Significant Bradyarrhythmias Research Articles

Long-term results of cardioneuroablation evaluated by implantable loop recorder

Abstract Background Cardioneuroablation (CNA) is a catheter ablation technique based on radiofrequency application in the atrial endocardium to decrease vagal response. Since the first series publication, its use has greatly increased, with CNA being now used in vasovagal syncope (VVS), functional atrioventricular block (AVB), symptomatic sinus bradycardia (SB) and Atrial Fibrillation (AFib). There is still limited data regarding long-term follow-up (FUP) of patients who have undergone this procedure. Purpose The aim of this study was to evaluate long-term results of CNA in a single center with the use of an implantable loop recorder (ILR). Methods We performed a prospective single-center cohort study. Patients with significant documented functional bradyarrhythmias between September 2019 and October 2023 were enrolled. All patients underwent ILR implantation before ablation. CNA was performed using catheter ablation aiming at right epicardial GPs with 3-dimensional electroanatomical mapping support. A 2 mg atropine test (bolus) was carried out before and after CNA and the subsequent heart rate (HR) increase registered. Successful CNA was defined as absence of HR increase with atropine after the ablation. HR pre and post ablation was compared. Immediate and late procedure complications were assessed. Recurrence of symptoms, the presence significant vagal-induced bradyarrhythmias on ILR and the need for pacemaker (PM) implantation were also assed. Results Fifteen patients (pts) were included, with a mean age of 64 (± 12 years) and a 53.3% male prevalence. None of the pts had structural heart disease. The main indication for CNA was AFib with brady-tachy syndrome (8 pts, 53.3%), followed by VVS (4 pts, 26.7%), SB (2 pts, 13.3%) and AVB (2:1 AVB; 1 pt). The most common symptom was syncope (46.7%), followed by pre-syncope (40%) and fatigue (20%). There was a significant improvement in HR after CNA (55 ± 13 vs. 67 ± 14 bpm pos-CNA, p=0.002). The achievement of success was verified in all patients (mean HR variation with atropine before CNA 35 ± 10% vs. 2 ± 2% after CNA; p=0.001). Procedure mean time was 28 ± 12 min. During a maximum FUP of 48 months (minimum 1 month, median 5), 1 patient had recurrence of VVS with a 10s pause documentation on ILR requiring PM implantation and 1 patient had a 4s pause without translation into symptoms and a duration decreasing tendency during FUP. Freedom from recurrence of symptoms was 93.3%, freedom from pacemaker implantation was 93.3% and freedom from significant bradyarrhythmias was 86.7% – Figure 1. No immediate or long-term complications were seen. Conclusions CNA aiming at the right GPs is a safe and quick procedure for patients with functional bradyarrhythmias. This ablation technique in most patients not only reduces symptoms, but also avoids early PM implantation, therefore improving quality of life. Further randomized clinical trials are needed to support these data and refine patient selection criteria.

Cardioneuroablation for symptomatic bradyarrhythmia: for whom it fails?

Abstract Background Cardioneuroablation (CNA) has been proposed as a new therapeutic approach in selected patients with symptomatic functional bradyarrhythmia including recurrent neurally-mediated syncope. Purpose In patients after CNA, we investigated the potential predictors of the recurrence of clinically significant bradyarrhythmia. Methods A retrospective study included 187 consecutive patients (age: 40±12 years; 57 % of males; predominant AV nodal phenotype of the disorder in 37 % of patients; post-atropine sinus rate acceleration by 72±31 %) who underwent their first CNA at our centre from 2014 to 2022 and were followed for the minimum of 3 months. Biatrial radiofrequency ablation was performed under general anaesthesia by irrigated-tip catheter at empirical sites of ganglionated plexi (GP) with the navigation by 3D electroanatomic mapping system and intracardiac echocardiography. Anterior right GP and posteromedial left GP were always targeted to modulate the innervation of both sinoatrial and atrioventricular nodes, irrespective of the clinical manifestation of the disease. The loss of responsiveness of both nodes to extracardiac vagus nerve stimulation (frequently bilateral) was the procedural endpoint. The association of baseline, procedural, and early follow-up characteristics with the recurrence of clinically significant bradyarrhythmia was analyzed. Results CNA with the procedural duration of 154±32 min and radiofrequency time of 14±7 min resulted acutely in sinus rate acceleration by 27±13 bpm, shortening of AH interval by 16±28 ms, an increase of Wenckebach point by 26±28 bpm, shortening of AV node effective refractory period by 114±128 ms, and sinus node recovery time by 462±867 ms. At the 3-month visit, the sinus rate was still significantly higher (83±14 bpm) than at baseline (61±13 bpm); with acceleration by 23±14 bpm. During a median follow up of 33 months (IQR: 18-48 months), recurrence of clinically significant bradyarrhythmia was documented in 18 (10 %) patients. Re-CNA was performed in 11 patients and was scheduled in 3 patients. In 6 (3 %) patients, a pacemaker was finally implanted. Compared to the rest of the population, patients with bradyarrhythmia recurrence were non-significantly younger (36±12 vs. 40±12 years, P=0.16) and had non-significantly less acceleration of sinus rate at the 3-month post-CNA visit (by 18±11 vs. 23±13 bpm, P=0.10) suggesting a trend to more pronounced reinnervation of the sinus node. Conclusion Long-term clinical efficacy of CNA is reasonably high. We did not identify practically useful predictors of CNA failure. This investigation was significantly limited by the low rate of clinical events.

