Arrhythmia detection using an implantable loop recorder after a negative electrophysiology study in Brugada syndrome: Observations from a multicenter international registry

BACKGROUND

Risk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of the electrophysiology study (EPS) has been a subject of debate. In some centers, it is common practice to use an implantable loop recorder (ILR) after a negative EPS to help in risk stratification. However, the diagnostic value of this approach has never been specifically addressed.

OBJECTIVE

The aim of this study was to describe the baseline characteristics and the main findings of a diagnostic workup strategy with an ILR after a negative EPS in BrS.

METHODS

We conducted a retrospective international registry including patients with BrS and negative EPS (ie, noninducible ventricular tachycardia or ventricular fibrillation) before ILR monitoring.

RESULTS

The study included 65 patients from 8 referral hospitals in The Netherlands, Spain, and the United Kingdom (mean age, 39 ± 16 years; 72% male). The main indication for ILR monitoring was unexplained syncope/presyncope (66.2%). During a median follow-up of 39.0 months (Q1 25.0-Q3 47.6 months), 18 patients (27.7%) experienced 21 arrhythmic events (AEs). None of the patients died during follow-up. Bradyarrhythmias were the most common finding (47.6%), followed by atrial tachyarrhythmias (38.1%). Only 3 patients presented with ventricular arrhythmias. AEs were considered incidental in 12 patients (66.7%). In 11 patients (61.1%), AEs led to specific changes in treatment.

CONCLUSION

The use of ILR after a negative EPS in BrS is a safe strategy that reflected the high negative predictive value of EPS for ventricular arrhythmia in this syndrome. In addition, it allowed the detection of AEs in a significant proportion of patients, with therapeutic implications in most of them.

Feasibility and safety of left bundle branch area pacing in cardiac amyloidosis. A single center experience

BACKGROUND

Conventional right ventricle (RV) pacemaker stimulation has been associated with worse clinical outcomes in patients with cardiac amyloidosis (CA). Left bundle branch area pacing (LABPP) has been suggested as a promising alternative. We sought to assess the safety, feasibility, and outcomes of LABPP in patients with CA.

METHODS

We retrospectively analyzed echocardiography and pacing parameters and clinical outcomes in 23 consecutive patients with CA and LBBAP implanted from June 2020 to October 2022.

RESULTS

LBBAP was successfully performed in 22 over 23 patients (19 male, 78.6 ± 11.7 years, 20 ATTR, mean LVEF 45.5 ± 16.2%). After the procedure, 9 patients showed Qr pattern and 11 a qR pattern in V1 on ECG. Average procedure time was 67 ± 28 min. After 7.7 ± 5.2 months follow-up, no procedure-related complications had occurred. Although, a significant reduction in QRS width (p = .001) was achieved, we did not observe significant changes in LVEF and Nt ProBNP at 6 months of follow-up. Pacing parameters were stable during follow-up: LBB capture threshold and R wave amplitude were 1.0 ±  0.5 V and 10.6 ± 6.0 mV versus 0.8 ±  0.1 V, p = .21 and 10.6 ± 5.1 mV (p = .985) at follow up.

CONCLUSION

LBBAP is safe and feasible pacing technique for patients with CA. LBBAP is associated with significant narrowing of QRSd without worsening in LVEF and Nt-proBNP.

Experience and insights from a prolonged electrocardiographic monitorization with a wearable system after an embolic stroke of unknown source

BACKGROUND

Embolic cerebrovascular events that remain of unknown etiology after a thorough diagnostic evaluation, are known as Embolic Strokes of Undetermined Source (ESUS). Subclinical atrial fibrillation (AF) represents a significant underlying cause of ESUS. Our aims were to examine the overall diagnostic yield of a prolonged cardiac monitoring wearable system (PCMw) after an ESUS to detect AF and factors associated with it, including the time frame from the ESUS event to PCMw initiation. Additionally, to evaluate the frequency of unexpected arrhythmic events (UAE) and their prognostic implications.

METHODS

We retrospectively analyzed 200 ECG recordings (3-leads, 30 days duration) by means of a PCMw in patients with an ESUS to detect AF lasting longer than 30 s, between 2017 and 2021. UAE were defined as arrhythmia events that were not correlated to the main reason of prolonged cardiac monitoring.

RESULTS

AF was detected in 21 patients (10.5%). Patients with AF had more left atrial enlargement (OR = 4.22 [1.59-6.85]; p = .01) and atrial arrythmias in the initial 24-h Holter during hospitalization (OR = 5.73 [2.03-16.49]; p = .001). The detection of AF was significatively higher if the PCMw was worn within the first 30 days after the ESUS compared to beyond 30 days (17% vs. 10.3%; p = .002). Fifty three patients (26.5%) had UAE during PCMw. In six of them these findings led to targeted treatment.

CONCLUSION

PCMw represents a feasible non-invasive device that could reliably detect subclinical AF episodes after an ESUS. Diagnostic yield was significatively higher when used within the first 30 days after the event, especially in selected patients. UAE were common, but did not impact prognosis.

Efficacy and safety of Proglide use and early discharge after atrial fibrillation ablation compared to standard approach. PROFA trial

BACKGROUND AND OBJECTIVES

The common practice after atrial fibrillation ablation is to admit patients for an overnight stay. The aim of this study was to compare a strategy of vascular suture mediated closure system utilization and early discharge (strategy A) compared to traditional closure and overnight hospitalization (strategy B) regarding feasibility, safety, quality of life and health care cost effectiveness.

