High-degree Atrioventricular Block Research Articles

Importance of Raw-Data Analysis When Determining the Cause of Pause Alerts Transmitted by an Implantable Loop Recorder Remote Monitoring Devices.

Use of implantable loop recorder (ILR) for the diagnosis and documentation of cardiac arrhythmia has gained popularity during the last decade. Most ILRs are accompanied by remote monitoring (RM) devices, which allow automated daily interrogations of the ILR. These transmit arrhythmic or pause alerts to the treating clinic, enabling timely medical attention and treatment. Although ILR RM transmissions have been shown to have significant false positive alerts, a true positive alert suggesting a wrong arrhythmia diagnosis has not been shown to date. We revised all ILR pause transmissions arriving to our hospital device clinic during 2024, looking for pause alerts which were initially misdiagnosed. We report a case series of patients in whom a RM pause alert has been transmitted with a suspected apparent diagnosis of sinus arrest. However, when interrogating the ILR in clinic, these episodes were diagnosed as high-degree atrioventricular block (AVB) pauses, for which an urgent permanent pacemaker (PPM) might be indicated. Review of these cases revealed that in contrast with the automated RM PDF alerts, in which the figure resolution cannot be changed (and thus small P waves may be unnoticed), the raw-data episode recording on the RM web page enables one to increase the image resolution to clearly discern initially unnoticed non-conducted P waves. ILR RM pause alerts should always be reviewed via the raw-data RM web page or alternatively via ILR device interrogations, to achieve a sufficiently high-resolution image to assure these pauses are not due to AVB.

Recovery time of atrioventricular conduction and its influencing factors in patients presenting late with inferior wall acute myocardial infarction and atrioventricular block

ObjectivesTo explore the recovery time of atrioventricular conduction and its influencing factors in patients presenting late and diagnosed with inferior wall acute myocardial infarction (AMI) and high-degree atrioventricular block (AVB) on admission.MethodsWe conducted a retrospective study in patients presenting > 12 h after symptom onset and diagnosed with inferior wall AMI and new onset second-degree type 2 or third-degree AVB on admission. All of them underwent percutaneous coronary intervention (PCI). The clinical characteristics, time to PCI and time to AVB recovery after symptom onset were studied.ResultsAmong the 80 patients, 68 were male, aged 63 ± 10 years. The median admission time after symptom onset was 36 h. 10 patients presented with second-degree type 2 AVB and 70 patients with third-degree AVB. The median time of AVB recovery from AMI onset was 5d (Q1-Q3:4-7d; Min-max: 1-15d). Patients were divided into two groups according to the median AVB recovery time. Compared to the late recovery group (> 5 days), patients in the early recovery group (≤ 5 days) had shorter admission time after AMI onset (P < 0.001) and received PCI earlier (P < 0.001). Multivariate Logistic regression analysis showed that admission time from AMI onset (OR:1.032, 95%CI: 1.013–1.052, P = 0.001) and time from AMI onset to PCI (OR: 1.449, 95%CI: 1.163–1.804, P = 0.001) were independent factors for early AVB recovery.ConclusionsIn patients presenting late with inferior wall AMI complicated with high-degree AVB, the median time of AVB recovery was 5 days. Shorter admission time from AMI onset and earlier PCI treatment were independently associated with earlier AVB recovery.

Prevalence of high ventricular pacing burden in patients requiring permanent pacemaker post TAVR.

Transcatheter aortic valve replacement (TAVR) is occasionally complicated by high degree atrioventricular block (AVB) requiring permanent pacemaker (PPM) placement. Newer valve design, delivery platform evolution, and deployment technique refinement have lowered this risk. Ventricular pacing ≥ 30% has been previously identified as a predictor for worse clinical outcomes in this population. This study aims to assess the prevalence of high long-term pacing burden in this cohort. This is a retrospective study to evaluate patients from 2019 to 2023 who required PPM for high degree AVB following TAVR. Baseline demographics, clinical characteristics, procedural details were obtained. Ventricular pacing (VP) percentages were collected from PPM interrogations at 1, 6 and 12 months. 138 patients had PPM placement post-TAVR. Approximately one third of patients demonstrated ventricular pacing less than 25% at 1 month, 6 months, and 12 months (Fig.1). Roughly 50% of patients had > 75% ventricular pacing at 1 month, 6months and 12 months. There was no difference in baseline demographics or EKG characteristics at 1 month. In a univariable logistic regression analysis, there were no statistically significant predictors of VP ≥ 30%. Although, balloon expandable valves and lower STS scores demonstrated an association with lower risk of VP ≥ 30%. Our study suggests that a significant portion of patients with PPM for high degree AVB after TAVR have low pacing burden at 6-12 months. Further investigation is needed to assess valve-specific predictors and alternative pacing approaches of AVB management.