Abatacept for immune checkpoint inhibitor associated myocarditis (ATRIUM): Phase 3, investigator-initiated, randomized, placebo-controlled study to evaluate the efficacy and safety of abatacept compared to placebo in hospitalized patients with immune checkpoint inhibitor associated myocarditis.

TPS2680 Background: Patients with myocarditis secondary to treatment with an immune checkpoint inhibitor (ICI) represent a poor prognosis population with a critical unmet clinical need. Data have shown that the rate of major adverse cardiac events (MACE) with ICI myocarditis despite administration of corticosteroids ranges from 25-50%. Abatacept is a selective co-stimulation modulator that inhibits T cell activation by binding to CD80 and CD86, thereby blocking its interaction with CD28. In preclinical animal models of ICI myocarditis, the administration of abatacept led to a reduction in cardiac immune activation and an increase in survival. Methods: The abatacept for immune checkpoint inhibitor associated myocarditis (ATRIUM) trial is designed as a phase 3, investigator-initiated, randomized, placebo-controlled study to evaluate the efficacy and safety of abatacept compared to placebo in hospitalized participants with ICI associated myocarditis. Hospitalized participants diagnosed with ICI-related myocarditis, as defined by the International Cardio-Oncology Society, ≥ 18, with serum evidence of ongoing myocardial injury (troponin ≥5 times the upper limit normal), and treated, or with intent to treat, with 1000 mg of solumedrol/day are eligible. In the randomized protocol, participants receive either abatacept (10 mg/kg) or placebo given IV followed by study drug infusion/placebo again at 24 hours and on day 14. Of note, there is an optional 4th dose on day 28. The primary aim is to test whether abatacept, as compared to placebo, is associated with a reduction in MACE among participants hospitalized with myocarditis secondary to an ICI. The primary outcome, MACE, is a composite of first occurrence of cardiovascular death, non-fatal sudden cardiac arrest, cardiogenic shock, significant ventricular arrhythmias, significant bradyarrhythmias, or incident heart failure. Each component of the primary composite end point will be evaluated individually as a secondary endpoint, as are troponin levels, rates of deep venous thrombosis and pulmonary embolism, and incidence rates of treatment-related adverse events. Exploratory outcomes focus on cancer outcomes, healthcare utilization, quality of life, and correlative studies. Recently, the trial has been amended to allow eligible participants who have achieved an ATRIUM primary end-point prior to randomization to be eligible for inclusion in the RESCUE arm of the protocol where they will be given open-label Abatacept on day 1, 2, 14, with optional dose at 28. The study is open at 20 sites across the US with a plan for a total of 50 locations across US and Canada. This study is recruiting at time of submission. Target enrollment is 390 patients. Clinical trial information: NCT05335928 .

Non-canonical role of the sympathetic nervous system in the day-night rhythm in heart rate.

Although, for many decades, the day-night rhythm in resting heart rate has been attributed to the parasympathetic branch of the autonomic nervous system (high vagal tone during sleep), recently we have shown that there is a circadian clock in the cardiac pacemaker, the sinus node, and the day-night rhythm in heart rate involves an intrinsic rhythmic transcriptional remodelling of pacemaker ion channels, particularly Hcn4. We have now investigated the role of the sympathetic branch of the autonomic nervous system in this and shown it to have a non-canonical role. In mice, sustained long-term block of cardiac β-adrenergic receptors by propranolol administered in the drinking water abolished the day-night rhythm in pacemaking in the isolated sinus node. Concomitant with this, there was a loss of the normal day-night rhythm in many pacemaker ion channel transcripts. However, there was little or no change in the local circadian clock, indicating that the well-known day-night rhythm in sympathetic nerve activity is directly involved in pacemaker ion channel transcription. The day-night rhythm in pacemaking helps explain the occurrence of clinically significant bradyarrhythmias during sleep, and this study improves our understanding of this pathology. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

