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

BACKGROUND

There is a paucity of evidence on impact of a delay in Cardiac Sarcoidosis (CS) diagnosis after high-grade atrioventricular-block (AVB) and this study aims to fill this void.

METHODS

Consecutive CS patients (n = 77) with high grade AVB referred to one specialist hospital in London between February 2007 to February 2023 were retrospectively reviewed. The median time from AVB to diagnosing CS (112 days) was used to define the Early (n = 38) and Late (n = 39) cohorts. The primary endpoint was a composite of all-cause mortality, cardiac transplantation, ventricular arrhythmic events or heart failure hospitalisation. Secondary endpoints included difference in maintenance prednisolone dose, need for cardiac device upgrade and device complications.

RESULTS

The mean age of the cohort was 54.4 (±10.6) years of whom 64 % were male and 81 % Caucasian. After a mean follow up of 54.9 (±45.3) months, the primary endpoint was reached by more patients from the Late cohort (16/39 vs. 6/38, p = 0.02; multivariable HR 6.9; 95 %CI 1.5-32.2, p = 0.01). Early Group were more likely to have received an Implantable Cardioverter Defibrillator or Cardiac Resynchronisation Therapy-defibrillator as index device after AVB (19/38 vs. 6/39; p < 0.01) and had fewer device upgrades (19/38 vs. 30/39, p = 0.01) and a trend towards fewer device complications (1 vs. 5, p = 0.20). The maintenance dose of prednisolone was significantly higher in Late Group [20.7(±9.7) mg vs. 15.3(±7.9) mg, p = 0.02].

CONCLUSION

A late diagnosis of CS was associated with more adverse events, a greater probability of needing a device upgrade and required higher maintenance steroid dose.

Novel method to avoid serious injurious effects on the atrioventricular nodal (AVN) conduction during catheter ablation of the AVN slow pathway utilizing cryofreezing energy

BACKGROUND

Slow pathway elimination of the atrioventricular node (AVN) is essential to treat AVN reentrant tachycardia (AVNRT). However, injury to the AVN conduction (IAVN) is one of the serious complications. Cryofreezing energy is expected to reduce the incidence of IAVN. This study aimed to investigate the usefulness of a novel method to avoid IAVN during cryoablation of AVNRT.

METHODS

A total of 157 patients (average age, 65.8 years; male, 71) suffering from AVNRT were included. Once the AVNRT terminated during cryo-ablation, then rapid atrial constant pacing (RACP) was performed during freezing at a rate lower 10 bpm than that inducing Wenchebach AV block in 74 (47.1 %) patients (Group A). The RACP rate was decreasingly reduced by 10 bpm in case of the occurrence of IAVN. When the RACP reached 100 bpm, the cryoablation was prematurely terminated. Group B patients (83 = 52.9 %) underwent cryoablation during sinus rhythm. All patients were allocated in a randomized fashion. We compared the severity of the IAVN between Groups A and B.

RESULTS

There were no significant differences at 12 months regarding the freedom from the AVNRT between Groups A and B. However, the duration of the IAVN was significantly longer in Group B than A (p = 0.02). There were no significant differences regarding the distance between the His recording sites and successful ablation sites between Groups A and B. No permanent IAVN requiring pacemaker implantation was provoked in either group.

CONCLUSION

RACP was useful to avoid sustained and serious IAVN during cryoablation of AVNRT.

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

BACKGROUND

Atrioventricular block (AVB) is a frequent complication in patients undergoing transcatheter aortic valve implantation (TAVI). Right apex ventricular pacing (RVP) represents the standard treatment but may induce cardiomyopathy over the long term. Left bundle branch area pacing (LBBAP) is a promising alternative, minimizing the risk of desynchrony. However, available evidence with LBBAP after TAVI is still low.

OBJECTIVE

To assess the feasibility and safety of LBBAP for AVB post-TAVI compared with RVP.