Accessory Fascicolo-Ventricular Pathway in Hypertrophic Phenotype Cardiomyopathy Suspected for Prkag2 Mutation: Diagnostic Role of Myocardial Biopsy

Accessory Fascicolo-Ventricular Pathway in Hypertrophic Phenotype Cardiomyopathy Suspected for Prkag2 Mutation: Diagnostic Role of Myocardial Biopsy

Role of Routine Electrophysiological Study Performed During Transcatheter Aortic Valve Replacement to Predict AV Block.

Periprocedural electrophysiological (EP) testing may be useful to predict high degree atrioventricular block (HAVB) risk in patients undergoing transcatheter aortic valve replacement (TAVR). To determine whether pre- and immediate post-TAVR ECG and HV interval findings are predictive of HAVB. Consecutive TAVR patients without prior pacemaker (PM) implantation underwent ECG and standardized HV interval measurements pre- and post-TAVR using the quadripolar catheter for rapid pacing. The primary outcome was HAVB >24 h after TAVR or ventricular pacing need RESULTS: Out of 97 included patients, 8 experienced the primary outcome (7 with HAVB and 1 with PM need). On univariate analysis, pre- and post-TAVR PR, post-TAVR HV, and Delta-HV intervals were predictors of the primary outcome. A Delta-HV interval ≥18ms predicted HAVB with sensitivity = 50% and specificity = 90% (AUC = 0.708, PPV = 31%), while an HV interval ≥60ms after TAVR had sensitivity = 63% and specificity = 79% (AUC = 0.681, PPV = 21%). None of the patients with a PR interval ≤180ms post-TAVR experienced the primary outcome. Among patients with new-onset LBBB, an HV interval post-TAVR >65ms was the only predictor of HAVB (AUC = 0.776, PPV = 33%, and NPV = 97%). The yield of periprocedural EP assessment during TAVR is limited considering that about half of the at-risk patients fail to be identified. However, early periprocedural risk stratification may be more useful in the subset of patients with new-onset LBBB. Among ECG findings, a post-TAVR PR interval ≤180ms identifies a subgroup at very low risk, independently of QRS interval and morphology.

How to correct QT interval after cardiac resynchronisation therapy.

How to correct QT interval after cardiac resynchronisation therapy.

Sick sinus syndrome and high-degree atrioventricular block in dementia with Lewy bodies and other dementia subtypes: A study of ≈ 73,000 patients with dementia.

Sick sinus syndrome and high-degree atrioventricular block in dementia with Lewy bodies and other dementia subtypes: A study of ≈ 73,000 patients with dementia.

Intermittent High-Degree AV Block, Rash, and Facial Droop with Negative Lyme PCR

Intermittent High-Degree AV Block, Rash, and Facial Droop with Negative Lyme PCR

Safety and tolerability of the M2 muscarinic acetylcholine receptor modulator BAY 2413555 in heart failure with reduced ejection fraction in the REMOTE-HF study