PO-04-138 FINDING THE SIGNAL TO BURN: OPTIMIZED FRACTIONATION MAPPING FOR IDENTIFYING GANGLION PLEXUSES DURING CARDIONEURAL ABLATION

Cardioneural ablation (CNA) is a novel catheter-based technique to treat patients with clinically significant bradyarrhythmia due to cardioinhibitory response in vasovagal syncope (VVS). Three common techniques used to locate areas of ganglion plexuses (GPs) prior to CNA include high frequency stimulation, fractionation mapping (FM), and empiric ablation based on presumed anatomical location of GPs. Optimal intra-procedural diagnostic parameters of fractionation mapping which predict GP location remain ill-defined. To determine the parameters of FM which most precisely locate successful GP ablation sites. Consecutive patients with cardioinhibitory VVS underwent CNA at a single center between March and April 2021. GP sites were targeted with radiofrequency (RF) ablation based on areas demonstrating fractionation, response to high-frequency stimulation, and overall anatomic location. GP sites exhibiting abrupt sinus rate increases with RF delivery were tagged as successful. Following the case, multiple FMs were retrospectively analyzed at 5 sensitivities (range 0.01-0.10 mV), each utilizing 4 combinations of EGMs with width (range 5-10 ms) and refractory interval (range 6-25 ms). Each FM was reviewed and deemed predictive if it identified all successful RF sites without incorrectly annotating sites lacking an RF response. We identified 40 unique FMs for analysis. Setting EGM width to 5 ms and refractory interval to 6 ms predicted all successful ablation sites (positive predictive value [PPV] 100%, p < 0.01). Broadening annotation parameters diminished predictability in a stepwise fashion (5 ms/15 ms, 10 ms/15 ms, 10 ms/25 ms yielded PPV 90%, 70%, 40%, respectively, p < 0.01). Sensitivity settings did not correlate with map utility (PPV 75%, p = 0.98). The optimal fractionation parameters which identified successful ablation sites were those with the narrowest electrogram width and shortest refractory interval. Analysis in a larger cohort is needed to confirm these findings.

Long-term prognostic impact of beta-blockers in patients with Takotsubo syndrome: Results from the RETAKO Registry

BackgroundNo evidence-based therapy has yet been established for Takotsubo syndrome (TTS). Given the putative harmful effects of catecholamines in patients with TTS, beta-blockers may potentially decrease the intensity of the detrimental cardiac effects in those patients. ObjectiveThe purpose of this study was to assess the impact of beta-blocker therapy on long-term mortality and TTS recurrence. MethodsThe cohort study used the national Spanish Registry on TakoTsubo Syndrome (RETAKO). A total of 970 TTS post-discharge survivors, without pheochromocytoma, left ventricular outflow tract obstruction, sustained ventricular arrhythmias, and significant bradyarrhythmias, between January 1, 2003, and July 31, 2018, were assessed. Cox regression analysis and inverse probability weighting (IPW) propensity score analysis were used to evaluate the association between beta-blocker therapy and survival free of TTS recurrence. ResultsFrom 970 TTS patients, 582 (60.0%) received beta-blockers. During a mean follow-up of 2.5±3.3 years, there were 87 deaths (3.6 per 100 patients/year) and 29 TTS recurrences (1.2 per 100 patient/year). There was no significant difference in follow-up mortality or TTS recurrence in unadjusted and adjusted Cox analysis (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.59–1.27, and 0.95, 95% CI 0.57–1.13, respectively). After weighting and adjusting by IPW, differences in one-year survival free of TTS recurrence between patients treated and untreated with beta-blockers were not found (average treatment effect −0.01, 95% CI −0.07 to 0.04; p=0.621). ConclusionsIn this observational nationwide study from Spain, there was no significant association between beta-blocker therapy and follow-up survival free of TTS recurrence.

Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study.

Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain. The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of predialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours before an HD session. Associations with CSBA were analyzed with mixed-effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters and associations of peridialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next. There were 551 CSBA that occurred in the last 12 hours of the interdialytic interval preceding 100 HD sessions in 12% of patients and 1475 CSBA events in 23% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 versus 8, P=0.04). Use of dialysate sodium concentrations ≤135 (versus 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next. Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.

