Active Arrhythmia Pattern: A Novel Predictor of ICD Shocks-A Subanalysis From the PARTITA Study

BACKGROUND

In the PARTITA trial (Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator?), antitachycardia pacing (ATP) predicted the occurrence of implantable cardioverter defibrillator (ICD) shocks. Catheter ablation of ventricular tachycardia after the first shock reduced the risk of death or worsening heart failure. A threshold of ATPs that might warrant an ablation procedure before ICD shocks is unknown. Our aim was to identify a threshold of ATPs and clinical features that predict the occurrence of shocks and cardiovascular events.

METHODS

We analyzed data from 517 patients in phase A of the PARTITA study. We used classification and regression tree analysis to develop and test a risk stratification model based on arrhythmia patterns and clinical data to predict ICD shocks. Secondary end points were worsening heart failure and cardiovascular hospitalization.

RESULTS

Classification and regression tree classified patients into 6 leaves by increasing shock probability. Patients treated with ≥5 ATPs in 6 months (active arrhythmia pattern) had the highest risk of ICD shocks (93% and 86%, training and testing samples, respectively). Patients without ATPs had the lowest (1% and 2%). Other predictors included left ventricle ejection fraction<35%, age of <60 years, and obesity. Survival analysis revealed a higher risk of worsening heart failure (hazard ratio, 5.45 [95% CI, 1.62-18.4]; P=0.006) and cardiovascular hospitalization (hazard ratio, 7.29 [95% CI, 3.66-14.5]; P<0.001) for patients with an active arrhythmia pattern compared with those without ATPs.

CONCLUSIONS

Patients with an active arrhythmia pattern (≥5 ATPs in 6 months) are associated with an increased risk of ICD shocks, as well as heart failure hospitalization and cardiovascular hospitalization. These data suggest that additional treatments may be helpful to this high-risk group as a preventive strategy to reduce the incidence of major events. Further prospective randomized trials are needed to confirm the benefits of early ventricular tachycardia ablation in this setting.

Incidental and anticipated arrhythmic diagnoses in patients with an implantable cardiac monitor

AIMS

In this study, we investigated a cohort of unselected patients with various indications for an implantable cardiac monitor (ICM). Our main objectives were to determine the incidence of arrhythmic diagnoses, both anticipated and incidental in relation to the ICM indication, and to assess their clinical relevance.

METHODS

We examined remote monitoring transmissions from patients with an ICM at four Italian sites to identify occurrences of cardiac arrhythmias. Concurrently, we collected data on medical actions taken in response to arrhythmic findings.

RESULTS

The study included 119 patients, with a median follow-up period of 371 days. ICM indications were syncope/presyncope (46.2%), atrial fibrillation management (31.1%), and cryptogenic stroke (22.7%). In the atrial fibrillation management group, atrial fibrillation was the most common finding, with an incidence of 36% [95% confidence interval (CI) 22-55%] at 18 months. Rates of atrial fibrillation were not significantly different between patients with cryptogenic stroke and syncope/presyncope [17% (95% CI 7-40%) vs. 8% (95% CI 3-19%), P = 0.229].For patients with cryptogenic stroke, the incidence of asystole and bradyarrhythmias at 18 months was 23% (95% CI 11-45%) and 42% (95% CI 24-65%), respectively, similar to estimates obtained for patients implanted for syncope/presyncope (P = 0.277 vs. P = 0.836).Overall, 30 patients (25.2%) required medical intervention following ICM-detected arrhythmias, predominantly involving atrial fibrillation ablation (10.9%) and medication therapy changes (10.1%).

CONCLUSION

In a real-life population with heterogeneous insertion indications, approximately 25% of patients received ICM-guided medical interventions within a short timeframe, including treatments for incidental findings. Common incidental arrhythmic diagnoses were bradyarrhythmias in patients with cryptogenic stroke and atrial fibrillation in patients with unexplained syncope.

Implantable loop recorder in Brugada syndrome: Insights from a single-center experience

Background

This study aimed to investigate the characteristics and outcomes of patients diagnosed with Brugada syndrome (BrS) who underwent implantable loop recorder (ILR) insertion during routine clinical activity.

Methods

We conducted a comprehensive screening of all consecutive patients diagnosed with BrS at our institution. We analyzed baseline clinical characteristics, arrhythmic findings, and outcomes.

Results

Out of 147 BrS patients, 42 (29 %) received an ILR, 13 (9 %) underwent implantable cardioverter-defibrillator (ICD) placement, and 92 patients (63 %) continued regular cardiological follow-up. Patients who received an ILR had a higher prevalence of suspected arrhythmic syncope (43 % vs. 22 %, p = 0.012) and tended to be younger (median age 38 years, interquartile range 30-52, vs. 43 years, 35-55, p = 0.044) with a higher presence of SCN5A gene mutations (17 % vs. 6 %, p = 0.066) compared to those who continued regular follow-up. Additionally, compared to patients with an ICD, those with an ILR had a significantly lower frequency of positive programmed ventricular stimulation (0 % vs. 91 %, p < 0.001). During a median follow-up period of 14.7 months (4.7-44.8), no deaths occurred among the patients with ILR. Eight individuals (19 %) were diagnosed with arrhythmic findings through continuous ILR monitoring, primarily atrial fibrillation, and asystolic pauses. The median time from insertion to the occurrence of these events was 8.7 months (3.6-46.4). No adverse events related to ILR were reported.

Conclusion

Continuous monitoring with ILR may facilitate the timely detection of non-malignant rhythm disorders in BrS patients with risk factors but without an indication for primary prevention ICD implantation.

Device-detected atrial sensing amplitudes as a marker of increased risk for new onset and progression of atrial high-rate episodes

BACKGROUND

Atrial high-rate episodes (AHREs) are frequent in patients with cardiac implantable electronic devices. A decrease in device-detected P-wave amplitude may be an indicator of periods of increased risk of AHRE.

OBJECTIVE

The objective of this study was to assess the association between P-wave amplitude and AHRE incidence.

METHODS

Remote monitoring data from 2579 patients with no history of atrial fibrillation (23% pacemakers and 77% implantable cardioverter-defibrillators, of which 40% provided cardiac resynchronization therapy) were used to calculate the mean P-wave amplitude during 1 month after implantation. The association with AHRE incidence according to 4 strata of daily burden duration (≥15 minutes, ≥6 hours, ≥24 hours, ≥7 days) was investigated by adjusting the hazard ratio with the CHA2DS2-VASc score.

RESULTS

The adjusted hazard ratio for 1-mV lower mean P-wave amplitude during the first month increased from 1.10 (95% confidence interval [CI], 1.05-1.15; P < .001) to 1.18 (CI, 1.09-1.28; P < .001) with AHRE duration strata from ≥15 minutes to ≥7 days independent of the CHA2DS2-VASc score. Of 871 patients with AHREs, those with 1-month P-wave amplitude <2.45 mV had an adjusted hazard ratio of 1.51 (CI, 1.19-1.91; P = .001) for progression of AHREs from ≥15 minutes to ≥7 days compared with those with 1-month P-wave amplitude ≥2.45 mV. Device-detected P-wave amplitudes decreased linearly during the 1 year before the first AHRE by 7.3% (CI, 5.1%-9.5%; P < .001 vs patients without AHRE).

CONCLUSION

Device-detected P-wave amplitudes <2.45 mV were associated with an increased risk of AHRE onset and progression to persistent forms of AHRE independent of the patient's risk profile.

Temporal relationship between haemodynamic changes and activation of closed-loop stimulation during a tilt-induced vasovagal syncope

AIMS

A dual-chamber pacemaker with closed-loop stimulation (CLS) mode is effective in reducing syncopal recurrences in patients with asystolic vasovagal syncope (VVS). In this study, we explored the haemodynamic and temporal relationship of CLS during a tilt-induced vasovagal reflex.

METHODS AND RESULTS

Twenty patients underwent a tilt test under video recording 3.9 years after CLS pacemaker implantation. Three patients were excluded from the analysis because of no VVS induced by the tilt test (n = 1) and protocol violation (n = 2). In 14 of the remaining 17 patients, CLS pacing emerged during the pre-syncopal phase of circulatory instability when the mean intrinsic heart rate (HR) was 88 ± 12 b.p.m. and systolic blood pressure (SBP) was 108 ± 19 mmHg. The CLS pacing rate thereafter rapidly increased to 105 ± 14 b.p.m. within a median of 0.1 min [inter-quartile range (IQR), 0.1-0.7 min] when the SBP was 99 ± 21 mmHg. At the time of maximum vasovagal effect (syncope or pre-syncope), SBP was 63 ± 17 mmHg and the CLS rate was 95 ± 13 b.p.m. The onset of CLS pacing was 1.7 min (IQR, 1.5-3.4) before syncope or lowest SBP. The total duration of CLS pacing was 5.0 min (IQR, 3.3-8.3). Closed-loop stimulation pacing was not observed in three patients who had a similar SBP decrease from 142 ± 22 mmHg at baseline to 69 ± 4 mmHg at the time of maximum vasovagal effect, but there was no significant increase in HR (59 ± 1 b.p.m.).

CONCLUSION

The reproducibility of a vasovagal reflex was high. High-rate CLS pacing was observed early during the pre-syncopal phase in most patients and persisted, although attenuated, at the time of maximum vasovagal effect.

REGISTRATION

ClinicalTrials.gov identifier: NCT06038708.

