Advanced Atrioventricular Block in Athletes: Prevalence and Role of Anti-Ro/Sjögren Syndrome-Related Antigen A Antibodies.

BACKGROUND: Advanced atrioventricular block (AVB), that is, higher than second-degree Mobitz-1, is an abnormal finding in athletes. Despite intensive investigation, in several cases the pathogenesis remains unknown, but frequently pacemaker implantation is still indicated. Increasing evidence points to circulating anti-Ro/Sjögren syndrome-related antigen A (SSA) antibodies cross-reacting with L-type calcium channel and inhibiting the related current as an epidemiologically relevant and potentially reversible cause of isolated AVB in adults. The aim of the study was to determine the prevalence of anti-Ro/SSA-associated advanced AVBs in a large sample of young athletes. METHODS AND RESULTS: A total of 2536 consecutive athletes aged <40 years without a history of cardiac diseases/interventions were enrolled in a cross-sectional study. Resting and exercise electrocardiography was performed, and those presenting any AVB were further evaluated by 24-hour Holter ECG. Athletes with second-degree AVBs and their mothers underwent anti-Ro/SSA testing. Moreover, purified immunoglobulin G from subjects with anti-Ro/SSA-positive and anti-Ro/SSA-negative advanced AVB were tested on L-type calcium current and L-type-calcium channel expression using tSA201 cells. The global prevalence of advanced AVB in the overall sample was ≈0.1%, but the risk considerably increased (2%) when intensely trained postpubertal male subjects were selectively considered. While none of the athletes with advanced AVB showed heart abnormalities, in 100% of cases anti-Ro/SSA antibodies were detected. Ex vivo experiments showed that immunoglobulin G from anti-Ro/SSA-positive but not -negative subjects with advanced AVB acutely inhibit L-type calcium current and chronically downregulate L-type-calcium channel expression. CONCLUSIONS: Our study provides evidence that advanced AVB occurs in young athletes, in most cases associated with anti-Ro/SSA antibodies blocking L-type calcium channels. These findings may open new avenues for immunomodulating therapies to reduce the risk of life-threatening events in athletes, avoiding or delaying pacemaker implantation.

A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.

BACKGROUND: Atrioventricular block (AVB) is rare in hyperthyroidism (HTH). Little is known about the true prevalence, clinical course, optimal management, and outcomes of different types of AVBs in patients with HTH. To address these uncertainties, we aimed to conduct a systematic review by combining the available literature to provide more meaningful data regarding AVBs in HTH. METHODS: We systematically searched PubMed, Scopus, Embase, and Google Scholar for articles reporting patients who developed AVB in the context of HTH. Data were analysed in STATA 16. The main outcomes included types of AVB, frequency of pacemaker insertion, and resolution of AVB. The systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number CRD42022335598. RESULTS: A total of 56 studies (39 case reports, 12 case series, 3 conference abstracts, 1 retrospective study, and 1 prospective observational study) with 87 patients were included in the analysis, with a mean age of 39.1 ± 17.6 years. Females constituted 65.7% (n = 48) of the cohort. Complete heart block (CHB) was the most commonly reported AVB (N = 45, 51.7%), followed by first-degree AVB (16.1%) and second-degree AVB (14.9%). Overall, 21 patients underwent pacing. A permanent pacemaker was inserted in one patient with second-degree AVB and six patients with CHB. Mortality was reported in one patient with CHB. The clinical course and management of HTH and AVBs did not differ in patients with CHB or lower-degree blocks. Apart from lower rates of goitre and more use of carbimazole in those who underwent pacing, no differences were found when compared to the patients managed without pacing. CONCLUSION: Current data suggest that CHB is the most common type of AVB in patients with HTH. Most patients can be managed with anti-thyroid management alone. Additionally, whether pacemaker insertion alters the clinical outcomes needs further exploration.

Pan pneumo: an unusual complication following pacemaker implantation.

Implantation of cardiac devices is usually considered to be a safe procedure. Rare complications, such as pneumothorax, may occur after the procedure. The association with pneumopericardium or pneumomediastinum is even more uncommon. We present the case of a patient in his 70s, on haemodialysis, admitted for complete atrioventricular block. He underwent implantation of a dual-chamber pacemaker. He presented with chest pain the day after implantation. Chest CT scan revealed a pneumothorax associated with a pneumopericardium and pneumomediastinum 'pan pneumo', due to an atrial perforation. We opted for a conservative management strategy. Repeat CT scan of the chest 8 days after the procedure showed a complete resorption of the 'pan pneumo'. The objective of this case report is to describe this rare complication and provide further insight into its management, particularly in the absence of specific guidelines.