Holter Monitoring in assessing Cardiac Arrhythmias in Symptomatic Patients: A Prospective Observational Study

BACKGROUND The 24hr ECG Holter monitoring system is helpful in assessing cardiac arrhythmias in patients presenting with palpitation, dizziness, presyncope and syncope, which are not detected by standard office electrocardiogram.&#x0D; METHODS This was a single center prospective observational study conducted to assess the prevalence of cardiac arrhythmias among 78 patients consisting of 41 males and 37 females referred for 24 hr ECG Holter monitoring in BPKIHS, Dharan, Nepal, between October 2021 to December 2021.&#x0D; RESULTS The most common indication for 24 hr ECG Holter monitoring in these patients was unexplained palpitation. Ventricular ectopics were the most common arrhythmias detected, followed by supraventricular ectopics, most of which were benign. Among 18 patients with significant bradyarrhythmia, 3 had sinus bradycardia with significant pause, 3 had AF with significant pause, and 2 had high grade/complete AV block.&#x0D; CONCLUSIONS The study showed that most of the arrhythmias detected are benign and prevalence of potentially fatal ventricular and supraventricular tachyarrythmias are relatively low in our population.

Abstract 9338: In-hospital Complications During 35747 Permanent Pacemaker Implantations from 2009-2018: A Statewide Australian Cohort Study

Background: Permanent pacemaker implantation (PPI) is standard of care for significant bradyarrhythmia since the early 1960’s. Understanding its utilisation and projection in our ageing populations has important implications on medical resource utilisation. This study reports the rates of PPI in the state of New South Wales (NSW), Australia from 2009-2018. Hypothesis: We hypothesized PPI in patients ≥80yrs has increased faster than in &lt;80yrs over past decade. Methods: We examined the prevalence of PPI from Jan 2009 to Dec 2018 by extracting administrative details of all permanent pacemakers implanted statewide, including patient’s characteristics and in-hospital complications using the NSW Centre-for-Health-Record-Linkage datasets. All analysis was stratified by age &lt;80yrs vs ≥80yrs old. Results: A total of 35747 admissions involved PPI (60% males) during the study period. The mean ±SD implantation rate and age was 3574±311 PPI per annum and 78±10yrs respectively. 18187 (50.9%) of PPI were in patients ≥80yrs. The mean annual rate of PPI was 593.4±57.6 per 100000 persons for ≥80yrs, compared to 24.5±2.1 per 100000 persons in &lt;80yrs (p=0.0001). The overall mean rate of increase in PPI from 2009-2018 for ≥80yrs old was 2.6±3.7% compared to 1.7±3.2% per annum in &lt;80yrs (p=0.001). The median (interquartile range [IQR]) length of stay (LOS) in patients ≥80yrs requiring emergency PPI was 8 (5-14) days, compared to 1 (1-3) days in those who had an elective PPI procedure, p&lt;0.05. For patients &lt;80yrs old, the median (IQR) LOS was 7 (4-12) days compared to 1 (1- 2) days, p&lt;0.05 respectively. Overall, complications of pacemaker implantation excluding death was 8%. Although overall in-hospital mortality was low, it was higher for patients ≥80yrs compared to the &lt;80yrs group (0.9% vs 0.6%; p&lt;0.001). Overall complication rates declined only in last two years of the study period, with no significant change for in hospital death. Conclusion: Overall PPI increased between 2009-2018, with the increase greatest in patients ≥80yrs. Overall complication rates remained elevated, with in-hospital mortality higher in the older group. Future studies should examine strategies that reduce in-hospital complications during pacemaker implantations.

Implantable Loop Recorders-Syncope, Cryptogenic Stroke, Atrial Fibrillation.

The implantable loop recorder (ILR) is a subcutaneous, single-lead, electrocardiographic (ECG) monitoring device used for diagnosis in patients with recurrent, unexplained episodes of palpitations or syncope, for long-term monitoring in patients at risk for atrial fibrillation (AF), and to guide clinical management in patients with known AF. These devices are capable of storing and transmitting ECG data automatically in response to a significant bradyarrhythmia or tachyarrhythmia or in response to patient activation. This document aims to review the clinical utility of ILRs for arrhythmia monitoring in common clinical situations such as syncope, cryptogenic stroke, and management of patients with known AF.

Prevalence of bradyarrhythmias needing pacing in COVID-19.