Predicting worsening heart failure hospitalizations in patients with implantable cardioverter defibrillators: is it all about alerts? A pooled analysis of nine trials

AIMS

To predict worsening heart failure hospitalizations (WHFHs) in patients with implantable defibrillators and remote monitoring, the HeartInsight algorithm (Biotronik, Berlin, Germany) calculates a heart failure (HF) score combining seven physiologic parameters: 24 h heart rate (HR), nocturnal HR, HR variability, atrial tachyarrhythmia, ventricular extrasystoles, patient activity, and thoracic impedance. We compared temporal trends of the HF score and its components 12 weeks before a WHFH with 12-week trends in patients without WHFH, to assess whether trends indicate deteriorating HF regardless of alert status.

METHODS AND RESULTS

Data from nine clinical trials were pooled, including 2050 patients with a defibrillator capable of atrial sensing, ejection fraction ≤ 35%, NYHA class II/III, no long-standing atrial fibrillation, and 369 WHFH from 259 patients. The mean HF score was higher in the WHFH group than in the no WHFH group (42.3 ± 26.1 vs. 30.7 ± 20.6, P < 0.001) already at the beginning of 12 weeks. The mean HF score further increased to 51.6 ± 26.8 until WHFH (+22% vs. no WHFH group, P = 0.003). As compared to the no WHFH group, the algorithm components either were already higher 12 weeks before WHFH (24 h HR, HR variability, thoracic impedance) or significantly increased until WHFH (nocturnal HR, atrial tachyarrhythmia, ventricular extrasystoles, patient activity).

CONCLUSION

The HF score was significantly higher at, and further increased during 12 weeks before WHFH, as compared to the no WHFH group, with seven components showing different behaviour and contribution. Temporal trends of HF score may serve as a quantitative estimate of HF condition and evolution prior to WHFH.

Strategic reprogramming of implantable cardiac monitors reduces the false-positive remote alert burden in a nurse-led service

AIMS

Implantable cardiac monitors (ICMs) can generate false-positive (FP) alerts. Although these devices have an extended programmability, there are no recommendations on their optimization to reduce not-relevant activations.We tested a strategic programming optimization guide based on the type of FP and investigated the safety and feasibility of the nurse-led insertion of ICMs with a long-sensing vector.

METHODS AND RESULTS

Consecutive patients implanted by trained nurses with long-sensing vector ICM were enrolled in a 1-month observational stage (Phase A). Patients who had ≥10 FP episodes underwent ICM reprogramming based on the predefined guide and were followed for an additional month (Phase B). A total of 78 patients had successful ICM insertion by nurses with a mean R wave amplitude of 0.96 ± 0.43 mV and an 86% P wave visibility. Only one patient reported a significant device-related issue, and nurse-delivered ICM was generally well accepted by the patients. During Phase A, 11 patients (14%) generated most of FP (3,627/3,849; 94%) and underwent ICM reprogramming. In the following month (Phase B), five patients (45%) were free from FP and six (55%) transmitted 57 FP alerts (98% reduction compared with Phase A). The median number of FP per patient was significantly reduced after reprogramming [195 (interquartile range, 50-311) vs. one (0-10), P = 0.0002].

CONCLUSION

A strategic reprogramming of ICM in those patients with a high FP alert burden reduces the volume of erroneous activations with potential benefits for the remote monitoring service. No concerns were raised regarding nurse-led insertion of ICMs with a long-sensing vector.

Daily and automatic remote monitoring of implantable cardiac monitors: A descriptive analysis of transmitted episodes

BACKGROUND

Remote Monitoring (RM) is recognized for its ability to enhance the clinical management of patients with implantable cardiac monitor (ICM). This study aims to provide a comprehensive description of the arrhythmic episodes transmitted by a daily and automatic RM system from a cohort of ICM patients.

METHODS

The study retrospectively analyzed daily transmissions from consecutive patients who had been implanted with a long-sensing vector ICM (BIOMONITOR III/IIIm) at four sites. All transmitted arrhythmic recordings were evaluated to determine whether they were true positive episodes or false positives (FP).

RESULTS

A total of 14,136 episodes were transmitted from 119 patients (74.8% male, median age 62 years old) during a median follow-up of 371 days. The rate of arrhythmic episodes was 14.2 per patient-year (interquartile range: 1.8-126), with 97 patients (81.5%) experiencing at least one ICM activation. Fifty-five percent of episodes were identified as FP, and 67 patients (56.3%) had at least one inappropriate activation. The FP rate was 1.4 per patient-year (0-40). The best per-episode predictive positive values were observed for bradycardia and atrial fibrillation (0.595 and 0.553, respectively). Notably, the implementation of an algorithm designed to minimize false detections significantly reduced the prevalence of atrial fibrillation FP episodes (17.6% vs. 43.5%, p = 0.008).

CONCLUSION

Daily and automatic RM appears to be a reliable tool for the comprehensive remote management of ICM patients. However, the number of arrhythmic episodes requiring review is high, and further improvements are needed to reduce FP and facilitate accurate interpretation of transmissions.

Permanent his bundle pacing: Description and comparison of four implantation techniques

INTRODUCTION

Permanent His bundle pacing (HBP) is the most physiological pacing modality, and new implantation systems are now available. The aim of the present study was to describe and compare four different techniques to perform HBP.

METHODS AND RESULTS

We included all consecutive patients who underwent a HBP attempt in our initial experience between June 2020 and May 2022. The success and characteristics of the procedure were compared among four implantation techniques: the Biotronik Selectra 3D sheath with Solia S60 lead (Selectra 3D), the Boston Scientific Site Selective Pacing Catheter with Ingevity lead (SSPC), the Abbott steerable stylet locator with Tendril lead (Locator), and the use of a standard stylet manually pre-shaped with a conventional pacing lead (Curved stylet). Ninety-eight patients (median age 79 years [interquartile range, 73-83], 83% men) were identified. The Selectra 3D technique was used in 43 procedures, SSPC in 26, Locator in 18 and Curved stylet in 11. The groups had similar clinical characteristics. Overall, procedural success was achieved in 91 patients (93%) with similar proportions among groups (p = .986). Fluoroscopy and procedural times were 6.0 (4.4-8.5) and 60 (45-75) min, respectively, without significant differences (p = .333 and p = .790). The rate of selective capture, the pacing threshold, and the paced QRS duration were also comparable. There was one pre-discharge HBP lead dislodgment (1%) that required implant revision.

CONCLUSION

In our experience, four techniques for HBP achieved comparable results in terms of safety and effectiveness. The availability of different systems may lead to widespread use of physiological pacing.

Long-term outcomes following transvenous lead extraction: Data from a tertiary referral center

BACKGROUND

Transvenous lead extraction (TLE) has shown a safe and efficacy profile in the intraoperative and short-term setting; however, data on long-term outcomes are limited.

OBJECTIVE

The purpose of this study was to assess long-term outcomes and prognostic factors in patients who underwent TLE.

METHODS

Consecutive patients with cardiac implantable electronic device (CIED) who underwent TLE between 2014 and 2016 were retrospectively studied. The primary outcome was the composite endpoint of death and repeated TLE stratified by infective/non-infective indication. Individual components of the primary outcome were also evaluated.

RESULTS

One hundred ninety-one patients were included in the analysis, 50% extracted for CIED-related infection. Complete procedural success was achieved in 189 patients (99%) with no major acute complications. After a median of 6.5 years, infection indication was associated with significantly lower event-free survival (67% vs. 83% non-infection group, adjusted hazard ratio [aHR] 1.97, 95% confidence interval [CI] 1.02-3.81, p = 0.04). All-cause mortality rate was higher in the TLE infection group (30% vs. 10%, p < 0.01). The rate of repeated TLE did not differ between groups (4% vs. 7%, p = 0.62). Among patients who had TLE for infection, the presence of vegetation (aHR 2.56; 95%CI 1.17-5.63, p = 0.02) and positive blood cultures (aHR 2.64; 95%CI 1.04-6.70, p = 0.04) were independently associated with the primary outcome.

CONCLUSION

Patients who underwent TLE for CIED-related infection exhibit a high mortality risk during long-term follow-up. Vegetation and positive blood cultures in patients with CIED-related infection are associated with a worse prognosis regardless of successful and uncomplicated TLE.

Temporal association between drops in thoracic impedance and malignant ventricular arrhythmia: A longitudinal analysis of remote monitoring trends

INTRODUCTION

Thoracic impedance (TI) drops measured by implantable cardioverter-defibrillators (ICDs) have been reported to correlate with ventricular tachycardia/fibrillation (VT/VF). The aim of our study was to assess the temporal association of decreasing TI trends with VT/VF episodes through a longitudinal analysis of daily remote monitoring data from ICDs and cardiac resynchronization therapy defibrillators (CRT-Ds).

METHODS AND RESULTS

Retrospective data from 2384 patients were randomized 1:1 into a derivation or validation cohort. The TI decrease rate was defined as the percentage of rolling weeks with a continuously decreasing TI trend. The derivation cohort was used to determine a TI decrease rate threshold for a ≥99% specificity of arrhythmia prediction. The associated risk of VT/VF episodes was estimated in the validation cohort by dividing the available follow-up into 60-day assessment intervals. Analyses were performed separately for 1354 ICD and 1030 CRT-D patients. During a median follow-up of 2.0 years, 727 patients (30.4%) experienced 3298 confirmed VT/VF episodes. In the ICD group, a TI decrease rate of >60% was associated with a higher risk of VT/VF episode in a 60-day assessment interval (stratified hazard ratio, 1.42; 95% confidence interval (CI), 1.05-1.92; p = .023). The TI decrease preceded (40.8%) or followed (59.2%) the VT/VF episodes. In the CRT-D group, no association between TI decrease and VT/VF episodes was observed (p = .84).

CONCLUSION

In our longitudinal analysis, TI decrease was associated with VT/VF episodes only in ICD patients. Preventive interventions may be difficult since episodes can occur before or after TI decrease.

