Advanced Atrioventricular Block Research Articles

Association between Preeclampsia and Long-term Risk of Arrhythmias.

Preeclampsia (PE), a pregnancy-induced hypertensive disorder, affects 4-5% of pregnancies worldwide. It is well known that hypertension is associated with an increased risk of arrhythmias; however, data on the association between PE and arrhythmias are sparse. In this observational cohort study, we identified all primiparous women who gave birth in Denmark (1997-2016) using Danish nationwide registries. The women were stratified on whether they developed PE during primiparous pregnancy, and followed from primiparous pregnancy to incident arrhythmia, emigration, death, or end of study (December 31, 2018). A total of 523,271 primiparous women with a median age of 28 years were included and 23,367 (4.5%) were diagnosed with PE. During a median follow-up of 10.1 years, women with vs without PE were associated with a higher incidence of arrhythmias (1.42% vs 1.02%): 1) Composite of cardiac arrest, ventricular tachycardia/fibrillation, or ICD implantation (adjusted HR 1.60 [95% CI 1.14-2.24]), 2) Composite of advanced 2nd degree or 3rd degree atrioventricular block, sinoatrial dysfunction, or pacemaker implantation (adjusted HR 1.48 [95% CI 0.97-2.23]), 3) Composite of supraventricular tachyarrhythmias or extra systoles (adjusted HR 1.34 [95% CI 1.19-1.51]), 4) Composite of all the above-mentioned arrhythmias (adjusted HR 1.37 [95% CI 1.23-1.54]). Preeclamptic women were associated with a significantly and at hitherto unknown long-term increased rate of arrhythmias. This finding suggests that women with PE may benefit from cardiovascular risk assessment, screening, and preventive education.

Ten-year prognosis of acute atrial fibrillation in ST-elevation myocardial infarction: recurrence and stroke risk

Abstract Funding Acknowledgements None. Background Atrial fibrillation (AF) often complicates ST elevation acute myocardial infarction (STEMI), with associated risks including stroke and mortality. Anticoagulation therapy for these patients and AF prognosis remains controversial. The aim was to evaluate long-term prognosis of STEMI patients complicated with AF in the acute phase. Methods We performed a prospective register involving 4,184 patients admitted for STEMI to the intensive cardiac care unit of two tertiary centres from 2007 to 2015. Patients with pre-existing permanent AF were excluded. Out of these, 269 (6.4%) patients developed AF within the first 48 hours after STEMI and were matched with a control group based on age and left ventricular ejection fraction (LVEF). Results After matching, a total of 470 patients were included (n=235, AF-STEMI; n=235, control group). Mean age 69.0 years, and 31.7% women. No differences were found in gender, cardiovascular risk factors or ischemic heart disease. AF-STEMI patients experienced more sustained ventricular tachycardia (12.8% vs. 4.7%; p=0.003), advanced atrioventricular block (13.2% vs. 6.0%; p=0.012), heart failure (28.5% vs. 18.7%; p=0.017), and cardiogenic shock (17.4% vs. 8.5%; p=0.006). In-hospital mortality was also higher in AF-STEMI patients (11.9% vs 7.2%, p=0.008). After 10-years follow-up, the AF-STEMI group had remained with higher mortality (50.5% vs. 36.2%; p=0.003) and a greater recurrence of AF (44.2% vs. 14.7%; p<0.001), without differences in stroke incidence (10.1% vs. 9.3%). Conclusion Patients with AF complicating STEMI have higher rates of heart failure, cardiogenic shock, and in-hospital mortality. After a 10-years follow up, they exhibit a high risk of AF recurrence, with no significant differences in stroke incidence.Kaplan Meier curves

Direct vs. staged TAVI in the acute management of decompensated severe aortic stenosis

