of patients with HFmrEF undergoing CRT. Randomized controlled trials comparing CSP with BVP will be necessary to confirm these results.

Long-Term Safety and Efficacy of Intraoperative Leadless Pacemaker Implantation During Valve Surgery

BackgroundIntraoperative implantation of leadless cardiac pacemakers (LCPs) under direct visualization during cardiac surgery is a novel strategy to provide pacing to patients with an elevated risk of postoperative conduction disorders or with a preexisting pacing indication undergoing valve surgery. ObjectivesThis study sought to evaluate the long-term safety and efficacy of intraoperative LCP implantation in 100 consecutive patients. MethodsRetrospective single-center cohort study of consecutive patients (n = 100) who underwent intraoperative LCP implantation during valve surgery. Safety and efficacy were assessed at implantation and follow-up visits. ResultsA total of 100 patients (age 68 ± 13 years, 47% female) underwent intraoperative LCP implantation. The surgery involved the tricuspid valve in 99 patients (99%), including tricuspid valve repair in 59 (59%) and tricuspid valve replacement in 40 (40%). Most of the patients (78%) underwent multivalve surgery. The indication for LCP implantation was elevated risk of postoperative atrioventricular block in 54% and preexisting bradyarrhythmias in 46%. LCP implantation was successful in all patients. During a median of 10.6 months (IQR: 2.0-22.7 months) of follow-up, no device-related complications occurred. At 12-month follow-up, the pacing thresholds were acceptable (≤2.0 V at 0.24 milliseconds) in 95% of patients. ConclusionsIntraoperative LCP implantation under direct visualization is a safe strategy to provide permanent pacing in patients undergoing valve surgery, with a postoperative electrical performance comparable to percutaneously placed LCPs.

Atrioventricular Synchrony Delivered by a Dual-Chamber Leadless Pacemaker System.

A dual-chamber leadless pacemaker system has been designed for atrioventricular synchronous pacing using wireless, beat-to-beat, implant-to-implant (i2i) communication between distinct atrial and ventricular leadless pacemakers. The atrioventricular synchrony achieved across various ambulatory scenarios has yet to be systematically evaluated. A prospective, single-arm, unblinded, multicenter, international clinical trial of the leadless pacemaker system was conducted in patients with a conventional dual-chamber pacing indication enrolled from February 2022 to March 2023. Leadless pacemaker systems were implanted, and 12-lead Holter electrocardiographic recordings were collected 3 months after implantation over various postures/activities: sitting, supine, left lateral recumbent, right lateral recumbent, standing, normal walk, and fast walk. An independent Holter core laboratory performed a manual adjudication of the percent of atrioventricular synchronous beats using the standard 300-millisecond PR interval limit. Atrium-to-ventricle and ventricle-to-atrium i2i communication success rates were also assessed. Post hoc summary statistics describing the relationships between atrioventricular synchrony and i2i success, posture/activity, implantation indication, atrioventricular event, and heart rate were calculated. In the evaluable population (n=384 of 464 enrolled [83%]; 61% male; age, 70 years; weight, 82 kg; 60% ejection fraction; 95% of beats evaluable), the mean atrioventricular synchrony of 98% of beats observed across all postures using the standard 300-millisecond limit was greater than both atrial-to-ventricular i2i (94%) and ventricular-to-atrial i2i (94%; P<0.001), exceeding both i2i values in 95% of patients. Atrioventricular synchrony was achieved in >95% of evaluable beats across all postures/activities, implantation indications, atrioventricular paced/sensed event combinations, and heart rate ranges (including >100 bpm). This dual-chamber leadless pacemaker system demonstrated atrioventricular synchrony in 98% of evaluable beats at 3 months after implantation. Atrioventricular synchrony was maintained across postures/activities and remained robust for heart rates >100 bpm.

Aveir VR, retrievable leadless pacing in the young.