Not only Van Gogh: a case of BRASH syndrome with concomitant digoxin toxicity.

BACKGROUND: Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a potentially life-threatening clinical condition characterized by bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia. It constitutes a vicious circle in which the accumulation of pharmacologically active compounds and hyperkalemia lead to hemodynamic instability and heart failure. CASE PRESENTATION: A 66-year-old Caucasian female patient was admitted to the emergency department presenting with fatigue and bradycardia. Upon examination, the patient was found to be anuric and hypotensive. Laboratory investigations revealed metabolic acidosis and hyperkalemia. Clinical evaluation suggested signs of digoxin toxicity, with serum digoxin concentrations persistently elevated over several days. Despite the implementation of antikalemic measures, the patient's condition remained refractory, necessitating renal dialysis and administration of digoxin immune fab. CONCLUSION: Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a life-threatening condition that requires prompt management. It is important to also consider potential coexisting clinical manifestations indicative of intoxication from other pharmacological agents. Specifically, symptoms associated with the accumulation of drugs eliminated via the kidneys, such as digoxin. These manifestations may warrant targeted therapeutic measures.

A long-standing conundrum: an unusual case of 2:1 atrioventricular block with conflicting findings.

A 2:1 atrioventricular (AV) block can occur anywhere within the conduction system, and noninvasive measurements may not always predict the exact site of the block. Although localization of the block is critical for deciding any treatment, patients should also be carefully questioned about symptoms both at rest and during exertion. A case of 2:1 AV block that was symptomatic only during exertion, appeared infranodal by noninvasive diagnostic methods, but was found to be intranodal on electrophysiological study is reported.

Atrioventricular conduction disorders in aortic valve infective endocarditis.

BACKGROUND: Aortic valve infective endocarditis may be complicated by high-degree atrioventricular block in up to 10-20% of cases. AIM: To assess high-degree atrioventricular block occurrence, contributing factors, prognosis and evolution in patients referred for aortic infective endocarditis. METHODS: Two hundred and five patients referred for aortic valve infective endocarditis between January 2018 and March 2021 were included in this study. A comprehensive assessment of clinical, electrocardiographic, biological, microbiological and imaging data was conducted, with a follow-up carried out over 1 year. RESULTS: High-degree atrioventricular block occurred in 22 (11%) patients. In univariate analysis, high-degree atrioventricular block was associated with first-degree heart block at admission (odds ratio 3.1; P=0.015), periannular complication on echocardiography (odds ratio 6.9; P<0.001) and severe biological inflammatory syndrome, notably C-reactive protein (127 vs 90mg/L; P=0.011). In-hospital mortality (12.7%) was higher in patients with high-degree atrioventricular block (odds ratio 4.0; P=0.011) in univariate analysis. Of the 16 patients implanted with a permanent pacemaker for high-degree atrioventricular block and interrogated, only four (25%) were dependent on the pacing function at 1-year follow-up. CONCLUSIONS: High-degree atrioventricular block is associated with high inflammation markers and periannular complications, especially if first-degree heart block is identified at admission. High-degree atrioventricular block is a marker of infectious severity, and tends to raise the in-hospital mortality rate. Systematic assessment of patients admitted for infective endocarditis suspicion, considering these contributing factors, could indicate intensive care unit monitoring or even temporary pacemaker implantation in those at highest risk.

Third-Degree Atrioventricular Block And Asystole After Lung Resection: A Rare Complication.

Surgical resection remains the optimal therapeutic option for early-stage operable NSCLC. Despite significant advances in recent years related to anesthetic and surgical techniques, cardiopulmonary complications remain major causes for postoperative morbimortality. In this paper we present a case of a patient who developed complete AV block followed by asystole after lung resection surgery. The patient underwent surgery via right VATS and the procedure was uneventful.  On the first post-operative day patient developed a third-degree atrioventricular block followed by 6 seconds asystole. Pharmacological treatment was instituted and implementation of a permanent pacemaker occurred on the third post-operative day, without complications. The remaining postoperative course was uneventful and the patient was discharged home on the sixth post-operative day. It is the objective of the authors to report and highlight this rare and potencial fatal complication of lung resection.

Incidence, Risk Factors, and Outcomes of Left Atrial Enlargement in Patients Requiring Right Ventricular Pacing: A Retrospective Study of 461 Cases from 2012 to 2020.