Permanent His bundle pacing in patients with right atriomegaly: The value of different dedicated delivery sheaths

BACKGROUND

An enlarged right atrium (RA) is a challenging anatomy that can limit the successful use of His bundle pacing (HBP). It is unknown whether new implantation tools could help overcome these challenges.

METHODS

Consecutive patients with RA volume index >25 mL/m² in men and >21 mL/m² in women underwent permanent HBP. We used a stylet-driven lead (SDL) with an extendable helix delivered via a dedicated delivery sheath (Selectra 3D, Biotronik) as a first attempt. In case of failure, a second attempt was performed with the same lead but with a different delivery curve. Finally, a lumen-less lead (LLL) was also available as a third attempt.

RESULTS

The study cohort included 24 patients (median age 75.7 years [interquartile range, 70.9-79.0], 88% men) with a RA volume of 49 mL/m² (45-54). Using SDL, HBP was achieved with a single sheath curve in 17 patients (71%). The second attempt with the same lead but a different sheath was successful in four more patients (SDL success 87%). The fluoroscopy time increased significantly when the second attempt was necessary (8 min [6-11] vs. 15 min [13-17], p < .001). In the remaining three patients, HBP was further attempted with a LLL leading to a final procedural success of 96%. No lead dislodgment nor significant increase in pacing threshold was observed at 1-month (1.2 [0.7-1.7] V@1.0 ms vs. 1.1 [0.8-1.7] V@1.0 ms, p = .939).

CONCLUSION

The availability of different dedicated delivery systems for HBP can improve procedural outcomes even in challenging circumstances, such as in patients with right atriomegaly.

Prevalence of asystole during tilt test-induced vasovagal syncope may depend on test methodology

This review addresses tilt-testing methodology by searching the literature which reports timing of asystole and loss of consciousness (LOC). Despite the Italian protocol being the most widely adopted, its stipulations are not always followed to the letter of the European Society of Cardiology guidelines. The discrepancies permit reassessment of the incidence of asystole when tilt-down is early, impending syncope, compared with late, established LOC. Asystole is uncommon with early tilt down and diminishes with increasing age. However, if LOC is established as test-end, asystole is more common, and it is age-independent. Thus, the implications are that asystole is commonly under-diagnosed by early tilt-down. The prevalence of asystolic responses observed using the Italian protocol with a rigorous tilt down time is numerically close to that observed during spontaneous attacks by electrocardiogram loop recorder. Recently, tilt-testing has been questioned as to its validity but, in selection of pacemaker therapy in older highly symptomatic vasovagal syncope patients, the occurrence of asystole has been shown to be an effective guide for treatment. The use of head-up tilt test as an indication for cardiac pacing therapy requires pursuing the test until complete LOC. This review offers explanations for the findings and their applicability to practice. A novel interpretation is offered to explain why pacing induced earlier may combat vasodepression by raising the heart rate when sufficient blood remains in the heart.

Implantable cardioverter defibrillator lead performance: A systematic review and individual patient data Meta-analysis

BACKGROUND

Reliable post-approval surveillance of implantable cardioverter-defibrillator (ICD) lead performance remains a challenge. In the past, two ICD leads were recalled due to a high frequency of failures. In this meta-analysis, we sought to provide a combined estimate of failure-free rate for ICD leads by reconstructing individual patient data from published Kaplan-Meier (KM) curves and to investigate whether estimates could be influenced by the characteristics of the study.

METHODS

Observational studies assessing failure-free estimates of transvenous ICD leads with KM method, were identified through a systematic search up to November 2021.

RESULTS

Forty-four studies were eligible that included 41,870 (63.1%) non-recalled leads and 24,493 (36.9%) recalled leads. The 8-year cumulative failure-free rate was 94.1% (CI, 93.6% - 94.6%) for contemporary non-recalled leads and 81.2% (80.3% - 82.0%) for recalled leads (hazard ratio [HR], 3.15 [2.85-3.47], p < 0.001). Failure-free rate was lower in single-center studies in both the non-recalled (HR, 0.28 [0.15-0.51], p < 0.001) and recalled (HR, 0.54 [0.33-0.88], p = 0.014) group compared with multicenter studies. Similarly, estimates were significantly lower in small (i.e. extracted KM curve with <312 leads) versus large studies (HR non-recalled group, 0.54 [CI, 0.33-0.89], p = 0.015; HR recalled group, 0.62 [CI, 0.43-0.89], p = 0.009).

CONCLUSIONS

In this meta-analysis including >66,000 leads, we provide pooled survival curves that may play a role in generating evidence-based standards for assessing clinically acceptable failure rates for ICD leads. Lead performance was underestimated with single-center and small-sized studies; multicenter studies remain the main tool to reliably conduct post-market surveillance of ICD leads.

Insertable cardiac monitor with a long sensing vector: Impact of obesity on sensing quality and safety

Background

Fat layers in obese patients can impair R-wave detection and diagnostic performance of a subcutaneous insertable cardiac monitor (ICM). We compared safety and ICM sensing quality between obese patients [body mass index (BMI) ≥ 30 kg/m²] and normal-weight controls (BMI <30 kg/m²) in terms of R-wave amplitude and time in noise mode (noise burden) detected by a long-sensing-vector ICM.

Materials and methods

Patients from two multicentre, non-randomized clinical registries are included in the present analysis on January 31, 2022 (data freeze), if the follow-up period was at least 90 days after ICM insertion, including daily remote monitoring. The R-wave amplitudes and daily noise burden averaged intraindividually for days 61-90 and days 1-90, respectively, were compared between obese patients (n = 104) and unmatched (n = 268) and a nearest-neighbour propensity score (PS) matched (n = 69) normal-weight controls.

Results

The average R-wave amplitude was significantly lower in obese (median 0.46 mV) than in normal-weight unmatched (0.70 mV, P < 0.0001) or PS-matched (0.60 mV, P = 0.003) patients. The median noise burden was 1.0% in obese patients, which was not significantly higher than in unmatched (0.7%; P = 0.056) or PS-matched (0.8%; P = 0.133) controls. The rate of adverse device effects during the first 90 days did not differ significantly between groups.

Conclusion

Although increased BMI was associated with reduced signal amplitude, also in obese patients the median R-wave amplitude was >0.3 mV, a value which is generally accepted as the minimum level for adequate R-wave detection. The noise burden and adverse event rates did not differ significantly between obese and normal-weight patients.Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04075084 and NCT04198220.

336 TEMPORAL CONNECTION BETWEEN HOME MONITORING TRENDS OF THORACIC IMPEDANCE AND SUSTAINED VENTRICULAR ARRHYTHMIAS

Introduction

Implantable cardioverter defibrillators (ICDs) provide daily values of thoracic impedance (TI) that are inversely correlated with fluid accumulation in the lungs. Since sustained ventricular arrhythmias (SVA) are known to have a short-term relationship with heart failure exacerbations, our objective was to assess TI trends temporally related to SVA episodes.

Methods

This study analyzed data daily transmitted from patients with ICD or cardiac resynchronization therapy defibrillator (CRT-D) of the nationwide Home Monitoring Expert Alliance network. Device-detected SVAs were adjudicated for appropriateness. Patients were randomly split into a derivation and validation cohort. To identify the most significant TI trend (TI-index), several numerical TI transformations were tested in a cross-sectional analysis of the derivation cohort modelling the odds of first SVA with univariate logistic regressions. In the same cohort, the threshold of the selected transformation was identified to maximize the projected specificity. The relative risk of SVA for TI-index above threshold was estimated in the validation cohort by applying Cox proportional hazard models stratified by individual patients to 60-day duration windows. Analyses were performed separately in the ICD and CRT-D groups.

Results

The study cohort included 2,384 patients with 69 years of age (interquartile range: 60, 77); 19% were women, 42% had coronary artery disease, and 43% had a CRT-D. After a median follow-up of 2.0 (1.0, 3.4) years, there were 3,298 appropriate SVA episodes in 727 patients (30%).

The derived IT-index consisted of the percentage of 6-day intervals of the rolling average of TI values showing monotone decrease in the last 82 days. The increase in the risk of SVA was 3% (p&lt;0.0001) per unit of percentage. The threshold of 60% of intervals with monotone decrease was associated with 99.9% projected specificity and 70.3% accuracy.

In the validation cohort, the TI-Index was associated with a 42% increased risk of SVA episodes in the ICD group (hazard ratio [HR] 1.42, 95% confidence interval [CI] 1.05-1.92, p=0.023). The TI-index exceeded the 60% threshold before the episode in 38% of the detected episodes. The association was not significant in the CRT-D group (HR 0.96, 95% CI 0.62-1.47, p=0.84).

Conclusions

In our analysis of remote monitoring data, a specific monotonic decreasing trend of TI was temporally associated with SVA in patients with ICD. Careful monitoring of TI can identify a period of susceptibility to ventricular arrhythmias that deserves more intensive attention.

Ventricular Arrhythmias and Implantable Cardioverter-Defibrillator Therapy in Women: A Propensity Score-Matched Analysis

BACKGROUND

Causes of sex differences in incidence of sustained ventricular arrhythmias (SVAs) are poorly understood.

OBJECTIVES

This study aims to investigate sex-specific risk of SVAs and device therapies by balancing sex groups in relation to several baseline characteristics with the propensity score (PS).

METHODS

We used a large remote monitoring dataset from implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds). Study endpoints were time to the first appropriate SVA, time to the first device therapy for SVA, and time to the first ICD shock. Results were compared between females and a PS-matched male subgroup.