METHODS

Consecutive patients developing AVB early after TAVI were enrolled between 1 January 2022 and 31 December 2022 at three high-volume hospitals and received LBBAP or RVP. Data on procedure and at short-term follow-up (at least 3 months) were collected.

RESULTS

A total of 38 patients (61% men, mean age 83 ± 6 years) were included; 20 patients (53%) received LBBAP. Procedural success was obtained in all patients according to chosen pacing strategy. Electrical pacing performance at implant and after a mean follow-up of 4.2 ± 2.8 months was clinically equivalent for both pacing modalities. In the LBBAP group, procedural time was longer (70 ± 17 versus 58 ± 15 min in the RVP group, P  = 0.02) and paced QRS was shorter (120 ± 19 versus 155 ± 12 ms at implant, P  < 0.001; 119 ± 18 versus 157 ± 9 ms at follow-up, P  < 0.001). Complication rates did not differ between the two groups.

CONCLUSION

In patients with AVB after TAVI, LBBAP is feasible and safe, resulting in a narrow QRS duration, either acutely and during the follow-up, compared with RVP. Further studies are needed to evaluate if LBBAP reduces pacing-induced cardiomyopathy in this clinical setting.

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

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

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

BACKGROUND

There is little literature on the use of temporary pacemakers in children with fulminant myocarditis. Therefore, we summarized the use of temporary cardiac pacemakers in children with fulminant myocarditis in our hospital.

METHODS

The clinical data of children with fulminant myocarditis treated with temporary pacemakers in Wuhan Children's Hospital from January 2017 to May 2022 were retrospectively analyzed.

RESULTS

A total of 6 children were enrolled in the study, including 4 boys and 2 girls, with a median age of 50 months and a median weight of 15 kg. The average time from admission to pacemaker placement was 2.75 ± 0.4 h. The electrocardiogram showed that all 6 children had third-degree atrioventricular block (III°AVB). The initial pacing voltage, the sensory sensitivity of the ventricle and the pacing frequency were set to 5-10 mV, 5 V and 100-120 bpm respectively. The sinus rhythm was recovered in 5 patients within 61 h (17-134) h, and the median time of using temporary pacemaker was 132 h (63-445) h. One of the children had persistent III°AVB after the temporary pacemaker. With parental consent, the child was fitted with a permanent pacemaker on the 12th day of his illness.

CONCLUSIONS

When fulminant myocarditis leads to severe bradycardia or atrioventricular block in children, temporary pacemakers have the characteristics of high safety to improve the heart function.

Impact of New-Onset Right Bundle-Branch Block After Transcatheter Aortic Valve Replacement on Permanent Pacemaker Implantation

BACKGROUND

A delayed and recurrent complete atrioventricular block (CAVB) is a life-threatening complication of transcatheter aortic valve replacement (TAVR). Post-TAVR evaluation may be important in predicting delayed and recurrent CAVB requiring permanent pacemaker implantation (PPI). The impact of new-onset right bundle-branch block (RBBB) after TAVR on PPI remains unknown.

METHODS AND RESULTS

In total, 407 patients with aortic stenosis who underwent TAVR were included in this analysis. Intraprocedural CAVB was defined as CAVB that occurred during TAVR. A 12-lead ECG was evaluated at baseline, immediately after TAVR, on postoperative days 1 and 5, and according to the need to identify new-onset bundle-branch block (BBB) and CAVB after TAVR. Forty patients (9.8%) required PPI, 17 patients (4.2%) had persistent intraprocedural CAVB, and 23 (5.7%) had delayed or recurrent CAVB after TAVR. The rates of no new-onset BBB, new-onset left BBB, and new-onset RBBB were 65.1%, 26.8%, and 4.7%, respectively. Compared with patients without new-onset BBB and those with new-onset left BBB, the rate of PPI was higher in patients with new-onset RBBB (3.4% versus 5.6% versus 44.4%, P<0.0001). On post-TAVR evaluation in patients without persistent intraprocedural CAVB, the multivariate logistic regression analysis showed that new-onset RBBB was a statistically significant predictor of PPI compared with no new-onset BBB (odds ratio [OR], 18.0 [95% CI, 5.94-54.4]) in addition to the use of a self-expanding valve (OR, 2.97 [95% CI, 1.09-8.10]).