Successful implantations of the Aveir VR, have been effectively demonstrated in adults; however, there remain limited reports supporting safe and feasible implantation of the Aveir VR in the young population. Retrospective, observational study of Aveir VR implantation of young patients (≦21 years old) at UC Davis Medical Center from November 2022 to January 2024 via the internal jugular or femoral vein implantation approaches. Indications for pacing, patient demographics, pacing thresholds and longevity were reported at the time of implantation and last follow-up. A total of 10 patients received the Aveir VR with a median age of years (IQR 12.5-17) and median weight of 50.8kg (IQR 44.6-60.9) kg. The majority were male (80%). Aveir VR leadless pacemaker occurred via internal jugular venous (90%) or femoral venous (10%) approaches. Indications for placement were intermittent complete heart block (60%) and sinus pauses (40%). Adequate impedance, sensing and thresholds were maintained from implantation to a median follow-up of 9 months. Predicted pacemaker longevity at follow-up median was 23.8 years. There were no complications in any of the 10 patients. Aveir VR implantation via the internal jugular and femoral veins is feasible in the young patient population with stable pacing parameters at follow-up.

Clinical significance and prognostic value of right bundle branch block in permanent pacemaker patients.

In patients undergoing pacemaker implantation with no prior history of heart failure (HF), the presence of left bundle branch block (LBBB) has been identified as an independent predictor of HF-related death or hospitalization, while the prognostic significance of right bundle branch block (RBBB) remains uncertain. We aimed to assess the long-term risk of all-cause mortality in patients with a standard indication for permanent pacing and normal or moderately depressed left ventricular function when RBBB is detected at the time of implantation. We retrospectively enrolled 1348 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center, from January 1990 to December 2022. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded. The baseline 12-lead electrocardiogram revealed an RBBB in 241 (18%) and an LBBB in 98 (7%) patients. During a median follow-up of 65 [25th-75th percentile: 32-117] months, 704 (52%) patients died. The combined endpoint of cardiovascular death or HF hospitalization was reached by 173 (13%) patients. On multivariate analysis, RBBB was confirmed as an independent predictor of death [hazard ratio, 1.33; 95% confidence interval (CI), 1.09-1.63; P = 0.005]. However, when considering the combined endpoint of cardiovascular death and HF hospitalization, this endpoint was independently associated with LBBB (hazard ratio, 2.13; 95% CI, 1.38-3.29; P < 0.001), but not with RBBB. In patients with standard pacemaker indications and normal or moderately depressed left ventricular function, the presence of basal RBBB was an independent predictor of mortality. However, it was not associated with the combined endpoint of cardiovascular death and HF hospitalization.

Leadless pacemaker implantation following tricuspid interventions: multicenter collaboration of feasibility and safety

Abstract Background Permanent pacing is often required following valve intervention (either surgical or percutaneous), however tricuspid interventions pose specific challenges to conventional pacing. Therefore, leadless pacemaker (LP) implantation may be the preferred strategy when permanent pacing is required after tricuspid valve intervention. Objective To report periprocedural outcomes and follow-up of patients undergoing implantation of a LP system following tricuspid valve interventions. Methods Consecutive patients with previous tricuspid valve intervention at the time of attempted implantation of a LP were included. Results Between 2019 and 2022, 40 patients underwent LP implantations following tricuspid interventions in 5 large tertiary centers. The mean age was 68.9 ± 13.7 years, and 48 % patients were male. The indication for pacing was as following: AVB in 27 (68%) patients, AF with slow ventricular response in 10 (25%) patients, and refractory rapid atrial fibrillation (AF) referred to AV junction ablation in 3 (7%) patients. Most of the patients received Micra VR (78 %). Procedure was successful in all patients. Mean procedural time of 58 ± 32 min and median fluoroscopy time of 7.5 min. Electrical parameters were within normal range (threshold: 1.35 ± 1.2 V@0.24 ms, impedance: 772 ± 245 Ohm, R-wave: 6.9 ± 5.4 mV). No acute complications were observed. During a mean follow-up of 10 months, electrical parameters remained stable, and 4 deaths were occurred (not related to the procedure). Conclusion A LP is safe and efficient option following tricuspid valve interventions.Micra LP in a patient with bioprostheticMicra LP in a patient with tricuspid rin

LV systolic function assessment in conventional cardiac pacing: a simple and forgotten parameter - MAPSE