RESULTS

In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. After selecting 488 men PS-matched for 19 variables relative to baseline demographics, implant indications, principal comorbidities, and concomitant therapy, yet the SVA rate at the 2.1-year median follow-up was significantly lower in women than in man (adjusted HR: 0.65; 95% CI: 0.51-0.81; P < 0.001). Women also showed a reduced risk of any device therapy (HR: 0.59; 95% CI: 0.45-0.76; P < 0.001) and shocks (HR: 0.66; 95% CI: 0.47-0.94; P = 0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR: 0.78; 95% CI: 0.55-1.09; P = 0.14) nor in those with an ejection fraction <30% (HR: 0.80; 95% CI: 0.52-1.23; P = 0.31).

CONCLUSIONS

After matching demographics, indications, principal comorbidities, and concomitant therapy, women still exhibited a lower SVA risk profile than men, except in the subgroups of CRT-D or/and ejection fraction <30%.

Lead-related infective endocarditis with vegetations: Prevalence and impact of pulmonary embolism in patients undergoing transvenous lead extraction

INTRODUCTION

The prevalence and impact of pulmonary embolism (PE) in patients with lead-related infective endocarditis undergoing transvenous lead extraction (TLE) are unknown.

METHODS

Twenty-five consecutive patients with vegetations ≥10 mm at transoesophageal echocardiography were prospectively studied. Contrast-enhanced chest computed tomography (CT) was performed before (pre-TLE) and after (post-TLE) the lead extraction procedure.

RESULTS

Pre-TLE CT identified 18 patients (72%) with subclinical PE. The size of vegetations in patients with PE did not differ significantly from those without (median 20.0 mm [interquartile range: 13.0-30.0] vs. 14.0 mm [6.0-18.0], p = 0.116). Complete TLE success was achieved in all patients with 3 (2-3) leads extracted per procedure. There were no postprocedure complications related to the presence of PE and no differences in terms of fluoroscopy time and need for advanced tools. In the group of positive pre-TLE CT, post-TLE scan confirmed the presence of silent PE in 14 patients (78%). There were no patients with new PE formation. Large vegetations (≥20 mm) tended to increase the risk of post-TLE subclinical PE (odds ratio 5.99 [95% confidence interval (CI): 0.93-38.6], p = 0.059). During a median 19.4 months follow-up, no re-infection of the implanted system was reported. Survival rates in patients with and without post-TLE PE were similar (hazard ratio: 1.11 [95% CI: 0.18-6.67], p = 0.909).

CONCLUSION

Subclinical PE detected by CT was common in patients undergoing TLE with lead-related infective endocarditis and vegetations but was not associated with the complexity of the procedure or adverse outcomes. TLE procedure seems safe and feasible even in patients with large vegetations.

Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator? Results From the Multicenter Randomized PARTITA Trial

BACKGROUND

Optimal timing for catheter ablation of ventricular tachycardia is an important unresolved issue. There are no randomized trials evaluating the benefit of ablation after the first implantable cardioverter defibrillator (ICD) shock.

METHODS

We conducted a 2-phase, prospective, multicenter, randomized clinical trial. Patients with ischemic or nonischemic dilated cardiomyopathy and primary or secondary prevention indication for ICD were enrolled in an initial observational phase until first appropriate shock (phase A). After reconsenting, patients were randomly assigned 1:1 in phase B to immediate ablation (within 2 months from shock delivery) or continuation of standard therapy. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure. Amiodarone intake was not allowed except for documented atrial tachyarrhythmias. On July 23, 2021, phase B of the trial was interrupted as a result of the first interim analysis on the basis of the Bayesian adaptive design.

RESULTS

Of the 517 patients enrolled in phase A, 154 (30%) had ventricular tachycardia, 56 (11%) received an appropriate shock over a median follow-up of 2.4 years (interquartile range, 1.4-4.4), and 47 of 56 (84%) agreed to participate in phase B. After 24.2 (8.5-24.4) months, the primary end point occurred in 1 of 23 (4%) patients in the ablation group and 10 of 24 (42%) patients in the control group (hazard ratio, 0.11 [95% CI, 0.01-0.85]; P=0.034). The results met the prespecified termination criterion of >99% Bayesian posterior probability of superiority of treatment over standard therapy. No deaths were observed in the ablation group versus 8 deaths (33%) in the control group (P=0.004); there was 1 worsening heart failure hospitalization in the ablation group (4%) versus 4 in the control group (17%; P=0.159). ICD shocks were less frequent in the ablation group (9%) than in the control group (42%; P=0.039).

CONCLUSIONS

Ventricular tachycardia ablation after first appropriate shock was associated with a reduced risk of the combined death or worsening heart failure hospitalization end point, lower mortality, and fewer ICD shocks. These findings provide support for considering ventricular tachycardia ablation after the first ICD shock.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01547208.

Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator? Results From the Multicenter Randomized PARTITA Trial

BACKGROUND

Optimal timing for catheter ablation of ventricular tachycardia is an important unresolved issue. There are no randomized trials evaluating the benefit of ablation after the first implantable cardioverter defibrillator (ICD) shock.

METHODS

We conducted a 2-phase, prospective, multicenter, randomized clinical trial. Patients with ischemic or nonischemic dilated cardiomyopathy and primary or secondary prevention indication for ICD were enrolled in an initial observational phase until first appropriate shock (phase A). After reconsenting, patients were randomly assigned 1:1 in phase B to immediate ablation (within 2 months from shock delivery) or continuation of standard therapy. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure. Amiodarone intake was not allowed except for documented atrial tachyarrhythmias. On July 23, 2021, phase B of the trial was interrupted as a result of the first interim analysis on the basis of the Bayesian adaptive design.

RESULTS

Of the 517 patients enrolled in phase A, 154 (30%) had ventricular tachycardia, 56 (11%) received an appropriate shock over a median follow-up of 2.4 years (interquartile range, 1.4-4.4), and 47 of 56 (84%) agreed to participate in phase B. After 24.2 (8.5-24.4) months, the primary end point occurred in 1 of 23 (4%) patients in the ablation group and 10 of 24 (42%) patients in the control group (hazard ratio, 0.11 [95% CI, 0.01-0.85]; P=0.034). The results met the prespecified termination criterion of >99% Bayesian posterior probability of superiority of treatment over standard therapy. No deaths were observed in the ablation group versus 8 deaths (33%) in the control group (P=0.004); there was 1 worsening heart failure hospitalization in the ablation group (4%) versus 4 in the control group (17%; P=0.159). ICD shocks were less frequent in the ablation group (9%) than in the control group (42%; P=0.039).

CONCLUSIONS

Ventricular tachycardia ablation after first appropriate shock was associated with a reduced risk of the combined death or worsening heart failure hospitalization end point, lower mortality, and fewer ICD shocks. These findings provide support for considering ventricular tachycardia ablation after the first ICD shock.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01547208.

Ventricular arrhythmias and implantable cardioverter-defibrillator therapy in women: a propensity score-matched analysis

Funding Acknowledgements

Type of funding sources: None.

Introduction

The implantable cardioverter-defibrillator (ICD) is an established therapy for the prevention of sudden cardiac death in selected patients. Although current guidelines apply to both women and men, there is a growing awareness that the incidence of cardiac arrhythmias and device interventions is influenced by sex.

Purpose

To investigate sex-specific risk of sustained ventricular arrhythmias (SVAs) and device therapies, using remote monitoring data from ICDs and cardiac resynchronization therapy defibrillators (CRT-Ds).

Methods

Study endpoints were time to the first appropriate SVA, time to the first appropriate device therapy for SVA, and time to the first ICD shock. Appropriateness of device-detected SVAs was adjudicated by three expert electrophysiologists. Results were compared between women and a 1:1 propensity score (PS)-matched subgroup of men.

Results

In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. As compared to men, women more frequently had a CRT-D (51% vs. 40%, p&lt;0.001), and nonischemic cardiomyopathy (65% vs. 45%, p&lt;0.001). After a median follow-up of 2.1 years, SVAs occurred in 123 women (25.2%) and in 174 of the 488 PS-matched men (35.6%) with an adjusted hazard ratio (HR) of 0.65 (95% confidence interval [CI], 0.51-0.81; p&lt;0.001). Women also showed a reduced risk of any device therapy (HR, 0.59; CI, 0.45-0.76; p&lt;0.001) and shocks (HR, 0.66; CI, 0.47-0.94, p=0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR, 0.78; CI, 0.55-1.09; p=0.14) and in those with an ejection fraction &lt;30% (HR, 0.80; CI, 0.52-1.23; p=0.31).

Conclusion

In our analysis of remote monitoring data, women exhibited a lower SVA risk profile than PS-matched men in the subgroup of patients with an ICD or/and ejection fraction ≥30%.

C4 PERMANENT HIS BUNDLE PACING USING STYLET–DRIVEN LEAD IN PATIENTS WITH RIGHT ATRIOMEGALY: A SINGLE–CENTER EXPERIENCE

Background

His bundle pacing (HBP) is becoming an increasing widespread approach for physiological pacing. However, successful HBP procedure could be hampered by limited implantation tools especially in challenging anatomies. We aimed to report our experience with HBP technique using a novel stylet–driven lead system in patients with right atriomegaly.

Methods

Consecutive patients with right atrium (RA) volume &gt;25 mL/m2 in men and &gt;21 mL/m2 in women who underwent permanent HBP for standard indications were enrolled from March 2020 to March 2021. The tool of first choice for HBP attempt was a stylet–driven lead (Solia S 60, Biotronik) delivered via a dedicated introducer sheath (Selectra 3D, Biotronik). The acute, 1–month and 6–month procedural success rate was assessed.