BackgroundThe Sars‐Cov‐2 infection is a multisystem illness that can affect the cardiovascular system. Tachyarrhythmias have been reported but the prevalence of bradyarrhythmia is unclear. Cases have been described of transient high‐degree atrioventricular (AV) block in COVID‐19 that were managed conservatively.MethodA database of all patients requiring temporary or permanent pacing in two linked cardiac centers was used to compare the number of procedures required during the first year of the pandemic compared to the corresponding period a year earlier. The database was cross‐referenced with a database of all patients testing positive for Sars‐Cov‐2 infection in both institutions to identify patients who required temporary or permanent pacing during COVID‐19.ResultsThe number of novel pacemaker implants was lower during the COVID‐19 pandemic than the same period the previous year (540 vs. 629, respectively), with a similar proportion of high‐degree AV block (38.3% vs. 33.2%, respectively, p = .069). Four patients with the Sars‐Cov‐2 infection had a pacemaker implanted for high‐degree AV block, two for sinus node dysfunction. Of this cohort of six patients, two succumbed to the COVID‐19 illness and one from non‐COVID sepsis. Device interrogation demonstrated a sustained pacing requirement in all cases.ConclusionHigh‐degree AV block remained unaltered in prevalence during the COVID‐19 pandemic. There was no evidence of transient high‐degree AV block in patients with the Sars‐Cov‐2 infection. Our experience suggests that all clinically significant bradyarrhythmia should be treated by pacing according to usual protocols regardless of the COVID status.

Anatomic guided ablation of the atrial right ganglionated plexi is enough for cardiac autonomic modulation in patients with significant bradyarrhythmias

IntroductionCardiac autonomic system modulation by endocardial ablation targeting atrial ganglionated plexi (GP) is an alternative strategy in selected patients with severe functional bradyarrhythmias, although no consensus exists on the best ablation strategy. The aim of this study was to evaluate if a simplified approach by a purely anatomical guided ablation of just the atrial right GP is enough for the treatment of these patients. MethodsWe prospectively enrolled patients with significant functional bradyarrhythmias and performed endocardial ablation purely guided by 3D electroanatomic mapping directed at the atrial right GP and accessed parameters of parasympathetic modulation and recurrence of bradyarrhythmias. ResultsThirteen patients enrolled (76.9% male, median age 51, 42–63 years). After ablation, a median RR interval shortening of 28.3 (25.6–40.3)% occurred (1111, 937.5–1395.4 ms to 722.9, 652.2–882.4 ms, p = 0.0002). The AH interval also shortened (19, 10.5–35.7%) significantly after the procedure (115, 105–122 ms to 85, 71–105 ms, p = 0.0023) as well as Wenckebach cycle length (11.1, 5.9–17.8% shortening) from 450, 440–510 ms to 430, 400–460 ms, p = 0.0127. On 24-h Holter monitoring there was significant increase in heart rates (HR) of patients after ablation (minimal HR increased from 34 (26–43)bpm to 49 (43–56)bpm, p = 0,0102 and mean HR from 65 (47–72)bpm to 78 (67–87)bpm, p = 0.0004). No patients had recurrence of symptoms or significant bradyarrhythmias during a median follow-up of 8.4 months. ConclusionsA purely anatomic guided procedure directed only at the atrial right ganglionated plexi seems to be enough as a therapeutic approach for cardioneuroablation in selected patients with significant functional bradyarrhythmias.

Late arrhythmias in patients with new-onset persistent left bundle branch block after transcatheter aortic valve replacement using a balloon-expandable valve.

The arrhythmic burden after discharge in patients with new-onset left bundle branch block (LBBB) undergoing transcatheter aortic valve replacement (TAVR) with the balloon-expandable SAPIEN 3 (S3) valve remains largely unknown. The purpose of this study was to determine the incidence of late arrhythmias in patients with new-onset LBBB undergoing TAVR with the balloon-expandable S3 valve. This was a multicenter, prospective study that included 104 consecutive TAVR patients with new-onset persistent LBBB following TAVR with the S3 valve. An implantable cardiac monitor (Reveal XT, Reveal LINQ) was implanted before discharge. The primary endpoint was the incidence of high-degree atrioventricular block or complete heart block (HAVB/CHB). A total of 40 patients (38.5%) had at least 1 significant arrhythmic event, leading to a treatment change in 17 (42.5%). Significant bradyarrhythmias occurred in 20 of 104 patients (19.2%) (34 HAVB/CHB episodes, 252 severe bradycardia episodes), with 10 of 20 patients (50%) exhibiting at least 1 episode of HAVB/CHB. Most HAVB/CHB episodes (60%) occurred within 4 weeks after discharge. Nine patients (8.7%) underwent permanent pacemaker implantation at 12 months based on the Reveal findings (6 HAVB/CHB, 3 severe bradycardia). S3 valve recipients with new-onset LBBB have a high arrhythmic burden, with more than one-third of patients exhibiting at least 1 significant arrhythmic episode within 12 months (HAVB/CHB in 10% of patients). About one-half of bradyarrhythmic events occurred within 4 weeks after discharge. These results should inform future strategies on the use of continuous electrocardiographic monitoring in TAVR S3 patients with new conduction disturbances following the procedure.