BACKGROUND Long-term right ventricular (RV) pacing has been linked to left atrial enlargement (LAE). The incidence and risk factors associated with significant LAE after RV pacing remain unknown. This retrospective study included 461 patients requiring RV pacing at 2 centers between 2012 and 2020 and aimed to evaluate the incidence, risk factors, outcomes, and complications of LAE. MATERIAL AND METHODS A total of 461 patients with normal-sized pre-implant left atrial dimension and dual-chamber pacing pacemaker implantation for complete atrioventricular block were enrolled. Patients were grouped based on a ≥20% increase from their baseline left atrial dimension by echocardiography, indicating significant LAE, and initial characteristics, echocardiographic data, and outcomes were compared. RESULTS During a mean 7.0±4.9 years follow-up period, 96 patients (20.8%) developed significant LAE, whereas 365 patients did not. In multivariate logistic regression analysis, smaller pre-implant left atrial dimension (OR, 0.776; 95% CI, 0.728-0.828; P<0.001), lower post-implant left ventricular ejection fraction (OR, 0.976; 95% CI, 0.957-0.995; P=0.014), post-implant development of moderate to severe mitral regurgitation (OR, 2.357; 95% CI, 1.172-4.740; P=0.016), and RV pacing duration ≥3.3 years (OR, 1.576; 95% CI, 1.039-2.646; P=0.045) were independent predictors of significant LAE after RV-dependent pacing. There was a significant difference in the incident stroke events between patients without and with significant LAE (9.9% vs 17.7%; log-rank P=0.047). CONCLUSIONS Long-term RV pacing was linked to significant LAE in 20.8% of patients with complete atrioventricular block, with those affected experiencing a higher stroke rate during follow-up.

Clinical analysis of temporary pacemaker implantation in 6 children with fulminant myocarditis.

BACKGROUND: There is little literature on the use of temporary pacemakers in children with fulminant myocarditis. Therefore, we summarized the use of temporary cardiac pacemakers in children with fulminant myocarditis in our hospital. METHODS: The clinical data of children with fulminant myocarditis treated with temporary pacemakers in Wuhan Children's Hospital from January 2017 to May 2022 were retrospectively analyzed. RESULTS: A total of 6 children were enrolled in the study, including 4 boys and 2 girls, with a median age of 50 months and a median weight of 15 kg. The average time from admission to pacemaker placement was 2.75 ± 0.4 h. The electrocardiogram showed that all 6 children had third-degree atrioventricular block (III°AVB). The initial pacing voltage, the sensory sensitivity of the ventricle and the pacing frequency were set to 5-10 mV, 5 V and 100-120 bpm respectively. The sinus rhythm was recovered in 5 patients within 61 h (17-134) h, and the median time of using temporary pacemaker was 132 h (63-445) h. One of the children had persistent III°AVB after the temporary pacemaker. With parental consent, the child was fitted with a permanent pacemaker on the 12th day of his illness. CONCLUSIONS: When fulminant myocarditis leads to severe bradycardia or atrioventricular block in children, temporary pacemakers have the characteristics of high safety to improve the heart function.

Left bundle branch area versus conventional pacing after transcatheter valve implant for aortic stenosis: the LATVIA study.

BACKGROUND: Atrioventricular block (AVB) is a frequent complication in patients undergoing transcatheter aortic valve implantation (TAVI). Right apex ventricular pacing (RVP) represents the standard treatment but may induce cardiomyopathy over the long term. Left bundle branch area pacing (LBBAP) is a promising alternative, minimizing the risk of desynchrony. However, available evidence with LBBAP after TAVI is still low. OBJECTIVE: To assess the feasibility and safety of LBBAP for AVB post-TAVI compared with RVP. METHODS: Consecutive patients developing AVB early after TAVI were enrolled between 1 January 2022 and 31 December 2022 at three high-volume hospitals and received LBBAP or RVP. Data on procedure and at short-term follow-up (at least 3 months) were collected. RESULTS: A total of 38 patients (61% men, mean age 83 ±â€Š6 years) were included; 20 patients (53%) received LBBAP. Procedural success was obtained in all patients according to chosen pacing strategy. Electrical pacing performance at implant and after a mean follow-up of 4.2 ±â€Š2.8 months was clinically equivalent for both pacing modalities. In the LBBAP group, procedural time was longer (70 ±â€Š17 versus 58 ±â€Š15 min in the RVP group, P  = 0.02) and paced QRS was shorter (120 ±â€Š19 versus 155 ±â€Š12 ms at implant, P  < 0.001; 119 ±â€Š18 versus 157 ±â€Š9 ms at follow-up, P  < 0.001). Complication rates did not differ between the two groups. CONCLUSION: In patients with AVB after TAVI, LBBAP is feasible and safe, resulting in a narrow QRS duration, either acutely and during the follow-up, compared with RVP. Further studies are needed to evaluate if LBBAP reduces pacing-induced cardiomyopathy in this clinical setting.

