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Rationale: The use of transvenous pacing leads is associated with the risk of tricuspid valve dysfunction, mainly due to the continuous presence of the leads can have an impact on subsequent tricuspid function and possible operation injury of the tricuspid valve during implantation or operation., Patient Concerns: A 69-year-old female with a history of syncope for 9 months was admitted to the hospital. The electrocardiogram showed sinus bradycardia, junctional escape rhythm, and a heart rate of 44 bpm. Echocardiography suggested a downward displacement and severe insufficiency of the tricuspid valve and atrial septal defect., Diagnoses: The cause of syncope was considered to be sick sinus syndrome. The patient was diagnosed with Ebstein anomaly and is considered a candidate for surgical intervention., Interventions: To avoid aggravating tricuspid insufficiency by pacing leads crossing the tricuspid valve and hindering subsequent tricuspid valve surgery, a single-chamber pacing mode with atrial pacing (AAI) lead and Micra AV was chosen for maintaining atrioventricular synchrony after multidisciplinary discussion., Outcomes: The patient had stable parameters and was in good general condition at 1- and 3-month outpatient follow-ups after discharge., Lessons: This is the first case of new implantation of single-chamber atrial pacing + leadless ventricular pacing with Micra AV, an alternative strategy to epicardial or coronary sinus system for tricuspid valve displacement and severe tricuspid regurgitation., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Seldom are reports of phase 4 block or bradycardia-dependent conduction block in atrial tissue found in the literature. Here, we describe the case of a patient with sick sinus syndrome with Torsade de Pointes who, following the implantation of a double-chamber implantable cardioverter defibrillator, developed intra-atrial bradycardia-dependent conduction block. The patient's optimal pacing parameters were achieved by raising the rate., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Sinus arrest and inappropriate sinus bradycardia are sinus node dysfunction (SND), which cause loss of consciousness. Cardiac pacing is recommended in patients with symptoms, such as syncope or dizziness. Several conditions can induce these arrhythmias; however, whether or not intracranial infectious diseases, such as herpes simplex encephalitis (HSE), can cause secondary SND is unclear. We encountered a patient with sinus arrest and transient sinus bradycardia associated with HSE. Since cardiac pause was never monitored and the bradycardia improved after HSE treatment, HSE was suspected to be the cause of SND. Although the underlying mechanisms have not yet been completely elucidated, HSE may cause secondary SND.

Background: New antithrombotic medications and improved stent designs have reduced branch occlusion, although the sino-atrial nodal artery (SANA) may still be occluded after a percutaneous coronary intervention (PCI), causing sinus node dysfunction (SND). Ischemic sinus nodes are usually asymptomatic but can cause sinus arrest sometimes requiring pacemaker placement. In rare cases, junctional escape rhythms, a manifestation of sinus exit blocks after PCI, can predict cardiogenic shock., Methods: We present a case study of a patient who underwent bifurcation PCI to the LMCA to the LCX but subsequently developed cardiogenic shock as a result of SND, a junctional escape rhythm required substantial inotropic support. This case offers an exemplification of a sparsely documented, yet infrequent manifestation of iatrogenic ischemic SND at an unorthodox site, the confluence of the LMCA-LCX. In addition, we conducted a comprehensive analysis of 22 scholarly works pertaining to the subject of sinus node dysfunction (SND) subsequent to PCI resulting from ischemia caused by stenosis or occlusion of the SANA., Results: RCA was responsible for 96.1% of SND cases, whereas LCX was responsible for 3.9%. SND was asymptomatic in 49.3% of cases and junctional escape rhythm in 37.6% of symptomatic cases. 28% needed a temporary transvenous pacemaker, while 7.8% needed a permanent one. Interventional management recanalized the SANA in 5.2% of patients, restoring flow., Conclusion: Transient sino-atrial node ischemia after PCI can cause acute SND. Before stent implantation, doctors should consider SND. Complete plaque evaluation around the SANA is needed before choosing the best PCI procedure., (© 2024 Wiley Periodicals LLC.)

Aims: Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing., Methods and Results: Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms., Conclusion: Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing., Competing Interests: Conflict of interest: G.L.B. received speaker’s fee from Abbott, Biotronik, Boston Scientific, Medtronic, and MicroPort. M.D.M., D.G., and A.G. are employees of Biotronik Italia S.p.A., an affiliate of Biotronik SE & Co. KG (study sponsor and manufacturer of investigational devices). All remaining authors have declared no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

BACKGROUND Compression of the vagus nerve by a pharyngeal mass is a well-documented condition that can result in sinus node dysfunction (SND). However, there is scarce literature on extrinsic vagal nerve compression from a tonsillar abscess. CASE REPORT A 59-year-old woman with a history of asthma and chronic throat discomfort presented to the Emergency Department with bradycardia, palpitations, and voice changes. Following a shellfish allergy hospitalization, an otolaryngology evaluation revealed an enlarged right tonsil, recommending tonsillectomy, but scheduling challenges persisted. The patient reported mild throat pain, dysphagia, hoarseness, rhinorrhea, and exertional dyspnea and was admitted for the evaluation of peritonsillar mass. She was found to be bradycardic with a heart rate of 47, with an electrocardiogram revealing SND. Albuterol and ipratropium nebulizers, as well as dexamethasone and pantoprazole, were initiated. With this treatment, the patient symptomatically improved with a new heart rate of 68. She was discharged with outpatient appointments, but was unfortunately lost to follow-up. CONCLUSIONS This case reveals sinus node dysfunction resulting from extrinsic vagal nerve compression by a tonsillar abscess. Pressure on the vagus nerve can trigger bradycardia and low blood pressure, possibly due to compensatory overfiring of afferent vagal nerve signals from local mass effect. Early recognition and antibiotic treatment are essential to prevent cardiac complications. Clinicians must remain vigilant for such extrinsic causes, particularly in patients with chronic sore throat and cardiac symptoms. Further research and case reports are needed to deepen our understanding of this rare yet significant association.

We herein report a 76-year-old woman with situs inversus and dextrocardia who underwent pacemaker implantation for sick sinus syndrome. Situs inversus with dextrocardia, which is frequently associated with cardiovascular malformation, is a rare congenital malformation wherein the thoracic and abdominal viscera are inverted compared with their normal positions. This renders the implantation of cardiac devices an arduous task. We therefore decided to gather preoperative anatomical information on patients with situs inversus and dextrocardia. We used three-dimensional computed tomography to collect preoperative information in order to facilitate the safe implantation of cardiac devices.

