Ventricular Pacemaker Research Articles

A comparison of procedure-related adverse events between two right ventricular leadless pacemakers.

The Medtronic Micra VR and Abbott AVEIR VR are the leadless pacemakers (LPM) currently available in the United States (US). Micra VR employs fixation tines and the AVEIR VR uses an active fixation helix. Micra VR requires fixation before electrical measurements are obtained, while R-waves may be mapped by AVEIR VR without fixation. Little comparative data is available for these LPMs. Accordingly, we compared the incidences of procedure-related major adverse clinical events (MACE) and device problems in the US for Micra VR and AVEIR VR during 2022-2024. We searched the FDA's Manufacturer and User Facility Device Experience (MAUDE) database for US reports of MACE and device problems that were filed from April 2022 to December 2023 for AVEIR VR, and from June 2022 to April 2024 for Micra VR. Totals for US-registered LPM implants were obtained from the manufacturers' product performance reports. During the study period, 5990 AVEIR VR and 10 940 Micra VR implants were registered in the US. We found 305 MAUDE reports for AVEIR VR (5.1%), versus 541 MAUDE reports for Micra VR (4.9%) (p = .702). The incidence of MACE was 0.72% (43/5990) for AVEIR VR versus 0.59% (65/10 940) for Micra VR, (p = .387). The incidences of procedure-related death, cardiac perforation. cardiac arrest, emergency pericardial drainage or reparative surgery were similar for both LPMs (p > .05). Micra VR had more unacceptable thresholds requiring LPM replacement compared to AVEIR VR (95;0.9% vs. 24;0.4%; p = .001). AVEIR VR had a statistically higher incidence of device dislodgement during (32) and after (21) implant compared to Micra VR (53 (0.9%) vs. 46 (0.4%), p < .001). Micra VR and AVEIR VR have similar procedural safety profiles, including the incidences of death and perforation. However, device problems differed significantly, possibly related to their design differences. Compared to Micra VR, AVEIR VR appears to have an advantageous threshold measurement capability but is more prone to device dislodgement.

Impact of early detection and steroid treatment on fetal ventricular heart rate and pacemaker implantation in anti-Ro/SSA positive congenital heart block.

We investigated the effects of timing of detection and transplacental fluorinated steroid treatment on ventricular heart rate (HR) and age at pacemaker implantation in fetal third-degree atrioventricular block (AVB). Twenty-five of 31 fetuses diagnosed with Ro/SSA autoantibody-positive AVB II-III at our tertiary fetal cardiology center (2000-2020) and AVB III as final feto-neonatal outcome were reviewed. AVB was detected approximately 5 weeks earlier in pregnancy if followed in a surveillance program compared to cases referred from primary care for bradycardia (20.6 [2.3] [mean (SD)] vs. 25.4 [3.2] weeks, p = 0.001). AVB detected before 24 weeks had higher HR than those detected later in gestation (63.3 [6.9] vs. 57.2 [6.9] bpm, p = 0.042), with a larger proportion having HR >60 bpm (80% vs. 33%, p = 0.041). The 17/25 cases that received treatment with fluorinated steroid were diagnosed earlier in gestation, with higher HR at diagnosis (61.7 [7.1] vs. 54.7 [6.3] bpm, p = 0.026), 1-2 weeks after diagnosis/treatment start, and before birth (65.4 [12.4] vs. 54.9 [5.7] bpm, p = 0.030) than untreated cases. Overall, 11 cases were commenced on betamimetics: three at diagnosis and eight at or after the examination made 1-2 weeks after diagnosis/treatment start, without any HR improvement. Two of 24 surviving babies were born preterm, and 4/24 received a neonatal pacemaker. Age at pacemaker implantation correlated significantly with HR before birth (Spearman R 0.57, p = 0.004), and fetuses with HR >60 bpm had a higher rate of pacemaker-free survival at three (90% vs. 40%, p = 0.018) and 12 months of age (80% vs. 13%, p = 0.002). The same trend was observed in pacemaker-free survival at 3 months of age in fluorinated steroid-treated compared to untreated cases (71% vs. 38%, ns). Our data confirm that AVB III detected earlier in gestation have a higher HR, and suggest that this higher HR can be successfully maintained to the end of gestation in cases treated with fluorinated steroids. Fetuses with HR >60 bpm before birth had a lower rate of pacemaker implantation at 3 and 12 months of age.