CONCLUSIONS

Patients with new-onset RBBB after TAVR are at high risk for PPI.

Transvenous lead advancement in pediatric pacing to overcome growth-induced lead straightening and stretching

BACKGROUND

The stretching of the lead caused by somatic growth may lead to complications (dislodgement, fracture, failure) of transvenous leads implanted in pediatric patients. Atrial loop and absorbable ligatures may prevent it. Periodical lead advancement with lead pushing from the pocket may be an option to growth-induced stretching. Our aim was to analyze retrospectively the outcome of periodical transvenous lead advancement in children with pacemaker (PM).

METHODS

A procedure of lead advancement was performed in patients with a single-chamber PM implanted for isolated congenital complete atrioventricular block or sinus node dysfunction with growth-induced lead straightening/stretching. The PM pocket was opened, the lead was released from subcutaneous adherences and was gently advanced to shape again a loop/semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are described as median (25th-75th centiles).

RESULTS

14 patients with 13 VVIR and 1 AAIR PM implanted at 6.8 (5.9-8.0) years of age, 23 (19-26) kg, 118 (108-124) cm, underwent 30 advancement procedures, 1.5 (1.0-2.3) per patient, during follow-up [45 (35-63) months]. Delta between procedures was: 18 (14-25) months, 11 (7-13) cm, 6 (4-9) kg; 90% of leads were successfully advanced without complications. Three unsuccessful procedures occurred with longer times [30 (14-37) months]. Electrical lead parameters did not show significant differences pre-/post-procedures.

CONCLUSION

the advancement of transvenous leads in children seems safe and effective. This procedure may be another possible choice to preserve transvenous lead position and function until growth has completed.

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

INTRODUCTION

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.

METHODS

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%.

RESULTS

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.

CONCLUSION

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 conduction disorders in aortic valve infective endocarditis

BACKGROUND

Aortic valve infective endocarditis may be complicated by high-degree atrioventricular block in up to 10-20% of cases.

AIM

To assess high-degree atrioventricular block occurrence, contributing factors, prognosis and evolution in patients referred for aortic infective endocarditis.

METHODS

Two hundred and five patients referred for aortic valve infective endocarditis between January 2018 and March 2021 were included in this study. A comprehensive assessment of clinical, electrocardiographic, biological, microbiological and imaging data was conducted, with a follow-up carried out over 1 year.

RESULTS

High-degree atrioventricular block occurred in 22 (11%) patients. In univariate analysis, high-degree atrioventricular block was associated with first-degree heart block at admission (odds ratio 3.1; P=0.015), periannular complication on echocardiography (odds ratio 6.9; P<0.001) and severe biological inflammatory syndrome, notably C-reactive protein (127 vs 90mg/L; P=0.011). In-hospital mortality (12.7%) was higher in patients with high-degree atrioventricular block (odds ratio 4.0; P=0.011) in univariate analysis. Of the 16 patients implanted with a permanent pacemaker for high-degree atrioventricular block and interrogated, only four (25%) were dependent on the pacing function at 1-year follow-up.

CONCLUSIONS

High-degree atrioventricular block is associated with high inflammation markers and periannular complications, especially if first-degree heart block is identified at admission. High-degree atrioventricular block is a marker of infectious severity, and tends to raise the in-hospital mortality rate. Systematic assessment of patients admitted for infective endocarditis suspicion, considering these contributing factors, could indicate intensive care unit monitoring or even temporary pacemaker implantation in those at highest risk.