Rates of Permanent Pacemaker Implantation in the Elderly in a State-wide Australian Cohort From 2009–2018

Permanent pacemaker implantation (PPI) has become standard of care for significant bradyarrhythmia since the early 1960s. Understanding pacemaker utilisation and projection in our ageing populations has important implications for medical resource utilisation.

Device therapy guided by implantable loop recorders: predictors of bradyarrhythmic events

Abstract Background Implantable loop recorders (ILR) improved diagnostic yield in unexplained syncope patients (pts). Data on possible predictive factors for bradycardia requiring device implantation in these pts is limited. We aim to identify clinical predictors for device implantation due to a significant bradyarrhythmia in patients who underwent ILR insertion for the study of syncopal/presyncopal (S/pS) events. Methods Single-center retrospective study of patients who implanted an ILR for the study of unexplained S/pS episodes between 2013 and 2018. The primary endpoint was a documented bradyarrhythmia requiring device implantation during the follow-up. Results A total of 251 pts were included. Mean age was 68±15 years and 53% were female. The majority of pts (220; 88%) had normal ejection fraction. Fifty-two (21%) pts had atrial fibrillation (AF). Regarding basal electrocardiographic characteristics, 34 (14%) pts had 1st degree auriculo-ventricular block (AVB), 31 (12%) pts had left bundle branch block (L-BBB), 22 (9%) pts had R-BBB and 13 (5%) pts had bifascicular block. During a median follow-up of 20 (IQR 9–34) months, 74 (29%) pts required device implantation because of a significant bradyarrhythmia (92% pacemaker, 4% CRT, 4% ICD). Median duration from ILR until device implantation was 5 (IQR 1–10) months. The indications were sick-sinus-syndrome in 47 (64%) pts, advanced AV block in 23 (31%) pts and symptomatic slow AF in 4 (5%) pts. Patients who required device implantation were older (73±12 vs 66±15 years, p &amp;lt;0.001), had more hypertension (73% vs 59% p=0.048), a higher prevalence of AF (34% vs 15% p=0.001) and a lower glomerular filtration rate (GFR&amp;lt;60 ml/min: 32% vs 21%, p=0.047). They also had more 1st AVB (22% vs 11%, p=0.026) and intraventricular conduction disturbances (38% vs 25%, p=0.025). There was a trend for a higher device implantation in pts with concomitant 1st AVB and left anterior fascicular block (7% vs 2%, p=0.063) In a logistic regression model, age &amp;gt;75 years (HR: 1.7; 95% CI: 1.1–2.8) and the presence of AF (HR: 1.8; 95% CI: 1.1–3.0) were independent predictors for device implantation. Conclusion An older age and the presence of AF were independent predictors for device therapy in pts who implanted an ILR for the study of S/pS. These factors may identify a higher risk group and should be considered in the initial workup of these pts. Funding Acknowledgement Type of funding source: None

Risk of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: role of correlation between symptoms and electrocardiogram findings.

To evaluate the risk of syncopal recurrences after pacemaker implantation in a population of patients with syncope of suspected bradyarrhythmic aetiology. Prospective, multicentre, observational registry enrolling 1364 consecutive patients undergoing pacemaker implantation for syncope of bradyarrhythmic aetiology (proven or presumed). Before pacemaker implantation, all patients underwent a cardiac work-up in order to establish the bradyarrhythmic aetiology of syncope. According to the results of the diagnostic work-up, patients were divided into three groups: Group A, patients in whom a syncope-electrocardiogram (ECG) correlation was established (n = 329, 24.1%); Group B, those in whom clinically significant bradyarrhythmias were detected without a documented syncope-ECG correlation (n = 877, 64.3%); and Group C, those in whom bradyarrhythmias were not detected and the bradyarrhythmic origin of syncope remained presumptive (n = 158, 11.6%). During a median follow-up of 50 months, 213 patients (15.6%) reported at least one syncopal recurrence. Patients in Groups B and C showed a significantly higher risk of syncopal recurrences than those in Group A [hazard ratios (HRs): 1.60 and 2.66, respectively, P < 0.05]. Failure to establish a syncope-ECG correlation during diagnostic work-up before pacemaker implantation was an independent predictor of syncopal recurrence on multivariate analysis (HR: 1.90; P = 0.002). In selecting patients with syncope of suspected bradyarrhythmic aetiology for pacemaker implantation, establishing a correlation between syncope and bradyarrhythmias maximizes the efficacy of pacing and reduces the risk of syncopal recurrences.