Transcatheter non-acute retrieval of the tine-based leadless ventricular pacemaker.

We report our single-centre experience of mid-term to long-term retrieval and reimplantation of a tine-based leadless pacemaker [Micra transcatheter pacing system (TPS)]. The TPS is a clinically effective alternative to transvenous single-chamber ventricular pacemakers. Whereas it is currently recommended to abandon the TPS at the end of device life, catheter-based retrieval may be favourable in specific scenarios. We report on nine consecutive patients with the implanted TPS who subsequently underwent transcatheter retrieval attempts. The retrieval system consists of the original TPS delivery catheter and an off-the-shelf single-loop 7 mm snare. The procedure was guided by fluoroscopy and intracardiac echocardiography. After an implantation duration of 3.1 ± 2.8 years (range 0.4-9.0), the overall retrieval success rate was 88.9% (8 of 9 patients). The mean procedure time was 89 ± 16 min, and the fluoroscopy time was 18.0 ± 6.6 min. No procedure-related adverse device events occurred. In the one unsuccessful retrieval, intracardiac echocardiography revealed that the TPS was partially embedded in the ventricular tissue surrounding the leadless pacemaker body in the right ventricle. After retrieval, three patients were reimplanted with a new TPS device. All implantations were successful without complications. A series of transvenous late retrievals of implanted TPS devices demonstrated safety and feasibility, followed by elective replacement with a new leadless pacing device or conventional transvenous pacing system. This provides a viable end-of-life management alternative to simple abandonment of this leadless pacemaker.

Efficacy and safety of leadless ventricular pacemaker: a single-center retrospective observational study

Efficacy and safety of leadless ventricular pacemaker: a single-center retrospective observational study

Prevalence of cardiomyopathy following pacemaker insertion in an iranian population; a cross-sectional study

Objectives: This study aimed to determine the prevalence of pacemaker-induced cardiomyopathy in patients with pacemaker implantation and to identify the associated risk factors. Methods: This cross-sectional study examined all patients who were implanted with a pacemaker at Afshar Hospital Yazd in 2019 and wore it for two to three years. A new EF test was performed for all patients and compared with the old EF. If a reduction in EF of more than 10% was observed, or the EF was less than 50% due to another reason, it was considered HF. All data were analyzed using SPSS, version 22. Results: One hundred eleven patients participated in this study, 52 (46.8%) men and 59 (53.2%) women. The results showed that ejection fraction (EF) was more than 50% in 93 patients (83.8%). The mean EF decreased from 62.1 to 36.2% over three years. Statistical analysis showed that there is a significant association between diabetes and the incidence of cardiomyopathies in these patients (p = 0.016), but there was no association with hypertension. The mean length of the QRS wave in the electrocardiogram was significantly longer in the group with cardiac pacemakers than in the other patients (P = 0.49). Conclusions: We concluded that 22.5% of referring patients with implantation of a right ventricular pacemaker will develop cardiomyopathy within 2-3 years.

Chronic clinical performance of a novel subxiphoidal pacemaker system: Early feasibility study design.

Extravascular and leadless pacemakers are a new class of cardiac devices that may reduce the rate of complications common to traditional cardiac pacemakers with intracardiac leads. These devices also have the potential of expanding access to cardiac pacing therapy by simplifying the complexity and cost of implantation. The objective of this study is to evaluate the implantation, chronic safety, and performance of a novel subxiphoidal pacemaker. This study is an open-label, non-randomized, early feasibility study. Ten patients indicated for implantation of a single-chamber ventricular pacemaker will be enrolled and implanted with the investigational device. The pacemaker will be inserted underneath the ribcage and clipped to the xiphoid process, with stimulation electrodes positioned on the cardiac pericardium. Patients will be programmed to chronic pacing; pacing capture threshold, sensing amplitude, and lead impedance will be measured at implant and regularly scheduled follow-up visits. 24-h Holter ECG and cardiac troponin will also be periodically measured. Adverse events will be recorded throughout the study period. This study is designed to assess the feasibility, safety, and chronic performance of a novel extravascular pacemaker, and will provide valuable data on whether this device has the potential to be a viable alternative to conventional pacemakers.

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.

Pacemaker-induced atrial fibrillation reconsidered-associations with different pacing sites and prevention approaches.