Comparing outcomes of an 'early' versus 'late' diagnosis of cardiac sarcoidosis following a baseline presentation of high-grade atrioventricular block.

BACKGROUND: There is a paucity of evidence on impact of a delay in Cardiac Sarcoidosis (CS) diagnosis after high-grade atrioventricular-block (AVB) and this study aims to fill this void. METHODS: Consecutive CS patients (n = 77) with high grade AVB referred to one specialist hospital in London between February 2007 to February 2023 were retrospectively reviewed. The median time from AVB to diagnosing CS (112 days) was used to define the Early (n = 38) and Late (n = 39) cohorts. The primary endpoint was a composite of all-cause mortality, cardiac transplantation, ventricular arrhythmic events or heart failure hospitalisation. Secondary endpoints included difference in maintenance prednisolone dose, need for cardiac device upgrade and device complications. RESULTS: The mean age of the cohort was 54.4 (±10.6) years of whom 64 % were male and 81 % Caucasian. After a mean follow up of 54.9 (±45.3) months, the primary endpoint was reached by more patients from the Late cohort (16/39 vs. 6/38, p = 0.02; multivariable HR 6.9; 95 %CI 1.5-32.2, p = 0.01). Early Group were more likely to have received an Implantable Cardioverter Defibrillator or Cardiac Resynchronisation Therapy-defibrillator as index device after AVB (19/38 vs. 6/39; p < 0.01) and had fewer device upgrades (19/38 vs. 30/39, p = 0.01) and a trend towards fewer device complications (1 vs. 5, p = 0.20). The maintenance dose of prednisolone was significantly higher in Late Group [20.7(±9.7) mg vs. 15.3(±7.9) mg, p = 0.02]. CONCLUSION: A late diagnosis of CS was associated with more adverse events, a greater probability of needing a device upgrade and required higher maintenance steroid dose.

Transient 2:1 Atrioventricular Block with Peri-Conduction System Pacing After Leadless Pacemaker Implantation.

This report discusses a case of transient 2:1 atrioventricular block with conduction system pacing 4 hours after leadless right ventricular pacemaker implantation in a 19-year-old patient with a history of cardioinhibitory syncope and asystole cardiac arrest but without preexisting atrioventricular block. The atrioventricular block was resolved spontaneously. Pacing morphology was suggestive of right bundle branch pacing. Neither 2:1 atrioventricular block nor conduction system pacing has previously been a reported outcome of right ventricular leadless pacemaker implantation. The report demonstrates that conduction system pacing with leadless devices is achievable. Further study of techniques, limitations, and complications related to intentional right ventricular leadless conduction system pacing is warranted.

Severe ST-segment elevation and AV block during pulsed-field ablation due to vasospastic angina - a novel observation.

Catheter ablation of atrial fibrillation using non-thermal electroporation represents a promising ablation modality due to its believed superior safety profile. Still, if electroporation is delivered in proximity to a coronary artery, vasospasms can occur. We report the first case of severe right coronary artery vasospasm resulting in ST-segment elevation and AV block despite a remote distance from the ablation site to the right coronary artery, indicating a different mechanism. In this case, electroporation most likely triggered a previously unknown Prinzmetal vasospastic angina in the patient, resulting in the coronary vasospasm. Thus, meticulous monitoring of ST-segment changes following PFA delivery even from regions remote to coronary arteries is required.

His potential injury as the end point of screwing by a continuous recording technique in His bundle pacing: A case report.

BACKGROUND: His bundle pacing (HBP) engaged electrical activation of both ventricles by stimulating the His-Purkinje network, which could avoid marked ventricles dyssynchrony. The lead was given three to five clockwise rotations at the site with the His potential to anchor the interventricular septum. In 2018, the Multicenter His Bundle Pacing Collaborative Working Group recommended that the His bundle capture threshold should be lower than 2.5 V/1 ms in non-pacing-dependent patients, and pacing-dependent patients should have a lower adjacent ventricular capture threshold as self-backup. Therefore, to avoid safety issues such as loss of capture caused by increased threshold, we believe that more stringent criteria should be adopted in patients with atrioventricular block (AVB). In previous studies, the connection cable needed to be disconnected during the screwing. When the procedure was finished, the performer found that the patients with His bundle injury could obtain a lower threshold than those without His bundle injury. Although no studies of new bundle branch block (BBB) or AVB by the acute His bundle injury was reported. However, It is worrying that the damage of His bundle seems random during the procedure. How to balance avoiding severe injury with a lower capture threshold? At present, we report a case of light His injury and lower His capture threshold under continuous intracardiac electrocardiogram monitoring.