This case report discusses a 42-year-old male with dextro-transposition of the great arteries (D-TGA) status post Mustard repair and sick sinus syndrome status post dual-chamber pacemaker implant, who developed symptomatic superior vena cava (SVC) baffle stenosis. He was treated with a combined pacemaker extraction and subsequent SVC baffle stenting. The case highlights the complexities of treating SVC baffle stenosis in the presence of cardiac implantable devices and demonstrates the efficacy of this combined approach. Furthermore, the authors delve into the intricacies of D-TGA, its surgical history, and the long-term complications associated with atrial switch procedures., Competing Interests: Disclosure The authors have no conflict to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Pacemaker implantation can be challenging in patients with congenital heart disease., Methods and Results: In a patient with Ebstein disease and symptomatic sinus node dysfunction, despite multiple attempts, the Micra® pacemaker could not be implanted in the severely dilated right ventricle. In that context, and after iodine injection to confirm the appropriate location, the Micra® pacemaker was successfully implanted in the right appendage at the first attempt., Conclusion: Despite the recent development of dedicated dual-chamber leadless pacemaker, to the best of our knowledge, this case is the first off-label Micra® implantation in a right appendage., (© 2024 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

A persistent left superior vena cava (PLSVC) is a commonly observed anatomical anomaly that is frequently detected incidentally via computed tomography (CT) imaging. However, the occurrence of a PLSVC with a right superior vena cava (RSVC) defect, also known as "isolated PLSVC," is a much rarer anomaly. This peculiar malformation can lead to sinoatrial dysfunction, thus necessitating pacemaker implantation, which requires delicate manipulation due to various anatomical complexities. We herein present a case of a sick sinus syndrome with this rare anomaly, which required special consideration when performing pacemaker lead placement.

Background: The stretching of the lead caused by somatic growth may lead to complications (dislodgement, fracture, failure) of transvenous leads implanted in pediatric patients. Atrial loop and absorbable ligatures may prevent it. Periodical lead advancement with lead pushing from the pocket may be an option to growth-induced stretching. Our aim was to analyze retrospectively the outcome of periodical transvenous lead advancement in children with pacemaker (PM)., Methods: A procedure of lead advancement was performed in patients with a single-chamber PM implanted for isolated congenital complete atrioventricular block or sinus node dysfunction with growth-induced lead straightening/stretching. The PM pocket was opened, the lead was released from subcutaneous adherences and was gently advanced to shape again a loop/semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are described as median (25th-75th centiles)., Results: 14 patients with 13 VVIR and 1 AAIR PM implanted at 6.8 (5.9-8.0) years of age, 23 (19-26) kg, 118 (108-124) cm, underwent 30 advancement procedures, 1.5 (1.0-2.3) per patient, during follow-up [45 (35-63) months]. Delta between procedures was: 18 (14-25) months, 11 (7-13) cm, 6 (4-9) kg; 90% of leads were successfully advanced without complications. Three unsuccessful procedures occurred with longer times [30 (14-37) months]. Electrical lead parameters did not show significant differences pre-/post-procedures., Conclusion: the advancement of transvenous leads in children seems safe and effective. This procedure may be another possible choice to preserve transvenous lead position and function until growth has completed., (© 2024 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Background: Tachycardia-bradycardia syndrome (TBS) is a subtype of sick sinus syndrome characterized by prolonged sinus pause (≥3 s) following termination of tachyarrhythmias, primarily atrial fibrillation (AF). There is controversy regarding whether the long-term prognosis of AF ablation is superior to pacemaker implantation. This study aimed to compare the effects of AF ablation and pacemaker therapy in patients with TBS., Methods: We conducted a comprehensive search of electronic databases, including PubMed, Cochrane, EmBase, Web of Science, and Chinese BioMedical, up until December 1, 2023. We included studies that reported the effects of AF ablation vs pacemaker therapy in patients with TBS. From this search, we identified 5 studies comprising 843 participants with TBS who underwent catheter AF ablation or pacemaker therapy., Results: Our meta-analysis revealed that AF ablation and pacemaker therapy had similar effects on cardiovascular death (odds ratio [OR] = 0.62 and 95% confidence interval [CI]: 0.14-2.65), procedural complications (OR = 1.53 and 95% CI: 0.67-3.48), and cardiovascular rehospitalization (OR = 0.57 and 95% CI: 0.26-1.22). However, AF ablation provided greater benefits than pacemaker therapy in terms of all-cause mortality (OR = 0.37 and 95% CI: 0.17-0.82), thromboembolism (OR = 0.25 and 95% CI: 0.12-0.49), stroke (OR = 0.28 and 95% CI: 0.13-0.57), heart failure (OR = 0.27 and 95% CI: 0.13-0.56), freedom from AF (OR = 23.32 and 95% CI: 7.46-72.92), and prevention of progression to persistent AF (OR = 0.12 and 95% CI: 0.06-0.24). Furthermore, AF ablation resulted in a reduced need for antiarrhythmic agents (OR = 0.21 and 95% CI: 0.08-0.59)., Conclusion: AF ablation can effectively reduce the risk of all-cause mortality, thromboembolism, stroke, heart failure, and progression to persistent AF in patients with TBS. Additionally, it may eliminate the need for further pacemaker therapy in most cases after ablation. Therefore, AF ablation is considered superior to pacemaker therapy in the management of patients with TBS., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Transvenous pacemaker placement is an integral component of therapy for severe dysrhythmias and a core skill in emergency medicine., Objective: This narrative review provides a focused evaluation of transvenous pacemaker placement in the emergency department setting., Discussion: Temporary cardiac pacing can be a life-saving procedure. Indications for pacemaker placement include hemodynamic instability with symptomatic bradycardia secondary to atrioventricular block and sinus node dysfunction; overdrive pacing in unstable tachydysrhythmias, such as torsades de pointes; and failure of transcutaneous pacing. Optimal placement sites include the right internal jugular vein and left subclavian vein. Insertion first includes placement of a central venous catheter. The pacing wire with balloon is then advanced until electromechanical capture is obtained with the pacer in the right ventricle. Ultrasound can be used to guide and confirm lead placement using the subxiphoid or modified subxiphoid approach. The QRS segment will demonstrate ST segment elevation once the pacing wire tip contacts the endocardial wall. If mechanical capture is not achieved with initial placement of the transvenous pacer, the clinician must consider several potential issues and use an approach to evaluating the equipment and correcting any malfunction. Although life-saving in the appropriate patient, complications may occur from central venous access, right heart catheterization, and the pacing wire., Conclusions: An understanding of transvenous pacemaker placement is essential for emergency clinicians., Competing Interests: Declaration of competing interest None., (Published by Elsevier Inc.)

Left bundle branch pacing (LBBP) has been subject to increasing interest over the last few years due to its capacity for physiological conduction and its advantages compared to His bundle pacing. His bundle pacing has certain limitations, such as a small pacing area for the His bundle, a high threshold that leads to battery depletion, a low R-wave amplitude that may result in atrial or His oversensing, and ventricular signal undersensing. In this case series, four patients (two female and two male) aged 62.2 ± 8.4 years old with symptomatic sick sinus disease and no scar tissue in the interventricular septum underwent LBBP. All LBBPs were done with standard LBBP using a lumenless SelectSecure 3830 lead (Medtronic®, Minneapolis, USA) with a fixed helix. The lead parameters showed a good R-wave amplitudes (13 ± 7.4 mV) and a low threshold  (0.77 ± 0.17 V @ 0.4 ms). All patients were discharged on the next day. During follow-up period of 13.3 ± 12.9 months, all patients were well and no complications were noted. In conclusion, LBBP may be as an alternative of novel conduction pacing techniques and can be done relatively easy and safe, even with limited experience center.