Results

We enrolled 24 patients (median age 75 [70–79] years, 85% men) with an average RA volume of 50.7±7.8 mL/m2. At implant, conduction system pacing using stylet–driven lead was achieved in 21 patients (87%): 12 (50%) selective HBP, 6 non–selective HBP (25%) and 3 left bundle branch area pacing (12.5%). In the 3 failures, HBP was further attempted with a different system with final procedural success in 2 cases. In the successful cases, there was a significant reduction of QRS duration between paced and spontaneous beats (152.5 (130–167.5) ms vs 130 (122.5– 137.5) ms, p = 0.003). No lead dislodgment nor significant pacing threshold increase was observed at 1–month (1.30±0.76 V@0.4 vs. 1.32±0.80 V@0.4ms, p &gt; 0.9) and 6–month follow–up (1.30±0.76 V@0.4 vs. 1.38±0.97 V@0.4ms, p = 0.66).

Conclusions

In our experience, the novel stylet–driven lead system showed high implant success rates and capture threshold stability also in patients with right atriomegaly.

Programming Optimization in Implantable Cardiac Monitors to Reduce False-Positive Arrhythmia Alerts: A Call for Research

No studies have investigated whether optimizing implantable cardiac monitors (ICM) programming can reduce false-positive (FP) alerts. We identified patients implanted with an ICM (BIOMONITOR III) who had more than 10 FP alerts in a 1-month retrospective period. Uniform adjustments of settings were performed based on the mechanism of FP triggers and assessed at 1 month. Eight patients (mean age 57.5 ± 23.2 years; 37% female) were enrolled. In 4 patients, FPs were caused by undersensing of low-amplitude premature ventricular contractions (PVCs). No further false bradycardia was observed with a more aggressive decay of the dynamic sensing threshold. Furthermore, false atrial fibrillation (AF) alerts decreased in 2 of 3 patients. Two patients had undersensing of R waves after high-amplitude PVCs; false bradycardia episodes disappeared or were significantly reduced by limiting the initial value of the sensing threshold. Finally, the presence of atrial ectopic activity or irregular sinus rhythm generated false alerts of AF in 2 patients that were reduced by increasing the R-R variability limit and the confirmation time. In conclusion, adjustments to nominal settings can reduce the number of FP episodes in ICM patients. More research is needed to provide practical recommendations and assess the value of extended ICM programmability.

The Role of Preoperative Venography in Predicting the Difficulty of a Transvenous Lead Extraction Procedure

INTRODUCTION

We hypothesized that an accurate assessment of preoperative venography could be useful in predicting transvenous lead extraction (TLE) difficulty.

METHODS AND RESULTS

A dedicated preoperative venogram was performed in consecutive patients with cardiac implantable electronic device who underwent TLE. The level of stenosis was classified as without significant stenosis, moderate, severe, and occlusion. The presence of extensive lead-venous wall adherence (≥50 mm) was also assessed. A total of 105 patients (median age 71 years; 72% male) with a median of 2(1-2) leads to extract were enrolled. Preoperative venography showed moderate to severe stenosis in 31(30%), complete occlusion in 15(14%), and extensive lead-venous wall adherence in 50 (48%) patients. Complete TLE success was achieved in 103(98%) patients. Fifty-five (52%) were advanced extractions as they required a power mechanical and/or laser sheath. They were more prevalent in the group with extensive lead-venous wall adherence (72% vs. 34%, p<0.001), while no differences were found between patients with and without venous occlusion. In multivariate analysis, the presence of adherence was a predictor of advanced extraction (odds ratio 2.89[1.14-7.32], p=0.025). The fluoroscopy time was also significantly longer (14.0[8.2-18.7] vs. 5.1[2.1-10.0] min, p<0.001). The rate of complications did not differ based on the presence of venous lesions.

CONCLUSION

Although procedural success and complication rates were similar, patients with extensive lead-venous wall adherence required a longer fluoroscopy time and were 3 times more likely to need advanced extraction tools. Conversely, the presence of total venous occlusion had no impact on the procedure complexity. This article is protected by copyright. All rights reserved.

Remote assessment of QT interval: A new perspective for implantable cardiac monitors

BACKGROUND

There is an unmet need for simple tools for monitoring QT intervals. The feasibility of measuring the QT interval on the single‑lead subcutaneous electrocardiogram (subECG) recorded and transmitted by implantable cardiac monitors (ICMs) has never been tested.

METHODS

We performed a standard ECG in patients who had already been implanted with a long sensing vector ICM (BIOMONITOR, Biotronik SE&Co.) to calculate the corrected QT interval in lead II (QTc ECG). The QTc was then evaluated on the subECG provided by ICM both by using the programmer printout (QTc subECG) and the snapshot transmitted via home monitoring (QTc HM). Values were compared with Bland-Altman analyses.

RESULTS

The study cohort consisted of 23 ICM recipients (age 58 ± 19 years, 35% female) implanted mainly for unexplained syncope (78%). The mean QTc ECG interval was 404 ± 31 ms. The T-wave was visible and QTc could be calculated in all patients using the ICM programmer printout and in 21 (91%) patients remotely. The QTc subECG and QTc HM were 405 ± 34 and 406 ± 32 ms. Compared to the QTc ECG, Bland-Altman analyses revealed a bias of -0.9 (95% confidence interval: -6.8/4.9) ms and 0.1 (-12.7/12.9) ms for QTc subECG and QTc HM, respectively.

CONCLUSIONS

The QTc interval can be reliably estimated on in-person and remote subECG in most patients without bias compared to the ECG lead II assessment. This technology has the potential to facilitate remote QT interval monitoring.

Cardiac Pacing in Cardioinhibitory Reflex Syncope: Clinical Use of Closed-loop Stimulation

Cardiac pacing has been studied extensively in patients with reflex syncope over the past two decades. The heterogeneity of the forms and clinical manifestations of reflex syncope explain the controversial results of older randomised clinical trials. New evidence from recent trials has changed medical practice, now leading to clear indications for pacing in patients with asystolic syncope documented during carotid sinus massage, implantable cardiac monitoring or tilt testing. Given that recent trials in reflex syncope have been performed using the closed-loop stimulation algorithm, the authors will briefly discuss this pacing mode, review hypotheses about the mechanisms underlying its activation during syncope and provide practical instructions for programming and troubleshooting.

dST-Tiso Interval, a Novel Electrocardiographic Marker of Ventricular Arrhythmia Inducibility in Individuals With Ajmaline-Induced Brugada Type I Pattern

The aim of this study was to investigate the reliability of a novel electrocardiographic (ECG) marker in predicting ventricular arrhythmia (VA) inducibility in individuals with drug-induced Brugada syndrome (BrS) type I pattern. Consecutive patients with drug-induced type I BrS pattern underwent programmed ventricular stimulation (PVS) and, according to their response, were divided into 2 groups. Clinical characteristics and 12-lead ECG intervals before and after ajmaline infusion were compared between the 2 groups. A novel ECG marker named dST-Tiso interval consisting in the interval between the onset of the coved ST-segment elevation and its termination at the isoelectric line was also evaluated. Our cohort included 76 individuals (median age 44 years, 75% male). Twenty-five (32.9%) had VA inducibility requiring defibrillation. As compared with not inducible subjects, those with VA inducibility were more frequently male (92% vs 65%, p = 0.013), had longer PQ interval (basal: 172 vs 152 ms, p = 0.033; after ajmaline: 216 vs 200 ms, p = 0.040), higher J peak (0.6 vs 0.5 mV, p = 0.006) and longer dST-Tiso (360 vs 240 ms, p < 0.001). The dST-Tiso showed a C-statistics of 0.90 (95% confidence interval: 0.82 to 0.99) and an adjusted odds ratio for VA of 1.03 (1.01 to 1.04, p < 0.001). A dST-Tiso interval >300 ms yielded a sensitivity of 92.0%, a specificity of 90.2%, positive and negative predictive values of 82.1% and 95.8%. In conclusion, the dST-Tiso interval is a powerful predictor of VA inducibility in drug-induced BrS type I pattern. External validation is needed, but this marker might be useful in the clinical counseling process of these individuals before invasive PVS.

One-year mortality after implantable defibrillator implantation: do risk stratification models help improving clinical practice?

PURPOSE

The purpose of this study was to assess the available mortality risk stratification models for implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) patients.

METHODS

We conducted a review of mortality risk stratification models and tested their ability to improve prediction of 1-year survival after implant in a database of patients who received a remotely controlled ICD/CRT-D device during routine care and included in the independent Home Monitoring Expert Alliance registry.

RESULTS

We identified ten predicting models published in peer-reviewed journals between 2000 and 2021 (Parkash, PACE, MADIT, aCCI, CHA2DS2-VASc quartiles, CIDS, FADES, Sjoblom, AAACC, and MADIT-ICD non-arrhythmic mortality score) that could be tested in our database as based on common demographic, clinical, echocardiographic, electrocardiographic, and laboratory variables. Our cohort included 1,911 patients with left ventricular dysfunction (median age 71, 18.3% female) from sites not using any risk stratification score for systematic patient screening. Patients received an ICD (53.8%) or CRT-D (46.2%) between 2011 and 2017, after standard physician evaluation. There were 56 deaths within 1-year post-implant, with an all-cause mortality rate of 2.9% (95% confidence interval [CI], 2.3-3.8%). Four predicting models (Parkash, MADIT, AAACC, and MADIT-ICD non-arrhythmic mortality score) were significantly associated with increased risk of 1-year mortality with hazard ratios ranging from 3.75 (CI, 1.31-10.7) to 6.53 (CI 1.52-28.0, p ≤ 0.014 for all four). Positive predictive values of 1-year mortality were below 25% for all models.

CONCLUSION

In our analysis, the models we tested conferred modest incremental predicting power to ordinary screening methods.