Prolonged Continuous Electrocardiographic Monitoring Prior to Transcatheter Aortic Valve Replacement: The PARE Study

ObjectivesThis study sought to determine, using continuous electrocardiographic monitoring (CEM) pre–transcatheter aortic valve replacement (TAVR), the incidence and type of unknown pre-existing arrhythmic events (AEs) in TAVR candidates, and to evaluate the occurrence and impact of therapeutic changes secondary to the detection of AEs pre-TAVR. BackgroundScarce data exist on the arrhythmic burden of TAVR candidates (pre-procedure). MethodsThis was a prospective study including 106 patients with severe aortic stenosis and no prior permanent pacemaker screened for TAVR. A prolonged (1 week) CEM was implanted within the 3 months pre-TAVR. Following heart team evaluation, 90 patients underwent elective TAVR. ResultsNew AEs were detected by CEM in 51 (48.1%) patients, leading to a treatment change in 14 of 51 (27.5%) patients. Atrial fibrillation or tachycardia was detected in 8 of 79 (10.1%) patients without known atrial fibrillation or tachycardia, and nonsustained ventricular arrhythmias were detected in 31 (29.2%) patients. Significant bradyarrhythmias were observed in 22 (20.8%) patients, leading to treatment change and permanent pacemaker in 8 of 22 (36.4%) and 4 of 22 (18.2%) patients, respectively. The detection of bradyarrhythmias increased up to 30% and 47% among those patients with pre-existing first-degree atrioventricular block and right bundle branch block, respectively. Chronic renal failure, higher valve calcification, and left ventricular dysfunction determined (or tended to determine) an increased risk of AEs pre-TAVR (p = 0.028, 0.052, and 0.069, respectively). New onset AEs post-TAVR occurred in 22.1% of patients, and CEM pre-TAVR allowed early arrhythmia diagnosis in one-third of them. ConclusionsProlonged CEM in TAVR candidates allowed identification of previously unknown AEs in nearly one-half of the patients, leading to prompt therapeutic measures (pre-TAVR) in about one-fourth of them. Pre-existing conduction disturbances (particularly right bundle branch block) and chronic renal failure were associated with a higher burden of AEs.

Assessing the impact of a combination of sofosbuvir and daclatasvir treatment for hepatitis C virus infection on heart rate, rhythm and heart rate variability using 24-hour ECG monitoring

BackgroundDirect-acting antiviral agents (DAAs) cure patients with hepatitis C virus (HCV) infection. Concerns have arisen the occurrence of significant bradyarrhythmias during treatment with DAAs. The aim of this study was to assess the impact of a DAA combination for the treatment of HCV infection on heart rate, rhythm, and heart rate variability (HRV) using 24-h ECG monitoring.ResultsA prospective randomized study of 50 treatment-naïve patients with HCV infection treated with a combination of sofosbuvir 400 mg daily and daclatasvir 60 mg daily for 12 weeks. Surface ECG and 24-h ECG monitoring were performed at baseline and after completion of therapy to assess PR interval, corrected QT interval (QTc), minimum heart rate (HR), maximum HR, average HR, HRV time-domain and frequency-domain measures, significant pauses, tachycardias, bradycardias, premature atrial contractions (PACs), and premature ventricular contraction (PVCs).No differences were detected in all examined parameters between baseline and after completion of treatment. PR interval was 154 ± 25.95 vs 151.4 ± 23.82 ms, respectively (p = 0.124). QTc interval was 397.34 ± 29.38 vs 395.04 ± 30.23 ms, respectively (p = 0.403). No differences were detected for minimum HR, maximum HR, average HR, HRV time-domain and frequency-domain measures, the occurrence of significant pauses, sinus tachycardia episodes, sinus bradycardia episodes, PACs, and PVCs. No episodes of bradyarrhythmias, syncope, and atrial fibrillation, supraventricular, or ventricular tachycardias were reported or detected.ConclusionIn non-cardiac patients receiving no cardioactive medications, the combination of sofosbuvir and daclatasvir for the treatment of HCV infection has no effect on HR, rhythm, conductivity, or HRV. No symptomatic bradycardias, tachycardias, or syncope were reported or detected using 24-h ECG monitoring.