Abstract Funding Acknowledgements None. Background Transcatheter aortic valve implantation (TAVI) has emerged as a preferred treatment for severe aortic stenosis across a spectrum of surgical risks, potentially diminishing the role of balloon aortic valvuloplasty (BAV) as a transient solution or a bridge to definitive intervention. With advancements in TAVI technology and expertise, patients even in unstable conditions are increasingly receiving direct, definitive TAVI, avoiding the risks associated with staged, multiple procedures. Aims The study set out to assess whether immediate TAVI is safer and more effective than BAV followed by elective aortic valve replacement (AVR) in acute severe aortic stenosis. Methods Conducted as a retrospective analysis at a single center, this study encompassed a cohort of consecutive patients who received either urgent or emergency BAV, as bridge to AVR, or TAVI to manage decompensated severe aortic stenosis from May 2012 to May 2023. The primary outcomes were mortality rates at both 30 days and one year following the procedures. Results In this cohort, 258 cases of urgent or emergent percutaneous aortic valvuloplasty were evaluated. BAV was performed in 47 patients, whereas 211 received direct TAVI. A significantly higher proportion of the BAV group (36%) was treated due to cardiogenic shock as the primary indication, compared with just 11% in the TAVI group (p< 0.001). Demographic parameters and comorbid condition profiles were equivalently balanced across both groups. The median age was 81 years (interquartile range: 74-85, p= 0.40), and males constituted 56% of the patient population (p= 0.72). Most patients (65%) presented with left ventricular systolic dysfunction, and nearly half (49%) were diagnosed with obstructive coronary artery disease. The reduction in peak aortic valve gradient was significantly more pronounced in the TAVI group (-56±25 mmHg) compared to the BAV group (-27±19 mmHg, p< 0.001). TAVI recipients also had a higher incidence of VARC-2 minor and major bleeding events (26% versus. 6% for BAV, p<0.001), and a greater occurrence of advanced atrioventricular block necessitating temporary pacing (19% vs. 9% for BAV, p= 0.02). Thirty-day survival rates favored the TAVI group (93%) over BAV (86%). This trend persisted at the one-year mark, with survival rates of 84% for TAVI and 70% for BAV. Furthermore, the one-year hazard ratio for mortality among patients undergoing BAV was 2.01 (95% confidence interval: 1.34–3.01, p< 0.001). Conclusion The data from this retrospective analysis indicate that for patients with decompensated severe aortic stenosis, immediate TAVI may confer a mortality benefit over BAV followed by elective procedures. Despite a higher rate of procedural complications, the direct TAVI approach was associated with better survival rates at both 30 days and one year. These outcomes suggest a potential reevaluation of treatment strategies in acute settings may be warranted.

Paced QRS morphology mimicking complete left bundle branch block induced by right ventricular pacing is associated with pacing-induced cardiomyopathy.

Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing-induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development. We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB-like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%. Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB-like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89-0.98, p = 0.006) and CLBBB-like paced QRS (OR: 2.69, 95% CI: 1.25-5.76, p = 0.011) were significantly associated with PICM development. CLBBB-like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB-like QRS morphology, may need to be avoided, and patients with CLBBB-like paced QRS should be followed-up carefully.

Atrioventricular block secondary to transient causes and long-term recurrence after an index event.

Atrioventricular block (AVB) secondary to transient causes can recover with its correction. However, studies assessing predictors of recovery and long-term recurrence are lacking. Patients with advanced or complete AVB who had a reversible cause admitted in a single expert center were retrospectively studied. Patients with AVB secondary to acute coronary syndromes were excluded from analysis. In a population of 162 patients, the main factors associated with recovery of rhythm without a permanent pacemaker (PPM) implantation were the presence of chronic kidney disease (CKD) on dialysis (OR 7.6; CI 95% 1.2-47.5 (p=.03)); greater serum potassium levels (OR 2.3; CI 95% 1.28-4.0 (p<.01)), higher dosage of bradycardic drugs (OR 2.2; CI 95% 1.13-4.4 (p=.02)), the association between different bradycardic drugs (OR 9.0; CI 95% 2.02-40.3 (p<.01)) and between drug therapy and hyperkaliemia (OR 5.2; CI 95% 1.8-15.1 (p<.01)). There was an overall high burden of conductions abnormalities which did not correlate with recovery of rhythm (OR 0.5; CI 95% 0.19-1.5 (p=.23)). In 29 patients (17.9%) there was a correction of the AVB. During a maximum follow-up of 130 months, 24 patients (82.8%) had a recurrence which warranted a PPM. In the overall cohort only five patients (3%) had sustained recovery of rhythm. Recovery of AVB was mainly observed with higher doses of drug therapy, higher serum potassium levels or a combination of factors and regardless of baseline conduction abnormalities. The high rate of recurrence during follow-up warrants a close follow-up or PPM implantation at index admission.