[High-degree atrioventricular (AV) block]

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

Utility of new FDG-PET/CT guidelines for diagnosing cardiac sarcoidosis in patients with implanted cardiac pacemakers for atrioventricular block

Diagnosing cardiac sarcoidosis (CS), especially in isolated cases, is challenging, particularly due to the limitations of endomyocardial biopsy, leading to potential undiagnosed cases in pacemaker-implanted patients. This study aims to provide real world findings to support new guideline for CS using 18F-fluoro-deoxyglucose positron-emission tomography computed tomography (FDG-PET/CT) which give a definite diagnosis of isolated CS (iCS) without histological findings. We examined consecutive patients with cardiac pacemakers for atrioventricular block (AV-b) attending our outpatient pacemaker clinic. The patients underwent periodical follow-up echocardiography and were divided into two groups according to echocardiographic findings: those with suspected CS and those without suspected CS. Patients suspected of having nonischemic cardiomyopathy underwent FDG-PET/CT for CS diagnosis. We investigated the utility of the new guideline for CS using FDG-PET/CT. Among the 272 patients enrolled, 97 patients were implanted with cardiac pacemakers for AV-b. Twenty-two patients were suspected of having CS during a median observation period of 5.4 years after pacemaker implantation. Of these, one did not consent, and nine of 21 cases (43%) were diagnosed with definite CS according to the new guidelines. Five of these nine patients were diagnosed with iCS using FDG-PET/CT. The number of patients diagnosed with definite CS using the new guidelines tended to be approximately 2.3 times that of the conventional criteria (p = 0.074). Three of the nine patients underwent steroid treatment. The composite outcome, comprising all-cause death, heart failure hospitalization, and a substantial reduction in left ventricular ejection fraction, were significantly lower in patients receiving steroid treatment compared to those without steroid treatment (p = 0.048). The utilization of FDG-PET/CT in accordance with the new guidelines facilitates the diagnosis of CS, including iCS, resulting in approximately 2.3 times as many diagnoses of CS compared to the conventional criteria. This guideline has the potential to support the early identification of iCS and may contribute to enhancing patient clinical outcomes.

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

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

Centennial of the original description of Mobitz type II second-degree atrioventricular block

The year 2024 marks the centenary of Mobitz's description of type II second-degree atrioventricular block. Its definition remains valid to this day with only minor modification for the diagnosis of infranodal conduction block. Mobitz a century ago indicated that his type II atrioventricular block was associated with Stock-Adams attacks and a prolonged duration of the QRS complex before the eventual description of bundle branch block.

T-wave oversensing after implantation of pacemakers with automatic sensitivity adjustment in patients with atrioventricular block

T-wave oversensing in pacemakers is rare because the set sensitivity is generally fixed. However, several models of pacemaker employ automatic sensitivity adjustment. Here, we present two cases of atrioventricular block treated by implantation of the pacemaker with automatic sensitivity adjustment. After implanting the pacemaker with automatic sensitivity adjustment, ventricular pacing suppression due to T-wave oversensing occurred. In both cases, T-wave oversensing disappeared after adjusting the setting sensitivity from 0.9 to 2.0 mV.

Postoperative Atrioventricular Block in Pediatric Patients: Impact of Congenital Cardiac Malformations and Medications

Postoperative atrioventricular block may occur after pediatric cardiac surgery. A small proportion of those who develop atrioventricular block will require pacemaker placement. The primary aim of this study was to determine factors associated with postoperative atrioventricular block. Secondary aims included determining factors associated with pacemaker placement in those with atrioventricular block. Data from the PHIS data were utilized to identify patients under 18 years of age who underwent cardiac surgery. Those who did and did not develop atrioventricular block. Univariable analyses and regression analyses were conducted to determine factors associated with postoperative atrioventricular block. Similar analyses were conducted to determine factors associated with pacemaker placement in those with atrioventricular block. A total of 43,716 admissions were identified. Of these, 2093 (5%) developed atrioventricular block and 480 (1% of total admissions) underwent pacemaker placement. Approximately 70% of those with atrioventricular block received steroids but this was not associated with a decrease in pacemaker placement. Risk factors (congenital malformations of the heart, comorbidities, medications) associated with increased risk of atrioventricular block and pacemaker placement were identified. Postoperative atrioventricular block occurred in 5% of pediatric admissions for cardiac surgery. Of these admissions with postoperative atrioventricular block, 23% required pacemaker placement. Isoproterenol and steroids were not associated with a reduction in the likelihood of pacemaker placement.

