Dual-chamber vs. single-chamber pacemaker in patients in sinus rhythm with an atrioventricular block: a nationwide cohort study.

AIMS: In complete atrioventricular block (AVB) with underlying sinus rhythm, it is recommended to implant a dual-chamber pacemaker rather than a single-chamber pacemaker. However, no large-scale study has been able to demonstrate the superiority of this choice on hard clinical criteria such as morbimortality. METHODS AND RESULTS: This retrospective observational study included all patients who received a primary pacemaker implantation in the indication of complete AVB with underlying sinus rhythm in France, based on the national administrative database between January 2013 and December 2022. After propensity score matching, we obtained two groups containing 19 219 patients each. The incidence of all-cause mortality was 9.22%/year for the dual-chamber pacemaker group, compared with 11.48%/year for the single-chamber pacemaker group (hazard ratio (HR) 0.807, P < 0.0001]. Similarly, there was a lower incidence of cardiovascular mortality (HR 0.766, P < 0.0001), heart failure (HR 0.908, P < 0.0001), atrial fibrillation (HR 0.778, P < 0.0001), and ischaemic stroke (HR 0.873, P = 0.008) in the dual-chamber pacemaker group than in the single-chamber pacemaker group. Regarding re-interventions and complications, there were fewer upgrades (addition of atrial lead or left ventricular lead) in the dual-chamber group (HR 0.210, P < 0.0001), but more haematomas (HR 1.179, P = 0.006) and lead repositioning (HR 1.123, P = 0.04). CONCLUSION: In the indication of complete AVB with underlying sinus rhythm, our results are consistent with current recommendations to prefer implantation of a dual-chamber pacemaker rather than a single-chamber pacemaker for these patients. Implantation of a dual-chamber pacemaker is associated with a lower risk of mortality, heart failure, atrial fibrillation, and stroke during follow-up.

Reply to the comments on "Effect of Bedside Ultrasound­Guided Versus Fluoroscopy­Guided Transvenous Cardiac Temporary Pacing in Children with Bradyarrhythmia".

The article "Effect of Bedside Ultrasound­Guided Versus Fluoroscopy­Guided Transvenous Cardiac Temporary Pacing in Children with Bradyarrhythmia" offers valuable insights into comparative short-term pacing strategies for pediatric bradyarrhythmias. There are some comments that the study overlooks the impact of genetic factors on bradyarrhythmias and treatment outcomes, lacks detailed information on the influence of medications, and does not address the cost-effectiveness of the pacing techniques. The analysis and explanation are made here, and it is hoped that through further research in the future, the conclusions will be more reliable.

Response to "Effect of Bedside Ultrasound­Guided Versus Fluoroscopy­Guided Transvenous Cardiac Temporary Pacing in Children with Bradyarrhythmia".

The article "Effect of Bedside Ultrasound­Guided Versus Fluoroscopy­Guided Transvenous Cardiac Temporary Pacing in Children with Bradyarrhythmia" offers valuable insights into comparative short-term pacing strategies for pediatric bradyarrhythmias. This letter commends the study for its relevance and potential to improve patient care but highlights several limitations. Notably, the study overlooks the impact of genetic factors on bradyarrhythmias and treatment outcomes, lacks detailed information on the influence of medications, and does not address the cost-effectiveness of the pacing techniques. Future research should address these aspects to enhance the validity and applicability of the findings.

Effect of Bedside Ultrasound-Guided Versus Fluoroscopy-Guided Transvenous Cardiac Temporary Pacing in Children with Bradyarrhythmia.

To compare the efficacy and safety of bedside ultrasound-guided and fluoroscopy-guided transvenous cardiac temporary pacing in the treatment of bradyarrhythmia in children. Children treated by temporary intravenous cardiac pacing from January 2016 to June 2023 in Hunan Provincial Children's Hospital were enrolled, and the characteristics and data of the cases were summarized. Patients were divided into bedside ultrasound-guided group (ultrasound group) and fluoroscopy-guided group (fluoroscopy group) according to the implantation guidance methods. The efficacy, safety, and incidence of complications in children were compared, and follow-up analysis was carried out. A total of 30 children were enrolled, including 18 males and 12 females, with a median age of 5.5 (2.9, 10.0) years and a median weight of 18.7 (12.7, 32.7) kg. The most common primary diseases were fulminant myocarditis (13/30 cases) and congenital high-grade AVB (10/30 cases). Among them, the proportion of congenital high AVB in the fluoroscopy group was significantly higher than that in the ultrasound group, and the difference was statistically significant (p = 0.007). The implantation process was successful in all 30 children. From the time of pacing decision to implantation, the median time of ultrasound group was 56 (30, 60) min and that of fluoroscopy group was 154 (78,180) min, with a statistically significant difference (P < 0.001). A total of 5 cases developed complications. There was no statistically significant difference between the two groups (P > 0.05). Compared with traditional fluoroscopic temporary pacing, bedside ultrasound-guided temporary pacing technology can effectively shorten the operation time and reduce the occurrence of complications and has become a better choice for children's emergency and critical care treatment. The right internal jugular vein is preferred for intravenous implantation.

