Repeated complete atrioventricular block during remifentanil administration in a pediatric patient with brain tumor and acute hydrocephalus: a case report.

BACKGROUND: Remifentanil, an ultra-short-acting µ-opioid receptor agonist, is commonly used for anesthetic management due to excellent adjustability. Remifentanil is known to cause sinus bradycardia, however, because it has a direct negative chronotropic effect on the cardiac conduction system and there is an indirect negative chronotropic effect via the parasympathetic nervous system. CASE PRESENTATION: An 8-year-old Japanese boy was diagnosed with acute hydrocephalus due to a brain tumor in the fourth ventricle and underwent emergency surgery. Imaging examination showed brainstem compression. Endoscopic third ventriculostomy and ventriculoperitoneal shunt surgery were scheduled. Remifentanil was started during induction of general anesthesia, but electrocardiogram showed sinus bradycardia, then Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was immediately discontinued, and we administered atropine sulfate. Complete atrioventricular block was restored to sinus rhythm. When remifentanil was restarted, however, the electrocardiogram again showed sinus bradycardia, Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was again immediately discontinued, we administered adrenaline, and then complete atrioventricular block was restored to sinus rhythm. Fentanyl was used instead of remifentanil with continuous infusion of dopamine. There has since been no further occurrence of complete atrioventricular block. CONCLUSIONS: This is the first known case of complete atrioventricular block in a pediatric patient with increased intracranial pressure seemingly caused by administration of remifentanil.

Misinterpretation of sleep-induced second-degree atrioventricular block.

A number of publications have claimed that Mobitz type II atrioventricular block (AVB) may occur during sleep. None of the reports defined type II AVB and representative electrocardiograms were either misinterpreted or missing. Relatively benign Wenckebach type I AVB is often misdiagnosed as Mobitz type II which is an indication for a pacemaker. Review of the published reports indicates that Mobitz type II AVB does not occur during sleep when it is absent in the awake state. Conclusion: There is no proof that sleep is associated with Mobitz type II AVB.

Navigating challenges: Cleidocranial dysplasia and complexities in transvenous pacemaker implantation.

Cleidocranial dysplasia (CCD) is a rare genetic disorder characterized by skeletal abnormalities, including hypoplastic or absent clavicles, delayed closure of cranial sutures, and dental anomalies. We present a case of a 72-year-old female with a history of breast cancer treated with mastectomy and radio chemotherapy with the port-a catheter still in place in the left subclavian region. She presented to the emergency room with syncope related to a complete atrioventricular (AV) block. The patient underwent temporary pacing via femoral access while awaiting definitive pacemaker implantation. The absence of the right clavicle, first observed during prepuncture fluoroscopy and later confirmed on postprocedure imaging, significantly influenced the approach to pacemaker implantation. Venography played a crucial role in visualizing the venous trajectory and guiding the puncture, ensuring successful lead placement. The procedural challenges encountered due to the patient's skeletal anomalies highlight the importance of individualized approach and careful consideration of anatomical variations in interventional cardiology procedures.

Cardiac Involvement in LAMA2-Related Muscular Dystrophy and SELENON-Related Congenital Myopathy: A Case Series.

Background: LAMA2-related muscular dystrophy (LAMA2-MD) and SELENON-related myopathy (SELENON-RM) are two rare neuromuscular diseases characterized by proximal and axial muscle weakness, scoliosis, spinal rigidity, low bone quality and respiratory impairment. Cardiac involvement has previously been described in retrospective studies and case reports, but large case series and prospective studies in unselected cohorts are lacking. Objective: The objective of this study is to conduct prevalence estimations, perform cardiac phenotyping, and provide recommendations for clinical care. Methods: In this case series including two time points, we conducted comprehensive assessments with electrocardiography (ECG) and transthoracic echocardiography (TTE). ECGs were systematically assessed for a large subset of variables. TTE included left and right ventricular ejection fraction (LVEF/RVEF) and left ventricular global longitudinal strain (GLS), the latter being a more early and sensitive marker of left ventricular dysfunction. Results: 21 LAMA2-MD (M = 5; 20±14 years) and 10 SELENON-RM patients (M = 7; 18±12 years) were included. In most patients, QRS fragmentation and Q waves, markers of heterogeneous ventricular activation, were present both at baseline and at follow-up. GLS was abnormal (age specific in children, > -18% in adults) in 33% of LAMA2-MD and 43% of SELENON-RM patients at baseline. Reduced LVEF (<52% in males, <54% in females and <55% in pediatric population) was observed in three LAMA2-MD patients at baseline and in none of the SELENON-RM patients. GLS and LVEF did not change between baseline and follow-up. RVEF was normal in all patients. Conclusion: ECG abnormalities and abnormal GLS are prevalent in LAMA2-MD and SELENON-RM, yet abnormal LVEF was only seen in LAMA2-MD patients. One LAMA2-MD patient had a clinically relevant deterioration in LVEF during 1.5-year follow-up. We advise routine screening of all patients with LAMA2-MD or SELENON-RM with ECG and echocardiography at diagnosis, minimally every two years from second decade of life and if new cardiac signs arise.