BAY 2413555 is a novel selective and reversible positive allosteric modulator of the type 2 muscarinic acetylcholine (M2) receptor, aimed at enhancing parasympathetic signaling and restoring cardiac autonomic balance for the treatment of heart failure (HF). This study tested the safety, tolerability and pharmacokinetics of this novel therapeutic option. REMOTE-HF was a multicenter, double-blind, randomized, placebo-controlled, phase Ib dose-titration study with two active arms. Study participants had an established diagnosis of HF with NYHA Class I-III and LVEF ≤ 45%. Patients were required to have an implanted cardiac defibrillator (ICD) or cardiac resynchronization therapy (CRT) device because of the potential for bradycardia or AV conduction delay, which may be induced by BAY 2413555. The study period included a screening and run-in period, followed by a treatment period of over 28 days, consisting of two parts, A and B, comprising 14 days each. Participants were randomized into 1 of 3 arms: a placebo arm and two BAY 2413555 arms—one receiving 1.25 mg in both Part A and Part B (BAY 1.25 mg–1.25 mg) and the other receiving 1.25 mg in Part A followed by 5 mg in Part B (BAY 1.25 mg–5 mg). The primary safety endpoint was the number of participants with treatment-emergent adverse events (TEAEs). Secondary endpoints included number of participants with high degree AV block or symptomatic pauses/ bradycardia and changes from baseline in resting heart rate after 2 and 4 weeks of dosing with BAY 2413555. Changes from baseline in heart rate recovery (HRR) at 1 and 2 min after exercise testing and chronotropic reserve (CR) were also assessed. Of the anticipated 129 participants, 22 participants were randomized: 7 to placebo, 8 to BAY 1.25 mg–1.25 mg, and 7 to BAY 1.25 mg–5 mg. The study was terminated early based on new and unexpected preclinical findings from a chronic animal toxicology study in monkeys in which evidence of increased vascular inflammation was observed, leading to a no longer favorable risk-benefit balance for the intended long-term (i.e., life-long) treatment of heart failure patients. Comparable adverse events were not encountered in REMOTE-HF. Overall, until the termination of the study, BAY 2413555 was safe and well tolerated, with no deaths or TEAEs leading to discontinuation, and no symptomatic bradycardia or AV blocks observed. There was a larger change in the mean HRR at 60 s in the pooled BAY 2413555 treatment arms in Part A (1.25 mg) compared to the placebo (+ 7.3 vs. −6.7 bpm), indicating enhanced cardiac parasympathetic activity. Administration of 1.25 mg and 5 mg BAY 2413555 was safe and well tolerated in both active treatment arms, with no concerning safety findings observed. However, due to the limited number of subjects resulting from early termination, the results should be considered with caution and viewed as exploratory. There were promising signs of target engagement, providing grounds for further exploration of the mechanism

Clinically suspected acute right ventricular fulminant dengue myocarditis masquerading with dual lethal arrhythmias: a case report

BackgroundAcute right ventricular myocarditis is rare, comprising only 18% of myocarditis cases. Despite being relatively infrequent at 12.4%, dengue-induced myocarditis has a high mortality risk of 26.4%. This report presents a novel case of acute fulminant right ventricular myocarditis due to severe dengue infection, complicated by dual electrical disturbances: complete heart block and ventricular tachycardia.Case reportA 49-year-old Asian male patient was referred to our hospital with a temporary pacemaker due to a complete heart block. He had a history of recurrent syncope over three days and a fever five days before admission. Initial electrocardiography showed a total atrioventricular nodal block progressing to a high-degree atrioventricular block with a left bundle branch block, indicating an infra-Hisian block. Laboratory findings included thrombocytopenia, elevated troponin, high creatinine, increased liver transaminases, and a positive dengue nonstructural protein 1 test, confirming a diagnosis of dengue infection. Echocardiography showed reduced right ventricular systolic function, normal left ventricular systolic function (ejection fraction: 50%), and dyskinetic intraventricular septum. Coronary angiography revealed normal coronary anatomy. An endomyocardial biopsy was deferred due to severe thrombocytopenia. On the third day, the patient's condition worsened, developing cardiogenic shock and left ventricular systolic dysfunction (ejection fraction: 35%). He subsequently experienced a seizure and slow ventricular tachycardia originating from the right coronary cusp, followed by cardiac arrest. The patient’s family claimed not to resuscitate the patient. Furthermore, the patient died shortly after.ConclusionThis case underscores the critical need for prompt diagnosis and aggressive management of clinically suspected acute fulminant right ventricular myocarditis because complications can rapidly progress to left ventricular systolic dysfunction, leading to cardiogenic shock and sudden cardiac death.