Prevalence of transthyretin cardiac amyloidosis in patients with high-degree AV block

OBJECTIVE

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative cardiac disorder caused by deposition of wild type or mutated transthyretin. As ATTR-CM is associated with conduction disease, we sought to determine its prevalence in patients with idiopathic high-degree atrioventricular (AV) block requiring permanent pacemaker (PPM) implantation.

METHODS

Consecutive patients aged 70-85 years undergoing PPM implantation for idiopathic high-degree AV block between November 2019 and November 2021 were offered a 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scan. Demographics, comorbidities, electrocardiographic and imaging data from the time of device implantation were retrospectively collected.

RESULTS

39 patients (79.5% male, mean (SD) age at device implantation 76.2 (2.9) years) had a DPD scan. 3/39 (7.7%, all male) had a result consistent with ATTR-CM (Perugini grade 2 or 3). Mean (SD) maximum wall thickness of those with a positive DPD scan was 19.0 mm (3.6 mm) vs 11.4 mm (2.7 mm) in those with a negative scan (p=0.06). All patients diagnosed with ATTR-CM had spinal canal stenosis and two had carpal tunnel syndrome.

CONCLUSIONS

ATTR-CM should be considered in older patients requiring permanent pacing for high-degree AV block, particularly in the presence of left ventricular hypertrophy, carpal tunnel syndrome or spinal canal stenosis.

Unusual atrial pacing induced by type II far-field p-wave sensing in a patient with complete atrioventricular block

An 88-year-old Japanese woman underwent DDD pacemaker (MicroPort KORA 250 DR, V lead: VEGA R52) implantation for complete atrioventricular block. A 12-lead electrocardiogram for a routine examination showed atrial pacing within the intrinsic P wave, followed by inhibition of ventricular pacing. Pacemaker interrogation revealed no abnormalities in the basic parameters; however, ventricular pacing was inhibited by far-field sensing of intrinsic atrial waves before atrial events; type II far-field P-wave sensing. As a result, unusual atrial pacing occurred due to the pause suppression algorithm, which is the one of the functions that prevent atrial fibrillation development.

Strategies to improve atrioventricular synchrony in patients with a Micra AV leadless pacemaker

The second generation of transcatheter pacing systems, called Micra AV, can provide atrioventricular (AV) synchronous pacing via a new pacing algorithm relying on sensing mechanical atrial contraction. Several novel programming parameters were introduced to enable AV synchronous pacing, including an A3 window and A4 window as well as a conduction mode switch and an activity mode switch. In addition to several automated features, manual programming optimization of some of the novel parameters is key to improving AV synchrony. A solid knowledge of the features and their programming is essential for electrophysiologists implanting or following patients with Micra AV devices. Differences in programming optimization might partially explain the high variability of AV synchrony published in real-world data reports. This article reviews the key programming parameters of Micra AV. Subsequently, optimal programming recommendations for defined patient profiles are presented. Those were established by consensus within an expert panel comprised of 11 European electrophysiologists from high-volume Micra AV centres. The patient profiles were (1) high degree AV block and slow sinus rhythm; (2) high degree AV block and fast sinus rhythm; and (3) intermittent AV block. The panel recommended to evaluate the mechanical atrial activity on transthoracic echocardiography prior to implant. It was also agreed that Auto A3 Threshold and Tracking Check should be turned off in all patients, AV conduction mode switch should be turned off in all patients with high degree AV block, and the lower rate should be programmed to 50 bpm with exceptions based on individual clinical assessment. Future studies will be useful to evaluate the strength of those recommendations to improve the AV synchrony.

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

BACKGROUND

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.

METHODS AND RESULTS

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.

CONCLUSIONS

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.