Third-generation laser balloon ablation for atrial fibrillation treatment: a multicenter experience

Background

Laser balloon ablation is a promising option for performing pulmonary vein isolation (PVI) which is the cornerstone of invasive atrial fibrillation (AF) treatment.

Purpose

We aimed to investigate the acute efficacy and safety of the novel third-generation of the laser balloon system in an initial multicenter experience.

Methods

First and consecutive patients who underwent PVI with LB3 for drug-resistant paroxysmal or persistent AF at 7 Italian sites were included in this analysis. Study endpoints were acute procedural efficacy, defined as successful isolation of all identified PVs without radiofrequency touch-up, total and fluoroscopy times, and periprocedural complications.

Results

Our population included 86 patients (81% males, mean age 60.6±9.5 years) who underwent a procedure of PVI using LB3 between June 2020 and March 2021.

Most patients had paroxysmal AF (74%) and were in sinus rhythm at the beginning of the procedure. The mean procedure time was 138±60 min; fluoroscopy time was 22±17 min and the mean ablation time was 44±40 min. Of the 313 targeted PVs, 311 (99.4%) could be isolated with first-pass LB3 application, while 2 (0.6%) required radiofrequency touchup. At the end of the procedure, all patients were in sinus rhythm and 26 (32%) received electrical cardioversion to achieve stable sinus rhythm.

The total rate of major compilations was 1.2% (1/82 patients): one pericardial tamponade requiring epicardial puncture. No surgical intervention was necessary, and the patient recovered without any sequalae. There were no vascular access complications or phrenic nervy palsy. Three pinhole balloon raptures (3.5%) were observed during energy applications that required replacement of the whole system but had no effect on patient safety.

Conclusions

In a first multicenter experience, the LB3 system for PVI was safe with excellent acute efficacy.

Funding Acknowledgement

Type of funding sources: None.

Real use of a novel automatic motorized laser balloon for the ablation of atrial fibrillation

Background

Electric isolation of the pulmonary veins (PVs) can successfully treat patients with atrial fibrillation (AF). Isolation of pulmonary veins can be achieved by several methods: radiofrequency, cryoballoon or laser balloon ablation (LBA). The main procedural challenge with either method is to achieve a continuous circumferential lesion at the left atrium-PVs junction, with the persistence of functional gaps.

Purpose

A novel endoscopic ablation system equipped with a precise motor control system (MCS) has been evaluated. The balloon is used with an endoscope to directly visualize and ablate tissue at the left atrial-PVs junction with laser energy. This system enables uninterrupted, high-speed, circumferential lesion creation under direct control of the physician. The MCS is intended to reduce procedure time and to ensure continuity of ablation lesions. The feasibility of the motorized ablation in terms of extent of applicability along each PV-left atrium junction and time of use of the manual point-by-point mode has been investigated.

Methods

27 consecutive patients (male 70.3%, age 61.2±8.7 years) with paroxysmal or persistent AF who underwent LBA were enrolled in our institution. Exclusion criteria were any contraindication for the procedure including the presence of intracavitary thrombosis and contraindications to general anesthesia or deep sedation. After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and laser energy were projected onto the target.

Results

A total of 110 PVs were treated with LBA; in 9 patients there was a redundant right intermediate pulmonary vein; in 4 patients there was a right common ostium and in 2 a left common ostium. MCS was used for 82 PVs (74.5%): in particular, MCS was used continuously between 180° and 325° degrees (50 to 90% of PV circumference) for 35 PVs (31.8%) and between 326° and 359° degrees (91 to 99% of PV circumference) for 25 veins (22.7%). In 13 PVs (12%) MCS was used for the entire circumference. During 8508 (19.6%) seconds out of a total of 43.368 seconds, laser energy delivery occurred in the rapid mode by MCS.

No clinical complications, either local or systemic (stroke or TIA, pericardial effusion, pericardial tamponade, pulmonary vein stenosis, esophageal injury, temporary or permanent phrenic nerve palsy), were observed neither during the use of MSC nor during the use of manual point-by-point mode. Of note, a pinhole rupture of the balloon occurred in 3 cases of our series, during the use of MCS, without harm to the patient and requiring only replacement of the LBA.

Conclusions

In our case series, laser balloon ablation with the help of motor control system appears safe and feasible in most cases for large portions of pulmonary vein circumference, providing considerable time sparing (74.5% of total ablation extent in 19.6% of total ablation time).

Funding Acknowledgement

Type of funding sources: None.

Third-generation laser balloon ablation: rapid mode applicability is associated with shorter time to pulmonary vein isolation

Background

The rapid mode feature implemented in the latest version of the laser balloon system (LB3, HeartLight, X3, Cardiofocus) offers an automated continuous 360° lesion for pulmonary vein isolation (PVI). However, data on its clinical applicability and the potential reduction of procedural times are not yet available.

Purpose

To explore the use of the rapid mode and its association with PV total and fluoroscopy times in our initial experience with LB3.

Methods

This analysis included consecutive patients who underwent PVI procedure with LB3. We attempted to perform a complete circular ablation line using the rapid mode at 13 W, but if needed to achieve successful isolation, rapid mode was interrupted and manual mode (5.5–8.5 W) applications were used. The percentage of rapid mode use on the 360° lesion was measured for each PV. Total and fluoroscopy times to complete PVI were also collected.

Results

A total of 110 PVs were identified in 27 LB3 procedures and successfully isolated with a mean procedural time of 85±31 min. Sixty (55%) PVs were treated by using rapid mode for more than 50% (180°) lesion and 13 (12%) of them had a pure rapid mode ablation (without necessity of manual mode applications). Right inferior PV had the highest use of rapid mode (median value 70%). The main reasons for manual applications were poor PV occlusion, imperfect ostium visualization and presence of blood. PVs with &gt;50% rapid mode use were treated in a significantly shorter time (21.2±13.7 vs 26.8±12.4, p=0.043). Fluoroscopy time did not differ significantly (4.7±4.2 vs 5.4±4.9, p=0.48). Three pinhole balloon ruptures were observed during rapid mode energy application in the second, third and twenty-fifth procedure. No other complications occurred.

Conclusions

Few PVs could be isolated using pure rapid mode; however, its applicability for more than 50% lesion was observed more frequently and significantly reduced the time to isolation.

Funding Acknowledgement

Type of funding sources: None. Time to isolation using Rapid Mode

Cardiac resynchronization therapy defibrillators in patients with permanent atrial fibrillation

Aims

There are conflicting data on the benefit of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with permanent atrial fibrillation (AF). We aimed to compare patient outcomes according to the presence or absence of permanent AF at device implantation.

Methods and results

We retrospectively analysed remote monitoring data from 1141 CRT defibrillators. Propensity score with inverse‐probability weighting method was used to balance AF and sinus rhythm (SR) groups. Analysis endpoints included total mortality, appropriate defibrillation shocks, and CRT percentage. There were 229 patients (20.1%) in the AF group and 912 patients (79.9%) in the SR group. Compared with SR patients, AF patients were older (median age, 77 vs. 72 years, P < 0.001), more frequently male (82.5% vs. 75.5%, P = 0.02), and had higher heart rate (75.7 vs. 71.0 b.p.m., P < 0.001). Of the 229 AF patients, 162 (70.7%) received suboptimal CRT (<98%) and 67 (29.3%) had adequate CRT (≥98%). During a median follow‐up of 24 months, total mortality did not differ between AF and SR groups (propensity‐score‐weighted hazard ratio, HR 1.32 [95% confidence interval, 0.82–2.15], P = 0.25). The risk of appropriate shocks was significantly higher in the AF group with <98% CRT than in the SR group (weighted‐HR, 1.99 [1.21–3.26], P = 0.006) and was similar in the AF group with ≥98% CRT versus the SR group (1.29 [0.66–2.53], P = 0.45). During follow‐up, sinus rhythm was recovered in 23 patients in the AF group (10%) after a median time of 106 (42–256) days. The rate of sinus rhythm recovery in the AF group was 4.5 (95% CI, 2.8–6.7) per 100 patient‐years; the rate of permanent AF occurrence in the SR group was 2.5 (95% CI, 1.9–3.3) per 100 patient‐years.

Conclusions

Although mortality was similar across patient groups, patients with permanent AF and suboptimal CRT had twofold higher risk of appropriate shocks than SR patients or AF patients with CRT ≥ 98%.

Combining Home Monitoring temporal trends from implanted defibrillators and baseline patient risk profile to predict heart failure hospitalizations: results from the SELENE HF study

AIMS

We developed and validated an algorithm for prediction of heart failure (HF) hospitalizations using remote monitoring (RM) data transmitted by implanted defibrillators.

METHODS AND RESULTS

The SELENE HF study enrolled 918 patients (median age 69 years, 81% men, median ejection fraction 30%) with cardiac resynchronization therapy (44%), dual-chamber (38%), or single-chamber defibrillators with atrial diagnostics (18%). To develop a predictive algorithm, temporal trends of diurnal and nocturnal heart rates, ventricular extrasystoles, atrial tachyarrhythmia burden, heart rate variability, physical activity, and thoracic impedance obtained by daily automatic RM were combined with a baseline risk-stratifier (Seattle HF Model) into one index. The primary endpoint was the first post-implant adjudicated HF hospitalization. After a median follow-up of 22.5 months since enrolment, patients were randomly allocated to the algorithm derivation group (n = 457; 31 endpoints) or algorithm validation group (n = 461; 29 endpoints). In the derivation group, the index showed a C-statistics of 0.89 [95% confidence interval (CI): 0.83-0.95] with 2.73 odds ratio (CI 1.98-3.78) for first HF hospitalization per unitary increase of index value (P < 0.001). In the validation group, sensitivity of predicting primary endpoint was 65.5% (CI 45.7-82.1%), median alerting time 42 days (interquartile range 21-89), and false (or unexplained) alert rate 0.69 (CI 0.64-0.74) [or 0.63 (CI 0.58-0.68)] per patient-year. Without the baseline risk-stratifier, the sensitivity remained 65.5% and the false/unexplained alert rates increased by ≈10% to 0.76/0.71 per patient-year.