Abstract 4138981: Indication and electrical performance of conventional, resynchronisation and conduction system pacing in Transthyretin Amyloid Cardiomyopathy (ATTR-CM)

Background: Conduction system disease, atrial and ventricular arrhythmias may require pacemaker or ICD implantation in transthyretin amyloid cardiomyopathy (ATTR-CM). The optimal pacing mode in ATTR-CM patients remains unknown. Objective: To assess how availability of cardiac resynchronization and conduction system pacing influenced pacemaker indications and to compare early electrical performance of conventional, resynchronisation and conduction system pacing in ATTR-CM. Methods and Results: 67 of 250 (26.8%) patients presenting with ATTR-CM between June 2019 and February 2023 received a pacemaker [HA1] and were included in this retrospective analysis. Pacemaker implantation occurred in 25 patients (37.3%) prior to, and in 42 (62.7%) after ATTR-CM diagnosis. Implantation of conventional single- (VVI) or dual-chamber (DDD) pacemakers was more common (n=17/25, 68%) in undiagnosed ATTR-CM, while physiological pacing systems (CRT/ CSP) were preferably implanted in patients (n=24/42; 57.1%) after diagnosis. Sick sinus syndrome (11/35; 31.4% vs. 6/32; 18.8%) and higher degree AV-block (20/35; 57.1% vs. 9/32; 28.1%) were more common indications for VVI/DDD compared to CRT/CSP pacemakers, with pursuit of a pace/ablate strategy (12/32; 37.5%) and heart failure (5/32; 15.6%) contributing significantly to implantation of CRT/CSP. QRS width was significantly lower with CSP [122ms (IQR: 120-139)], compared to CRT [155ms (IQR: 141-160); p=0.005] or VVI/DDD [160ms (IQR: 144-180)], with the latter resulting in a significant increase in QRS width compared to intrinsic QRS [from 138 (IQR: 123-150) (p&lt;0.001)]. LV/LBBAP pacing capture thresholds (0.4ms pulse width) were significantly lower after CSP [0.75V (IQR: 0.5-1.2)] compared to CRT [1.3V (IQR: 1.0-1.6); p=0.049]. RA and RV lead performance were comparable between all pacing systems (p&gt;0.05). Conclusions: Pacing indications are changing with earlier diagnosis of ATTR-CM. CSP may offer improved electrical performance and resynchronization, the effect of conduction system pacing on clinical outcomes should be further explored.

Abstract 4112639: A Rare Case of Atypical Sarcoidosis Presenting as an Intra-Atrial Septal Mass

Introduction: Sarcoidosis is a granulomatous disease that can affect multiple organ systems, including the heart. Cardiac Sarcoidosis (CS) is one of the most severe manifestations. It is characterized by a dysregulated T-cell driven immune response which generates non-necrotic inflammatory granulomas with myocardial infiltration. CS has a range of clinical syndromes: impaired conduction, arrhythmias, heart failure, and sudden cardiac death. We discuss a rare presentation of CS as an intra-atrial septal mass. Case Description: A 27-year-old Caucasian female with history of depression on citalopram presented with a one-month history of palpitations, fatigue, and dyspnea with exertion. An EKG demonstrated sinus rhythm with first-degree AV block. A cardiac monitor revealed intermittent 2-1 AV block and high degree AV block occurring mostly during sleep. An echocardiogram revealed normal biventricular function and morphology. Due to the concern for infiltrative cardiomyopathy, she underwent a cMRI which revealed a focal mass centered along the intra-atrial septum extending from the fossa ovalis to the septal AV junction, measuring 4.5 cm in size. She underwent pacemaker implantation with mild improvement of symptoms. PET scan demonstrated hypermetabolic activity of the intra-atrial region. She underwent surgical resection of the cardiac mass. Pathology was significant for fibrotic tissue with non-caseating granuloma and multinucleated giant cells consistent with an extremely rare presentation of CS. She was started on immunosuppressive medications. Subsequent cMRI and PET demonstrated resolution of the mass and hypermetabolic activity. Discussion: CS is a severe condition that most commonly presents with symptoms of heart failure, conduction abnormalities, and cardiac morphological changes of hypertrophy or thinning. However, it is often missed as a diagnosis, even in patients with extracardiac sarcoidosis. It is rare for CS to present as an isolated cardiac mass, especially in a younger patient as in this case. Advances in imaging techniques such as echocardiography, MRI, and PET have improved the ability to diagnosis CS and provide timely specialized treatment. This case highlights the need to include CS as an important diagnosis on the differential for a patient presenting with conduction abnormalities, heart block, and dyspnea. It also accentuates the critical role of multimodality imaging in working up this disease.