The incidence of atrial fibrillation (AF) is significantly higher in patients with pacemakers than in the general population, which could be due to patient characteristics and the diagnostic tool of the pacemaker in detecting atrial high-rate episodes and subclinical AF, but also to the pacemaker itself providing AF-promoting conditions. It is well known that high ventricular pacemaker burden increases the likelihood of AF occurrence. However, the sites of atrial and ventricular pacing may also influence the risk for AF. The conventional sites for atrial and ventricular pacing are in the right atrial appendage and in the right ventricular apex. However, growing evidence suggests that alternative pacing sites may be superior for the prevention of AF. Bachmann bundle pacing, for example, promotes interatrial excitation conduction, resulting in atrial synchronicity and a shorter total atrial activation time, which may be preventive for the occurrence of AF. Moreover, in recent years, new ventricular pacing sites have come into focus with His bundle and left bundle branch pacing. In addition to the hemodynamic and electrophysiological cardiac benefits, these new options may also offer benefits in the prevention of AF. This review provides an overview of pacing-induced AF mechanisms and the association with different pacing sites, as well as approaches for prevention of pacing-induced AF, highlighting different sites and modes of atrial pacing and the newer sites of ventricular pacing.

A leadless ventricular pacemaker providing atrioventricular synchronous pacing in the real-world setting: 12-Month results from the Micra AV post-approval registry

BackgroundAdvances in leadless pacemaker technology have enabled accelerometer-based atrioventricular (AV) synchronous pacing by sensing atrial mechanical contraction. ObjectiveThe purpose of this study was to report the performance of the Micra AV leadless pacemaker from the worldwide Micra AV post-approval registry (PAR) through 12 months. MethodsThe Micra AV PAR is a prospective, single-arm, observational registry designed to assess the safety and effectiveness of Micra AV in a real-world setting. For the present interim analysis, major complications and system revisions through 12 months were summarized and compared to a historical cohort of 2667 patients implanted with a transvenous dual-chamber pacing system. ResultsThe device was successfully implanted in 796 of 801 patients (99.4%) at 97 centers in 19 countries. Micra AV patients were older (74.1 years vs 71.1 years; P < .0001) with a higher incidence of renal disease (22.3% vs 9.8%; P < .0001) compared with transvenous dual-chamber patients. Through 12 months, the major complication rate was 3.7% in Micra AV patients compared with 8.8% in transvenous dual-chamber patients (hazard ratio 0.42; 95% confidence interval 0.28–0.61; P < .001). The system revision rate was 1.5% in Micra AV patients compared with 5.5% for transvenous dual-chamber patients (hazard ratio 0.25; 95% confidence interval 0.13–0.47; P < .001); this reduction was largely driven by the absence of lead dislodgments requiring revision. The median AV synchrony index was 79.4% (interquartile range 65.2%–86.4%) in patients paced >90%. ConclusionThe Micra AV leadless pacemaker was implanted with a high rate of success in patients with multiple comorbidities, with a significantly lower rate of complications and system revisions through 12 months compared to a historical cohort of patients with transvenous dual-chamber pacemakers.

Upgrading a single-chamber leadless pacemaker to a dual-chamber leadless pacemaker system