COVID-19 and cardiac arrhythmias

BackgroundEarly studies suggest that coronavirus disease 2019 (COVID-19) is associated with a high incidence of cardiac arrhythmias. Severe acute respiratory syndrome coronavirus 2 infection may cause injury to cardiac myocytes and increase arrhythmia risk.ObjectivesThe purpose of this study was to evaluate the risk of cardiac arrest and arrhythmias including incident atrial fibrillation (AF), bradyarrhythmias, and nonsustained ventricular tachycardia (NSVT) in a large urban population hospitalized for COVID-19. We also evaluated correlations between the presence of these arrhythmias and mortality.MethodsWe reviewed the characteristics of all patients with COVID-19 admitted to our center over a 9-week period. Throughout hospitalization, we evaluated the incidence of cardiac arrests, arrhythmias, and inpatient mortality. We also used logistic regression to evaluate age, sex, race, body mass index, prevalent cardiovascular disease, diabetes, hypertension, chronic kidney disease, and intensive care unit (ICU) status as potential risk factors for each arrhythmia.ResultsAmong 700 patients (mean age 50 ± 18 years; 45% men; 71% African American; 11% received ICU care), there were 9 cardiac arrests, 25 incident AF events, 9 clinically significant bradyarrhythmias, and 10 NSVTs. All cardiac arrests occurred in patients admitted to the ICU. In addition, admission to the ICU was associated with incident AF (odds ratio [OR] 4.68; 95% confidence interval [CI] 1.66–13.18) and NSVT (OR 8.92; 95% CI 1.73–46.06) after multivariable adjustment. Also, age and incident AF (OR 1.05; 95% CI 1.02–1.09) and prevalent heart failure and bradyarrhythmias (OR 9.75; 95% CI 1.95–48.65) were independently associated. Only cardiac arrests were associated with acute in-hospital mortality.ConclusionCardiac arrests and arrhythmias are likely the consequence of systemic illness and not solely the direct effects of COVID-19 infection.

235Anatomic guided ablation of the right ganglionated plexus is enough for cardiac autonomic denervation in patients with significant bradyarrhythmias

Abstract Background In patients with significant bradyarrhytmias, cardiac denervation is an alternative therapeutic approach. Previous reports proposed different methods (as high frequency ednocardial stimulation of ganglionated plexus and specific atrial electrogram identification) and targets (right and left atrial ganglionated plexus) for adequate denervation. There is no consensus on the best way to perform these procedures, in spite the right atrial ganglia plexus (GP) ablation seeming to be the most contributive to its success. Purpose To assess the results of a purely anatomic approach for ablation of just the right atrial plexus in patients with severe vagal bradyarrhytmias. Methods We enrolled patients referred for ablation of cardiac parasympathetic ganglia, with or without atrial fibrillation ablation. We performed eletroanatomic mapping of the right and left atria and used an irrigated tip catheter for ablation, aiming at the anterior right GP at the right pulmonary veins antrum along with ablation at the superior vena cava junction and the inferior right GP at the posterior aspect of the right inferior pulmonary vein along with ablation of the right aspect of the interatrial septum, between the posterior wall and coronary sinus ostium (Figure 1). We assessed the PW and Wenckenback cycle lengths (CL) pre and post procedure in patients with sinus arrest or AV block, respectively, and the patients had new 24h holter readings at least 30 days from the index procedure. Results We enrolled 12 patients: 9 males (75%), median age of 49,5 years (IQR 36-61,75). All patients had structurally normal hearts. 7 patients had only ablation of the parasympathetic ganglia and 5 patients had simultaneous pulmonary vein isolation for previously documented atrial fibrillation. 7 patients (58,3%) had sinus bradycardia (2 patients had sinus arrest with pauses of 8 and 13 seconds), 2 patients with cardioinhibitory syncope (with pauses of 23 and 28 seconds) and 3 patients had transient high degree AV block. The ablation procedure led to a median sinus rate acceleration of 15 bpm (IQR 3-29), a median decrease of 320 ms in PW (IQR 23,75-609,5) in patients with sinus arrest and a decrease of 80 ms in wenckenback CL (IQR 60-200) in patients with AV block. With a median follow up of 133,50 days (IQR 36-61,75), no patient had recurrence of symptoms or conduction disturbances. Conclusions In selected patients with severe functional paroxysmal bradyarrhytmias, cardiac denervation using an ablation strategy purely based on anatomic aspects and targeting only the right GP, seems to be an effective therapeutic approach. Abstract Figure 1: Abl of right ganglionated plex