[Arrhythmias in sarcoidosis]. / Arrhythmien bei Sarkoidose.

Cardiac sarcoidosis (CS) is difficult to diagnose and often requires a careful evaluation of numerous diagnostic findings. Typical features at initial presentation are a high-grade atrioventricular (AV) block and ventricular tachycardias that cannot be explained by other common entities, especially in younger patients. CS is frequently misdiagnosed and inappropriately treated, which may have deleterious consequences for the patients. In this review article, we focus on special features of the arrhythmias typical of sarcoidosis and also discuss the underlying substrate and the approach in special situations. Furthermore, we provide recommendations from our daily clinical experience, discuss open questions, and explain the need for research.

Case Report: Bradycardia in neonatal lupus: differential diagnosis between atrioventricular block and premature atrial contractions with block.

Neonatal lupus may be associated with severe cardiac conduction problems, including high-degree or complete atrioventricular (AV) block, necessitating immediate pacemaker implantation during the neonatal period. However, cardiac manifestations of neonatal lupus may extend beyond AV block. Our case was a full-term female neonate, who presented with fetal arrhythmia and bradycardia with a heart rate of approximately 70-75 beats per minute after birth. Neonatal lupus was diagnosed later due to positive maternal and neonatal anti-SSA/Ro antibody. High-degree AV block was considered initially but bigeminy premature atrial contractions (PACs) with block was confirmed through a detailed evaluation of an electrocardiogram, which demonstrated unfixed PP intervals and fixed RR intervals. Atrial tachycardia (AT) developed when the neonate was 23 days old. The key point that differentiates high-degree AV block from PACs with block is the PP interval. The PP interval is fixed in high-degree AV block and unfixed in PACs with block. Careful differential diagnosis is required in neonates with bradycardia because it may lead to very different management. Our case presents a good illustration of why these arrhythmias need to be differentiated. Furthermore, our case may be the first of neonatal lupus with AT.

Systematic review and meta-analysis on the impact on outcomes of device algorithms for minimizing right ventricular pacing.

AIMS: Physiological activation of the heart using algorithms to minimize right ventricular pacing (RVPm) may be an effective strategy to reduce adverse events in patients requiring anti-bradycardia therapies. This systematic review and meta-analysis aimed to evaluate current evidence on clinical outcomes for patients treated with RVPm algorithms compared to dual-chamber pacing (DDD). METHODS AND RESULTS: We conducted a systematic search of the PubMed database. The predefined endpoints were the occurrence of persistent/permanent atrial fibrillation (PerAF), cardiovascular (CV) hospitalization, all-cause death, and adverse symptoms. We also aimed to explore the differential effects of algorithms in studies enrolling a high percentage of atrioventricular block (AVB) patients. Eight studies (7229 patients) were included in the analysis. Compared to DDD pacing, patients using RVPm algorithms showed a lower risk of PerAF [odds ratio (OR) 0.74, 95% confidence interval (CI) 0.57-0.97] and CV hospitalization (OR 0.77, 95% CI 0.61-0.97). No significant difference was found for all-cause death (OR 1.01, 95% CI 0.78-1.30) or adverse symptoms (OR 1.03, 95% CI 0.81-1.29). No significant interaction was found between the use of the RVPm strategy and studies enrolling a high percentage of AVB patients. The pooled mean RVP percentage for RVPm algorithms was 7.96% (95% CI 3.13-20.25), as compared with 45.11% (95% CI 26.64-76.38) of DDD pacing. CONCLUSION: Algorithms for RVPm may be effective in reducing the risk of PerAF and CV hospitalization in patients requiring anti-bradycardia therapies, without an increased risk of adverse symptoms. These results are also consistent for studies enrolling a high percentage of AVB patients.