Background and Objectives : Atrioventricular (AV) dyssynchrony as well as atrial and ventricular pacing affect left atrial (LA) function. We conducted a study evaluating the effect of atrial and ventricular pacing on LA morphological and functional changes after dual-chamber pacemaker implantation. Materials and Methods : The study prospectively enrolled 121 subjects who had a dual-chamber pacemaker implanted due to sinus node disease (SND) or atrioventricular block (AVB). Subjects were divided into three groups based on indication and pacemaker programming: (1) SND DDDR 60; (2) AVB DDD 60 and (3) AVB DDD 40. Subjects were invited to one- and three-month follow-up visits. Three subsets based on pacing burden were analyzed: (1) high atrial (A) low ventricular (V); (2) high A, high V and (3) low A, high V. LA function was assessed from volumetric parameters and measured strains from echocardiography. Results : The high A, low V group consisted of 38 subjects; while high A, high V had 26 and low A, high V had 23. A significant decrease in reservoir and contractile LA strain parameters were only observed in the high A, low V pacing group after three months (reservoir 25.9 ± 10.3% vs. 21.1 ± 9.9%, p = 0.003, contractile -14.0 ± 9.0% vs. -11.1 ± 7.8, p = 0.018). While the re-established atrioventricular synchrony in the low A, high V group maintained reservoir LA strain at the baseline level after three months (21.4 ± 10.4% vs. 22.5 ± 10.4%, p = 0.975); in the high A, high V group, a further trend to decrease was noted (20.3 ± 8.9% vs. 18.7 ± 8.3%, p = 0.231). Conclusions : High atrial pacing burden independently of atrioventricular dyssynchrony and ventricular pacing impairs LA functional and morphological parameters. Changes appear soon after pacemaker implantation and are maintained.

Sudden alterations in the heart rate may be associated with diverse symptoms. Sinus node dysfunction (SND), also known as sick sinus syndrome, is a sinoatrial (SA) node disorder. SND is primarily caused by the dysfunction of the pacemaker, as well as impaired impulse transmission resulting in a multitude of abnormalities in the heart rhythms, such as bradycardia-tachycardia, atrial bradyarrhythmias, and atrial tachyarrhythmias. The transition from bradycardia to tachycardia is generally referred to as "tachy-brady syndrome" (TBS). Although TBS is etiologically variable, the manifestations remain consistent throughout. Abnormal heart rhythms have the propensity to limit tissue perfusion resulting in palpitations, fatigue, lightheadedness, presyncope, and syncope. In this review, we examine the physiology of tachy-brady syndrome, the practical approach to its diagnosis and management, and the role of adenosine in treating SND., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare that are relevant to the content of this article., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Permanent pacemakers are an established treatment for sick sinus syndrome and high-grade atrioventricular block. Permanent cardiac pacemaker implantations may damage the myocardium., Objective: This study evaluated markers of myocardial injury, oxidative stress and inflammation in elderly patients with permanent pacemaker implantations., Methods: Various markers were measured at 1, 2, 3 and 4 months after permanent pacemaker implantations in elderly patients., Results: The levels of high-sensitivity troponin T (hsTnT), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), malondialdehyde-modified low-density lipoprotein (MDA-LDL), oxidized low-density lipoprotein (OX-LDL), tumour necrosis factor-α (TNF-α), toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) were increased in 2-month group compared with control and 1- month groups (P<0.001), and were further increased at 4-month group compared with 2- and 3- month groups after pacemaker implantations (P<0.001). Patients with dual-chamber pacemakers had higher levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB than patients with single chamber pacemakers (P<0.001). Patients who underwent the pacemakers with the active fixation leads had raised levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB compared patients with pacemakers using the passive fixation leads (P<0.001). Myocardial blood flows in 3-month and 4-month groups were lower than 1-month and 2-month groups (P<0.001)., Conclusion: Levels of hsTnT, LOX-1, MDA-LDL, OX-LDL, TNF-α, TLR4 and NF-κB were elevated in elderly patients with permanent pacemaker implantations and the activations of oxidative stress and pro-inflammatory signalling pathways may be associated with myocardial damages and ischemia after pacemaker implantations in elderly patients., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Empty sella syndrome (ESS) is characterized by the herniation of cerebrospinal fluid into the sella, which results in the enlargement of the sella and compression of the pituitary gland. ESS commonly accompanies pituitary dysfunction and abnormal secretion of one or more hormones, which manifests as symptoms like cold intolerance, fatigue, and memory impairment. However, the occurrence of sick sinus syndrome (SSS) in ESS has not been reported. A 66-year-old female patient was admitted to the hospital with complaints of dizziness and fatigue. Electrocardiogram (ECG) revealed sinus arrest, junctional escape rhythm, and a heart rate of 40 bpm. Then, the patient was diagnosed with SSS. Thyroid function test indicated decreased thyroxine levels and slightly elevated thyroid-stimulating hormone levels. Additionally, hyposecretion of cortisol and insulin-like growth factors was observed. Magnetic resonance imaging of the pituitary gland confirmed the diagnosis of ESS. The patient was treated with hydrocortisone and euthyrox, relieving the symptoms of dizziness and fatigue. Thyroid function tests during the follow-up period showed normal hormone levels, and ECG examination revealed no abnormalities.

Background: The temporary pacing lead routinely is placed into right ventricular (RV), which pose a risk of dislocation and cardiac perforation., Objective: We aim to evaluate the effectiveness and safety of temporary transvenous cardiac pacing (TTCP) leads placement into the coronary sinus vein (CSV) in patients with sick sinus syndrome (SSS)., Methods: We investigated patients with SSS who underwent TTCP lead placement into the CSV under the guidance of X-ray between January 2013 and May 2023. Patients were randomly divided into two groups: RV group (n = 33) and CSV group (n = 22). The ordinary passive bipolar electrodes were applied in both groups. In RV groups, electrodes were placed into RV. In CSV group, electrodes were placed into CSV. We evaluated the operation duration, fluoroscopic exposure, first-attempt success rate of leads placement, pacing threshold, success rate of leads placement, rate of leads displacement, and complications., Results: Compared with that in RV group, the procedure time, fluoroscopic exposure was significantly prolonged, while the first-attempt success rate of lead placement was obviously increased in CSV group (both p < .05). Compared with that in RV group, the rate of leads displacement is lower in CSV group (both p < .05). There were three patients occurred cardiac perforation in RV group, but no cardiac perforation was reported in CSV group (p > .05)., Conclusion: TTCP leads placement into the CSV is an effective and safe strategy in patients with SSS. It indicates a high rate of pacing effectiveness with low device replacement and complication rates., (© 2023 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Introduction: Single atrial stimulation (AAI) has been commonly used for permanent pacing in sick sinus syndrome and significant bradycardia., Objective: The study aimed to evaluate long‑term AAI pacing and to identify timing and reasons for pacing mode change., Patients and Methods: Retrospectively, we included 207 patients (60% women) with initial AAI pacing, who were followed‑up for an average of 12 years., Results: At the time of death or loss to follow‑up, 71 patients (34.3%) had unchanged AAI pacing mode. The reason for an upgrade of the pacing system was development of atrial fibrillation (AF) in 43 patients (20.78%) and atrioventricular block (AVB) in 34 patients (16.4%). The cumulative ratio for a pacemaker upgrade reoperation reached 2.77 per 100 patient‑years of the follow‑up. Cumulative ventricular pacing below 10% after an upgrade to dual‑chamber pacemaker was observed in 28.6% of the patients. Younger age at implant was the leading independent predictor of the change to dual‑chamber simulation (hazard ratio, 1.98; 95% CI, 1.976-1.988; P = 0.001). There were 11 (5%) lead malfunctions that required reoperation. Subclavian vein occlusion was noted in 9 upgrade procedures (11%). One cardiac device-related infection was observed., Conclusions: The reliability of AAI pacing decreases with each year of observation due to development of AF and AVB. However, in the current era of effective AF treatment, the advantages of AAI pacemakers, such as lower incidence of lead malfunction, venous occlusion, and infection, as compared with dual-chamber pacemakers, may make AAI pacemakers a viable option.