Cardioneuroablation for pediatric patients with functional sinus node dysfunction and paroxysmal atrioventricular block

INTRODUCTION

Severe transitory episodes of bradycardia with subsequent syncope in children are common, and generally portend a benign prognosis. Rarely, patients may experience prolonged asystolic episodes secondary to significant sinus pauses (SP) or paroxysmal atrioventricular block (AVB). Cardioneuroablation (CNA) is a catheter-based intervention, used to identify and ablate the epicardial ganglionated plexi (GP), which results in disruption of the vagal-mediated parasympathetic input to the sinus and atrioventricular node.

OBJECTIVE

Describe the methodology and role of CNA for treatment of pediatric patients with functional AVB or SP.

METHODS

This is a single-center, case series study. Patients with SP or AVB, 21 years of age or younger, who underwent CNA between 2015 and 2021 were included. CNA was performed via anatomically guided and high-frequency stimulation methods.

RESULTS

Six patients were included. The median age was 18.9 years (range 12.3-20.9 years), 33% female. Two patients had prolonged SP, two had paroxysmal AVB, and two had both SP and AVB. Four patients had prior syncope. The median longest pause was 8.9 s (range 3.9-16.8) with 11 total documented pauses (range 2-231) during the 6 months pre-CNA. Post-CNA, the median longest pause was 1.3 s (range 0.8-2.2) with one documented SP after termination of atrial tachycardia at the 3-month follow-up. At 6 months, the median longest pause was 1.1 s (0.8-1.3) with 0 documented pauses. No patients had syncope post-CNA.

CONCLUSION

CNA may be an effective alternative to pacemaker implantation in pediatric patients with syncope or significant symptoms secondary to functional SP or AVB.

Predictors for new-onset conduction block in patients with pure native aortic regurgitation after transcatheter aortic valve replacement with a new-generation self-expanding valve (VitaFlow Liberty™): a retrospective cohort study

BACKGROUND

New-generation self-expanding valves can improve the success rate of transcatheter aortic valve replacement (TAVR) for severe pure native aortic regurgitation (PNAR). However, predictors of new-onset conduction block post-TAVR using new-generation self-expanding valves in patients with PNAR remain to be established. Therefore, this study aimed to identify predictors of new-onset conduction block post-TAVR using new-generation self-expanding valves (VitaFlow Liberty™) in patients with PNAR.

METHODS

In this retrospective cohort study, patients were categorized into pacemaker and non-pacemaker groups based on their need for new postoperative permanent pacemaker implantation (PPI). Based on the postoperative presence of either new-onset complete left bundle branch block (cLBBB) or high-grade atrioventricular block (AVB), patients were further classified into conduction disorder and non-conduction disorder groups. Laboratory, echocardiographic, computed tomography, preoperative and postoperative electrocardiography, and procedural and clinical data were collected immediately after TAVR and during hospitalization and compared between the groups. Multivariate logistic regression analysis was performed incorporating the significant variables from the univariate analyses.

RESULTS

This study examined 68 consecutive patients with severe PNAR who underwent TAVR. In 20 patients, a permanent pacemaker was fitted postoperatively. Multivariate logistic regression analysis revealed an association between the need for postoperative PPI and preoperative complete right bundle branch block (cRBBB) or first-degree AVB, as well as a non-tubular left ventricular outflow tract (LVOT). In addition, valve implantation depth and angle of aortic root were independent predictors of new-onset cLBBB or high-grade AVB developing post-TAVR. The predictive value of valve implantation depth and angle of aortic root was further supported by receiver operating characteristic curve analysis results.

CONCLUSIONS

In patients with PNAR undergoing TAVR using self-expanding valves, preoperative cRBBB or first-degree AVB and a non-tubular LVOT were indicators of a higher likelihood of PPI requirement. Moreover, deeper valve implantation depth and greater angle of aortic root may be independent risk factors for new-onset cLBBB or high-grade AVB post-TAVR. Valve implantation depth and angle of aortic root values may be used to predict the possibility of new cLBBB or high-grade AVB post-TAVR.

