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His-bundle pacing has demonstrated feasibility in numerous adult studies to reverse and prevent pacing-induced cardiomyopathy, however, is met with higher capture thresholds with deployment sheaths designed for adults with his-bundles in the typical location. To describe 24 pediatric and adult congenital patients post-physiologic pacing. Patients at the University of Minnesota Masonic Childrens Hospital with congenital complete heart block or congenital heart disease and atrioventricular block presented for pacemaker placement between November 2019 and January 2021. Twenty-four patients had attempted his-bundle placement using either Medtronics C315 or C308 sheaths and 3830 leads except for 3 patients who had Boston Scientifics His system with the Shape 3 sheath and 7842 leads. Twenty-four total patients underwent physiologic pacing (23 his-bundle, 13 female, 11 male) with median age of 14 years (range 8-39 years) with median weight of 51 kg (range 21.2-81 kg) with five right-sided implants performed. Twelve patients had congenital heart disease including atrioventricular canal defects, tetralogy of Fallot, and ventricular septal defect repairs (nine patients with ventricular septal defect repairs). Twelve patients had selective His-bundle pacing (six with congenital heart disease). Median threshold to capture was 0.5 V at 0.4 ms (range 0.4 to 1.1 V at 0.4 ms), impedance 570 ohms (range 456-1140 ohms), and sensing median of 9.7 mV (range 1.5-13.8 mV if present). The median follow-up time was 610 days (range 240-760 days). No complications occurred peri-procedurally or during follow-up. His-bundle pacing is feasible in pediatric and congenital heart disease patients.

Introduction: Ferric derisomaltose is the newest available parenteral iron formulation. Studies have demonstrated a good safety profile with improved tolerability compared to alternative parenteral iron formulations. To date there have been no reported acute, life-threatening cardiac events associated with ferric derisomaltose.Case Report: An 86-year-old male who had previously tolerated routine iron infusions received a first dose of ferric derisomaltose at an outpatient infusion clinic. Six minutes into the infusion the patient became unresponsive with no palpable pulse. Return of spontaneous circulation was achieved after two minutes of chest compressions. Electrocardiogram showed complete heart block requiring transcutaneous pacing and vasopressor administration. The patient was transferred to the emergency department for stabilization and then admitted to the cardiac intensive care unit. During admission, the patient received a dual-chamber, permanent pacemaker without complication and was ultimately discharged.Conclusion: It may be reasonable to consider parenteral iron as a toxicological etiology for patients presenting with complete heart block temporally associated with parenteral iron administration, particularly in patients with underlying conduction abnormalities.

Introduction: Lithium is a medication used to treat bipolar disorder. It has a narrow therapeutic index, which frequently causes toxicity in patients.Case Report: We present an unusual case of a 66-year-old female with a history of bipolar disorder on chronic lithium, who developed a third-degree heart block, encephalopathy, and acute renal failure because of lithium toxicity.Conclusion: This case highlights a rare but life-threatening case of complete heart block in the setting of lithium toxicity. The patient was treated with hemodialysis and pacemaker placement.