Background . Pacemakers are used to treat syncope in patients with bradyarrhythmia; however, the risk of recurrent syncope has only been investigated in few and smaller studies. Objective. The aim of this study was to investigate the risk of recurrent syncope after pacemaker implantation in patients with bradyarrhythmia and prior syncope. Methods. This retrospective, population-based cohort study included patients with a prior syncope and implantation of a pacemaker using data from the Danish nationwide registers from 1996 to 2017. Cumulative incidence and cox regression was used to estimate the 5-year incidence and the risk of recurrent syncope, respectively. Results. In total, 11,126 patients (median age: 78 years, interquartile range: 69-85, 56% male) were included and the 5-year cumulative incidence of recurrent syncope was 19.6% (95% confidence interval (CI): 18.8-20.3%). Sinus node dysfunction (hazard ratio [HR]: 1.29, 95%CI: 1.17-1.42) and unspecified type of bradyarrhythmia (HR: 1.32, 95%CI: 1.15-1.52) were associated with an increased risk of syncope compared to advanced atrioventricular (AV) block. Male sex (HR: 1.22, 95%CI: 1.22-1.34), cerebrovascular disease (HR: 1.17, 95%CI: 1.05-1.30), and prior number of syncopes were significantly associated with a higher HR of recurrent syncope. Conclusion. Almost one-in-five patients with bradyarrhythmia and prior syncope who had a pacemaker implanted had a recurrent syncope within five years. A higher risk of syncope was observed among patients with sinus node dysfunction and unspecified type of bradyarrhythmia compared to AV block. Male sex, cerebrovascular disease, and prior number of syncopes were associated risk factors of recurrent syncope.

Background: Permanent pacemaker (PPM) implantation is a well-established treatment for symptomatic sinus node dysfunction (SND). The optimal timing of this intervention is unclear, with atrioventricular blocks often prioritized in resource stressed waiting lists due to mortality concerns., Methods: Mortality data was compared between patients receiving elective outpatient (OP) PPM implantation, and those presenting to hospital for urgent inpatient (IP) management for symptomatic SND. Survival analysis was conducted using Kaplan-Meier plots and compared using the log-rank test. Univariable and multivariable Cox regression, as well as propensity score matching analyses were performed to assess the prognostic effect on 30-day and 1-year all-cause mortality of inpatient implant., Results: Of the 1269 patients identified with isolated SND, 740 (58%) had PPMs implanted on an OP and 529 (42%) on an IP basis. Mortality was significantly worse in patients where management was driven by hospital admission on an urgent basis (Log-Rank χ2 = 21.6, p < 0.001) and remained an independent predictor of 1-year all-cause mortality (HR 3.40, 95% CI 1.97-5.86, p < 0.001) on multivariable analysis., Conclusions: SND is predominantly a disease associated with ageing and comorbid populations, where avoidance of deconditioning, hospitalization acquired infections, and polypharmacy is advantageous. Admission avoidance is therefore the preferable strategy., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Pacing indications in children are clearly defined, but whether an epicardial (EPI) or an endocardial (ENDO) pacemaker performs better remains to be elucidated. This systematic review and meta-analysis aimed to directly compare the incidence of pacemaker (PM) lead-related complications, mortality, hemothorax and venous occlusion between EPI and ENDO in children with atrioventricular block (AVB) or sinus node dysfunction (SND). Literature search was conducted in MEDLINE (via PubMed), Scopus by ELSEVIER, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and OpenGrey databases until June 25, 2022. Random-effects meta-analyses were performed to assess the pacing method's effect on lead failure, threshold rise, post-implantation infection and battery depletion and secondarily on all-cause mortality, hemothorax and venous occlusion. Several sensitivity analyses were also performed. Of 22 studies initially retrieved, 18 were deemed eligible for systematic review and 15 for meta-analysis. Of 1348 pediatric patients that underwent EPI or ENDO implantation, 542 (40.2%) had a diagnosis of congenital heart disease (CHD). EPI was significantly associated with higher possibility of PM-lead failure [pooled odds ratio (pOR) 3.00, 95% confidence interval (CI) 2.05-4.39; I 2  = 0%]; while possibility for threshold rise, post-implantation infection and battery depletion did not differ between the PM types. Regarding the secondary outcome, the mortality rates between EPI and ENDO did not differ. In sensitivity analyses the results were consistent results between the two PM types. The findings suggest that EPI may be associated with increased PM-lead failure compared to ENDO while threshold rise, infection, battery depletion and mortality rates did not differ., (© 2023. The Author(s).)

Objectives: The role of cardiac arrhythmia in ischaemic stroke is widely studied, but the size of the stroke risk in patients with sinus node dysfunction (SND) with and without atrial fibrillation (AF) is unclear. This systematic review and meta-analysis aimed to compare the risk of stroke and its associated factors in patients with SND with and without AF., Design: A systematic review and meta-analysis was conducted based on the Grading of Recommendations, Assessment, Development and Evaluation approach., Data Sources: PubMed, EMBASE and Cochrane Database were searched until December 2022., Eligibility Criteria for Selecting Studies: Studies that investigate stroke in patients with SND diagnosed with or without AF/atrial flutter., Data Extraction and Synthesis: Two independent authors screened studies for inclusion and extracted data. Literature quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Collaboration Tool. The overall risk of stroke was estimated using the random-effects model. The generic inverse variance method was used to calculate the pooled estimates of stroke-associated factors. We performed a sensitivity analysis using a fixed-effects model., Results: Of the 929 records retrieved, 6 papers (106 163 patients) met the inclusion criteria. The average yearly stroke incidence in patients with SND was 1.542% (95% CI: 1.334% to 1.749%). The stroke incidence was similar between the isolated SND (1.587%; 95% CI: 1.510% to 1.664%) and non-isolated (SND+AF) (1.660%; 95% CI: 0.705% to 2.615%) groups. AF (HR, 95% CI: 1.53 (1.01 to 2.33)), stroke/transient ischaemia attack/other thrombotic events (HR, 95% CI: 2.54 (1.14 to 5.69)), hypertension (HR, 95% CI: 1.51 (1.11 to 2.07)) and heart failure (HR, 95% CI: 1.41 (1.01 to 1.97)) were associated with stroke in the SND population., Conclusion: Our findings suggest that patients with SND carry a similar risk of stroke to those with combined SND and AF. Future studies are needed to investigate whether interventions targeting stroke prevention, such as anticoagulation therapy, can help to prevent stroke in patients with SND., Prospero Registration Number: CRD42023408436., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

We herein report two cases of atrial pacing with coronary sinus (CS) pacing performed to improve hemodynamic instability in cardiogenic shock due to percutaneous coronary intervention (PCI)-induced sick sinus syndrome (SSS). Ventricular pacing alone made it difficult to stabilize hemodynamics due to SSS, which had been caused by the lack of reflow and slow flow of the sinus node artery (SNA) jailed with a stent. Adding atrial pacing with CS pacing may be useful, as in our two cases, where ventricular pacing alone was unable to stabilize hemodynamics.