Intramural Hematoma and Acute Pulmonary Embolism Following Pacemaker Implantation: A Case Report.

Bleeding complications after pacemaker implantation pose risks, including infection and prolonged hospital stay. A case involving aortic intramural hematoma (IMH) arising from subclavian vein access during implantation and concomitant acute pulmonary embolism (PE) is presented. In the present case, IMH probably resulted from subclavian artery vasa vasorum trauma during vein puncture and guidewire advancement, leading to IMH and hemothorax. PE possibly stemmed from a prothrombotic state caused by the intervention and the IMH. Conservative management with serial CT scans was chosen due to hemodynamic stability and high surgical risk. IMH and PE resolution was confirmed at follow-up.

Case Report: A case suffered acute cerebral infarction after removal of temporary cardiac pacing lead which led to the perforation of interventricular septum.

We report an elderly male patient with frequent episodes of dizziness due to a complete atrioventricular block who underwent temporary pacemaker insertion in a local hospital. After the implantation of a permanent pacemaker and removal of the temporary pacemaker lead, the patient developed sudden neurological symptoms, upon which an acute cerebellar infarction was diagnosed via head CT. We will discuss the adequacy of the periprocedural administration.

Left versus right ventricular pacing during TAVR and balloon aortic valvuloplasty: A systematic review and meta-analysis.

INTRODUCTION: While right ventricular pacing (RVP) is the conventional temporary pacing modality used for transcatheter aortic valve replacement (TAVR), this approach possesses inherent risks and procedural challenges. We aim to assess and compare the safety and efficacy of left ventricular pacing (LVP) and RVP during TAVR and balloon aortic valvuloplasty (BAV). METHODS: Following PRISMA guidelines, a comprehensive literature search was conducted in four databases from inception to December 15th, 2023. We included observational studies and clinical trials comparing LVP with RVP during TAVR and BAV procedures. Primary outcomes included short-term mortality, mortality due to cardiac tamponade, and procedural complications including bleeding, vascular complications, and cardiac tamponade. Secondary outcomes comprised procedure duration and length of hospital stay. RESULTS: Five studies involving 830 patients with RVP and 1577 with LVP were included. Short-term mortality was significantly higher in the RVP group (RR 2.32, 95% CI: [1.37-3.93], P = .002), as was the incidence of cardiac tamponade (RR 2.19, 95% CI: [1.11-4.32], P = .02). LVP demonstrated shorter hospital stays (MD = 1.34 d, 95% CI: [0.90, 1.78], P < .001) and reduced procedure duration (MD = 7.75 min, 95% CI: [5.08, 10.41], P < .00001) compared to RVP. New pacemaker implantation was higher in the RVP group (RR 2.23, 95% CI: [1.14, 4.39], P = .02). CONCLUSION: LVP during TAVR and BAV emerges a safer alternative to RVP, offering reduced mortality, hospital stays, and procedure durations.

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

BACKGROUND: 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. METHODS: 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. CONCLUSION: 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.

Epicardial pacemaker placement is associated with low complication rate and improved quality of life in dogs.

OBJECTIVE: To describe complications and outcomes in dogs undergoing epicardial pacemaker (EP) implantation, identify factors associated with survival, and investigate improvement in clinical signs and health-related quality of life (HRQoL) following surgery. ANIMALS: 52 client-owned dogs that underwent EP placement. METHODS: Medical records of 4 UK-based referral hospitals were searched and data reviewed retrospectively between July 2010 and December 2022. Factors contributing to outcomes after EP placement were assessed. RESULTS: The primary reasons for referral included collapsing/syncopal episodes (n = 36), exercise intolerance (15), and significant bradycardia (46). Third-degree atrioventricular block (39/52 [75%]) was the predominant indication for pacemaker placement, and common reasons for EP placement included previous transvenous pacemaker dislodgment/loss of capture (n = 12) and small body size (10). Intra- and postoperative complications were documented in 11% and 23% of dogs, respectively. Overall, 96% of dogs survived to discharge, and median follow-up time was 462 days (range, 31 to 3,139 days). Presence of coexistent myocardial or valvular disease at the time of EP implantation was associated with a reduced survival. Owners reported decreased clinical signs, increased activity levels, and improved HRQoL. CLINICAL RELEVANCE: Epicardial pacemaker implantation is a valuable option for dogs requiring artificial cardiac pacing. Complications were common but did not impact the overall outcome. Dogs with a coexisting cardiac pathology had a shorter life expectancy after EP placement, but their HRQoL appeared to be good, with an improvement in clinical signs and increased activity levels.

