bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feasibility and safety of a single patch-based device for 30 days of continuous, uninterrupted ambulatory ecg monitoring
Authors: Turakhia M , Ellis J , Muresan A , Bame C , Wilk A , Crosson L , Clarkson K , Day M , Alexander J , Lenane J 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): iRhythm Technologies, Inc.

Background
14-day continuous ambulatory ECG monitoring (AEM) has been shown to have superior diagnostic yield to traditional 48-hour Holter monitoring for paroxysmal or undiagnosed atrial fibrillation and a wide range of clinical arrhythmias. 30-day recordings are typically from event recorders (non-continuous) and require frequent adhesive/electrode and battery replacement, all of which can impair patient compliance, wear time, and diagnostic yield. A new, uninterrupted patch-based AEM with next-generation breathable adhesive, storage, and battery life has received FDA clearance for 14-day wear. We evaluated the safety and feasibility of using this device for 30-days of continuous AEM.

Methods
We enrolled 30 participants with indications for AEM and applied a single Zio Monitor device for 30-days and analyzed wear time, analyzable time, and diagnostic yield, compared to with Zio Monitor 14-day use and with our standard, previous-generation product.

Results
In the cohort (76% female, 35% non-white, age 37±9 years, BMI 30.6±6.8), the median wear time was 29 continuous days (IQR 28-30) with no device changeouts and no clinically significant skin irritation. Although median analyzable times were high and similar across the previous (XT) and next-generation (Monitor) devices, the mean was significantly higher with Monitor, indicating fewer outliers that experienced premature termination of wear time. Arrhythmia yield (AF ≥30 sec, SVT ≥90 bpm & ≥4 bt, VT ≥100 bpm & ≥4 bt, inc PVT/TdP/VF, Pause ≥3 s, and/or AVB (any 2nd Deg or CHB) was significantly higher with the new Zio Monitor Device compared to Zio XT (80.9% vs 77.1%; p=0.017).

Conclusion
The application of a single, continuous, patch-based AEM for 30 days without adhesive (electrode) or battery replacement is feasible and safe. Analyzable time was high for 14-day and 30-day wear. The uninterrupted wear time and high compliance could lead to higher diagnostic yield than with traditional 30-day event recorders.
Predictive value of clinical risk scores for determination of left atrial low voltage area and arrhythmia recurrences in patients undergoing atrial fibrillation ablation
Authors: Sezenoz B , Yorgun H Y , Kilic G S , Demirci M , Coteli C , Ates A H , Aytemir K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Presence of left atrial low voltage area (LVA) is an independent predictor of atrial tachyarhythmia (ATa) recurrences after atrial fibrillation (AF) ablation. Thus identifying patients with LVA by using non-invasive methods is an important endeavour.

Purpose
In this study; we investigated the predictors of LVA and postablation recurrences especially focusing on clinical risk scores.

Methods
We enrolled 328 consecutive patients who underwent initial AF ablation procedure using high density mapping. LVAs were assessed and segmental distribution was noted in each patient. CHA2DS2-VASc, HATCH, APPLE and SPEED scores were calculated. Predictive value and arrhythmia recurrences were evaluated.

Results
Two hundred and twenty one patients (67.37%) were paroxysmal AF and 107 (32.62%) patients were non-paroxysmal AF at the time of ablation. Mean CHA2DS2-VASc score was 1.88±1.66, mean APPLE score was 1.20±1.20, HATCH score was 0.93±1.00 and SPEED score was 1.54±1.27 in the whole study group. LVA was detected in 131 patients (39.93%). Female gender [OR:2.94, CI: 1.34-6.43, p=0.007), non-paroxsymal AF (OR: 2.49 CI:1.13-5.46, p=0.023), APPLE score ≥1 (OR:1.69 CI:1.12-2.55, p=0.012) and SPEED score ≥ 1 (OR: 1.47 CI:1.00-2.14, p=0.045] were independent predictors for the presence of LVA in multivariate analysis. Presence of LVA (OR:1.98; CI:1.13-4.15; p=0.017) and HT (OR:2.00; CI:1.19-3.38; p=0.009) were the independent predictors of recurrences.

Conclusion
Higher clinical scores are associated with more LVA which is associated with ATa recurrence. However the predictive value of these risk scores is limited. Better risk scoring systems are needed to precisely identify the underlying atrial substrate in this patient group.
Evaluation of insertable cardiac monitor placement and safety in the LUX-Dx PERFORM study
Authors: Richards M , Stolen C , Simon T , Stoltz T , Manyam H , Dukes J W , Bavikati V , Rosman J , Rogers J D , Garner J 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): Boston Scientific Corporation

Background
The LUX-Dx PERFORM Study is designed to evaluate safety and performance of the LUX-Dx insertable cardiac monitor (ICM) in a general patient population. Enrollment and device insertions are complete, and all patients have completed 30 days of follow-up. This abstract describes the study population, characterizes device insertion, and reports on preliminary data for ICM system-related complications.