Background and Aims: High percentages of atrial pacing have been associated with an increased risk of atrial fibrillation. This study is aimed at evaluating whether atrial pacing minimization in patients with sinus node dysfunction reduces the incidence of atrial fibrillation., Methods: In a nationwide, randomized controlled trial, 540 patients with sinus node dysfunction and an indication for first pacemaker implantation were assigned to pacing programmed to a base rate of 60 bpm and rate-adaptive pacing (DDDR-60) or pacing programmed to a base rate of 40 bpm without rate-adaptive pacing (DDD-40). Patients were followed on remote monitoring for 2 years. The primary endpoint was time to first episode of atrial fibrillation longer than 6 min. Secondary endpoints included longer episodes of atrial fibrillation, and the safety endpoint comprised a composite of syncope or presyncope., Results: The median percentage of atrial pacing was 1% in patients assigned to DDD-40 and 49% in patients assigned to DDDR-60. The primary endpoint occurred in 124 patients (46%) in each treatment group (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.76-1.25, P = .83). There were no between-group differences in atrial fibrillation exceeding 6 or 24 h, persistent atrial fibrillation, or cardioversions for atrial fibrillation. The incidence of syncope or presyncope was higher in patients assigned to DDD-40 (HR 1.71, 95% CI 1.13-2.59, P = .01)., Conclusions: Atrial pacing minimization in patients with sinus node dysfunction does not reduce the incidence of atrial fibrillation. Programming a base rate of 40 bpm without rate-adaptive pacing is associated with an increased risk of syncope or presyncope., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Intraoperative sinus arrest is rarely seen during zygomatic fracture treatment. The patient was diagnosed with sick sinus syndrome based on repeated postoperative sinus arrest, which could have resulted in death if diagnosed late, making this case very significant to report., Case Presentation: Sick sinus syndrome is an arrhythmia associated with reduced automaticity of the sinoatrial node or impaired sinoatrial node conduction. We report the case of a 67-year-old man diagnosed with the syndrome after a sinus arrest that occurred during a zygomatic fracture treatment. The patient had cheek pain and mouth opening disorder, dizziness after fainting and sustaining a facial injury. Preoperative examination determined that the syncope was due to drug-induced arrhythmia, and surgery was authorized after drug withdrawal. During the operation, sinus arrest was observed due to trigeminal vagal reflex, and heart rate was restarted by stopping the operation and chest compressions. After the surgery, the patient showed symptoms of dizziness and palpitations, and sinus arrest following atrial fibrillation and supraventricular tachycardia, which was diagnosed as sick sinus syndrome, and a pacemaker was implanted. Currently, 8 years have passed since the surgery, and there are no symptoms of mouth opening disorder, dizziness, or palpitations., Conclusions: In the case of maxillofacial injuries due to syncope, cardiogenic syncope is a possibility, and repeated syncope is a risk for death due to delayed diagnosis. There are no reports of maxillofacial trauma leading to a diagnosis of sick sinus syndrome. The purpose of this case report is to disseminate the importance of diagnosing the cause of syncope as well as injury treatment., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Sinus node dysfunction (SND) is a multifaceted disorder most prevalent in older individuals, but may also occur at an earlier age. In most cases, the SND diagnosis is ultimately established by documenting its ECG manifestations. EPS has limited utility. The treatment strategy is largely dictated by symptoms and ECG manifestations. Not infrequently, both bradycardia and tachycardia coexist in the same patients, along with other diseases common in the elderly (e.g., hypertension, coronary artery disease), thereby complicating treatment strategy. Prevention of the adverse consequences of both bradyarrhythmia and tachyarrhythmia is important to reduce susceptibility to syncope, falls, and thromboembolic complications., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: A pacemaker implantation is not indicated in cases of reversible high-degree symptomatic sinus node dysfunction (SND) and atrioventricular block (AVB). However, it remains uncertain whether these reversible automaticity/conduction disorders may recur in some patients at follow-up, in the absence of reversible cause. This retrospective study aimed to determine the incidence and predictive factors of permanent pacemaker (PPM) implantation at follow-up and after reversible high-degree SND/AVB., Methods: Based on medical electronic files codes, we identified patients who were hospitalized in our cardiac intensive care unit between January 2003 and December 2020 due to reversible high-degree SND/AVB and who were discharged from the hospital alive and without PPM implantation. Acute myocardial infarction and post-cardiac surgery patients were excluded. We categorized the patients according to the need for PPM at follow-up due to non-reversible high-degree SND/AVB., Results: Of the 93 patients included, 26 patients (28%) were readmitted for PPM implantation at follow-up after hospital discharge. Among baseline characteristics, compared with patients who did not have high-degree SND/AVB recurrence, those who had subsequent PPM implantation had less frequent previous hypertension (70% vs. 46%, p = .031). Regarding the initial causes of reversible SND/AVB, isolated hyperkalemia was found more often in the patients readmitted for PPM (19% vs. 3% vs. p = .017). Moreover, recurrence of high-degree SND/AVB was significantly associated with the presence of intraventricular conduction disorders (either bundle branch block or left bundle branch hemiblock) on ECG at discharge (36% in patients without PPM vs. 68% in PPM patients, p = .012)., Conclusion: Almost one third of the patients discharged alive from the hospital after a reversible high-degree SND/AVB needed a pacemaker implantation at follow-up. Complete bundle branch block or left bundle branch hemiblock on discharge ECG after recovery of atrioventricular conduction and/or sinus automaticity was associated with a greater risk of recurrence leading to pacemaker implantation., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Background: Bradyarrhythmias including sinus node dysfunction (SND) and atrioventricular block (AVB) can necessitate pacemaker (PPM) implantation in orthotopic heart transplant (OHT) recipients. Prior studies have shown conflicting findings regarding the effect of PPM implantation on survival. We evaluated the effect of PPM indication on long-term re-transplant-free survival in OHT patients., Methods: We conducted a retrospective cohort study of OHT patients at UCLA Medical Center from 1985 to 2018. Indication for PPM (SND, AVB) was identified. Cox proportional hazards model with pacemaker implantation as a time-varying covariate was used to evaluate its effect on the primary endpoint of retransplant or death. We included 1609 OHTs in 1511 adult patients with median follow-up of 12 years., Results: At transplant, patients were aged 53 ± 13 years and 1125 (74.5%) were male. Pacemakers were implanted in 109 (7.2%) patients; 65 for SND (4.3%) and 43 for AVB (2.8%). Repeat OHT was performed in 103 (6.4%) cases and 798 (52.8%) patients died during the follow-up period. The risk of the primary endpoint was significantly higher in patients requiring PPM for AVB (HR 3.0, 95% CI 2.1-4.2, p < .01) after controlling for age at OHT, gender, hypertension, diabetes, renal disease, history of repeat OHT, acute rejection, transplant coronary vasculopathy, and atrial fibrillation, but not PPM for SND (HR 1.0, 95% CI 0.70-1.4, p = 1.0)., Conclusions: Patients who required PPM for AVB, but not SND, were at significantly higher risk of death or retransplant compared to patients who did not require PPM., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Aims: Sick sinus syndrome (SSS) and atrial fibrillation (AF) frequently coexist and show a bidirectional relationship. This systematic review and meta-analysis aimed to decipher the precise relationship between SSS and AF, further exploring and comparing different therapy strategies on the occurrence or progression of AF in patients with SSS., Methods and Results: A systematic literature search was conducted until November 2022. A total of 35 articles with 37,550 patients were included. Patients with SSS were associated with new-onset AF compared to those without SSS. Catheter ablation was associated with a lower risk of AF recurrence, AF progression, all-cause mortality, stroke and hospitalization of heart failure compared to pacemaker therapy. Regarding the different pacing strategies for SSS, VVI/VVIR has higher risk of new-onset AF than DDD/DDDR. No significant difference was found between AAI/AAIR and DDD/DDDR, as well as between DDD/DDDR and minimal ventricular pacing (MVP) for AF recurrence. AAI/AAIR was associated with higher risk of all-cause mortality when compared to DDD/DDDR, but lower risk of cardiac death when compared to DDD/DDDR. Right atrial septum pacing was associated with a similar risk of new-onset AF or AF recurrence compared to right atrial appendage pacing., Conclusion: SSS is associated with a higher risk of AF. For patients with both SSS and AF, catheter ablation should be considered. This meta-analysis re-emphasizes that high percentage of ventricular pacing should be avoided in patients with SSS in order to decrease AF burden and mortality., Competing Interests: Declaration of Competing Interest The authors report no relationships that could be construed as a conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aims: In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony., Methods and Results: PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres., Conclusion: The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes., Competing Interests: Conflict of interest: G.D.: fee for lectures and proctorship for conduction system pacing by Biotronik Italia; G.K., Le.M.: fee for proctorship for conduction system pacing by Biotronik and Medtronic Italia; M.Z.: received speaker’s fees from Abbott Medical, Biotronik, and Boston Scientific; F.N.: fees for statistical and methodological consulting from Abbott Medical. All other authors have no conflicts to declare., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: In bradycardia patients treated with dual-chamber pacing, we aimed to evaluate whether pacing with atrioventricular (AV) delay management [AV hysteresis (AVH)], compared with standard pacing with fixed AV delays, reduces unnecessary ventricular pacing percentage (VPP) and is associated with better clinical outcomes. Main study endpoints were the incidence of heart failure hospitalizations (HFH), persistent atrial fibrillation (AF), and cardiac death., Methods and Results: Data from two identical prospective observational studies, BRADYCARE I in the USA and BRADYCARE II in Europe, Africa, and Asia, were pooled. Overall, 2592 patients (75 ± 10 years, 45.1% female, 50% with AVH) had complete clinical and device data at 1-year follow-up and were analysed. Primary pacing indication was sinus node disease (SND) in 1177 (45.4%), AV block (AVB) in 974 (37.6%), and other indications in 441 (17.0%) patients. Pacing with AVH, compared with standard pacing, was associated with a lower 1-year incidence of HFH [1.3% vs. 3.1%, relative risk reduction (RRR) 57.5%, P = 0.002] and of persistent AF (5.3% vs. 7.7%, RRR = 31.1%, P = 0.028). Cardiac mortality was not different between groups (1.0% vs. 1.4%, RRR = 27.8%, P = 0.366). Pacing with AVH, compared with standard pacing, was associated with a lower (P < 0.001) median VPP in all patients (7% vs. 75%), in SND (3% vs. 44%), in AVB (25% vs. 98%), and in patients with other pacing indications (3% vs. 47%)., Conclusion: Cardiac pacing with AV delay management via AVH is associated with reduced 1-year incidence of HFH and persistent AF, most likely due to a reduction in VPP compared to standard pacing., Competing Interests: Conflict of interest: M.A. participated in clinical trials sponsored by Abbott and Biotronik; he received speaker honoraria from Biotronik. A.A. participated in clinical trials sponsored by Boston Scientific, Medtronic, EPD Philips, and XSpline; he received consultant or speaker fees from Abbott, Boston Scientific, Cairdac, Corvia, EP Solution, Microport CRM, Philips, Radcliffe Publishers, and XSpline, and he has intellectual properties with Boston Scientific, Biosense Webster, and Microport CRM. A.A. is the review editor of EP Europace and was not involved in the peer review process or publication decision. G.B. received speaker fees from Boston Scientific, Abbott, Daiichi, and Boehringer Ingelheim. A.P., W.L., and A.G. are Abbott employees. All remaining authors have declared no conflicts of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Although the anatomical basis of the pathogenesis of sinus node dysfunction (SND) and atrial fibrillation (AF) is located primarily in the left and right atria, increasing evidence suggests a strong correlation between SND and AF, in terms of both clinical presentation and formation mechanisms. However, the exact mechanisms underlying this association are unclear. The relationship between SND and AF may not be causal, but is likely to involve common factors and mechanisms, including ion channel remodeling, gap junction abnormalities, structural remodeling, genetic mutations, neuromodulation abnormalities, the effects of adenosine on cardiomyocytes, oxidative stress, and viral infections. Ion channel remodeling manifests primarily as alterations in the "funny" current (I f ) and Ca 2+ clock associated with cardiomyocyte autoregulation, and gap junction abnormalities are manifested primarily as decreased expression of connexins (Cxs) mediating electrical impulse propagation in cardiomyocytes. Structural remodeling refers primarily to fibrosis and cardiac amyloidosis (CA). Some genetic mutations can also cause arrhythmias, such as SCN5A, HCN4, EMD, and PITX2. The intrinsic cardiac autonomic nervous system (ICANS), a regulator of the heart's physiological functions, triggers arrhythmias.In addition, we discuss arrhythmias caused by viral infections, notably Coronavirus Disease 2019 (COVID-19). Similarly to upstream treatments for atrial cardiomyopathy such as alleviating CA, ganglionated plexus (GP) ablation acts on the common mechanisms between SND and AF, thus achieving a dual therapeutic effect., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Anderson-Fabry disease (AFD) is an X-linked inherited lysosomal disease caused by a defect in the gene encoding lysosomal enzyme α-galactosidase A (GLA). Atrio-ventricular (AV) nodal conduction defects and sinus node dysfunction are common complications of the disease. It is not fully elucidated how frequently AFD is responsible for acquired AV block or sinus node dysfunction and if some AFD patients could manifest primarily with spontaneous bradycardia in general population. The purpose of study was to evaluate the prevalence of AFD in male patients with implanted permanent pacemaker (PM)., Methods: The prospective multicentric screening in consecutive male patients between 35 and 65 years with implanted PM for acquired third- or second- degree type 2 AV block or symptomatic second- degree type 1 AV block or sinus node dysfunction was performed., Results: A total of 484 patients (mean age 54 ± 12 years at time of PM implantation) were enrolled to the screening in 12 local sites in Czech Republic. Out of all patients, negative result was found in 481 (99%) subjects. In 3 cases, a GLA variant was found, classified as benign: p.Asp313Tyr, p.D313Y). Pathogenic GLA variants (classical or non-classical form) or variants of unclear significance were not detected., Conclusion: The prevalence of pathogenic variants causing AFD in a general population sample with implanted permanent PM for AV conduction defects or sinus node dysfunction seems to be low. Our findings do not advocate a routine screening for AFD in all adult males with clinically significant bradycardia., Competing Interests: Declaration of Competing Interest ZF and SH received the travel grants and speaker's honoraria from Takeda. GD received honoraria and travel funding from Sanofi Genzyme, Takeda, Protalix, and Greenovation Biotech GmbH. DG is a consultant for Amicus Therapeutics, Sanofi Genzyme, and Shire; has received research support from Sanofi Genzyme and Shire; and has received speaker honoraria and travel support from Amicus Therapeutics, Sanofi Genzyme, and Shire. AL received consultancy honoraria from Amicus Therapeutics, Sanofi Genzyme, Takeda, and speaker's honoraria from Sanofi Genzyme and Takeda., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: The objective of the study was to establish the prognostic value of CSNRT regarding the necessity for pacemaker implantation in patients with atrial flutter (AFL) post-ablation., Methods: This prospective cohort study, conducted at the National Institute of Cardiology "Ignacio Chavez" in Mexico City, assessed patients who had undergone ablation procedures to correct AFL, posterior to which an autonomic blockade was performed, and CSNRT was measured., Results: The sample for this investigation was 40 patients. These were subdivided into two study groups depending on their requirement of pacemaker implant post-ablation (Pacemaker P, No Pacemaker NP). Sinus node (SN) dysfunction was diagnosed in 13 (32.5%) of the 40 participants, 10 (71.43%) of which required a pacemaker implant, while only 4 participants (28.57%) with normal SN function required pacemakers. Ten out of the 14 patients (71.43%) who required a pacemaker had an elevated CSNRT > 500 ms (p ≤ 0.01). Post-ablation CSNRT mean was 383.54 ms ± 67.96 ms in the NP group versus 1972.57 ms ± 3423.56 ms in the P group. Furthermore, SN pause in the P group had a mean of 1.86 s ± 0.96 s versus the NP group with 1.196 s ± 0.52 s., Conclusion: CSNRT has the potential to be a quantitative prognostic tool for the assessment of future pacemaker implants in patients with AFL post-ablation. This could aid in the timely diagnosis of sinus node dysfunction, which could, in the long run, result in the reduction of cardiac functional capacity loss due to cardiac remodeling., (Copyright: © 2023 Permanyer.)