Impact of the Tricuspid Valve Detachment Technique on Hard-to-Expose Ventricular Septal Defect Closure

Ventricular septal defect (VSD) closure is a common procedure in congenital heart surgery. The exposure of VSDs can be challenging, especially in cases involving the tricuspid septal or anterior leaflets, chordae, or subvalvular apparatus. Although tricuspid valve detachment has been suggested to improve surgical visibility, its long-term effects remain unclear. Herein, we investigated the outcomes of VSD closure with or without tricuspid valve detachment and assessed the impact of this technique on postoperative tricuspid valve function and atrioventricular conduction. In total, 175 patients who underwent isolated VSD closure through the right atrium were retrospectively enrolled and divided into 2 groups: the tricuspid valve detachment group (n = 17, 9.7%) and the nontricuspid valve detachment group (n = 158, 90.3%). Patient characteristics were comparable between the two groups, and medical records and echocardiography reports were reviewed for each patient. The primary outcomes were mortality and reoperation, whereas the secondary outcomes included residual VSD, tricuspid valve regurgitation, advanced atrioventricular block, and aortic valve regurgitation. Clinical variables were compared between the two groups. Overall, tricuspid valve detachment did not increase perioperative complications or affect long-term tricuspid valve function. There were no cases of mortality or reoperation in either group. Although the tricuspid valve detachment group had longer bypass and cross-clamp times, this did not significantly affect ventilation or intensive care unit stay duration. Follow-up echocardiography revealed no significant intergroup differences in tricuspid regurgitation, residual shunt, or aortic valve regurgitation. In conclusion, tricuspid valve detachment is a safe and reliable technique for the complete closure of hard-to-expose VSDs without compromising tricuspid valve function. Moreover, it does not increase the risk of adverse events, and its outcomes remain favorable during short- and long-term follow-ups.

Incidental Arrhythmias During Atrial Fibrillation Screening With Repeat 7-Day Holter ECGs in a Hospital-Based Patient Population.

Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study. In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration. We furthermore report treatment decisions because of incidental arrhythmias. A total of 2077 Holter ECGs were performed in 794 patients (mean age, 74.7 years; 49% women), resulting in a mean cumulative duration of analyzable ECG signal of 414±136 hours/patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were sinus node dysfunction in 14 patients (1.8%), AVB in 41 (5.2%), supraventricular tachycardia in 42 (5.3%), and ventricular tachycardia in 2 (0.3%). Second-degree AVB was found in 23 patients (2.9%), 2:1 AVB in 10 (1.3%), and complete AVB in 8 (1%). Subsequently, 8 patients underwent pacemaker implantation, 1 for sinus node dysfunction (post-AF conversion pause of 9 seconds) and 7 for advanced AVB. One patient had an implantable cardioverter-defibrillator implanted for syncopal ventricular tachycardia. Incidental arrhythmias were frequently detected during screening for AF in the STAR-FIB study and resulted in device therapy in 1.1% of our cohort patients.

His bundle pacing in nodal versus infranodal atrioventricular block: a mid-term follow-up study

IntroductionThis study evaluated the feasibility of His bundle pacing (HBP) in consecutive, unselected patients with advanced atrioventricular block (AVB) over a medium-term follow-up period, comparing procedural characteristics between nodal and...

Association between preeclampsia and long-term risk of arrhythmias

Abstract Background Preeclampsia (PE), a pregnancy-induced hypertensive disorder, affects 4-5% of pregnancies worldwide. It is well known that hypertension is associated with increased risk of arrhythmias; however, data on the association between PE and arrhythmias are sparse and there is a lack of knowledge on the long-term risk of arrhythmias. Purpose To compare the incidence of arrhythmias following preeclamptic and normotensive pregnancies. Methods In this observational cohort study, we identified all primiparous women without history of arrhythmias who gave birth in Denmark from 1997 to 2016 using Danish nationwide registries. The women were stratified on whether they developed PE during their primiparous pregnancy and were followed from primiparous pregnancy to incident arrhythmia, emigration, death, or end of study (December 31, 2018). The comparative risks of arrhythmias were assessed in cause-specific Cox regression analyses adjusted for known arrhythmogenic risk factors including obesity, smoking, hypertension, coronary artery disease, cardiomyopathy, congenital heart disease, thyroid disease, diabetes, and alcohol abuse. Results A total of 521,517 primiparous women with a median age of 28 years were included and 23,523 (4.5%) were diagnosed with PE. Women with versus without PE were of similar age but had a higher burden of comorbidities. During a median follow-up period of 10.2 years, women with PE were associated with higher absolute incidences of arrhythmias (Figure 1). No statistically significant association was found for the composite of cardiac arrest, ventricular arrhythmias, or ICD-implantation nor for the composite of advanced 2nd or 3rd degree atrioventricular block, sinoatrial dysfunction, or pacemaker-implantation. However, women with PE were associated with a significant increased risk of the composite of supraventricular tachyarrhythmias and extrasystoles (p&amp;lt;0.01) and the composite of all included arrhythmias (p&amp;lt;0.01). Factors associated with arrhythmias among women with PE included obesity (HR 1.40 (95%CI 1.03-1.91), coronary artery disease (HR 2.39 (95%CI 1.14-5.00), cardiomyopathy (HR 9.65 (95%CI 3.46-26.92), and congenital heart disease (HR 5.86 (95%CI 2.59-13.28). Conclusion Preeclamptic women were associated with a significantly higher rate of arrhythmias - mainly driven by supraventricular tachyarrhythmias and extrasystoles - than normotensive women. For the purpose of primary and secondary prevention, this finding suggests that women with a history of PE may benefit from evaluation of cardiovascular risk factors, screening of and education in prevention of cardiovascular disease.Figure 1