Postoperative atrioventricular block requiring pacemaker (AVB/PM) complicates 14% to 25% of biventricular repair operations for complex congenital heart disease (CHD) and in those with heterotaxy syndrome. This study aimed to evaluate if intraoperative His bundle (HB) mapping during complex biventricular CHD repair can be performed safely and reduce postoperative AVB/PM. HB mapping was performed using a commercially available multielectrode grid catheter in patients with complex CHD undergoing biventricular repair between 2019 and 2022 compared with an unmapped cohort. The primary outcome was postoperative AVB/PM. One hundred forty-nine patients underwent HB mapping compared to 201 unmapped controls. The median age of mapped patients was 1.9 years (Q1-Q3: 0.9-3.9 years). Heterotaxy syndrome was present in 31% (n = 46 of 149), ventricular septal defect in 95% (n = 142 of 149), and prior single ventricle palliation in 68% (n = 89 of 149). The HB was identified in 97% (n = 144 of 149) of cases. The median mapping time was 6 minutes. No episodes of intraoperative systemic air embolism occurred. Postoperative AVB/PM frequency was significantly reduced in mapped patients with heterotaxy (2% [n = 1 of 46] vs 16% [n = 11 of 67]; P = 0.026) and in patients without L-malposed great arteries (3% [n = 3 of 88] vs 11% [n = 15 of 134]; P = 0.045). Intraoperative HB mapping can be performed safely and is associated with significantly reduced postoperative AVB/PM in select populations undergoing complex biventricular repair, including heterotaxy syndrome and non–L-malposed great arteries. Nonetheless, certain subgroups remain at risk for AVB/PM, showing the need for further improvements to current intraoperative HB mapping technology and techniques. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective: Unusual clinical course Background: Atrial flutter is associated with significant morbidity and mortality. Standard treatment involves rate and rhythm control medications, with ablation procedures reserved for more persistent cases. While ablation is generally successful, it carries risks, such as complete heart block, as in this case. Case Report: A 73-year-old woman presented for ablation of recurrent atypical atrial flutter. Electro-anatomic mapping demonstrated counterclockwise mitral annular flutter. An anterior ablation line was initially created from the right superior pulmonary vein to the mitral valve annulus. As the line was extended to the anterior mitral valve annulus at the 9 o'clock position, complete heart block occurred, and ablation was immediately terminated. Complete recovery of atrioventricular (AV) conduction occurred within 1 min. The catheter tip was within 1.8 cm from the His bundle, as denoted by the yellow tag on the CARTO map. A second mitral line was created anteriorly at the 11 o'clock position on the mitral valve annulus and extended to the left atrial roof line, with the termination and creation of a bi-directional mitral isthmus block. She remained in sinus rhythm after ablation, with PR prolongation and no AV block. The following day, she developed severe bradycardia due to complete heart block, with a slow ventricular escape rhythm, requiring implantation of a permanent pacemaker. Conclusions: This case underscores the importance of precise catheter positioning during anterior mitral line ablation to prevent complications, such as AV block. Anterior mitral line ablation should be performed in a more anterior location away from the septum to minimize the risk of AV block. [ABSTRACT FROM AUTHOR]

Background/Purpose: Implantable loop recorders (ILR) are increasingly used in cardiac rhythm monitoring and diagnostic work‐up of unexplained syncope. ILR battery longevity, according to manufacturers' product performance specifications, typically ranges between 2 and 4 years, but real‐world data in this population are lacking. Methods: This monocentric, prospective, observational study included consecutive patients with unexplained syncope undergoing ILR implantation between October 2007 and 2019. The main purpose was to determine real‐world battery longevity of ILRs. Diagnostic yield and relationship between arrhythmogenic diagnosis and duration of ILR monitoring were explored. Results: The study included 309 patients (59 years [38–73], 49% female) with ILR implantation for unexplained syncope. Median battery longevity was 42 [40–45] months. A total of 99.5% of ILRs reached prespecified battery longevity. The time to end‐of‐life varied by up to 33 months among the same ILR models. Overall arrhythmogenic diagnostic yield counted 27% (73% sick sinus syndrome, 20% atrioventricular block, and 7% ventricular tachycardia). Median time to diagnosis was 10 [2–25] months, with the latest event at 43 months. The cumulative diagnostic yield for arrhythmogenic event explaining syncope was 4.2%, 6.1%, 9.4%, 14.6%, 19.4%, and 26.7% at 1, 2, 6, 12, 24, and 48 months, respectively. In univariate analysis, first degree AV block and prolonged HV time on EP study were predictors of diagnosis, while QRS duration abnormality borderline missed significance. Conclusions: Real‐world battery longevity of ILRs matched industry projected longevity in 99.5% of patients implanted with ILR for unexplained syncope. A battery longevity of minimum 3.5 years is recommended to maximize the diagnostic yield in this population. [ABSTRACT FROM AUTHOR]