Abstract Background/Introduction The first global dual-chamber leadless pacemaker (DR-LP) study included a group of subjects with a pre-existing upgradeable ventricular single chamber leadless pacemaker (VR-LP) in whom the addition of an atrial leadless pacemaker (AR-LP) was undertaken to allow upgrading to a dual chamber leadless pacing (DR-LP) system. Purpose Summarize success rates of single to dual chamber leadless pacemaker upgrades, as well as device and i2i throughput measurements, serious adverse device effects (SADEs) and mortality in this cohort. Methods Subjects with a pre-existing VR-LP who were indicated for a dual-chamber pacemaker were included. Upgrade procedures included downloading firmware to existing VR-LP, placing AR-LP, and pairing the devices to operate in a DR-LP mode. Electrical and i2i throughput measurements were collected at implant, pre-discharge, 1-mo, 3-mo, 6-mo, and 12-mo. Upgrade success rate was defined as an AR-LP upgrade procedure that resulted in a functional DR-LP system. SADEs included all reported events that were adjudicated as serious and possibly, probably or causally related to the procedure or system. SADEs and deaths were adjudicated by an independent clinical events committee. Results Out of 36 enrolled subjects (61.1% male, 70.4 ± 13.8 yrs., 55.6% sinus node dysfunction, 38.9% AV block), 35 had an attempted implant, and 32 of these were successful (91.4%). The 3 unsuccessful upgrade attempts were related to unsuccessful placement of the AR-LP due to complications during the procedure (n = 2) or an inability to implant an AR-LP (n = 1). Figure 1 illustrates a declining early mean pacing capture threshold, rising early P-wave amplitudes, and stable impedance for the AR-LP over the 12 months. Mean i2i throughput for communication from the RV to RA and the RA to RV improved from pre-discharge to 3 months and remained stable through the subsequent 9 months (Figure 2). A total of 5 subjects (5 of 36; 13.9%) experienced 7 SADEs (all procedure-related; 2 related to the AR-LP and 2 to the delivery catheter). One non-cardiovascular, non-device, non-procedure related death occurred in the upgrade population. Conclusions The single to dual-chamber upgrade cohort demonstrated a high upgrade success rate (91.4%), stable atrial and ventricular electrical measurements and consistently high i2i communication throughout the 12 months. AV synchrony (AVS) was not specifically measured in this upgrade cohort, but data from the main DR-LP study suggest that i2i throughput correlates with, but significantly underestimates AVS. Further, the rate of complications was acceptable (13.9%) and limited to the procedure. These data confirm the feasibility, safety and longer-term effectiveness of adding an atrial LP in patients with a pre-existing ventricular LP order to achieve effective dual chamber pacing.Fig. 1: Upgrade Electrical measurementsFig. 2: i2i communication for Upgrades

Leadless pacemaker implantation via the internal jugular vein a promising access for an established intervention

Abstract Background Leadless pacemaker therapy was introduced in 2013 to overcome lead- and pocket-related complications in conventional transvenous pacemaker therapy. These leadless devices are self-contained right ventricular single-chamber pacemakers implanted via a femoral percutaneous approach. However, the femoral route is not always possible due to various reasons. The aim of this analysis is to share our first experience using a jugulary approach for the implantation procedure. Purpose To evaluate safety and feasibility of leadless pacemaker implantation via the internal jugulary vein. Methods The records of the first 34 patients who underwent leadless pacemaker implantation via the right internal jugular venous route at our center were analyzed prospectively. Follow-up period was 3 months. Safety as well as efficacy including electrical parameters of the jugular approach were compared with the data of the first 100 patients who underwent a femoral leadless pacemaker implantation at our center (implanted from 2015-2019). Results Thirty-four patients underwent internal jugular vein leadless pacemaker implantation (mean age, 82.37 ± 7.58, 58.8% males). All leadless pacemakers were implanted successfully. The jugular approach was well tolerated by all patients. Mean procedure time was 33.29 ± 8.81 min with a mean fluoroscopy time of 3.66 ± 2.07 min. The device was positioned at the inferior septum in 11 patients, at the high septum in two and midseptal in 21 patients. The mean pacing threshold was 0.52 ± 0.22 V at 0.24 ms pulse width with a sensed amplitude of 9.13 ± 4.08 mV. There were no complications during the procedure as well as during 3-month follow-up. At follow-up, electrical parameters remained stable in all patients. Conclusion Implantation of a leadless pacemaker via the right internal jugulary vein is a safe and effective alternative to the femoral approach.Patient demographics/device parameterDevice value development over time.

Significant Mitral Regurgitation After Permanent Right Ventricular Pacemaker Implantation: Prognostic Implications

The underlying mechanisms leading to the development of mitral regurgitation (MR) after right ventricular (RV) pacemaker (PM) implantation and its prognostic value have yet to be fully understood. The purpose of this study was to evaluate the prevalence and clinical variables associated with the development of MR after RV pacing and its association with outcomes. A total of 451 patients (mean age 69 ± 15 years, 61% male) who underwent de novo RV PM implantation were included. The development of significant MR, defined as ≥moderate from mild or none/trace at baseline, occurred in 131 (29%) patients at a median of 2.4 years (interquartile range: 1.0 to 3.8 years) after PM implantation. Multivariate logistic regression analysis demonstrated that implantation of a single-chamber PM, left ventricular end-systolic volume index, and the presence of mild MR (vs no MR) at baseline were independently associated with the development of significant MR post-implant. Cardiac events, defined as the composite of all-cause mortality or heart failure hospitalization, occurred in 143 patients (31.7%) during a median follow-up of 5.4 years (interquartile range: 3.0 to 8.1 years). Multivariate Cox regression analysis demonstrated that the development of significant MR was independently related to the occurrence of cardiac events. In conclusion, the development of significant MR after PM implantation is seen in about one-third of recipients and is independently associated with adverse cardiac events.