Long-term stability of atrial sensing in implantable cardioverter-defibrillators with floating atrial dipole leads

Abstract Introduction To maintain the advantages of having atrial sensing without the need to implant an additional lead, a single-lead ICD system with a floating atrial dipole (VDD DX ICD, Biotronik) with active fixation to the right ventricle has been developed. In this generation of ICDs, specially filtered atrial signs may be high enough to allow early detection of atrial arrhythmias and improve discrimination between atrial and ventricular tachycardias. However, maintaining reliable and stable atrial sensing via the floating dipole could be a concern regarding this technology. We aimed to determine the long-term stability of atrial sensing in patients (P) with this type of device. Methods All P implanted with ICDs with an active fixation DX lead at our centre between 2013 and 2021 were included. Atrial sensing and ventricular or supraventricular arrhythmic events were recorded during follow-up. We retrospectively analysed the atrial sensing evolution and compared it with a control group that had been implanted with a VDD pacemaker (PM). Results Seventy DX ICD P (82.9% males, age 69±14 years [between 19 and 86], 81.4% implanted as primary prevention) with &amp;gt; 1-year follow-up were included. The control group included 52P (age 82±6.3 years) who underwent PM implantation due to an advanced atrioventricular block. The mean P-wave amplitude at implantation was 4.85±2.44 mV in the DX ICD group and 1.54±0.89 mV in the VDD PM group. At one year after implantation, P-wave amplitude was 4.26±2.68 mV in the DX ICD group and 1.20±1.16 mV in the control group. From the control group, 7P (15,6%) lost atrial sensing after one year of follow-up, having their PM programmed as VVI after that. None of the P in the ICD group had lost atrial sensing in the same time period. After one year of follow-up, the P-wave amplitude had a mean reduction of 41.3% in the DX ICD group and of 65% in the control group (P=0.05). Conclusions Atrial signals can be reliably sensed by the floating dipole rings of a DX ICD in a long-term follow-up. This technology resulted in a higher stability of atrial sensing when compared with that obtained in P with a VDD PM. Additionally, a noteworthy number of P with a VDD PM lost atrial sensing, which did not happen in the group with the DX ICD.Results

Abstract 11889: Ischemic Evaluation in Patients Presenting With Advanced Atrioventricular Block - Experience From a Large County Health System

Introduction: Coronary artery disease (CAD) is a risk factor for advanced (2 nd degree Mobitz II and 3 rd degree) atrioventricular (AV) block. Research Question: While AV block in the setting of acute myocardial infarction (AMI) is often reversible, data is limited on utility of ischemic evaluation in advanced AV block without AMI. Aim: We assessed whether ischemic evaluation and revascularization was associated with reversibility of advanced AV block not in the setting of AMI. Methods: We queried the electronic medical records of a large county health system that serves the Houston metropolitan area for patients with diagnosis of advanced AV block between 1/1/2018 and 1/1/2022. Demographic, medical history, ischemic evaluation (by coronary catheterization or stress test) data and pacemaker interrogation reports were abstracted from the medical records. Patients with AV block from AMI were excluded. Results: Over a period of 4 years, there were 116 patients who presented with advanced AV block, of which 73 (62.9%) underwent ischemic evaluation either by coronary angiography or non-invasive imaging. Patients who underwent ischemic evaluation were associated with lower pacing burden on device interrogation compared to those with no ischemic evaluation (Table 1). In multivariable regression, ischemic evaluation was associated with lower odds of pacing burden &gt;40% on device interrogation (OR -1.53, 95% CI -3.02, -0.03) but not AV block resolution (OR 0.41, 95% CI -1.76, 2.58). Of those who underwent ischemic evaluation, 26.0% had obstructive CAD, of which 78.9% underwent revascularization. AV block resolved in 13.3% who underwent revascularization. Conclusion: Among patients presenting with advanced AV block not in the setting of AMI, ischemic evaluation was associated with decreased pacing burden but not AV block resolution. In patients found to have obstructive CAD, a minority had resolution of AV block after revascularization.