Introduction: Atrial high‐rate episodes (AHRE) have been linked to increased thromboembolic risk and all‐cause mortality in patients with cardiac implantable electronic devices (CIEDs). Various predictors of AHRE development have been identified, emphasizing the need for close monitoring and the potential transition to clinical atrial fibrillation (AF). However, the predictive value of P wave characteristics on AHRE development remains conflicting. This meta‐analysis aims to summarize existing data to investigate this association. Method: We examined studies from MEDLINE and EMBASE databases up to May 2024 to investigate the association of baseline P‐wave duration (PWD), P‐wave dispersion (PWDIS), and interatrial block (IAB) with the risk of developing AHRE. We extracted the mean and standard deviations of PWD and PWDIS to calculate the pooled mean difference (MD). Risk ratios (RR) and 95% confidence intervals (CIs) were used to assess the association between IAB and AHRE risk, using the generic inverse variance method for combination. Results: The meta‐analysis included nine studies. Patients with AHRE had longer PWD and PWDIS compared to those without AHRE, with a pooled MD for PWD of 9.17 ms (95% CI: 4.74–13.60; I2 = 47%, p < 0.001) and a pooled MD for PWDIS of 20.56 ms (95% CI: 11.57–29.56; I2 = 57%, p < 0.001). Additionally, patients with IAB had a higher risk of developing AHRE, with a pooled RR of 3.33 (95% CI: 2.53–4.38; I2 = 0%, p < 0.001), compared to those without IAB. Conclusions: Our meta‐analysis found that patients with AHRE had higher PWD and PWDIS than those without AHRE. Additionally, IAB was associated with a higher risk of developing AHRE. These findings emphasize the importance of close monitoring and risk stratification, particularly for patients with P wave abnormalities. [ABSTRACT FROM AUTHOR]

Background: Atrioventricular block (AVB) is common in the elderly and therefore considered to be a degenerative disease of the cardiac conduction system. However, there exist other etiologies contributing to AVB in young patients. This study aimed to determine the etiologies in patients aged before 60 years receiving their first pacemaker implantation for AVB in China. Methods and Results: Medical records and diagnostic tests of AVB patients were reviewed to identify the etiologies between 2010 and 2021 at Guangdong Provincial People's Hospital. Eight hundred and twenty‐six patients (median age 47 years; 47.9% males) were included. The etiologies were identified in 336 (40.7%) cases, including complications to cardiac surgery (n = 190 [23.0%]), myocarditis (n = 57 [6.9%]), myocardial infarction (n = 25 [3.0%]), complications to catheter‐based interventional procedures (n = 21 [2.5%]) and others (n = 43 [5.2%]). AVB caused by myocardial infarction was more common in men (5.8% vs. 0.5%, p <.001), while women received pacing treatment earlier (48 vs. 46 years, p =.019). Men were more likely to suffer from dilated cardiomyopathy (6.6% vs. 2.1%, p =.001) and atrial fibrillation/flutter (23.0% vs. 12.8%, p <.001). The number of first pacemaker implantation increased with age especially among patients with unclear etiologies. Conclusion: The etiology of AVB was only determined in approximately 40% of patients receiving their first pacemaker implantation aged before 60 years. The predominance of AVB with unknown etiology and potential gender differences warrants further studies. [ABSTRACT FROM AUTHOR]

Introduction: Modern cardiovascular implantable electronic devices (CIEDs) have mechanisms that prevent damage from external electric shocks, and malfunction following accidental electrocution is rare. However, the effects of lightning injuries in patients with CIEDs are uncertain. Case presentation: A 74‐year‐old man with a dual‐chamber pacemaker due to complete heart block was struck by a lightning while farming. He had no serious injury at the time and sought medical evaluation 1 month later, when he presented with asymptomatic bradycardia. Device interrogation suggested major battery and lead damage, requiring extraction and subsequent placement of a new pacing system. Discussion: While a previous report depicted pacing threshold elevation without extensive device impairment, our patient presented with major damage to the whole pacing system. The factors contributing to these divergent outcomes are unclear. Differences in injury mechanism, pacemaker model, and the pattern of electric current dispersion within the device may each play a part in this discrepancy. [ABSTRACT FROM AUTHOR]