Six-month electrical performance of the first dual-chamber leadless pacemaker

BackgroundThe first dual-chamber leadless pacemaker (DC-LP) system consists of 2 separate atrial and ventricular devices that communicate to maintain synchronous atrioventricular pacing and sensing. The initial safety and efficacy were previously reported. ObjectiveThe purpose of this study was to evaluate the chronic electrical performance of the DC-LP system. MethodsPatients meeting standard dual-chamber pacing indications were enrolled and implanted with the DC-LP system (Aveir DR, Abbott), including right atrial and ventricular helix-fixation LPs (atrial leadless pacemaker [ALP], ventricular leadless pacemaker [VLP]). Pacing capture threshold, sensed amplitude, and pacing impedance were collected using the device programmer at prespecified timepoints from 0–6 months postimplant. ResultsDe novo devices were successfully implanted in 381 patients with complete 6-month data (62% male; age 69 ± 14 years; weight 82 ± 20 kg; 65% sinus nodal dysfunction, 30% atrioventricular block). ALPs were implanted predominantly in the right atrial appendage anterior base and VLPs primarily at the mid-to-apical right ventricular septum. From implant to 1 month, pacing capture thresholds (0.4-ms pulse width) improved in both ALPs (2.4 ± 1.5 V to 0.8 ± 0.8 V; P <.001) and VLPs (0.8 ± 0.6 V to 0.6 ± 0.4 V; P <.001). Sensed amplitudes improved in both ALPs (1.8 ± 1.3 mV to 3.4 ± 1.9 mV; P <.001) and VLPs (8.8 ± 4.0 mV to 11.7 ± 4.2 mV; P <.001). Impedances were stable in ALPs (334 ± 68 Ω to 329 ± 52 Ω; P = .17) and reduced in VLPs (789 ± 351 Ω to 646 ± 190 Ω; P <.001). Electrical measurements remained relatively stable from 1–6 months postimplant. No differences in electrical metrics were observed among ALP or VLP implant locations. ConclusionThis first in-human evaluation of the new dual-chamber leadless pacemaker system demonstrated reliable electrical performance throughout the initial 6-month evaluation period.

Helix-fixed leadless pacemaker implantation through a valve-in-valve tricuspid prosthesis via the femoral approach.

Leadless pacemakers offer the opportunity to avoid transvenous hardware among patients with tricuspid valve prostheses. We present the first case of a helix-based fixation leadless pacemaker implanted through valve-in-valve tricuspid prostheses in a 43-year-old female with extensive prior cardiac history. At the time of presentation, epicardial pacing was no longer a viable option in the setting of pacemaker dependence. Placement of a helix-fixed, leadless right ventricular pacemaker was performed as a bridge to dual-chamber leadless pacing. This was safely and effectively performed and highlighted favorable procedural characteristics that included RV cavity dimensions and prosthesis type.

Early real-world implant experience with a helix-fixation ventricular leadless pacemaker.

Roughly one in six patients receiving conventional transvenous pacemaker systems experience significant complications within 1year of implant, mainly due to the transvenous lead and subcutaneous pocket. A new helix-fixation single-chamber ventricular leadless pacemaker (LP) system capable of pre-deployment exploratory electrical mapping is commercially available. Such an LP may mitigate complications while streamlining the implantation. In this study, the initial real-world implant experience of the helix-fixation LP was evaluated following its commercial release. In patients indicated for single-chamber right ventricular pacing, helix-fixation Aveir VR LPs (Abbott, Abbott Park, IL) were implanted using the dedicated loading tool, introducer, and delivery catheter. Implant procedural characteristics, electrical parameters, and any 30-day procedure-related adverse events of consecutive implant attempts were retrospectively evaluated. A total of 167 patients with Class I indication for permanent pacing received implants in four North American centers (57% male, 70years old). Pre-fixation electrical mapping of potential sites allowed repositioning to be avoided in 95.7% of patients. Median [interquartile range] LP procedure and fluoroscopy durations were 25.5min [20.0, 35.0] and 5.7min [4.0, 9.2], respectively. Pacing capture threshold, sensed R-wave amplitude, and impedance were 0.8V [0.5, 1.3], 9.0mV [6.0, 12.0], and 705 Ω [550, 910], respectively. Implantation was successful in 98.8% of patients, with 98.2% free from acute adverse events. The initial, real-world experience of the helix-fixation ventricular leadless pacemaker demonstrated safe and efficient implantation with minimal repositioning, viable electrical metrics, and limited acute complications.