Abstract Background Mitral annular plane systolic excursion (MAPSE) was a widely used M-mode echocardiographic marker of left ventricular longitudinal systolic function. On the other hand, right ventricle (RV) apical pacing is associated with left ventricle (LV) dysfunction development due to dysynchronous activation, while non-apical pacing may provide a more physiological LV activation. The aim of this study is to ascertain the clinical usefulness of MAPSE in the assessment of LV contractile function in patients with permanent RV pacing. Methods Consecutive patients with indication for permanent cardiac pacing (with ventricular pacing percentages over 20% - Vp&amp;gt;20%) were retrospectively enrolled from 2019 to 2023. All patients were assessed by echocardiography with MAPSE, left ventricule ejection fraction (LVEF) and diastolic filling patterns being measured at the time of implant and at subsequent follow-ups. Results 359 patients (age range 41-80yo; mean age=60,5yo) were included, 244 men and 115 women, 173 implanted with single-chamber devices and 186 dual-chamber. 259 patients were paced from the RVA (right ventricle apex) and 62 had septal lead positioning. The mean follow-up period was 18±2 months. The results showed that a MAPSE cut off value of ≤10 mm was associated with a LVEF&amp;lt;42±2%, while MAPSE values &amp;gt;10mm were associated with LVEF&amp;gt;45±3% (p&amp;lt;0.01). RV septal pacing was associated with a higher average MAPSE value (14,28 mm) than RVA pacing (13,47). Conclusions MAPSE seems to corelate well with LVEF in RV conventional pacing. Younger patients with preserved LVEF and less than grade II diastolic dysfunction were not associated with a significant decrese in MAPSE value. However, older patients with HFmrEF and RVA pacing seem to have a more substantial reduction in MAPSE value, suggesting that non-apical or conduction system pacing might be beneficial in this subgroup. MAPSE seems to be a quick and reliable echocardiographic marker of LV systolic function in patients with permanent cardiac pacing. It may be used as an early predictive marker for heart failure in conventional RV paced patients.

Clinical significance and prognostic value of right bundle branch block in permanent pacemaker patients

Abstract Aim In patients undergoing pacemaker implantation with no prior history of heart failure (HF), the presence of left bundle branch block (LBBB) has been identified as an independent predictor of HF-related death or hospitalization, while the prognostic significance of right bundle branch block (RBBB) remains uncertain. We aimed to assess the long-term risk of all-cause mortality in patients with a standard indication for permanent pacing and normal or moderately depressed left ventricular function when RBBB is detected at the time of implantation. Methods We retrospectively enrolled 1348 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center, from January 1990 to December 2022. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded. Results The baseline 12-lead electrocardiogram revealed an RBBB in 241 (18%) and an LBBB in 98 (7%) patients. During a median follow-up of 65 [25th-75th percentile: 32-117] months, 704 (52%) patients died. The combined endpoint of cardiovascular death or HF hospitalization was reached by 173 (13%) patients. On multivariate analysis, RBBB was confirmed as independent predictor of death (Hazard Ratio, 1.33; 95% CI, 1.09–1.63; P=0.005). However, when considering the combined endpoint of cardiovascular death and HF hospitalization, this endpoint was independently associated with LBBB (Hazard Ratio, 2.13; 95% CI, 1.38–3.29; P&amp;lt;0.001), but not with RBBB. Conclusions In patients with standard pacemaker indications and normal or moderately depressed LV function the presence of basal RBBB was an independent predictor of mortality. However, it was not associated with the combined endpoint of cardiovascular death and HF hospitalization.Time to event

Effectiveness of left bundle branch area pacing to restore narrow QRS in patients with right bundle branch block