Clinical validation of the 2021 European Society of Cardiology guidelines on preexisting right bundle branch block in patients undergoing transcatheter aortic valve implantation.

Clinical validation of the 2021 European Society of Cardiology guidelines on preexisting right bundle branch block in patients undergoing transcatheter aortic valve implantation.

Behavior of leadless atrioventricular synchronous pacing during exercise

Behavior of leadless atrioventricular synchronous pacing during exercise

Clinical evidence of pacemaker implantation during gestation: a case series

Abstract Background Although recommended avoid any intervention during gestation in cases of poor tolerance to high degree atrioventricular block, pacemaker implantation may be necessary in pregnant women. Purpose To present outcomes of pacemaker implantation during gestation. Methods This prospective, single center study included 10 cases of pacemaker implantation during gestation (median age of patient - 26 years old at 18 weeks of gestation). We evaluated the further course of gestation and obstetric outcomes after implantation in comparison with pregnant with tachyarrythmias (n=111). Results Among 121 pregnant women with varying arrhythmias high degree atrioventricular block was detected in 10 cases (8,3%). In 6 cases this bradyarrhythmia diagnosed for the first time in gestation (60%). All pregnant with high degree atrioventricular block had clinical signs: dizziness and weakness (100%), syncope (70%), episodes of low blood pressure (100%). Pacemaker implantation performed due to hemodynamic instability and poor tolerance of bradyarrhythmia in all cases. Using electroanatomical mapping (Ensite Precision system)and echocardiographic guidance helped to reduce fluoroscopy time. For one pregnant implanted leadless pacemaker (Micra) with achieved more than 80% atrio-ventricular synchronization. Outcomes: further course of gestation characterized by increased incidence of uterine contractile activity (30%) in cases of high degree atrioventricular block, that was significantly higher than in pregnant with tachyarrhythmias (2%) (p=0.007). There were no differences in the rate of other complication: uterine blood flow violation (20% vs 12%, p=0.520), placental abraption (10% vs 5%, p=0.237) and preeclampsia (10% vs 5%, p=0.237). Vaginal type of delivery was in the majority of cases in both groups (70% vs 86%, p=0.553). Neonatal outcomes characterized with normal range of fetal birth weight (median 3163 vs 3212 grams, p=0.981) and 5 minute Apgar score (median 8.6 vs 8.7, p=0.564). There was no incidence of maternal and fetal mortality. In 12 month follow-up all patient have optimal electrical parameters of devise and remained stable over time. Conclusions High degree atrioventricular block in pregnant characterized by increased rate of uterine contractile activity. Pacemaker implantation during gestation can be effectively performed and associated with benign outcomes.

Clinical validation of the 2021 European Society of Cardiology guidelines on pre-existing right bundle branch block patients undergoing transcatheter aortic valve replacement

Abstract Introduction The management of patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve replacement (TAVR) remains challenging. In these patients, the 2021 ESC guidelines recommend early pacemaker (PM) implantation in case of PR prolongation, QRS axis change or transient high-degree atrioventricular block (HAVB). However, evidence for the proposed criteria is scarce. Purpose Our aim was to evaluate the ESC recommendation for risk stratification of RBBB patients undergoing TAVR. Methods We retrospectively analyzed patients with pre-existing RBBB undergoing TAVR at our institution between 2011-2023. A surface 12-lead electrocardiogram (ECG) was available before and after procedure in all patients. The following, proposed ESC criteria were validated: ΔPR interval ≥ 20ms, QRS axis change or transient HAVB &amp;lt; 24 hours after TAVR. Results Of a total 1412 patients undergoing TAVR, 109 had pre-existing RBBB and were eligible for final analysis (mean age 83±5 years, 39% female). Of 109 RBBB patients, 36 (33%) developed persistent HAVB and received a permanent PM. Among the other 73 patients (67%), 17 patients (23%) suffered delayed HAVB during 30-days FU. When applying the ESC Guidelines, PM placement would have been indicated in 52% (38/73) of patients with RBBB after TAVR: due to transient HAVB in 17 (23%), due to PR prolongation ≥ 20ms in 19 (26%) and due to QRS axis change in 20 patients (27%). The proposed ESC criteria identified 82% of patients (14/17) with delayed HAVB during 30-day FU, while missing 3 patients (18%, 2.8% of overall cohort, Figure). This resulted in a sensitivity of 82% and a negative predictive value of 91%. Among the 17 patients with delayed HAVB, 12 patients (71%) displayed transient atrioventricular (AV) block within 24 hours after TAVR. Conclusion In this large cohort of RBBB patients undergoing TAVR with contemporary valves and techniques, the proposed ESC criteria of PR prolongation, QRS axis change or transient HAVB correctly identified 4/5 patients developing HAVB during 30-day FU. Prospective studies are warranted to confirm these findings.