The relevance of the study is conditioned by the problem of implantation of an artificial cardiac pacemaker in atrial fibrillation in patients with tachy-brady syndrome according to the standard scheme related to the presence of a congenital anomaly, such as persistent left superior vena cava. The purpose of the study is to develop an operative method of implantation of a permanent two-chamber pacemaker in patients with tachy-brady syndrome with concomitant pathology of the persistent left superior vena cava. Research methods are the generally accepted clinical and instrumental examination of the patient, including taking anamnesis and a standard cardiological examination, electrocardiography, transthoracic echocardiography, plain radiography, angiocardiographic examination, and multispiral computed tomography, which, along with a general analysis, confirm the presence of tachy-brady syndrome with atrial fibrillation and congenital anomaly in the form of persistent left superior vena cava in patients. The study presents a developed model of surgical implantation of a permanent two-chamber pacemaker to stabilise the condition of patients with atrial fibrillation related to tachy-brady syndrome with concomitant persistent left superior vena cava; the standard implantation mechanism included the introduction of a radiopaque agent to clarify the anatomical structure of the vascular bed, further, its entry from the subclavian veins into the persistent left superior vena cava and into the cavity of the right atrium through the venous coronary sinus was detected, and then a gradual introduction of an endocardial right ventricular electrode was performed into the subclavian vein through the tricuspid valve along with its further positioning in the apex of the right ventricle; therefore, a permanent two-chamber pacemaker can be successfully installed, creating conditions for restoring sinus rhythm in this group of patients, which is of practical importance for the field of medicine (Tab. 3, Fig. 4, Ref. 20). Keywords: atrial fibrillation, persistent left superior vena cava, sick sinus syndrome, pacemaker implantation, cardiac surgery.