Relationship between systemic immune inflammation index and development of complete atrioventricular block in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

The systemic immune-inflammation index (SII), based on white blood cell, neutrophil, and platelet counts, is a proposed marker of systemic inflammation and immune activation. This study aimed to explore the relationship between SII and complete atrioventricular block (CAVB) development in STEMI patients undergoing primary PCI.

METHODS

We retrospectively analyzed data from 883 patients who underwent primary PCI for STEMI between January 2009 and December 2017. Patients were categorized into two groups based on CAVB development. SII levels were calculated from blood samples taken on admission.

RESULTS

Of the included patients, 48 (5.03%) developed CAVB. SII was higher in patients with CAVB compared to those without CAVB (1370 [1050-1779]x109/L vs. 771 [427-1462] x109/L, p < 0.001). Multivariate analysis showed a significant positive correlation between SII and the risk of CAVB development (OR:1.0003, 95%CI:1.0001-1.0005, P = 0.044). The cut-off value for the SII in the estimation of CAVB was 1117.7 × 109/L (area under the ROC curve [AUC]: 0.714, 95% CI = 0.657-0.770 with a sensitivity of 70.8% and specificity of 65.6%, p < 0.001).

CONCLUSION

This study showed a significant link between high SII levels and CAVB development in STEMI patients undergoing PCI. Our findings suggest that SII may be a valuable, routinely available, and inexpensive marker for identifying patients at increased risk of CAVB.

International Cohort of Neonatal Timothy Syndrome

INTRODUCTION

Timothy syndrome (TS) is an extremely rare, multisystem disorder classically associated with long QT, syndactyly, ventricular arrhythmias, and hypoglycaemia. A neonatal diagnosis allows maximal medical and device therapy to be implemented to avoid malignant arrhythmias and sudden cardiac death.

METHODS

This was a retrospective case series study of type I TS (TS1) patients using data from the Timothy Syndrome Foundation's international registry, encompassing patients with a genetic diagnosis (CACNA1C variant G406R in exon 8A) recruited over a 28-year period.

RESULTS

Forty-four cases of TS1 were included (26 male; 60%). Mean gestational age (GA) was 35.6 weeks (range 28 weeks - term), with 43% of patients born less than 37 weeks GA. In TS1 patients presenting with foetal bradycardia, mean GA was significantly lower (34.2 weeks, p < 0.05). Foetal bradycardia secondary to atrioventricular block was present in 20 patients (45%), resulting in premature delivery in 14 patients (32%). Fifteen patients (34%) were diagnosed with TS1 as neonates. Long QT at birth helped secure a diagnosis in 25 patients (57%). Syndactyly was seen in most patients (n = 40, 91%). Twenty patients died, with an average age of death of 2.3 years (range 1 month-6 years). Of the 7 patients who died before the first year of life (16%), the average age of death was 2.5 months.

CONCLUSION

TS is associated with high early mortality. TS should be considered in paediatric patients presenting with long QT and syndactyly. Recognition of TS in the neonatal period allows for early intervention to prevent life-threatening arrhythmias.

Complete atrioventricular block-an uncommon clinical presentation in an adult patient with proven dengue fever

Dengue is a viral disease that clinically presents with fever, thrombocytopenia-related haemorrhagic complications and shock in its severest form. This female patient in her 40s primarily presented to the emergency department of the cardiac centre as syncopal attacks with a complete atrioventricular block. Temporary cardiac pacing as an emergency procedure helped to maintain cardiac rhythm and haemodynamics. A history of recent onset fever helped us to suspect and confirmed by serology for dengue pathology. Normal sinus rhythm was restored after 2 days, and we removed the temporary pacing. Cardiac arrhythmia did not recur in 6 months of follow-up. The aetiology for dengue-related cardiac arrhythmia is still not established. In the recovery phase from fever, complete heart block may show up as a primary presentation in the emergency. Its timely diagnosis and temporary pacing may allow spontaneous recovery. The inclusion of electrocardiography in dengue patient guidelines should help clinicians to dictate its treatment.