CONCLUSION

With the developed algorithm, two-thirds of first post-implant HF hospitalizations could be predicted timely with only 0.7 false alerts per patient-year.

Factors affecting signal quality in implantable cardiac monitors with long sensing vector

PURPOSE

Electrical artefacts are frequent in implantable cardiac monitors (ICMs). We analyzed the subcutaneous electrogram (sECG) provided by an ICM with a long sensing vector and factors potentially affecting its quality.

METHODS

Consecutive ICM recipients underwent a follow-up where demographics, body mass index (BMI), implant location, and surface ECG were collected. The sECG was then analyzed in terms of R-wave amplitude and P-wave visibility.

RESULTS

A total of 84 patients (43% female, median age 68 [58-76] years) were enrolled at 3 sites. ICMs were positioned with intermediate inclination (n = 44, 52%), parallel (n = 35, 43%), or perpendicular (n = 5, 6%) to the sternum. The median R-wave amplitude was 1.10 (0.72-1.48) mV with P waves readily visible in 69.2% (95% confidence interval, CI: 57.8%-79.2%), partially visible in 23.1% [95% CI: 14.3%-34.0%], and never visible in 7.7% [95% CI: 2.9%-16.0%] of patients. Men had higher R-wave amplitudes compared to women (1.40 [0.96-1.80] mV vs 1.00 [0.60-1.20] mV, P = .001), while obese people tended to have lower values (0.80 [0.62-1.28] mV vs 1.10 [0.90-1.50] mV, P = .074). The P-wave visibility reached 86.2% [95% CI: 68.3%-96.1%] in patients with high-voltage P waves (≥0.2 mV) at surface ECG. The sECG quality was not affected by implant site.

CONCLUSION

In ordinary clinical practice, ICMs with long sensing vector provided median R-wave amplitude above 1 mV and reliable P-wave visibility of nearly 70%, regardless of the position of the device. Women and obese patients showed lower but still very good signal quality.

Circadian periodicity affects the type of ventricular arrhythmias and efficacy of implantable defibrillator therapies

INTRODUCTION

Factors influencing malignant arrhythmia onset are not fully understood. We explored the circadian periodicity of ventricular arrhythmias (VAs) in patients with implantable cardioverter and cardiac resynchronization defibrillators (ICD/CRT-D).

METHODS

Time, morphology (monomorphic/polymorphic), and mode of termination (anti-tachycardia pacing [ATP] or shock) of VAs stored in a database of remote monitoring data were adjudicated. Episodes were grouped in six 4-h timeslots from 00:00 to 24:00. Circadian distributions and adjusted marginal odds ratios (ORs), with 95% confidence interval (CI), were analyzed using mixed-effect models and logit generalized estimating equations, respectively, to account for within-subject correlation of multiple episodes.

RESULTS

Among 1303 VA episodes from 446 patients (63% ICD and 37% CRT-D), 120 (9%) self-extinguished, and 842 (65%) were terminated by ATP, 343 (26%) by shock. VAs clustered from 08:00 to 16:00 with 44% of episodes, as compared with 22% from 00:00 to 08:00 (p < .001) and 34% from 16:00 to 24:00 (p = .005). Episodes were more likely to be polymorphic at night with an adjusted marginal OR of 1.66 (CI, 1.15-2.40; p = .007) at 00:00-04:00 versus other timeslots. Episodes were less likely to be terminated by ATP in the 00:00-04:00 (success-to-failure ratio, 0.67; CI, 0.46-0.98; p = .039) and 08:00-12:00 (0.70; CI, 0.51-0.96; p = .02) timeslots, and most likely to be terminated by ATP between 12:00 and 16:00 (success-to-failure ratio 1.42; CI, 1.06-1.91; p = .02).

CONCLUSION

VAs did not distribute uniformly over the 24 h, with a majority of episodes occurring from 08:00 to 16:00. Nocturnal episodes were more likely to be polymorphic. The efficacy of ATP depended on the time of delivery.

Intracardiac thrombus in a patient with mitral bioprosthesis and atrial fibrillation treated with direct oral anticoaugulant: A case report

RATIONALE

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased morbidity, especially stroke and heart failure. There is also increasing awareness that atrial fibrillation is a major cause of embolic events which in 75% of cases are complicated by cerebrovascular accidents.

PATIENT CONCERNS

A 50-year-old woman with mitral bioprosthesis under warfarin for nonvalvular atrial fibrillation was referred to our Coronary Intensive Care Unit due to acute myocardial infarction without evidence of significant coronary artery stenosis.

DIAGNOSES

Cardiovascular examination showed an irregular pulse and a grade II diastolic murmur was audible at the apical area. The patient underwent coronary angiography showing absence of obstructive coronary artery disease. We decided to replace Warfarin with direct oral anticoagulants as anticoagulant therapy.

INTERVENTIONS

Transoesophageal echocardiography revealed a thrombus in left atrial appendage that was treated by replacing warfarin with an oral direct thrombin inhibitor.

OUTCOMES

At 2-month follow-up, the therapy showed to be effective for thrombus resolution.

LESSONS

Our case demonstrated how AF has high risk of thromboembolic complications, not only in terms of stroke but also of myocardial infarction and death.The use of direct oral anticoagulants in AF patients with bioprosthetic heart valves is still debated due to an unclear definition of "nonvalvular" AF.

Cardiac pacing in severe recurrent reflex syncope and tilt-induced asystole

Aim

The benefit of cardiac pacing in patients with severe recurrent reflex syncope and asystole induced by tilt testing has not been established. The usefulness of tilt-table test to select candidates for cardiac pacing is controversial.

Methods and results

We randomly assigned patients aged 40 years or older who had at least two episodes of unpredictable severe reflex syncope during the last year and a tilt-induced syncope with an asystolic pause longer than 3 s, to receive either an active (pacing ON; 63 patients) or an inactive (pacing OFF; 64 patients) dual-chamber pacemaker with closed loop stimulation (CLS). The primary endpoint was the time to first recurrence of syncope. Patients and independent outcome assessors were blinded to the assigned treatment. After a median follow-up of 11.2 months, syncope occurred in significantly fewer patients in the pacing group than in the control group [10 (16%) vs. 34 (53%); hazard ratio, 0.23; P = 0.00005]. The estimated syncope recurrence rate at 1 year was 19% (pacing) and 53% (control) and at 2 years, 22% (pacing) and 68% (control). A combined endpoint of syncope or presyncope occurred in significantly fewer patients in the pacing group [23 (37%) vs. 40 (63%); hazard ratio, 0.44; P = 0.002]. Minor device-related adverse events were reported in five patients (4%).

Conclusion

In patients aged 40 years or older, affected by severe recurrent reflex syncope and tilt-induced asystole, dual-chamber pacemaker with CLS is highly effective in reducing the recurrences of syncope. Our findings support the inclusion of tilt testing as a useful method to select candidates for cardiac pacing.

Study registration

ClinicalTrials.gov identifier NCT02324920, Eudamed number CIV-05-013546.

Real use of a novel automatic motorized laser balloon for the ablation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Electric isolation of the pulmonary veins (PVs) can successfully treat patients with atrial fibrillation (AF). Isolation of pulmonary veins can be achieved by several methods: radiofrequency, cryoballoon or laser balloon ablation (LBA). The main procedural challenge with either method is to achieve a continuous circumferential lesion at the left atrium-PVs junction, with the persistence of functional gaps.

Purpose

A novel endoscopic ablation system equipped with a precise motor control system (MCS) has been evaluated. The balloon is used with an endoscope to directly visualize and ablate tissue at the left atrial-PVs junction with laser energy. This system enables uninterrupted, high-speed, circumferential lesion creation under direct control of the physician. The MCS is intended to reduce procedure time and to ensure continuity of ablation lesions. The feasibility of the motorized ablation in terms of extent of applicability along each PV-left atrium junction and time of use of the manual point-by-point mode has been investigated.

Methods

sixteen consecutive patients (male 68.7%, age 60.9 ± 7.8 years) with paroxysmal or persistent AF who underwent LBA were enrolled in our institution. Exclusion criteria were any contraindication for the procedure including the presence of intracavitary thrombosis and contraindications to general anesthesia or deep sedation. After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and laser energy were projected onto the target.

Results

A total of 62 PVs were treated with LBA; in 3 patients there was a redundant right intermediate pulmonary vein; in 4 patients there was a right common ostium and in one a left common ostium. MCS was used for 41 PVs (66.1%): in particular, MCS was used continuously between 180° and 325° degrees (50 to 90% of PV circumference) for 22 PVs (35.5%) and between 326° and 359° degrees (91 to 99% of PV circumference) for 16 veins (25.8%).  In 3 PVs (4.8%) MCS was used for the entire circumference.  During 5.659 (23.6%) seconds out of a total of 23.986 seconds, laser energy delivery occurred in the rapid mode by MCS.

No clinical complications, either local or systemic (stroke or TIA, pericardial effusion, pericardial  tamponade, pulmonary vein stenosis, esophageal injury, temporary or permanent phrenic nerve palsy), were observed neither during the use of MSC nor during the use of manual point-by-point mode. Of note, a pinhole rupture of the balloon occurred in the first 2 cases of our series, during the use of MCS, without harm to the patient and requiring only replacement of the LBA.