History of cardiac pacemaker therapy in Germany

Cardiac pacemaker therapy began with successful stimulation of human hearts already in the first half of the 20thcentury. Complete implantation of apacemaker by the cardiac surgeon Åke Senning on October 8, 1958 at the Karolinska Hospital in Stockholm is considered the actual birth of today's pacemaker therapy. The first pacemaker implantation in Germany was performed by Hans-Joachim Sykosch on October 6, 1961 at the Surgical Clinic of the University of Düsseldorf. Two years later, the first implantation in East Germany (GDR) was carried out by Friedrich Flemming on September 2, 1963 at the Charité in East Berlin. The first pacemaker manufactured in West Germany arrived on the market 1963; East Germany started device production in 1978. In 1974, pacemaker therapy in West Germany showed a50% survival rate after 6.3years compared to < 1year with drug therapy. After initially using bare metal wires, pacemaker leads have significantly improved in both quality and reliability. Development culminated in the leadless pacemaker. Battery development led to avariety of inventions: rechargeable pacemakers, biogalvanic cells, bioenergy sources, nuclear generators and lithium batteries, the latter ultimately prevailed. In the beginning, only fixed-rate ventricular pacemakers were available. Subsequently, systems adapted to physiological requirements were developed: on-demand pacemakers, atrial-based pacing and rate-adaptive systems. However, it was not until the return to direct stimulation of the conduction system that truly physiological stimulation of the heart became possible.

Transient elevation of the ST segment during implantation of a ventricular pacemaker electrode for deep septal stimulation: A case report

Transient elevation of the ST segment during implantation of a ventricular pacemaker electrode for deep septal stimulation: A case report

First month global longtudinal strain for predicting early pacemaker-induced left ventricular dysfunction (PIVD) six month after pacemaker implantation

Abstract Background Pacemaker-induced ventricular dysfunction (PIVD) and pacemaker-induced cardiomyopathy (PICM) emerged as a complication following right ventricular permanent pacemaker (PPM) implantation, showing a great occurrence in the first year. Finding an early predictor of PIVD and PICM is crucial in order to alleviate mortality, morbidity, and increase health-care cost efficiency. Purposes to find new predictor by analyzing effect of first month GLS using 2D-speckle tracking echocardiography and reduction of left ventricular ejection fraction (LVEF), known as PIVD, in the first 6 month after PPM implantation. Methods A single center, prospective cohort study was conducted to all patients with normal LVEF, indicated for PPM implantation. Data of GLS was measured before and after one month of PPM implantation. Data of LVEF was measured before and six month after PPM implantation. The change of GLS in one month after PPM implantation was measured as delta GLS, and the change of LVEF in six month was measured as delta EF. Results Fifty-three patients from May 2018 until October 2020 was enrolled for this study based on inclusion and exclusion criteria. Patient’s baseline characteristics show 62±14 years of age, most of them had hypertension (54.7%) and had single chamber pacemaker implantation (81.1%). Study analysis reveals that ejection fraction (EF) reduce significantly after six months pacemaker implantation (66,5±5,6% become 60,7±10.7%; p= &amp;lt;0,00001). There were 6 patients (11.3 % ) suffering PICM. Correlation analysis between the change of GLS in the first month and the change of LVEF in the first six months after PPM implantation was statistically significant with moderate correlation (p&amp;lt;0.00001; r= -0.486). Linear regression analysis shows that every 1 point decrease of first month GLS, affecting 1.83 point decrease of sixth month LVEF (b= -0.1837, p=&amp;lt;0.00001). Conclusion There is significant moderate correlation between the change of GLS in the first month and early reduction of LVEF in the first 6 months after PPM implantation.The Scheme of Research Sampling Method

A leadless ventricular pacemaker providing atrioventricular synchronous pacing in the real-world setting: results from the Micra AV post-approval registry