A surgical resection case of myxoma arising from the posterior wall of the left atrium complicated with complete atrioventricular block.

An 80-year-old female was referred to our institution due to transient right upper limb weakness. Transthoracic and transesophageal echocardiography revealed a tumor in the left atrium. The tumor was attached to the posterior wall of the left atrium near the atrioventricular node. Intraoperative pathological examination revealed that the tumor was a myxoma, and complete resection was successfully performed. However, she experienced persistent complete atrioventricular block postoperatively and required pacemaker implantation.

Pause-Dependent Paroxysmal Episode of Third-Degree Atrioventricular Block Triggered by Premature Atrial Contraction.

BACKGROUND Paroxysmal third-degree atrioventricular block (AVB) can exhibit a vast array of symptoms, but commonly, paroxysmal AVB leads to presyncope, syncope, or possibly sudden cardiac death. We present a rare case of pause-dependent paroxysmal AVB that was triggered by a premature atrial contraction. CASE REPORT A 65-year-old man with frequent episodes of presyncope and syncope for 3 weeks was admitted to our hospital for further diagnosis. A resting 12-lead electrocardiogram showed an incomplete right bundle branch block, and a 24-h Holter recording showed multiple episodes of third-degree AVB. Intracardiac tracing revealed that the block site was distal, at the infra-His-Purkinje system. CONCLUSIONS This case highlights a rare case of pause-dependent paroxysmal AVB that was triggered by a premature atrial contraction. This type of AVB is an abrupt, unexpected, repetitive block of atrial impulses as they propagate to the ventricles. It is relatively rare, and due to its transient nature, it is often under recognized and can lead to sudden cardiac death.

The Average Age of Atrioventricular Block Onset in Middle Eastern Patients with Cardiac Rhythm Devices Adjusted for the Overall Young Population: Insights from a Multicenter International Registry.

Background: Previous registries have shown a younger average age at presentation with cardiovascular diseases in the Middle East (ME), but no study has examined atrioventricular block (AVB). Moreover, these comparisons are confounded by younger populations in the ME. We sought to describe the average age at presentation with AVB in ME and quantify the effect of being from ME, adjusted for the overall younger population. Methodology: This was a retrospective analysis of PANORAMA registries, which collected data on patients who underwent cardiac rhythm device placement worldwide. Countries with a median population age of ≤30 were considered 'young countries'. Multivariate linear regression was performed to assess the effect of being from ME, adjusted for being from a 'young country', on age at presentation with AVB. Results: The study included 5,259 AVB patients, with 640 (8.2%) from the ME. Mean age at presentation was seven years younger in ME than in other regions (62.9 ± 17.8 vs. 70 ± 14.1, P < 0.001). Being from a 'young country' was associated with 5.6 years younger age at presentation (95%CI -6.5--4.6), whereas being from ME was associated with 3.1 years younger age at presentation (95%CI -4.5--1.8), (P < 0.001 for both). Conclusion: The average age at presentation with AVB in the ME is seven years younger than in other regions. While this is mostly driven by the overall younger population, being from the ME appears to be independently associated with younger age. Determinants of the earlier presentation in ME need to be assessed, and care should be taken when applying international recommendations.

[High-degree atrioventricular (AV) block]. / Borreliakardit ­ ovanlig orsak till atrioventrikulärt block.

In elderly patients high-degree atrioventricular (AV) block is often due to irreversible degeneration of the cardiac conduction system. Reversible causes must however be excluded prior to pacemaker implantation. In younger patients reversible causes are more likely, as well as more unusual etiologies. Lyme carditis is a rare, but reversible cause of AV block. It is a manifestation of Lyme borreliosis - an infectious disease caused by the bacteria Borrelia burgdorferi. Lyme carditis should particularly be considered in young and middle-aged patients with a high-degree AV block. When pretest probability is intermediate to high, a positive serological test makes the diagnosis of Lyme carditis highly likely. In these cases antibiotic treatment may revert the conduction disturbance, thus preventing unnecessary implantation of a permanent pacemaker.