Abstract 14964: Unsupervised Machine Learning of Imaging-Based Sub-Phenotypes of Aortic Stenosis With Differential Risks of Conduction Disturbances After Transcatheter Aortic Valve Replacement

Background: It is currently unclear whether various measurements of the aortic valvular complex routinely performed on pre-operative computed tomography angiograms (CTA) can collectively predict the risk of conduction disturbances after transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS). Here, we aimed to use unsupervised machine learning to analyze a multitude of CTA features and identify distinct patient sub-phenotypes with different risks for TAVR-related conduction disturbances. Methods: The pre-TAVR CTAs of 660 AS patients (330 males, 330 females) were analyzed using TeraRecon to extract 21 features that included aortic valve leaflet calcification loads, dimensions of the aortic root (annulus, sinus of Valsalva, sinotubular junction) and the ascending aorta, coronary ostial heights, and aortic angle. Agglomerative hierarchical clustering was performed separately on male and female datasets using R, with assessment of clusterability based on Hopkins statistics and agglomerative coefficient and the optimal number of clusters based on 30 previously validated indices (NbClust package). Multivariable logistic regression was conducted to assess the dependence of significant conduction disturbances (new left bundle branch block, advanced atrioventricular block) on cluster type. Results: Both male and female datasets were fairly clusterable (Hopkins statistics, 0.70 vs 0.68; agglomerative coefficient, 0.93 vs 0.93), with 3 and 2 as the optimal number of clusters, respectively. Of the 3 male clusters identified, the cluster with intermediate median values of aortic valve leaflet calcification loads and aortic root dimensions (M2) was associated with the greatest risk of conduction disturbances, compared to clusters with low (M1) and high (M3) median values of these variables (OR M2/M1 =9.24, p =0.03; OR M2/M3 =1.33, p =0.40; OR M3/M1 =6.97, p =0.07). The risk of the M1 cluster was not statistically different from those of the female clusters (F1, F2; OR M1/F1 =0.31, p =0.27; OR M1/F2 =0.25, p =0.21), which were not different from each other (OR F1/F2 =0.82, p =0.68). Conclusion: Machine learning of pre-TAVR CTAs can help identify subgroups of patients with similar or varying risks of TAVR-related conduction disturbances.

Short- and long-term survival in patients over 90 years old undergoing pacemaker implantation.

In Italy, 12-month survival in the general population between 90 and 94 years old is 26%. In very old patients, the benefit of pacemaker implantation in terms of quality and duration of life is unclear. The aim of our study was to analyse clinical characteristics, outcome and factors associated with survival in patients at least 90 years old at the time of the first pacemaker implant. Clinical parameters, device characteristics, survival and predictors of outcome in patients at least 90 years old treated with a pacemaker in our centre in 2019-2020 were evaluated. Among the 554 patients undergoing pacemaker implantation in our centre during the study interval, 69 (12%) were at least 90 years old; a complete/advanced atrioventricular block was present in 65%. A cardiological comorbidity (excluding atrial fibrillation) was present in 22 patients (32%). Oncological, pulmonary and neurological comorbidities were present in 12 (17%), 19 (28%) and 32 (46%), respectively. Renal impairment was present in 25 patients (36%). After pacemaker implantation, a pneumothorax developed in two patients and lead dislodgment in one. During follow-up (median 17 months, interquartile range: 13-24), 32 patients died (46%), with a 12-month mortality probability of 24.6%. At multivariate analysis, the presence of oncological (hazard ratio (HR) 5.31; P < 0.001) and neurological (HR 6.44; P < 0.001) comorbidities was associated with mortality. Truncating the outcome at 6 months, renal impairment (HR 8.01; P = 0.003), anticoagulant therapy (HR 8.14; P = 0.003), oncological comorbidities (HR 14.1; P < 0.001) and left ventricular function (5% increase of left ventricular ejection fraction: HR 0.66; P < 0.001) were significantly associated with outcome. At our centre, patients at least 90 years old underwent pacemaker implantation mainly for advanced atrioventricular block. One-year survival was excellent, even better than expected in the general population.