Current Role of Conduction System Pacing in Patients Requiring Permanent Pacing.

His bundle pacing (HBP) and left bundle branch pacing (LBBP) are novel methods of pacing directly pacing the cardiac conduction system. HBP while developed more than two decades ago, only recently moved into the clinical mainstream. In contrast to conventional cardiac pacing, conduction system pacing including HBP and LBBP utilizes the native electrical system of the heart to rapidly disseminate the electrical impulse and generate a more synchronous ventricular contraction. Widespread adoption of conduction system pacing has resulted in a wealth of observational data, registries, and some early randomized controlled clinical trials. While much remains to be learned about conduction system pacing and its role in electrophysiology, data available thus far is very promising. In this review of conduction system pacing, the authors review the emergence of conduction system pacing and its contemporary role in patients requiring permanent cardiac pacing.

Factors associated with cardiac implantable electronic device-related infections, New South Wales, 2016-21: a retrospective cohort study.

OBJECTIVES: To quantify the rate of cardiac implantable electronic device (CIED)-related infections and to identify risk factors for such infections. DESIGN: Retrospective cohort study; analysis of linked hospital admissions and mortality data. SETTING, PARTICIPANTS: All adults who underwent CIED procedures in New South Wales between 1 January 2016 and 30 June 2021 (public hospitals) or 30 June 2020 (private hospitals). MAIN OUTCOME MEASURES: Proportions of patients hospitalised with CIED-related infections (identified by hospital record diagnosis codes); risk of CIED-related infection by patient, device, and procedural factors. RESULTS: Of 37 675 CIED procedures (23 194 men, 63.5%), 500 were followed by CIED-related infections (median follow-up, 24.9 months; interquartile range, 11.2-40.8 months), including 397 people (1.1%) within twelve months of their procedures, and 186 of 10 540 people (2.5%) at high risk of such infections (replacement or upgrade procedures; new cardiac resynchronisation therapy with defibrillator, CRT-D). The overall infection rate was 0.50 (95% confidence interval [CI], 0.45-0.54) per 1000 person-months; it was highest during the first month after the procedure (5.60 [95% CI, 4.89-6.42] per 1000 person-months). The risk of CIED-related infection was greater for people under 65 years of age than for those aged 65-74 years (adjusted hazard ratio [aHR], 1.71; 95% CI, 1.32-2.23), for people with CRT-D devices than for those with permanent pacemakers (aHR, 1.46; 95% CI, 1.02-2.08), for people who had previously undergone CIED procedures (two or more v none: aHR, 1.51; 95% CI, 1.02-2.25) or had CIED-related infections (aHR, 11.4; 95% CI, 8.34-15.7), or had undergone concomitant cardiac surgery (aHR, 1.62; 95% CI, 1.10-2.39), and for people with atrial fibrillation (aHR, 1.33; 95% CI, 1.11-1.60), chronic kidney disease (aHR, 1.54; 95% CI, 1.27-1.87), chronic obstructive pulmonary disease (aHR, 1.37; 95% CI, 1.10-1.69), or cardiomyopathy (aHR 1.60; 95% CI, 1.25-2.05). CONCLUSIONS: Knowledge of risk factors for CIED-related infections can help clinicians discuss them with their patients, identify people at particular risk, and inform decisions about device type, upgrades and replacements, and prophylactic interventions.

Safety and efficacy of adaptive atrial pacing regulated by blood pressure during low-level exercise: a proof-of-concept study.