Background and Objectives : Chronic atrial stimulation might impair left atrial (LA) function. We aimed to assess the impact of atrial pacing burden on LA volumetric and functional parameters after implantation of a dual-chamber pacemaker. Materials and Methods : The prospective study included 121 subjects with sinus node disease (SND) or atrioventricular block (AVB) that received a dual-chamber pacemaker. After device implantation, the subjects were divided into three groups: (1) SND with a lower rate (LR) set to 60 bpm and rate response enabled; (2) AVB with an LR set to 60 bpm and no rate response; and (3) AVB with an LR set to 40 bpm and no rate response. Subjects were followed at one and three months. Two subsets of patients with high and low atrial pacing burdens accompanied by low ventricular pacing percentage were analyzed. LA function was evaluated with volumetric and strain parameters from transthoracic echocardiography. Results : The high atrial low ventricular pacing group consisted of 38 subjects, and the low atrial low ventricular group consisted of 22 subjects. When looking at the change in volumetric parameters, we observed a tendency for volumes to increase in both groups; however, only minimal LA volume reached statistical significance at three months in the high atrial pacing group. A trend towards the lowering of an active emptying fraction at one month ( p = 0.076) became significant at three months ( p = 0.043), and was also only observed in the same group. Moreover, a decrease in the tendency to reach statistical significance at three months for reservoir and contractile strain parameters and stiffness index was only observed in the high atrial pacing group. Meanwhile, in the low atrial pacing burden group, all parameters remained significantly unchanged. Conclusions : The burden of right atrial pacing in patients with preserved left ventricular function negatively influences functional and morphologic LA parameters. Moreover, negative effects take place soon after pacemaker implantation and appear to be sustained.

Background Atrial fibrillation (AF) is associated with anatomical and electrical remodeling. Some patients with AF have concomitant sick sinus syndrome and may need permanent pacemaker (PPM) implantation. Association between catheter ablation of AF timing and need for PPM in sick sinus syndrome has not been assessed. Methods and Results We used pooled electronic health data to perform retrospective cross-sectional analysis of 66,  595 patients with AF and sick sinus syndrome to assess the need of PPM implantation temporally, with AF performed divided into earlier within 5 years (group 1), 5 to 10 years (group 2), or beyond 10 years (group 3) of diagnosis. PPM implantation was lowest among those who had catheter ablation within 5 years of sick sinus syndrome diagnosis: group 1 versus group 2 (18.15% versus 27.21%) and group 1 versus group 3 (18.15% versus 27.22%). Interestingly, there was no difference in risk of PPM between group 2 and group 3 (27.21% versus 27.22%; odds ratio [OR], 1.00 [95% CI, 0.85-1.20]). Conclusions Even after controlling known risk factors that increase the need for pacemaker implantation, timing of AF ablation was the strongest predictor for need for PPM. Patients adjusted OR of PPM was lower if patients had catheter ablation within 5 years of diagnosis compared with later than 5 years (adjusted OR, 0.64 [95% CI, 0.59-0.70]).