Clinical manifestation of patients with Fabry disease and R356W GLA variant

BackgroundThe R356W GLA variant is an ultra-rare cause of Fabry disease (FD). The clinical manifestations of adult patients carrying this variant have never been reported. This study aims to describe the clinical phenotype of the R356W GLA variant. MethodsThe cohort consisted of consecutive patients diagnosed with FD and carrying the R356W GLA variant. An observational, longitudinal, retrospective cohort study design was used. Clinical, laboratory, and imaging data have been collected from the baseline evaluation to the last clinical review. ResultsSix families, including 36 patients with FD and the R356W GLA variant (age 41.1 ± 15.9 years, 67% females), were evaluated. Eleven patients (31%) showed left ventricular hypertrophy (LVH), and 6 (17%) had chronic kidney disease (CKD). Patients with LVH were older (53.4 ± 8.5 vs. 35.7 ± 15.5, p-value 0.001), showed a higher prevalence of CKD (45% vs. 4%, p-value 0.002), and worse structural and functional cardiac parameters at echocardiographic evaluation. During a median follow-up of 42 (IQR 21–98) months, one patient experienced advanced atrioventricular block requiring pacemaker implantation and one end-stage renal disease requiring dialysis. No patients experienced major adverse events. ConclusionThis study suggests that the R356W GLA variant could be a late-onset FD-causing variant with incomplete penetrance and predominantly cardiac manifestations.

Treatment strategy for acute myocarditis in pediatric patients requiring emergency intervention

BackgroundPatients with acute myocarditis present with a wide range of symptoms. Treatment strategies for pediatric patients with circulatory failure comprise extracorporeal membrane oxygenation (ECMO), emergency temporary pacing, and pharmacotherapy. However, they remain controversial. ECMO is an effective treatment but gives rise to several complications; the goal is therefore to avoid excessive treatment as much as possible. We aimed to evaluate the importance of electrocardiogram findings in differentiating severity and establish an appropriate treatment strategy in pediatric patients with acute myocarditis who required emergency interventions.MethodsThis retrospective study enrolled pediatric patients admitted to and treated in our hospital for acute myocarditis between April 1983 and December 2021. Patients were retrospectively divided into whether circulatory failure occurred (ECMO or temporary pacing was needed; emergency intervention group) or not (pharmacotherapy alone).ResultsOf the 26 pediatric patients, 11 experienced circulatory failure while 15 did not. In the circulatory failure group, six patients were treated with ECMO (ECMO group) and five patients with temporary pacing (pacing group). In the pacing group, all patients were diagnosed with complete and/or advanced atrioventricular block (CAVB and/or advanced AVB) and narrow QRS. Furthermore, these patients improved only with temporary pacing and pharmacotherapy, without requiring ECMO. Wide QRS complexes (QRS ≥ 0.12 ms) with ST-segment changes were detected on admission in five of six patients in the ECMO group and none in the pacing group (P = 0.015). Although all patients in the ECMO group experienced complications, none did in the pacing group (P < 0.008).ConclusionsRegarding emergency intervention for acute myocarditis, ECMO or temporary pacing could be determined based on electrocardiogram findings, particularly wide QRS complexes with ST-segment changes on admission. It is important to promptly introduce ECMO in patients with wide QRS complexes with ST-segment changes, however, patients with CAVB and/or advanced AVB and narrow QRS could improve without undergoing ECMO. Therefore, excessive treatment should be avoided by separating ECMO from temporary pacing based on electrocardiogram findings on admission.

Cardiac sarcoidosis as initial presentation of multisystemic sarcoidosis

Sarcoidosis is a multisystemic inflammatory disorder whose clinical presentation varies from asymptomatic disease to organ failure and death. Isolated cardiac sarcoidosis (CS) often escapes detection in absence of clinically apparent disease in other organs. Our case illustrates the evaluation of a young female presenting with syncopal attack with complete heart block which was later diagnosed being due to sarcoidosis. This is a rare case of sarcoidosis presenting with cardiac symptoms as its initial presentation. Our study emphasizes that the differential diagnosis of sarcoidosis should be kept in an advanced atrioventricular block especially in a young patient with no predisposing factors. Establishing the diagnosis of CS enables benefit from immunosuppressant therapy and prevents morbidity as well as mortality.