AIMS: Despite half of all heart failure patients suffering from heart failure with preserved ejection fraction (HFpEF), treatment options are limited. This study aims to compare safety and efficacy of standard pacemaker programming (DDD or DDDR) and a novel pacing algorithm PressurePace™ (BaroPace Inc, Issaquah, WA, USA) which modulates atrial pacing rate based on blood pressure (BPAP). METHODS: This prospective, randomized, double-blind, non-significant risk proof of concept study was conducted at two large cardiology clinics in Los Angeles, California, USA. Subjects underwent two modified Bruce protocol graded treadmill exercise tests in which pacemaker programming was randomized to either standard programming (DDD or DDDR), or BPAP at least 1 week apart. Physiological measurements of heart rate (HR), and systolic and diastolic blood pressure (BP) were collected at 2 min intervals. During the BPAP treadmill test, the pacemaker activity sensor was disabled. The PressurePace algorithm instructed the pacemaker technician to modify or leave unchanged the atrial pacing rate based on these BP measurements. Subjects and clinical staff were blinded to pacemaker programming, only the pacemaker technician was unblinded. RESULTS: Ten subjects with HFpEF associated with hypertension who also had permanent dual-chamber pacemakers, previously implanted for standard clinical indications, participated in the study. Mean age was 70.1 ± 6.8 years, left ventricular ejection fraction of 54.8 ± 1.9%. Exercise duration increased in all 10 subjects, when paced in the BPAP mode compared with standard pacemaker programming, showing a mean increase of 117 s (26%, P = 0.0016). The algorithm could adjust HR at each 2 min interval. The majority of subjects (60%) had their atrial pacing rate increased an average of 20% at t = 2 min. In the remaining 40% of subjects, the algorithm instructed HR to be unchanged. In two subjects, the pacing rate was not increased until t = 6 min. In contrast, subjects programmed to DDDR experienced an average of 45% increase in atrial pacing rate at t = 2 min. In the post-treadmill recovery period, SBP was higher for subjects who underwent BPAP. This difference in SBP was most pronounced immediately post-treadmill and diminished as subjects progressed through the 30 min recovery period. Statistical significance was achieved at t = 0, 20, and 30 min post-treadmill. CONCLUSIONS: An increase in exercise duration was reported in HFpEF subjects using a pacing algorithm that modulated HR based on BP compared with standard programming. These encouraging results form the basis for a larger, randomized cross-over trial to confirm these initial observations, further characterize the safety, efficacy, and possible mechanisms of action in both acute and longer-term treatment.

First-in-man clinical implantation and acute pacing performance of a novel subxiphoidal pacemaker system.

BACKGROUND: Intravascular cardiac pacemakers are an established therapy for bradycardic indications. Recently, a new class of leadless pacemakers have mitigated some of the complications related to pacemaker leads. In this study, we evaluate the implantation and performance of a novel extravascular technology that delivers epicardial pacing through a subxiphoidal approach. METHODS: Fifteen patients undergoing non-emergent open-heart surgery were enrolled. A midline incision was made just below the xiphoid process, and substernal tunneling was used to create a pocket for the device and to access the anterior pericardium over the right ventricle. The test device (Calyan Technologies, Oakdale, MN) was temporarily inserted underneath the ribcage and clipped to the xiphoid process. The sensing and pacing electrode (FlexArm) was positioned on the anterior pericardium. Ventricular sensing and pacing capture thresholds were measured. RESULTS: The test device was successfully implanted in all 15 patients. There were no device or procedure-related adverse events. The first five implanted patients had no pacing capture at maximum stimulation intensity. Design changes were made to the device, including different electrode size and shape, and successful ventricular capture was achieved in 9 of the subsequent 10 patients. In these patients, pacing threshold was 3.8 ± 1.6 mA with a pulse width of 0.5 ms. All devices were successfully explanted at the end of the procedure. CONCLUSIONS: In a first-in-human experience with a novel extravascular pacemaker, this study demonstrated the feasibility of pericardial ventricular pacing via a subxiphoidal approach. Further chronic studies are required to evaluate the safety and performance of this novel pacing technology.

Permanent Cardiac Pacing of the Right Ventricular Outflow Tract Guided by Real-time Assessment of Electromechanical Synchrony.

Permanent right ventricular apical pacing deteriorates cardiac systolic function in some patients. We investigated an alternative site for permanent pacemaker (PPM) lead positioning with the goal of achieving more physiological pacing. A total of 132 patients with bradyarrhythmias underwent PPM implantation at the right ventricular outflow tract (RVOT) with conventional active-fixation leads. A real-time cross-correlation analysis (CCA) was performed using the Synchromax® software (EXO Health, Seattle, WA, USA) to determine the optimal site for ventricular lead implantation based on the cardiac synchrony index. The follow-up period ranged from 6-36 months, and the following parameters were assessed: pacing capture threshold, lead stability, and the need for lead repositioning. Adequate parameters were achieved in 129 patients (98%), and there were no procedure-related complications. At follow-up, no leads were dislodged, pacing thresholds remained stable, and no lead required repositioning. Using real-time CCA as an intraoperative parameter during PPM implantation at the septal RVOT helps to achieve cardiac synchrony in the vast majority of cases. This technique is a simple, effective, and safe way to simplify and standardize PPM implantation at the RVOT.

Making certain that noninvasive therapy for vasovagal syncope has failed before proceeding to invasive interventions.

There is a perceived need to express concisely the advice of guidelines in the context of consideration of invasive management of highly symptomatic vasovagal syncope. In response to this need the table is presented as a checklist and the text adds explanation and details. It is anticipated that this will prove to be of value for clinicians.

New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.