Abstract Background/Introduction Left bundle branch area pacing (LBBaP) is an innovative technique used to capture conduction tissue and maintain ventricular synchrony during pacing. There are few data about the efficacy of LBBaP in right bundle branch block (RBBB). Purpose To compare the response to LBBaP, evaluated by the change in QRS duration (QRSd) after pacing, in patients with RBBB, left bundle branch block (LBBB) or without conduction disorder. Methods A total of 162 patients with pacemaker indication underwent LBBaP with stylet driven lead with dedicated sheaths, between November 2020 and April 2023. ECG characteristics were evaluated. Data are presented in mean ± standard deviation (SD) or n (%). Paired sample t-test was used to compare QRSd before and after pacing. Results Indications for pacing were atrioventricular block (AVB) 48,4 %, sinus node dysfunction (SND) 37,7 %, AVB and SND 10,7 % and cardiac resynchronization therapy 3,1 %. LBBaP was successfully performed in 98 % (159/162) of patients (78 ± 10 years, 62 % male). Overall, baseline QRSd was 113,2 ± 26,7 ms and paced QRSd was 112,3 ± 14,8 ms (p = 0,662), with left ventricular activation time (LVAT) of 69 ± 14 ms (table 1). Baseline ECG showed 18 LBBB, 29 RBBB and 11 undetermined conduction disorder. In every kind of conduction disorder, paced QRSd was reduced to &amp;lt; 120 ms (table 2). Notably, paced QRSd was &amp;lt; 120 ms, regardless of baseline QRSd. In patients with most important pre-existing conduction disorder (QRS ≥ 145 ms), an impressive reduction in QRSd was observed (Delta = -40,8 ms , table 1). Conclusion LBBaP with stylet driven lead is an effective approach to obtain short paced QRS regardless of baseline QRSd and of the nature of the initial conduction disorder. This opens new perspectives for cardiac resynchronization in patients with RBBB.

Left bundle branch area pacing in the setting of cardiac amyloidosis: a case series

Abstract Background Cardiac amyloidosis (CA) is a highly prevalent cause of congestive heart failure. It often requires cardiac pacing due atrioventricular conduction (AV) system disorders, often with cardiac resynchronization (CRT) to prevent development/deterioration of left ventricular (LV) dysfunction. Left bundle branch area pacing (LBBAP) is an emerging alternative to CRT, offering a strict physiological LV activation and very limited use of iodinated contrast. The feasibility of LBBAP in CA is considered limited due to the presence of septal pseudohypertrophy which theoretically limits left-sided conduction system engagement. Purpose To evaluate the feasibility and effectiveness of LBBAP in cardiac amyloidosis. Methods Consecutive patients with CA (both light-chain -AL- or wild-type transtiretin -wtATTr) with a pacing indication for AV conduction disorders were enrolled. Patients underwent baseline echocardiographic examination. LBBAP was achieved by means of stylet-driven leads advanced transeptally (right ventricle (RV) to LV) via dedicated delivery systems, with continuous monitoring of 12-lead electrocardiographic morphology and impedance until a typical QRS morphology in V1 was obtained (usually rSr’ or Sr’). Standard measures for left bundle (LB) capture were used (stimulus to peak R in V6 – S-RV6, V6-V1 interpeak interval, presence of transition in these measures during threshold testing, presence of fascicular signal during spontaneous QRS). Results Between January 2022 and June 2023, among 63 patients undergoing LBBAP, 7 patients (11%) had CA, 2 AL (28%) and 5 (72%) wtATTR. Patients were prevalently old (78±7 y) males (6, 85%); LV mean septal thickness was 17±2 mm (min 16, max 20 mm) and mean LV ejection fraction (LVEF) was 45±6%. Indications were PR prolongation in 3, bradycardic atrial fibrillation and LB branch block (LBBB) in 2, primary LBBB in 1 and chronic RV pacing in 1. Baseline QRS duration was 145±47 ms (QRS&amp;lt;120 ms: 97±15 ms, QRS&amp;gt;120 ms: 182±13 ms). LBBAP success was 100%. Fascicular electrograms were observed in ¾ of patients without LBBB; S-RV6 interval was 74 ±11 ms (³70 ms in 3), RV6-RV1 interpeak interval was 47±9 ms (³ 30 ms in 6 patients). DQRS in baseline broad QRS was -52 ms and +32 ms in narrow. No complications were observed. Over a short follow up of 6 months, an increase in average LVEF was observed (LVEF at 6 months: 51±3%, p&amp;lt;0.05). Conclusions In patients with CA, LBBAP is easily achievable with stylet-driven systems with frequent selective engagement of conduction system. QRS narrowing in baseline broad QRS is significant while QRS broadening in baseline narrow QRS is limited. Early results regarding follow-up of surrogate endpoint such as LVEF are promising.