Abstract Introduction Advances in leadless pacemaker technology have enabled accelerometer based atrioventricular synchronous (AVS) pacing by sensing atrial mechanical contraction. However, longer-term performance of these devices in real-world clinical practice has not been assessed. Objectives To report the performance of the Micra AV transcatheter pacemaker from the worldwide Micra AV post-approval registry (PAR) through 1-year post-implant. Methods The Micra AV PAR is an ongoing prospective single-arm observational study designed to assess the safety and effectiveness of the Micra AV system in the real-world setting. Patients enrolled in the Micra AV PAR will be followed for 3 years. For the present interim analysis, baseline characteristics, total AV synchrony index (sum of %AM-VP, %AM-VS, and AV conduction mode switch percentage), major complications, and system revisions through 12-months of implant were summarized and compared to a historical cohort of 2,667 transvenous dual chamber (TV-DC) pacing patients. Results The device was successfully implanted in 797 of 801 patients (99.4%) at 98 centers in 19 countries between February 2020 and April 2022. Mean age was 74.1±15.1 years, 42.2% were female, and 31.3% were precluded from transvenous device therapy. Micra AV patients were on average older (74.1 vs. 71.1 yrs, P&amp;lt;0.0001) and had a significantly higher incidence of renal disease (22.3% vs. 9.8%, P&amp;lt;0.0001) compared with TV-DC patients. Mean follow-up was 7.7±6.4 months. Through 12-months, the major complication rate was 4.2% in Micra AV patients compared to 8.8% TV-DC patients (HR: 0.48, P&amp;lt;0.001, Figure). At 12-months, the system revision rate was 1.9% in Micra AV patients compared to 5.5% for TV-DC patients (HR: 0.28, P&amp;lt;0.001). The reduction in system revisions was largely driven by the absence of lead dislodgements requiring revision. Of the 397 patients with device interrogation files available for analysis, 315 (79.4%) were programmed to VDD mode at last follow-up and had a median AV synchrony index of 86.4% (IQR: 68.8% - 97.4%). Conclusions The Micra AV leadless pacemaker was implanted with a high rate of success in patients with a high co-morbidity burden, with a significantly lower rate of complications and system revisions through 12-months compared to dual-chamber transvenous pacemakers despite patients being older and having a higher incidence of renal disease. Longer-term performance will continue to be assessed in this ongoing trial.Major Complications Through 12-months

Acute deterioration in dyssynchrony and systolic function from Lot-CRT to LBBB pacing

Abstract Background Better electrical synchronization and left ventricular (LV) systolic function was recently reported in left bundle branch–optimized cardiac resynchronization therapy ( Lot-CRT ) when compared with conventional CRT. The implantation of left bundle branch pacing (LBBP) is less expensive, easier to operate and has shorter exposure time to X-ray than Lot-CRT. Purpose To observe whether there are negative changes in dyssynchrony and LV systolic function when switched from Lot-CRT to LBBP. determine whether LBBP pacing alone can replace CRT therapy. Methods 30 patients (21 males, 64.4±9.5 years, 43% with persistent atrial fibrillation) who fulfilled the criteria of CRT implantation received Lot-CRT. The right atrial electrode of the patients with atrial fibrillation or the right ventricular electrode of those with sinus rhythm was implanted into the left bundle branch area. After six months, 20 patients whose LV ejection fraction (LVEF) increased by more than 5% and New York Heart Association functional class increased by at least 1 grade were selected for further investigation. Right and left ventricular pacemaker electrodes were programmed to shut off, leaving only the left bundle branch area pacing for one month. The LV size, systolic function, interventricular mechanical delay (IVMD), and LV mechanical dyssynchrony (LVMD) were compared by using two-dimensional speckle tracking echocardiography. Results It was found that QRS duration slightly widened, the LA size increased, the LV size slightly increased and LVEF decreased, p&amp;lt;0.05. There was no statistical significance in the IVMD (p=0.064). The LV mechanical dyssynchrony increased significantly, p&amp;lt;0.001. Conclusions Deteriotation of LV dyssynchrony and systolic function was recorded when Lot-CRT to LBBP for a short period in recovering patients with systolic dysfunction. It indicates that LBBP may not yet maintain the benefits of Lot-CRT in this group of patients.The comparison between Lot-CRT and LBBP