Introduction: Chronic obstructive pulmonary disease (COPD)-induced osteoporosis, myasthenia, and disequilibrium are important risk factors for hip fracture, and decreased respiratory function after hip fracture surgery can decelerate recovery of activities of daily living (ADL) in elderly patients. Case Presentation: A 90-year-old male patient underwent an open reduction and intramedullary pinning surgery for right femoral intertrochanteric fracture. After surgery, he remained confined to bed with pain and swelling in the right lower extremity. Due to his history of COPD, he had a postoperative pulmonary infection and respiratory insufficiency. Intervention: This patient received routine rehabilitation after surgery. However, severe respiratory symptoms prevented him from completing the rehabilitation procedure. Therefore, comprehensive pulmonary rehabilitation including airway clearance techniques, inspiratory resistance training, aerobic training, respiratory muscle training, and intermittent low-flow oxygen inhalation was carried out to enhance the recovery process. Outcomes: After 4 weeks of treatment, the patient improved from continuous oxygen inhalation to being able to complete bed resistance training without supplemental oxygen. After 8 weeks, ADL reached independence, while lower limb muscle strength, pulmonary function parameters, fatigue index, and cough efficiency were improved as compared to test values obtained before treatment. Conclusion: Compared with the 6-month recovery time reported in the literature for patients with hip fractures to achieve independence with basic ADLs, the recovery time of this patient was shortened to 2 months with the application of comprehensive pulmonary rehabilitation. It is feasible to carry out pulmonary rehabilitation for elderly patients after fracture surgery, but prospective clinical trials are needed to verify its efficacy. [ABSTRACT FROM AUTHOR]

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

Background: Acute mesenteric ischemia (AMI) usually presents with abrupt and severe abdominal pain associated with nausea and vomiting. This case is notable due to the occurrence of AMI secondary to acute systolic heart failure caused by new onset complete heart block. Case Presentation: A 65-year-old male presented with sudden onset epigastric pain. ECG showed complete AV block and acute ischemia, and a subsequent CTA revealed complete occlusion of the mid superior mesenteric artery. His emergent left heart catheterization showed non-occlusive coronary artery disease. The patient underwent emergent laparotomy and SMA thrombectomy. Postoperative complications included worsening congestive heart failure and persistent bradycardia, requiring a permanent pacemaker. The patient was discharged to a skilled nursing facility in stable condition. Conclusions: This case highlights the diagnostic challenges of AMI in the setting of acute heart failure and new onset AV block mimicking acute cardiac events and emphasizes the importance of a multidisciplinary approach in managing such complex cases. [ABSTRACT FROM AUTHOR]

Background: Conduction blocks complicating ST(ST-segment)-elevation myocardial infarction are associated with increased morbidity and mortality. Research indicates that anterior and inferior wall myocardial infarction were the most encountered causes of blocks but with conflicting results. However, patterns of conduction blocks have not been widely established in our population. The aim was to study the various patterns of conduction blocks following ST-elevation myocardial infarction and their prognostic implications. Methods: Prospectively, 70 patients, aged > 18 years, diagnosed with ST segment elevation myocardial infarction were included in the study. Post intensive care unit admission, all patients were observed for conduction blocks using a standard 12-lead electrocardiogram and repeated the same every 48 h throughout the hospitalization stay. Statistical analysis was performed using software R version 3.6.0. Results: Out of 70 patients, 70% were males. Mean age was 60.7 ± 13.4 years. The proportion of blocks was first-degree heart block (28.6%), Mobitz II heart block (20%), complete heart block (17.1%), Mobitz I heart block (11.4%), right bundle branch block (10%), left bundle branch block (10%), left anterior hemiblock (1.4%), and trifascicular block (1.4%). No significant difference was found between males and females with respect to various conduction heart blocks (P > .05). Mortality was observed only in patients with complete heart block (11.4%) and first-degree heart block (2.8%; P = .003). Statistically, no significant difference was observed between various conduction blocks with respect to cardiac enzymes, random blood sugar and lipid levels (P > .05). Conclusions: High mortality rate has been found in the patients with complete heart block indicating that severity of conduction block is a predictor of poor outcome in the ST-elevation myocardial infarction patients. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Neurally mediated syncope (NMS) is a well‐known condition that can be subdivided into three subgroups: vasopressor type, cardioinhibitory type, and mixed type. While different degrees of sinus bradycardia occur at the time of syncope in all types, complete heart block is a rare event that can lead to pulselessness during syncope. We present a case of a 14‐year‐old girl with documented NMS before and after temporary pacemaker implantation, who had complete heart block during syncope. The patient's temporary pacemaker placement was ineffective in preventing syncope during a repeat head‐up tilt test, indicating that permanent pacing may not be effective in this patient. Midodrine, an alpha‐adrenergic agonist, was started, and the patient experienced complete control of syncope episodes without recurrence during a 2‐month follow‐up. [ABSTRACT FROM AUTHOR]