METHODS AND RESULTS

Hundred patients were randomized to compare both strategies. No clinical differences were reported except diabetes mellitus. Six patients (6%) had and emergency visit or were admitted in the first 30 days after procedure. Three occurred in strategy A versus three in strategy B (p = 1) (p < .005 for non-inferiority). Forty out of 50 patients (80%) were safely discharged in a time frame of 3 h and 42 patients (84%) were discharged in the same day of the procedure in strategy A. Time to discharge was shorter in strategy A compared to strategy B. (5.89 ± 7.47 h vs. 27.09 ± 2.29 p < .005). No differences were obtained in quality-of-life outcomes. Mean (95% CI) euros cost saving per patient in strategy A was 379.16 ± 93.55 p < .001. Ten acute complications (10% patients CI 95% 4.02%-15.98%) were reported during the trial. Seven (14% CI 95% 4.04%-23.96%) occurred in strategy A patients versus 3 (6% CI 95% 0.8%-12.8%) in strategy B. (p = .182) CONCLUSION: A strategy of vascular suture mediated closure system utilization and early discharge was feasible, reduced time to discharge, saved costs and was not associated with more complications or admissions/emergency visits in a 30-day time frame after procedure compared to a strategy of regular admission and discharge after overnight stay. There were no differences regarding quality-of-life parameters between both strategies.

Estimation of the QTc interval in the presence of right bundle branch block: A comparative study using validated formulae for left bundle branch block

BACKGROUND

Adequate measurement of the QT interval is of clinical importance in order to identify patients at higher risk for ventricular arrhythmias. Previous studies have described different methods to estimate baseline QT in patients with left bundle branch block (LBBB). However, the evidence regarding the assessment of the QT in patients with right bundle branch block (RBBB) is scarce.

AIM

To analyze the feasibility and reliability of the different formulae described for LBBB in the estimation of the baseline QT in the presence of RBBB.

METHODS

We performed an observational study including patients who underwent electrophysiology study and/or ablation. Two types of RBBB were considered: 1) pacing-induced and 2) transient true RBBB. QRS, JT and QT intervals were measured during baseline and RBBB. Estimated QTc was calculated using LBBB formulae: Bogossian, Rautaharju, Tabatabaei, Tang-Rabkin, Yankelson, Wang. Linear correlation and intraclass correlation coefficients (ICC) were used to assess the reliability of these formulae for the estimation of baseline QTc.

RESULTS

We finally included a total of 100 patients. Correlations between baseline and estimated QTc were strong (R > 0.7) for all the formulae except for Tabatabaei. Yankelson and Wang showed the highest reliability (ICC = 0.775 and 0.727, respectively). Yankelson appeared to be the most accurate formula, with a mean estimated QTc closest to baseline values.

CONCLUSION

Previously described formulae for LBBB exhibited marked differences regarding reliability in the estimation of the QTc interval in the presence of RBBB. According to our results, Yankelson showed the most consistent and accurate agreement in this setting.

Benefits of cardiac pacing in ICD recipients with hypertrophic cardiomyopathy

PURPOSE

Implantable cardiac defibrillator (ICD) is the only definitive therapy for prevention of sudden cardiac death in hypertrophic cardiomyopathy (HCM). Conventional transvenous ICDs can provide cardiac pacing unlike new subcutaneous ICD, but the usefulness of cardiac pacing in HCM patients is not well defined. We sought to assess the usefulness of ICD pacing in HCM.

METHODS

We retrospectively analyzed 93 HCM patients who had undergone ICD implantation at our center. Usefulness of pacing was defined as follows: 1) need of pacing due to bradycardia or AV conduction disturbances, 2) improvement of LV outflow tract obstruction by sequential AV pacing, 3) need for CRT pacing, or 4) successful antitachycardia pacing without a subsequent shock. Independent predictors of useful pacing were investigated by multivariable analysis.

RESULTS

During a mean follow-up of 91.3 ± 5.5 months, 43 patients (46.2%) reached the composite endpoint. Independent predictors of pacing usefulness were older age (HR 1.36; 95%CI: 1.088-1.709; p=0.007) and NYHA functional class ≥ II (HR 2.15; 95%CI: 1.083-4.301; p=0.029). Twenty-eight (30.1%) patients had appropriate ICD interventions, triggered by a monomorphic ventricular tachycardia (MVT) in 22 of them (78.5%). In 17 individuals with MVT (77%), antitachycardia pacing successfully treated MVT.

CONCLUSIONS

In our HCM series of patients with ICD, 46% of individuals benefitted from cardiac pacing. MVT were documented in nearly 80% of the patients with ventricular arrhythmias and antitachycardia pacing successfully treated them in 77% of cases.

Intravascular imaging in Kounis syndrome: role of IVUS and OCT in achieving an etiopathogenic diagnosis

We report a case of a 60-year-old male patient presenting with anaphylactic response to anchovies associated with an acute coronary syndrome. His history was remarkable for coronary artery disease treated with a drug eluting stent to the right coronary artery six years before and stent fracture documented by coronary angiography four years prior to the event. Coronary angiography on admission revealed a very late stent thrombosis (VLST) in the right coronary artery. Intracoronary imaging techniques (IVUS and OCT) were used and were key to discard main causes of VLST. We described the characteristics of intracoronary images, along with the advantages and disadvantages of these techniques. The findings described in this case could explain a new physiopathological mechanism of stent thrombosis occurring in stent fractures.