Monitoring for arrhythmia in transthyretin cardiac amyloidosis with remote patch devices

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Transthyretin cardiac amyloidosis (ATTR-CA) is associated with an increased incidence of arrhythmias. We hypothesized that non-invasive, two-week outpatient cardiac rhythm monitoring of patients with ATTR-CA would detect high rates of ventricular tachycardia and atrial fibrillation/flutter (AF). Purpose To characterize arrhythmia in patients with ATTR-CA on two-week, non-invasive cardiac rhythm monitors. Methods 38 patients with ATTR-CA (mean age 76.9 SD 10.0 years, 89.5% male) who underwent two-week remote external patch monitoring were included in this single center retrospective study. An age-matched control group included 38 patients (mean age 73.9 SD 12.3, 76.3% male) who underwent the same cardiac rhythm monitoring as part of neurological workups. Results NSVT was detected on the remote monitor in 81.6% of ATTR-CA patients and AF was detected in 26.3% of patients. ATTR-CA was associated with higher rates of NSVT and AF compared to the control group (28.9% with NSVT and 5.3% with AF). As seen in Figure 1, there were only three ATTR-CA patients without either AF, NSVT, advanced atrioventricular block, or a significant pause detected on remote monitor. Among the ATTR-CA group, at median 45 weeks follow-up, there were 4 heart failure hospitalizations, 2 cardiovascular events (1 episode of sustained VT and 1 stroke), 6 permanent pacemakers placed, and 3 implantable cardioverter-defibrillators placed, including one for sustained VT. NSVT and AF were not associated with a composite of these adverse outcome. Conclusion ATTR-CA was associated with high rates of NSVT and AF on noninvasive remote monitors. While evidence regarding the management of arrhythmias, particularly NSVT/VT, in ATTR-CA remains limited, two-week noninvasive cardiac monitoring can be considered to aid in risk stratification for both atrial and ventricular arrhythmias in ATTR-CA.

Self-taught ultrasound-guided axillary vein access for pacemaker implantations - complication rates and outcomes

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac implantable electronic devices (CIEDs) are the mainstream therapy for advanced atrioventricular block or sustained ventricular arrhythmia. EHRA survey (1) showed that cephalic vein dissection and blind subclavian vein puncture are the preferred techniques for the implantation of CIED leads in European centres. Ultrasound (US) guided axillary puncture has emerged as feasible alternative for safe and rapid venous access for lead implantation. However, insufficient evidence to support its widespread adoption. Aim To compare the complication rates and clinical outcomes of CIED implantations utilising self-taught US guided axillary puncture versus non-US guided venous access (Subclavian puncture and fluroscopy guided axillary puncture). Assess the mean time to gain venous access and overall success rate in US guided technique. Methods Retrospective , observational study across two sites involving all CIED implantations of four experienced implanters over the year from January 2021 - June 2022. Patient's demographics, venous access time, complications and clinical outcomes were extracted from electronic database. US axillary access technique was self-taught. Results and Outcomes Venous access was obtained by US Guided axillary puncture in 146 patients, non-US guided in 208 patients. Successful axillary venous access by ultrasound guidance is 97%(146/151) with mean time to venous access of 2.1 minutes. Baseline demographics (age, gender) and comorbidities (hypertension, diabetes, cardiomyopathy, coronary artery disease, dyslipidemia, renal failure, oral steroid use, nicotine use) were similar between both US-guide and non-US guided groups, usage of oral anticoagulations (32.9% vs 39.4%,p=0.208) and antiplatelet agents(28.1% vs 35.1%,p=0.164) were not statistically different. Greater proportion of dual chamber pacemakers were implanted in US guided access group versus non-US guided (39.7% vs 27.9%,p=0.015). US Guided axillary access resulted in lower overall complication rate (2.1% vs 8.9%, p=0.0196): lower risk of pneumothorax (0% vs 3.8%,p=0.0236), lower risk of haemathoma (0% vs 3.4%,p=0.0448). No difference in short term pocket/lead infection or lead displacement. Severe vascular complications remains low in both groups. Stepwise binary regression analysis demonstrated US guidance as independent predictor of lower overall complication rate, odd-ratio 0.195 (95% CI 0.054 - 0.706). Summary: This multi-centered, retospective observational study demonstrated that US guided axillary access has high overall success rate, not time consuming and resulted in lower complication rates (especially pneumothorax and pocket haemathoma), despite the US access technique being self-taught and have greater proportion of dual chamber device implantations. US guided axillary access is demonstrated to be independently associated with 5-fold lower risk of complications.