Complete heart block in women of childbearing age is rare, and incidental diagnosis during pregnancy is more uncommon. Hence, there remain no well‑established guidelines on the management of patients with complete heart block presenting in labor. Here, we present a 26‑year‑old full‑term primigravida, with no known previous cardiac history, in active labor with asymptomatic bradycardia in the 30–40s unresponsive to atropine augmentation. After multidisciplinary consultation, the decision was to proceed with delivery as planned without indication for a temporary pacemaker. The patient successfully delivered a full‑term infant via operative vaginal delivery, with an ensuing cardiac workup completed postpartum. [ABSTRACT FROM AUTHOR]

The article discusses the case of a 67-year-old woman with a 3-week history of irregular heartbeats and a significant history of three prior ablations, including for AV nodal reentrant tachycardia (AVNRT) and para-His PVCs. Her Holter ECG revealed sinus rhythm with intermittent Mobitz type 1 AV block at rest, which worsened during exercise, indicating a need for further evaluation.

Background: The impact of the His bundle location and distance from the ablation site on ablation efficacy and complication risk remains unexplored. We determined the correlation between age, height, body mass index (BMI), and the His bundle location, and whether the distance between the His bundle and ablation target (DHIS‐ABL) affects ablation safety and efficacy. Methods: Overall, 346 patients with atrioventricular nodal re‐entrant tachycardia (AVNRT) and 96 with atrioventricular re‐entrant tachycardia (AVRT) were retrospectively analyzed. The distance between the His bundle and the coronary sinus ostium (DHis‐CS), the height of the His bundle (HHIS), and DHIS‐ABL were measured. Electrocardiograms were obtained 3 months post‐ablation to assess recurrence and complications. Results: Multiple linear regression showed that HHIS was negatively correlated with age in both groups. In AVNRT patients, DHIS‐ABL was associated with age, height, and BMI; DHIS‐CS was only negatively correlated with age. In AVRT patients, there was no significant correlation between the DHIS‐ABL and age, height, or BMI. The recurrence rates in the AVNRT and AVRT groups were 0.9% and 8.7%, respectively. Subgroup analysis showed that patients with DHIS‐ABL ≤ 10 mm had a higher recurrence rate than those with DHIS‐ABL > 10 mm (p =.013). The incidence of third‐degree atrioventricular block (AVB) complications was 0.2%. Conclusions: HHIS was negatively correlated with age but not with height and BMI. The DHIS‐ABL correlated with age, height, and BMI in AVNRT patients. A short DHIS‐ABL led to a higher rate of supraventricular tachycardia recurrence; whether this affects AVB risk warrants further studies with larger sample sizes. [ABSTRACT FROM AUTHOR]

We present a case of a neonate who presented with worsening heart failure due to congenital complete atrioventricular (AV) block, secondary to maternal anti Ro/SSA and anti‐LA/SSB antibodies. The patient was implanted a temporary pacemaker in view of hemodynamic deterioration and subsequently was weaned off ionotropic support and referred for permanent epicardial pacemaker implantation. We report temporary pacemaker implantation in a neonate with hemodynamic instability as a stabilizing measure and discuss technical challenges for the same. [ABSTRACT FROM AUTHOR]