Temporary-Permanent Pacemakers in the Management of Conduction Abnormalities in Patients Undergoing Transcatheter Aortic Valve Replacement.

Background: Injury to the cardiac conduction system requiring a permanent pacemaker (PPM) implantation is a known adverse outcome of transcatheter aortic valve replacement (TAVR). Temporary-permanent pacemakers (TPPM) have been used as a bridge to PPM implantation in patients with systemic infection; however, there are only a few reports of its routine use in patients undergoing TAVR. This study aimed to assess the utility of routine use of TPPM in patients undergoing TAVR with a high risk of needing a PPM or those who develop high-grade conduction abnormalities during/after TAVR. Methods: Between April 2015 and December 2021, 978 patients underwent TAVR at our institution, of whom 111 patients had TPPM placed before or during/after TAVR during the study period. In total, 89 patients were included in the final analysis. Results: The median age was 78 years (IQR, 71-84 years); 52 (58.4%) patients with preexisting native conduction disease were considered high risk for advanced heart block and had TPPM placed before TAVR. In addition, 37 (41.6%) patients had TPPM placed during/after TAVR. Of the 89 patients who received TPPM, 51 (57.3%) were treated with a balloon-expandable valve and 38 (42.7%) with a self-expandable valve. Of the patients who underwent TPPM placement, only 49 (55.1%) required a PPM, and TPPM was removed in 40 (44.9%) patients. TPPM was in place for a median of 6 days (IQR, 2-11 days). Only 1 of the 89 patients (1.1%) who received a TPPM had lead dislodgment. No other complications were noted. Median length of stay was 3 days (IQR, 2-4 days). Conclusions: In patients with high-risk baseline conduction abnormalities before TAVR and those who develop new high-grade conduction abnormalities during/after TAVR, TPPM provides a feasible and safe method for pacing that could allow early ambulation, facilitate early discharge, and prevent unnecessary PPM implantations in some patients.

Cardioneuroablation: the known and the unknown.

Cardioneuroablation (CNA) is a novel interventional procedure for the treatment of recurrent vasovagal syncope (VVS) and advanced atrioventricular block secondary to hyperactivation of vagal tone in young patients. By damaging the cardiac parasympathetic ganglia, CNA seems to be able to mitigate and/or abolish the excessive vagal activity and improve patients' outcome. This review is intended to give a detailed and comprehensive overview of the current evidences regarding (1) the clinical applications of CNA (2) the identification of ablation targets and procedural endpoints (3) the medium-long term effect of the procedure and its future perspectives. However, clinical data are still limited, and expert consensus or recommendations in the guidelines regarding this technique are still lacking.

Implantable cardiac monitor and leadless pacemaker in the management of syncope due to intermittent high-degree atrioventricular block: a case report.

BACKGROUND: Lead dislodgements, tricuspid valve failure, and wound infections are prominent issues addressed by leadless pacemakers (LPM). These devises have emerged as viable alternatives to conventional transvenous pacemakers. LPMs offer minimized complications and effective pacing, particularly beneficial for elderly patients with a low body mass index (BMI) who are at heightened infection of risk. The Micra AV leadless pacemaker was released in the US in 2020, featuring a VDD pacing mode akin to conventional pacemakers. It senses atrial activity to pace ventricular beats while maintaining the natural atrioventricular activation sequence. Micra AV achieves atrioventricular synchronization through mechanical sensing principles. Ongoing research aims to assess its efficacy, implantation feasibility, and clinical safety. CASE PRESENTATION: An 83-year-old man with a history of syncope was the focus of this case study. An implantable cardiac monitor (ICM) recorded occasional high-degree atrioventricular block in the patient. Subsequently, the Micra AV was implanted via the left femoral vein, and its settings were adjusted in accordance with data obtained from the ICM. No significant issues regarding pacing threshold or impedance were found during the follow-up examinations post-surgery. Importantly, the patient experienced a noticeable reduction in symptoms compared to before the implantation. DISCUSSION: This case underscores the significance of ICM monitoring in elucidating cardiac events leading to syncope and guiding appropriate treatment. It also highlights the successful outcomes and reliable implantation of the Micra AV for managing high-degree atrioventricular block. This study contributes to the growing body of evidence supporting the adoption of leadless pacemakers as a viable option for patients requiring cardiac pacing, particularly those vulnerable to complications associated with traditional pacemakers. It provides real-world evidence of Micra AV's efficacy and safety, further validating its role in clinical practice.