Aims: IMPROVE Brady assessed whether a process improvement intervention could increase adoption of guideline-based therapy in sinus node dysfunction (SND) patients., Methods: /Results: IMPROVE Brady was a sequential, prospective, quality improvement initiative conducted in India and Bangladesh. Patients with symptomatic bradycardia were enrolled. In Phase I, physicians assessed and treated patients per standard care. Phase II began after implementing educational materials for physicians and patients. Primary objectives were to evaluate the impact of the intervention on SND diagnosis and pacemaker (PPM) implant. SF-12 quality of life (QoL) and Zarit burden surveys were collected pre- and post-PPM implant. A total of 978 patients were enrolled (57.7 ± 14.8 years, 75% male), 508 in Phase I and 470 in Phase II. The diagnosis of SND and implantation of PPM increased significantly from Phase I to Phase II (72% vs. 87%, P < 0.001 and 17% vs. 32%, P < 0.001, respectively). Pacemaker implantation was not feasible in 41% of patients due to insurance/cost barriers which was unaltered by the intervention. Both patient QoL and caregiver burden improved at 6-months post-PPM implant (P < 0.001)., Conclusions: A process improvement initiative conducted at centers across India and Bangladesh significantly increased the diagnosis of SND and subsequent treatment with PPM therapy despite the socio-economic constraints., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: DWR: Advisor/Consultant: Medtronic; VR: Employee and shareholder: Medtronic; TB: Employee and shareholder: Medtronic; AD: Employee and shareholder: Medtronic; All other authors report no disclosures., (Copyright © 2022. Published by Elsevier, a division of RELX India, Pvt. Ltd.)

Introduction: Catheter ablation for atrial fibrillation (AF) in patients with tachycardia-bradycardia syndrome (TBS) can be a major therapeutic option to replace permanent pacemaker implantation (PMI). However, the very long-term outcome of more than 15 years in these patients has not been elucidated., Methods: From 2002 to 2008, 25 consecutive TBS patients (62 ± 7.9 years old, 68% male) with both AF and symptomatic sinus pauses (>3.0 s) were performed radiofrequency AF ablation. These patients were followed for 15 ± 2.7 years., Results: The median longest sinus pause before the ablation procedure was 6.0 s (4.4-8.0). Following 1.6± 0.8 ablation procedures, 18 (72%) patients remained free from AF. Three (12%) patients died due to noncardiovascular causes, and seven (28%) patients underwent PMI due to symptomatic sinus pause after recurrent AF in five patients and progression of sinus node dysfunction in two patients. The median duration from the first AF ablation to PMI was 6.3 years (range: 9 days to 11.0 years). Five and two patients required PMI more than 5 and 10 years after the first ablation procedure, respectively., Conclusion: AF ablation prevented PMI in 72% of TBS patients for a 15-year follow-up. However, in consideration of the long duration of PMI, a continuous careful long-term follow-up was warranted., (© 2022 Wiley Periodicals LLC.)

Background: Left bundle branch area pacing (LBBAP) is a form of conduction system pacing. Long-term data on the safety and performance of LBBAP 1 year postdevice implantation has not been well described., Methods and Results: Sixty-five patients (49% females) who received LBBAP for bradycardia indications using the SelectSecure 3830 lead (Medtronic) were retrospectively evaluated. Clinical variables were examined. Lead parameters were obtained at implant and during regular follow-up. Mean age of patients was 75.7 ± 10.1 years with left ventricular ejection fraction 59.8 ± 10.4%. Indications for pacing were atrioventricular block 55%, sinus node dysfunction 19%, tachy-brady syndrome 15%, atrioventricular node ablation 8%, and bail out cardiac resynchronization therapy 3%. Mean baseline QRS measured 120 ± 38 ms, paced QRS duration was 138 ± 22ms. Paced QRS narrowed by 24 ms in those with pre-existing left bundle branch block (BBB), increased by 1 ms in those with pre-existing right BBB, and increased by 42 ms in those with no BBB. LBBAP threshold at implant was 0.521 ± 0.153 V at 0.4 ms, and increased to 0.654 ± 0.186 V at 3 months (+26%), 0.707 ± 0.186 V at 6 months (+36%), and 0.772 ± 0.220 V at 12 months (+48%). Patients with left BBB showed the maximum benefit with QRS narrowing 24 ms. Pacing impedance remained unchanged with no procedure-related complications., Conclusion: LBBAP is a durable form of conduction system pacing with pacing thresholds remaining relatively stable over 12 months post device implantation. Patients with left BBB display the narrowest paced QRS., (© 2022 Wiley Periodicals LLC.)

A 33-year-old woman with Sick Sinus Node syndrome and persistent atrial fibrillation underwent a Maze IV procedure in order treat atrial fibrillation and concomitant atrial epicardial implantation of a leadless pacemaker to manage her sinus node insufficiency. Last option has been chosen due to rare pocket complication after previous classic dual-chamber pacemaker implantation., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Sick sinus syndrome (SSS) is a set of diseases with abnormal cardiac pacing, which manifests as diverse cardiac arrhythmias, especially bradycardia. The clinical presentation is inconspicuous in the early stage, but with the progression of this disease, patients may present with symptoms and signs of end-organ hypoperfusion. As a common result in the natural history of the disease, SSS coexisting with atrial fibrillation (AF) forms the basis of bradycardia-tachycardia syndrome. Age-related interstitial fibrosis is considered to be the common pathophysiological mechanism between SSS and AF. The combination of these diseases will adversely affect the condition of patients and the efficiency of subsequent treatment. Although the exact mechanism is not clear to date, the extensive structural and electrical remodeling of the atrium are considered to be the important mechanism for the occurrence of AF in patients with SSS. Pacemaker implantation is the first-line treatment for symptomatic patients with SSS and documented bradycardia history. In view of the adverse effects of AF on the treatment of SSS, researchers have focused on evaluating different pacing modes and algorithms to reduce the risk of AF during pacing. Catheter ablation may also be used as an alternative second-line therapy for some patients with SSS and AF., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

We report a case of a previously healthy 47-year-old female with syncope due to multiple episodes of nodal dysfunction and asystole. During these brief episodes, she was hypoxic in the mid-80's as a result of COVID-19 pneumonia. The patient was admitted and treated for viral pneumonia and found to have normal electrocardiograms (ECG's), normal troponin levels and a normal echocardiogram during her hospital stay. As she recovered from COVID-19, no further episodes of bradycardia or bradyarrhythmia were noted. This case highlights a growing body of evidence that arrhythmias, specifically bradycardia, should be anticipated by prehospital providers as a potential cardiac complication of SARS-CoV-2 infection.