Introduction: Cardioneuroablation (CNA) has proven effectiveness in addressing hypervagotonia symptoms, such as neurocardiogenic syncope. Methods and Results: In this case, we present the first‐time application of CNA in a case of vago‐glossopharyngeal neuralgia (VGPN). A 59‐year‐old female with near‐syncope, sinus bradycardia, and sinus pauses triggered by recurrent right‐sided neck pain was diagnosed with VGPN. The patient underwent successful treatment with carbamazepine and CNA. Subsequent follow‐up revealed the sustained absence of sinus bradycardia or pauses, even upon neck pain resurgence after discontinuing carbamazepine. Conclusion: In this patient, CNA successfully prevented pauses associated with VGPN, avoiding permanent pacemaker implantation. [ABSTRACT FROM AUTHOR]

Introduction: Severe obesity presents significant challenges in imaging and delivery of therapy, including pacemaker implant. Methods and Result: We present our experience implanting a leadless pacemaker (LP) in a severely obese man presenting with heart block. We describe our multidisciplinary approach using right internal jugular venous access and transesophageal imaging in lieu of fluoroscopy which failed to provide workable images in this instance. Conclusion: Ultrasound guided LP placement may have wider application in the midst of an ongoing obesity epidemic where fluoroscopy imaging is both limited and unsafe. [ABSTRACT FROM AUTHOR]

Introduction: Early‐onset atrial fibrillation (AF) has already been observed in approximately 2% of patients with genetically proven long QT syndrome (LQTS). This frequency is higher than population‐based estimates of early‐onset AF. However, the concomitant expression of AF in LQTS is likely underestimated. The purpose of this study was to examine the clinical presentation, genetic background, and outcomes of a cohort of patients with LQTS and early‐onset AF referred to a single tertiary center. Methods: Twenty‐seven patients diagnosed with congenital LQTS were included in the study based on the documentation of early‐onset (age ≤50 years) clinical or subclinical AF episodes in all available medical records, including standard electrocardiograms, wearable monitor or cardiac implantable electronic devices. Results: Seventeen patients experienced clinical AF during the follow‐up period. Subclinical AF was detected in 10 patients through insertable or wearable cardiac monitors. In our series, the mean heart rate during AF episodes was found to be relatively low despite the patients' young age and the low or minimal effective doses of beta‐blockers used for QTc interval control. All patients exhibiting LQTS and early‐onset AF were genotype positive, carrying mutations in the KCNQ1 (66%), KCNH2, KCNE1, and SCN5A genes. Notably, most of these patients carried the same p.(R231C) mutation in the KCNQ1 gene (59%) and were from the same families, suggesting concurrent expression of familial AF and LQTS. Conclusion: LQTS patients are prone to developing clinical and subclinical AF, even at a younger age. The occurrence of early‐onset AF in the LQTS population could be more frequent than previously assumed. AF should be considered as a potential dysrhythmia related to LQTS. Our study emphasizes the importance of carefully researching clinical and/or subclinical episodes of AF through strict heart rhythm monitoring in the LQTS population. [ABSTRACT FROM AUTHOR]

Background: Severely ill patients with coronavirus disease 2019 (COVID‐19) show an increased risk of new‐onset atrioventricular blocks (AVBs), associated with high rates of short‐term mortality. Recent data suggest that the uncontrolled inflammatory activation observed in these patients, specifically interleukin (IL)‐6 elevation, may play an important pathogenic role by directly affecting cardiac electrophysiology. The aim of our study was to assess the acute impact of IL‐6 changes on electrocardiographic indices of atrioventricular conduction in severe COVID‐19. Methods: We investigated (1) the behavior of PR‐interval and PR‐segment in patients with severe COVID‐19 during active phase and recovery, and (2) their association with circulating IL‐6 levels over time. Results: During active disease, COVID‐19 patients showed a significant increase of PR‐interval and PR‐segment. Such atrioventricular delay was transient as these parameters rapidly normalized during recovery. PR‐indices significantly correlated with circulating IL‐6 levels over time. All these changes and correlations persisted also in the absence of laboratory signs of cardiac strain/injury or concomitant treatment with PR‐prolonging drugs, repurposed or not. Conclusions: Our study provides evidence that in patients with severe COVID‐19 and high‐grade systemic inflammation, IL‐6 elevation is associated with a significant delay of atrioventricular conduction, independent of concomitant confounding factors. While transient, such alterations may enhance the risk of severe AVB and associated short‐term mortality. Our data provide further support to current anti‐inflammatory strategies for severe COVID‐19, including IL‐6 antagonists. [ABSTRACT FROM AUTHOR]