Conclusions

In our case series, laser balloon ablation with the help of motor control system appears safe and feasible in most cases for large portions of pulmonary vein circumference, providing considerable time sparing (66.1% of total ablation extent in 23.6% of total ablation time).

Impact of COVID-19 lockdown in patients with implantable cardioverter and cardiac resynchronization therapy defibrillators: insights from daily remote monitoring transmissions

Funding Acknowledgements

Type of funding sources: None.

Background

In Italy, a strict lockdown was imposed from 8 March 2020 to stop the spread of the Coronavirus Disease 2019 (COVID-19).

Purpose

To explore the effect of this lockdown on data transmitted by remote monitoring (RM) of implantable cardioverter and cardiac resynchronization therapy defibrillators (ICDs/CRT-Ds).

Methods

RM daily transmissions from ICDs and CRT-Ds were analyzed and compared in two consecutive 1-month frames pre- and post-lockdown: Period I (7 February–7 March 2020) and Period II (8 March–7 April 2020).

Results

The study cohort included 180 patients (81.1% male, 63.3% ICDs and 36.7% CRT-Ds) with a median age of 70 (interquartile range 62-78) years. The median value of physical activity provided by accelerometric sensors showed a significant reduction between Period I and II (13.1% [8.2-18.1%] versus 9.4% [6.3-13.8%], p < 0.001]. Eighty-nine percent of patients decreased their activity, for 43.3% the relative reduction was ≥25%. The mean heart rate decreased significantly (69.2 [63.8-75.6] bpm vs 67.9 [62.7- 75.3] bpm, p < 0.001), but with greater reduction (≈3 beats/minute) in patients aged < 70 years. Resting heart rate and thoracic impedance showed minor variations. No differences were observed in device pacing percentages and arrhythmias.

Conclusions

In cardiac patients, the lockdown imposed to contain COVID-19 outbreak significantly reduced the amount of physical activity and the mean heart rate. These side effects of in-home confinement quarantine should be taken in consideration for frail patients.

Transvenous lead extraction in patients with persistent left superior vena cava

PURPOSE

Predictors of difficulty and complications of transvenous lead extraction (TLE) have been investigated in several studies; however, little is known about the venous anatomical characteristics that can have an impact on procedural outcomes. Among them, the persistent left superior vena cava (PLSVC) is a common anomaly often discovered incidentally during cardiac device implantation and could raise concerns if TLE is indicated. We report technical considerations and outcomes of TLE for two patients with leads implanted via PLSVC.

METHODS AND RESULTS

Two cardiac implantable electronic device recipients with isolated PLSVC required TLE due to infective endocarditis in one case and lead failure in the other. In the first case, TLE procedure was performed in a hybrid operating room with minimally invasive video-assisted thoracoscopic monitoring due to the high procedural risk. Two active fixation 20-year-old pacing leads were removed with a relatively short fluoroscopy time. In the second case, we successfully extracted a single-coil active fixation lead without the need of a locking stylet or advanced extraction tools. There were no procedural complications or adverse events at 1-year follow-up.

CONCLUSION

TLE procedures for two patients with isolated PLSVC were successfully completed with less difficulty and tools than expected based on the characteristics of the targeted leads. If indicated, TLE in the presence of a PLSVC should be considered in experienced centers.

Second-generation laser balloon ablation for the treatment of atrial fibrillation assessed by continuous rhythm monitoring: the LIGHT-AF study

AIMS

Balloon-based technologies have been developed to simplify catheter ablation of atrial fibrillation (AF), to improve the clinical outcome of the procedure and to achieve durable pulmonary vein isolation (PVI). The objective of this study is to evaluate the safety and efficacy of second-generation laser balloon (LB2) ablation in the treatment of AF using a continuous cardiac rhythm monitoring strategy. Atrial tachyarrhythmias (ATas) recurrences were assessed with implantable cardiac monitors (ICMs) or devices.

METHODS AND RESULTS

All patients underwent LB2 ablation procedure. The primary endpoint was the first recurrence of any, >5.5 and >24 h duration ATas after the blanking period (90 days). In-hospital visits were performed at 3, 6, and 12 months. Seventy-three patients (68% male, mean age 59.8 ± 11.3) were included in the study. The average procedure, fluoroscopy, and laser ablation times were 81.5 ± 30.1, 21.5 ± 12.4, and 33.8 ± 9.7, respectively. All PVs were isolated using the LB2 with no need of touch-up using focal catheters. No major complications occurred during or after the procedures. The one-year freedom from recurrences was 66.9% (95% CI: 57.0-76.7%), 81.0% (69.5-88.5%), and 86.8% (76.1-92.9%) considering any, 5.5-h and 24-h cut-off duration, respectively. At 3, 6, and 12 months, any ATas was recorded in 22%, 32%, and 25% of patients, with a ≥5% arrhythmic burden documented in 4%, 5%, and 3%, respectively. Few patients reported AF-related symptoms (7%, 8%, and 5%).

CONCLUSION

LB2 ablation is a safe and effective procedure, showing a high freedom from recurrences and low arrhythmic burden as documented by a continuous rhythm monitoring strategy.

Remote monitoring of cardiac implantable devices during COVID-19 outbreak: "keep people safe" and "focus only on health care needs"

BACKGROUND

The COVID-19 pandemic has challenged the ability of health care organisations to provide adequate care. We report the experience of a national tertiary electrophysiology centre in the management of patients with cardiac implantable electronic devices (CIEDs) through the use of a fully remote follow-up model.

METHODS

We daily and prospectively collected remote monitoring (RM) relevant findings and following clinical actions performed from March 10^th to April 3^rd 2020, a period of suspension of routine ambulatory activity due to the national lockdown.

RESULTS

During the study period (25 days), we received 2,215 transmissions from 2,955 devices. Among them, 129 patients reported potential clinically actionable RM observations (event rate: 12.0/1000 patient-week). In 77 patients (60%), RM events triggered a clinical action, but only 5 patients needed an urgent in-hospital access (4 urgent procedures and 1 device reprogramming).

CONCLUSIONS

In the unprecedented COVID-19 pandemic, RM became an essential tool in healthcare delivery for CIED patients. We observed that RM was effective in "keep people safe" and "focus only on individuals with health care needs".

His-Purkinje system longitudinal dissociation: From bench to bedside. A case of output-dependent fascicular capture

INTRODUCTION

Histological studies reported that the His bundle (HB) is partitioned into narrow cords by collagen running in its long axis, providing the anatomical setting necessary for its longitudinal dissociation. Further confirmations came from the demonstration that direct HB pacing normalizes the QRS axis and duration in subjects with proximal HB lesions causing bundle branch block. However, there is no evidence of the possibility of selective HB partitions pacing destined to the composition of branches and fascicles.

METHODS AND RESULTS

We describe a case of intra-Hisian left bundle branch block in which permanent distal HB pacing corrects left ventricular delay and produces different QRS morphology at different voltage outputs, as an expression of different selective HB compartments recruitment.

CONCLUSION

This case would strengthen the limited data in the literature about HB longitudinal dissociation.

Home Monitoring trends during COVID-19 infection

BACKGROUND

Cardiac implantable electronic device (CIED) recipients could have an unfavorable prognosis if infected with the novel coronavirus (COVID-19). We aimed to analyze the data daily transmitted by the Home Monitoring (HM) system (BIOTRONIK, Berlin, Germany) of CIEDs during the infection.

METHODS

We identified CIED patients followed with the HM who experienced COVID-19 clinical manifestations. The daily trends of the following HM variables were analyzed: mean heart rate (HR), physical activity, thoracic impedance (TI), ventricular and atrial arrhythmic burden.

RESULTS

The study cohort included 10 CIED patients (median age 90 [84-92] years, male 90%) with acute respiratory syndrome. The HR showed an increase of a value ranging from 10 to 30 bpm well in advance of the severe clinical manifestations. The physical activity was generally low during the entire infection course. The TI decreased in patients presented with pulmonary edema, but increased significantly (8 to 25 Ω) in most COVID-19 patients (8 out of 10) suggesting an association with pulmonary fibrosis. Arrhythmic complications were also found in half of the patients.

CONCLUSION

The trends of HR and TI in CIEDs recipients infected by the COVID-19 often showed early recurrent patterns before adverse clinical manifestations.

Remote monitoring temporal trends during COVID-19 pneumonia in patients with implanted defibrillators

It is unknown whether some of the clinical parameters transmitted by remote monitoring (RM) of cardiac implanted devices could show recurrent patterns caused by COVID-19 infection. Our aim was to describe RM daily temporal trends for implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) recipients during COVID-19 infection. A 65-year-old woman with a CRT-D had a sudden increase of approximately 15 bpm and 10 bpm in nocturnal and mean heart rate, respectively, 11 days before hospitalization for COVID-19 pneumonia. At the same time physical activity decreased progressively and continuously. A 78-year-old woman with an ICD showed significant changes in RM trends starting from the COVID-19-related symptoms: strong decrease in physical activity, progressive increase in mean and nocturnal heart rate, irregular trend of heart rate variability, and rapid drop in thoracic impedance. Two months later, on hospitalization, computed tomography showed a "crazy-paving" pattern of the lungs, which is a clinical picture of COVID-19 pneumonia with concomitant pleural effusion. <Learning objective: Patients with complications related to the COVID-19 infection appeared to show variations in the remote monitoring (RM) temporal trends of clinical variables daily transmitted from implanted cardiac devices. These changes may not be specific to COVID-19, but owing to the severity of the pandemic, the use of RM to capture patient's condition makes intuitive sense for early diagnosis, intervention, and additional follow-up in this high-risk population.>.