Genotype-phenotype correlations in patients with titin variants and cardiomyopathy from a Swiss cohort

Abstract Background Alterations in titin (TTN) are mostly described with dilated cardiomyopathy (DCM). Few studies identified TTN variants in arrhythmogenic cardiomyopathy (ACM), but the overlap of dilated and arrhythmogenic phenotypes in TTN variants is scarcely studied. Most pathogenic TTN variants are located on the A-band, but there is few knowledge about the phenotypic presentation of I-band and Z-disc (non-A-band) variants. Purpose The aim of this study is to characterize and investigate the outcome of patients with cardiomyopathy and pathogenic (P) or likely pathogenic (LP) TTN variants with a particular focus on the cardiomyopathy phenotype (DCM vs. ACM) at initial presentation and follow-up. Further, we studied the association of the TTN variant (A-band vs. non-A-band regions) and a unique phenotype. Methods This is a retrospective multicenter study from a Swiss cohort including 34 patients with P/LP TTN variants and cardiomyopathy. The variables of the secured anonymized database include patient characteristics, genetic, ECG, echocardiographic, and cardiac magnetic resonance (CMR) data. Ventricular arrhythmia (VA) events were divided into non-sustained ventricular tachycardia (nsVT), sustained ventricular tachycardia (sVT) and sudden cardiac arrest (SCA +/- ventricular fibrillation). Results Of 34 included patients, 68% were male. Median age at presentation was 43.5 years. 29 (85%) patients presented with DCM, 7 (21%) left dominant ACM (2020 Padua criteria) and none ARVC (2010 ARVC Task Force criteria). At median follow-up of 48.5 months, 17 (50%) patients had VA events (15 nsVT, 5 sVT and 3 SCA events). VA events significantly increased over time (p=0.008) and were not associated with gender or left ventricular ejection fraction (LVEF) &amp;lt;35%. Under optimal guideline-directed medical therapy (GDMT) mean LVEF and right ventricular function increased significantly (LVEF: 28.3±14.4% vs. 41.9±9.8% and right ventricular fractional area change (RV FAC): 24.7±7.5% vs. 35.8±4.8%, p&amp;lt;0.05). Late gadolinium enhancement (LGE) on CMR was commonest in the basal septum, but no patient had higher degree atrioventricular block (AVB) at baseline and follow-up. At last follow-up, 8 (24%) patients fulfilled ACM and 13 (38%) DCM criteria (Figure 1). Most TTN variants were located on the A-band (21, 62%), 10 (29%) on the non-A-band regions. Latter had higher rates of sVT (log-rank p=0.041) during follow-up (Figure 2). 20 (59%) had LP and 11 (32%) P variants. P variant carriers were younger at disease presentation compared to LP variant carriers. Conclusion Patients with TTN variants frequently present as DCM, whereas presentation as left dominant ACM is less common. TTN does not seem to be a classical ARVC causing gene. Despite favourable biventricular remodelling under GDMT, ventricular arrhythmic events increase during follow-up. I-band and Z-disk variants are associated with a higher risk of sVT, which may help in the risk stratification process.

Long-term follow-up of single-chamber atrial pacing - system upgrade and wenckebach block point behavior: potential implications for leadless AAI pacing?