Background Atrioventricular block is common with adult congenital heart disease and pacemaker implantation is challenging. Atrioventricular synchronous pacing is important for better haemodynamics. This case reports the implantation of a dual-chamber leadless pacemaker in a patient with univentricular heart physiology and contributes to the literature regarding the management option in complex adult congenital heart disease patients with conduction abnormalities. Case summary A 25-year-old male with double inlet left ventricular, transposition of great arteries, hypoplastic aortic arch receive multiple surgeries including the Glenn shunt at the age of 1. He presented with 2:1 and 3:1 heart block at the age of 13 with a transvenous dual-chamber pacemaker implanted by pacing the superior vena cava stump and puncturing the Glenn shunt for the ventricular lead. A decade later, lead malfunctioned and the patient progressed to complete heart block. A subcutaneous implantable cardioverter defibrillator was implanted when he was 23 for monomorphic ventricular tachycardia. Given the anticipated challenges with transvenous lead extraction and epicardial pacemaker implantation, we implanted the novel dual-chamber leadless pacemakers which resulted in satisfactory atrioventricular synchronous pacing performance immediately post-op and 2 weeks after the procedure. Discussion We present a case of a novel dual-chamber leadless pacemaker implantation to maintain atrioventricular synchrony in the patient with complete heart block and univentricular physiology. This case illustrates an additional pacing option in complex adult congenital heart to maintain atrioventricular synchrony. [ABSTRACT FROM AUTHOR]

Background. Left ventricular hypertrabeculation (LVHT) is a myocardial disorder with different clinical manifestations, from total absence of symptoms to heart failure, arrhythmias, sudden cardiac death (SCD), and thromboembolic events. It is challenging to distinguish between the benign and pathological forms of LVHT. The aim of this study was to describe the arrhythmic manifestations of LVHT in a large group of pediatric patients and to correlate them with genetic results or other clinical markers. Methods. We retrospectively enrolled 140 pediatric patients with diagnosis of LVHT followed at our Institution from 2013 to 2023. Data regarding family history, instrumental exams, cardiac magnetic resonance, genetic testing and outcomes were collected. Most of them had isolated LVHT (80.7%); in other patients, mixed phenotypes (hypertrophic or dilated cardiomyopathy or congenital heart disease) were present. Results. Arrhythmias were found in 33 children (23.6%): 13 (9.3%) supraventricular tachyarrhythmias; 14 (10%) ventricular arrhythmias (five frequent PVCs (premature ventricular contractions), eight patients with ventricular tachycardia (VT), one ventricular fibrillation (VF)); two (1.4%) sinus node disfunctions; two (1.4%) complete atrio-ventricular blocks (AVB), three (2.1%) paroxysmal complete AVB, one (0.7%) severe I degree AVB. Three patients received an ICD (implantable cardioverter defibrillator). Comparison between LVHT patients with (33 pts) and without (107 pts) arrhythmias as regards genetic testing showed a statistical significance for the presence of class 4 or 5 genetic variants and arrhythmic manifestation (p = 0.037). Conclusions. In our pediatric cohort with LVHT, good outcomes were observed, but arrhythmias were not so rare (23.6%); no SCD occurred. [ABSTRACT FROM AUTHOR]