Clinical Characteristics and Comparative Proteomics Analysis of COVID-19-Related Atrioventricular Block.

Background: Atrioventricular block (AVB) is thought to be a rare cardiovascular complication of the coronavirus disease 2019 (COVID-19), though limited data are available beyond case reports. We aim to describe the baseline characteristics, proteomics profile, and outcomes for patients with COVID-19-related AVB. Methods: We prospectively recruited patients diagnosed with COVID-19-related AVB between November 2022 and March, 2023. Inclusion criteria were hospitalization for COVID-19 with the diagnosis of AVB. A total of 24 patients diagnosed with COVID-19 without AVB were recruited for control. We analyzed patient characteristics and outcomes and performed a comparative proteomics analysis on plasma samples of those patients and controls. Results: A total of 17 patients diagnosed with COVID-19-related AVB and 24 individuals diagnosed with COVID-19 infection without AVB were included. Among patients with COVID-19-related AVB, the proportion of concurrent pneumonia was significantly higher than controls (7/17 versus 2/24, p < 0.05). All 17 AVB patients (9 of permanent AVB, 8 of paroxysmal AVB) received permanent pacemaker implantation. No procedural-related complication occurred. In laboratory tests, the level of biomarkers indicating myocardial damage were substantially higher than controls, including high-sensitivity cardiac troponin-I (median 0.005 versus 0.002 ng/mL, p < 0.05), myoglobulin (median 39.0 versus 27.6 ng/mL, p < 0.05), and MB isoenzyme of creatine kinase (median 1.2 versus 0.8 U/L, p < 0.05). The level of N-terminal pro-b-type natriuretic peptide (median 241.0 versus 33.5 pg/mL, p < 0.05), C-reactive protein (median 4.8 versus 2.0 mg/L, p < 0.05), D-dimer (median 1.2 versus 0.2 µg/mL, p < 0.05), left ventricular end-diastolic diameter (median 49.3 versus 45.7 mm, p < 0.05) in patients with COVID-19-related AVB were significantly higher than controls. The level of albumin (median 41.9 versus 44.5 g/L, p < 0.05) was significantly lower than controls. In comparative proteomics analysis, we identified 397 human proteins. Several significantly altered plasma proteins related to inflammatory response (Serum amyloid A protein, C-reactive protein, Protein Adenosine 5'-monophosphate-activated protein kinase (AMPK), Alpha-2-macroglobulin), complement and coagulation cascades (Tetranectin, haptoglobin), and immune response (Neutrophil defensin 3, Fibrinogen beta chain) may contribute to the pathogenesis of COVID-19-related AVB. Conclusions: Patients with COVID-19-related AVB are more prone to have myocardial damage and concurrent pneumonia. Through laboratory tests and comparative proteomics analysis, we identified several differential expressed proteins (Serum amyloid A protein, Tetranectin, Neutrophil defensin 3) releated to the inflammatory response, complement and coagulation cascades, and immune response, which provides evidence of potential biomarkers and sheds light on the pathogenesis of COVID-19-related AVB.

Temporary Transvenous Pacemaker for the Treatment of Diphtheria Myocarditis and Progressive Conduction Block: A Case Report.

A case of severe respiratory diphtheria complicated by myocarditis is reported. Diphtheria myocarditis manifested as cardiogenic shock and progressive conduction disturbance. Temporary transvenous ventricular pacing was used to manage this complication successfully. However, this patient died from cardiogenic shock. This case highlights that sporadic cases of diphtheria still occur despite high vaccination rates in Saudi Arabia. Conduction abnormalities in diphtheria myocarditis carry a prognostic marker for the severity of cardiac injury.