Abstract Introduction Until recently leadless pacemakers (PM) did not support atrial pacing. A novel dual chamber leadless PM system now provides treatment option for a wide range of indications. Single-chamber atrial stimulation (AAI) for the treatment of symptomatic sick sinus syndrome (SSS) is scarcely used due to concerns about the potential development of atrioventricular block (AVB) and development of paroxysmal atrial fibrillation (AF). Long-term follow-up data of AAI-PM is however scarce. Little is known about the role of serial Wenckebach block point (WBP) measurements in AAI-PM patients for risk stratification. Purpose To assess the incidence of dual chamber upgrade of patients treated with AAI-PM for SSS during long-term follow-up and to investigate the role of serial WBP measurements for risk stratification. Methods Prospectively enrolled patients undergoing implantation of an AAI-PM between October 2002 and December 2023. WBP was measured at implantation and serially during follow up. Results We included a total of 178 patients, of which 58% were female and the median age at implantation was 78 [IQR 71 – 83] years. The median follow-up duration was 6.5 [IQR 2.0 – 9.7] years. 24 patients (13.5%) received a system upgrade to DDD including 3 patients (1.7%) with a mode change to ventricular pacing only (VVI). Adjusted for years of follow-up the upgrade rate was 2.1% per year. Median time to system upgrade was 5.2 [IQR 1.6 – 8.7] years. Reasons for system upgrade were high-degree AVB (38%), low WBP (17%), atrial arrhythmias (33%), unclear syncope (8%) and infection (4%). Median WBP at implantation was 130 [120 – 140] bpm, showing a significant decline over time in the upgrade-group with 105 [95 – 130] bpm compared to the rest of the cohort with 130 [120-130] bpm (p = 0.009). A decline in WBP &amp;gt;20 bpm was found in 17.9% patients and a decline of 10-20 bpm in 33.7% of patients. New-onset atrial arrythmias were found in 36 patients (20%), 29% in the upgrade group and 19% in the rest of the cohort (p = 0.3). Neither age at implantation, sex, WBP at implantation, nor atrial arrhythmia prior to implantation were predictive for the need of a future system upgrade. Conclusion In this cohort of patients undergoing AAI-PM implantation for SSS, a system upgrade was required in 2% per year. The WBP remained stable in 48% of patients. Therefore, AAI-PM due to SSS emerges as a judicious and secure therapeutic modality, warranting increased consideration in the light of new treatment options for leadless pacing.

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

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

Intracardiac leadless pacemaker: long term safety over traditional pacemakers. a systematic review and meta-analysis

Abstract Introduction Leadless pacemaker (LP) is a novel technology designed to reduce lead-related, including pocket infections, associated with traditional pacemakers. LP can be used in patients with high-degree AV block, sinus node dysfunction, and bradycardia with syncope. We conducted a systematic review and meta-analysis to examine the long-term safety of intra-cardiac leadless pacemakers compared with traditional pacemakers. Methods Our protocol was registered in advance on PROSPERO. Studies were eligible if they compared complications, revision, cardiac perforation, infections, and all-cause mortality between patients who received leadless pacemakers versus traditional pacemakers. The systematic search was conducted in five databases (MEDLINE, EMBASE, CENTRAL, Web of Science, Scopus) without restriction. The random-effect model was implemented to calculate pooled odds ratio (OR) with a 95% confidence interval (CI). Also, the Mantel-Haenszel method, Paule-Mandel estimator for tau^2, Q-Profile method for the confidence interval of tau^2 and tau, and Hartung-Knapp adjustment for random effects model methods were used for the prediction of data extracted directly from the curves. ROBINS-I tool was used for the risk of bias assessment, and the certainty of the evidence was evaluated with the GRADE approach. Results Of 6450 studies screened, we identified 21 observational studies of Nanostim and Micra leadless pacemakers. The pooled incidence of complications of leadless versus traditional pacemakers at 1, 6, 12-24 months show the odds are clinically and statistically different (OR=0.66, 95% CI: 0.42–1.02; OR=0.44, 95% CI: 0.22–0.86; OR=0.41, 95% CI: 0.32–0.53 respectively). The pooled incidence of infection rate at 6, 12-24 months is lower in patients with LP (OR=0.37, 95% CI: 0.31–0.44; OR=0.20, 95% CI: 0.00–97.31). The studies comparing all-cause mortality during 6, 12-24 months in leadless versus traditional pacemakers did not show statistically significant differences in these outcomes (OR=1.26, 95% CI: 0.88–1.81; OR=0.86, 95% CI: 0.25–2.92 respectively. Conclusion Our results show that complications and infections occur less frequently in patients with leadless pacemakers than in patients with conventional pacemakers with no difference in all-cause mortality. However, there is a need for high-quality randomized clinical trials and propensity score-matched studies focusing on this clinically relevant question.Complication Forest plotsInfection Forest plots