Objective: Congenital defects/diseases Background: In the last 2 decades, the use of bioprosthetic valves for surgical aortic valve replacements has surged, now accounting for over 85% of all such surgeries. However, their limited durability has led to an increase in aortic valve reoperations and re-interventions. Here, we describe a unique case involving a patient with severe aortic regurgitation and cardiogenic shock, caused by a bioprosthetic aortic valve with a flail leaflet, which was replaced via a surgical approach. Case Report: A 58-year-old man with a history of atrial fibrillation, stent placement in the left anterior descending artery, and 2 aortic valve replacements presented to the Emergency Department with severe chest pain and shortness of breath. A chest X-ray showed significant pulmonary vascular and interstitial congestion, and cardiac catheterization displayed nonobstructive coronary artery disease. A transesophageal echocardiogram (TEE) revealed severe regurgitation in the prosthetic aortic valve, resulting in the patient being sent for emergency aortic valve replacement. An intraoperative TEE showed evidence of prosthetic valve failure with complete prolapse of the noncoronary cusp. The prosthetic aortic valve's noncoronary cusp leaflet was found flailing into the left ventricular outflow tract, while the other 2 leaflets seemed normal. The valve was replaced and a new Medtronic Avalus size 27 mm valve was seated. Postoperatively, the patient developed a complete heart block requiring placement of a permanent dual-chamber pacemaker. Conclusions: Flailed leaflets in bioprosthetic aortic valves are a rare complication of aortic valve replacement. Redo surgical valve replacement is a viable treatment for bioprosthetic failure due to leaflet flail. [ABSTRACT FROM AUTHOR]

Implantable loop recorders (ILRs) are increasingly used to evaluate patients with unexplained syncope. Identification of all predictors of bradycardic syncope and consequent permanent pacemaker (PPM) insertion is of substantial clinical interest as patients in the highest risk category may benefit from upfront pacemaker insertion. We performed a systematic review and meta-analysis to identify risk predictors for PPM insertion in ILR recipients with unexplained syncope. An electronic database search (MEDLINE, Embase, Scopus, Cochrane) was performed in June 2023. Studies evaluating ILR recipients with unexplained syncope and recording risk factors for eventual PPM insertion were included. A random effects model was used to calculate the pooled odds ratio (OR) for clinical and electrocardiographic characteristics with respect to future PPM requirement. Eight studies evaluating 1007 ILR recipients were included; 268 patients (26.6%) underwent PPM insertion during study follow-up. PPM recipients were older (mean age, 70.2 ± 15.4 years vs 61.6 ± 19.7 years; P <.001). PR prolongation on baseline electrocardiography was a significant predictor of PPM requirement (pooled OR, 2.91; 95% confidence interval, 1.63–5.20). The presence of distal conduction system disease, encompassing any bundle branch or fascicular block, yielded a pooled OR of 2.88 for PPM insertion (95% confidence interval, 1.53–5.41). Injurious syncope and lack of syncopal prodrome were not significant predictors of PPM insertion. Sinus node dysfunction accounted for 62% of PPM insertions, whereas atrioventricular block accounted for 26%. Approximately one-quarter of ILR recipients for unexplained syncope require eventual PPM insertion. Advancing age, PR prolongation, and distal conduction disease are the strongest predictors for PPM requirement. [Display omitted] [ABSTRACT FROM AUTHOR]

Background ICI-associated myocarditis is a rare but severe and potentially life-threatening complication that typically manifests shortly after treatment initiation. It may present in many different ways, ranging from fulminant to non-fulminant, even including clinical and electrocardiographic findings mimicking ST-elevation Myocardial Infarction (STEMI). Case summary A 72-year-old woman with a history of non-small cell lung carcinoma presented at the emergency department with symptoms of general asthenia and chest pain, following recent ICI-therapy initiation. Electrocardiogram showed ST elevation in the lateral leads and led to prompt admission for urgent invasive coronary angiography, which ruled out significant coronary artery disease. Urgent cardiac magnetic resonance had to be aborted due to claustrophobia. Endomyocardial biopsy—performed the day after urgent hospital admission and before starting high-dose corticosteroids—confirmed acute ICI-associated myocarditis. On the sixth day of hospitalization, the patient developed transient complete heart block and non-sustained ventricular tachycardia, necessitating temporary transjugular pacemaker insertion. Cellcept (mycophenolate mofetil) was associated due to rising troponin levels. Following a three-week hospital stay, the patient was discharged with a regimen of gradually tapering steroids and continued Cellcept therapy. Two months post-discharge, the patient was readmitted due to severe pneumonia, ultimately resulting in the patient's demise. Discussion We present the case of a fulminant ICI-associated myocarditis. The case illustrates the diagnostic workup and treatment strategies of an (in the end) fatal adverse event from the use of immune checkpoint inhibitors. [ABSTRACT FROM AUTHOR]