Characterization of remodeling processes in the atria of atrioventricular block dogs: Utility as an early-stage atrial fibrillation model.

To characterize utility of atrioventricular block (AVB) dogs as atrial fibrillation (AF) model, we studied remodeling processes occurring in their atria in acute (<2 weeks) and chronic (>4 weeks) phases. Fifty beagle dogs were used. Holter electrocardiogram demonstrated that paroxysmal AF occurred immediately after the production of AVB, of which duration tended to be prolonged in chronic phase. Electrophysiological analysis showed that inter-atrial conduction time and duration of burst pacing-induced AF increased in the chronic phase compared with those in the acute phase, but that atrial effective refractory period was hardly altered. Echocardiographic study revealed that diameters of left atrium, right pulmonary vein and inferior vena cava increased similarly in the acute and chronic phases. Histological evaluation indicated that hypertrophy and fibrosis in atrial tissue increased in the chronic phase. Electropharmacological characterization showed that i.v. pilsicainide effectively suppressed burst pacing-induced AF with increasing atrial conduction time and refractoriness of AVB dogs in chronic phase, but that i.v. amiodarone did not exert such electrophysiological effects. Taken together, AVB dogs in chronic phase appear to possess such pathophysiology as developed in the atria of early-stage AF patients, and therefore they can be used to evaluate drug candidates against early-stage AF.

Mid-term clinical outcomes of left bundle branch area pacing compared to accurate right ventricular septal pacing.

BACKGROUND: Although left bundle branch area pacing (LBBAP) reportedly results in fewer adverse outcomes after implantation than conventional stylet-guided right ventricular septal pacing (RVSP), previous studies have not compared LBBAP with accurate RVSP using a delivery catheter. The aim of this study was to compare clinical outcomes between LBBAP and accurate RVSP among patients with atrioventricular block (AVB). METHODS: This single-center observational study enrolled 160 patients requiring RV pacing due to symptomatic AVB between September 2018 and December 2021. Primary composite outcomes included all-cause death, hospitalization due to heart failure (HF), and upgrading to biventricular pacing. Secondary composite outcomes included any procedural and postprocedural complications. RESULTS: Overall, 160 patients were analyzed (LBBAP, n = 81; RVSP, n = 79). No significant differences in baseline characteristics were observed between the two groups. The RV pacing burden at 1 year after implantation was 90.8% ± 20.4% and 86.2% ± 22.6%, respectively (p = 0.21). During a mean follow-up of 840 ± 369 days, the incidence of the primary outcome was significantly lower with LBBAP (4.9%) compared to RVSP (22.8%) (Log-rank p = 0.02). There was no significant difference in the incidence of the secondary outcome between the two groups (3.7% vs. 5.1%, p = 0.65). In the multivariate analysis, baseline QRS duration, RV pacing burden, and LBBAP were independently associated with the primary outcome (baseline QRS duration: hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00-1.02; p < 0.001; RV pacing burden: HR, 1.01; 95% CI, 1.00-1.02; p < 0.001; LBBAP: HR, 0.45; 95% CI, 0.31-0.64; p < 0.001). CONCLUSION: In patients requiring frequent RV pacing, LBBAP was associated with reduced adverse clinical outcome compared to accurate RVSP using a delivery catheter.

Incidental Findings of Congenital Unileaflet Mitral Valves in Young Patient Presenting Complete Atrioventricular Block.

The singular leaflet mitral valve is a rare and complex entity that has been described in only a few case reports. It is commonly observed in infancy and combined with symptomatic mitral regurgitation (MR). In most asymptomatic individuals, this complication is attributed mainly to a hypoplastic posterior mitral leaflet and is usually revealed in adulthood. We present the case of a 30-year-old man who presented with chest pain and dyspnea for two days. The electrocardiogram showed complete atrioventricular block with a beat rate of 30 bpm. Echocardiography revealed an elongated anterior mitral valve leaflet and an almost completely absent posterior mitral valve leaflet with no MR. Our case is unusual presentation of a unileaflet mitral valve that should be investigated even in adulthood as these patients are likely to be at risk of developing or worsening MR later in life; hence, performing periodic echocardiograms is important for detecting the progression of MR early.