P339 LIGHT–CHAIN CARDIAC AMYLOIDOSIS WITH FULMINANT EVOLUTION, A NOT–SO–RARE CONDITION: THE IMPORTANCE OF EARLY DIAGNOSIS

Abstract Introduction Amyloid AL results from misfolding of immunoglobulin light chain (kappa or lambda) secreted by abnormal plasma cells such as in multiple myeloma. It is a rare, multisystemic disease with an estimated annual incidence rate of 6 to 10 cases per million inhabitans in Western countries. The prognosis of this hematologic neoplasm is guided by the extent of cardiac involvement; if untreated, survival rate is less than 6 months; with early initiation of chemotherapy treatment, median survival can range from 4 to 10 years, except for high–risk cases. Case report: 58–year–old patient presented to emergency department in May 2022 with the first syncopal episode and sphincter release. The patient had no cardiovascular risk factors. Echocardiografy showed markedly hypertrophic left ventricle with hyper–reflective walls with a granular–sparkling appearance. Electromyography revealed sensory–motor polyneuropathy, early–stage autonomic neuropathy and bilateral carpal tunnel syndrome. Implantation of a loop recorder was performed to investigate the cause of syncope. In suspected amyloidosis, the patient underwent electrophoresis, which showed no monoclonal peaks, serum and urine kappa and lambda light chains were negative. Bone scintigraphy showed no osteotropic radiopharmaceutical uptake in the heart. Cardiac magnetic resonance imaging (MRI) revealed biventricular hypertrophic phenocopy (concentric hypertrophy) with diffuse edema–like tissue alterations. The patient was asymptomatic. In August 2022, hematologic evaluation revealed a monoclonal band for lambda light chains in repeated immunofixation and bone marrow biopsy showed 9–10% monoclonal lambda plasma cells. The patient was referred to a specialized center for amyloidosis, where a biopsy of peri–umbilical fat was performed to confirm the diagnosis and initiate therapy. In October 2022, due to recurrent syncope, advanced atrioventricular block and extreme bradycardia at loop recorder, a dual–chamber pacemaker was implanted. A few days after discharge, the patient suffered cardiac arrest at home due to electromechanical dissociation and died, only 5 months after the first symptom. Conclusion AL amyloidosis is an aggressive hematological neoplasm, with cardiac involvement. Early diagnosis is crucial for timely initiation of therapy, which is the only means available to increase patient survival. It is important to maintain a high level of awareness and diagnostic suspicion for this condition.

P369 AUTOIMMUNE LYMPHOCYTIC MYOCARDITIS: ONE SIZE DOES NOT FIT ALL

Abstract Fulminant myocarditis (MF) is an acute onset, rapidly progressive and potentially fatal inflammatory cardiomyopathy which could manifests with cardiogenic shock and incessant arrhythmias. There is often a need for aminic or mechanical support to the circulation in the acute phase, waiting to obtain a histological diagnosis as quickly as possible to establish a specific therapy. Mortality in the acute phases is high, with a worse prognosis than in other forms of presentation of myocarditis, even in the long term. We report the case of a 45–year–old Asian woman suffering from autoimmune hypothyroidism, who had been reporting atypical chest pain for about 3 days, associated with fever, asthenia, and vomiting. On admission, the patient was in cardiogenic shock; an echocardiogram revealed biventricular dysfunction. Pulmonary embolism and acute coronary syndrome were excluded. Blood tests showed a significant troponin rise, neutrophilic leukocytosis, and hypertransaminasemia. Anti heart antibodies (AHA) were negative. Amine support with dobutamine and norepinephrine was then started. The first EKG showed an advanced atrioventricular block with a ventricular escape with the need for emergency temporary PM placement. Right heart catheterization showed pressures in the pulmonary circulation at the upper limits with average resistance and reduced cardiac index. An endomyocardial biopsy (EMB) was performed, subsequently complicated by cardiac tamponade due to lead displacement, treated with urgent pericardiocentesis. At the end of the procedure, the appearance of incoming episodes of complete BAV was highlighted, for which ICD implantation was performed. The biopsy showed virus–negative diffuse acute lymphocytic myocarditis. Cortisone therapy was therefore started, with immediate benefit, until the aminic support was suspended. A follow–up echocardiogram showed a complete recovery of normal biventricular function. In MF, early diagnosis, and the possibility of establishing specific therapy are crucial to reduce mortality. EMB is the only method that allows you to make an etiological diagnosis and exclude a possible infectious genesis. The patient‘s prognosis, in fact, in addition to supportive therapy, depends on the possibility of establishing a targeted treatment as soon as possible, which in virus–negative autoimmune forms consists of an immunosuppressive therapy modulated on the patient‘s histological type and clinic.