Methods
The LUX-Dx PERFORM study is a prospective, multi-center, single arm, post-market, observational study. The ICM system-related complication-free rate (CFR) at 30 days post-insertion was calculated using Kaplan-Meier methodology and the 97.5% one-side lower confidence limit (LCL) was compared to the prespecified performance target of 94%. All ICM system-related adverse events were adjudicated by independent physician reviewers.

Results
727 patients were enrolled at 24 centers in the United States from March 2021 to May 2022. The study population was 49% male, 91% white and 66+/-14 years old. 717 patients had device insertions and were successfully registered in the LATITUDE Clarity data management system. There were 9 withdrawals prior to insertion and 1 aborted procedure due to deployment difficulty. ICM insertion was performed in-hospital 76% of the time (N=547) and in-clinic 24% of the time (N=171). 96% were de novo device insertions. A variety of closure techniques were used including surgical glue (62%), adhesive strips (45%), sutures (42%), and staples (9%). Median procedure time was 4 minutes (range 1 - 37). There were 4 ICM system-related complications in the first 30 days (CFR 99%, LCL 99%) which meets the acute safety performance goal. The system-related complications include 1 case of ICM deployment difficulty, 1 case of device expulsion three days post insertion, and 2 infections that were treated with oral antibiotics and resolved without further mitigation.

Conclusion
The LUX-Dx ICM can be inserted quickly, in both hospital and clinic settings, with a very low complication rate.
Incremental value of maximum voltage and activation-guided ablation for cavotricuspid isthmus-dependent atrial flutter
Authors: Crocamo A , Notarangelo M F , Sciarroni R , Vrenozaj R , Dinatale A , Bearzot L , Gonzi G , Fioravanti M , Niccoli G , Ardissino D 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.
Radiofrequency (RF) catheter ablation is an effective method for treatment of typical cavo-tricuspid isthmus (CTI) dependent atrial flutter. However, despite the widespread use of contact force irrigated catheter, 11% of patients don’t achieve a first-pass CTI block, requiring additional RF applications or additional line during the same or a second procedure.
From an anatomical point of view, CTI is composed of discrete bundles of muscle with intervening connective tissue, suggesting that its conduction proprieties are dependent of the anatomic architecture of the bundles.
The maximum voltage-guided (MGV) ablation technique targets high-voltage electrograms along CTI to ablate the functionally active anatomic muscle bundle, without drawing a complete anatomic line. [1;2]

Purpose
The aim of this study was to evaluate the efficacy of maximum voltage and activation-guided ablation (MVG/LAT) for CTI atrial flutter in real-world setting.

Methods
This was a prospective observational study in which all patients undergoing CTI atrial flutter ablation at the Electrophysiology Laboratory of our Department from 01/2021 to 10/2022 were recruited. Patients who were undergoing the ablation procedure after having already made an unsuccessful attempt of the same were excluded from the study.
Substrate and activation mapping of CTI, both during flutter and during pacing from the proximal coronary sinus (CSp), was performed in all patients, identifying the earliest activated high-voltage channels, without the use of fluoroscopy, using the Smart-Touch SF catheter (CARTO 3, V7, Biosense Webster). High-voltage channels were validate also during lateral RA pacing. CTI ablation was performed only in channels with high voltage and early activation (W 45, AI 500). Bidirectional CTI block were validate by differential atrial pacing maneuvers and activation mapping during pacing from CSp.

Results
Procedural data of 39 patients were evaluated (mean age 68±13 years; men 92.6%; mean right atrium volume 149 mL). The mean number of points taken per map per patient was 1151. Bipolar thresholds were customized (0.5-2.5 mV) with the aim of better visualizing high-voltage channels. In 20/39(51.2%) patients ablation was performed during atrial flutter, in 19/39(48.8%) during pacing from proximal CS. In 19/39(48.8%) patients high-voltage channels were not detected at the central isthmus line (6 o'clock, LAO). The median number of RF applications to achieve bidirectional block of the CTI were 6 (1-20) in all patients (p=NS) (Figure 1,2). During a mean follow-up of 260 days (90-531) no recurrences were documented in any patient.

Conclusions
MVG/LAT-guided ablation, targeting selectively conductive muscle fibers, decreases the number of RF applications and improves efficacy, mostly in patients with challenging anatomies.
Omnipolar mapping improves substrate characterization and critical isthmus identification in atypical atrial flutters
Authors: China P , Quinto L , Vio R , Vitale R , Marras E , Themistoclakis S 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Characterizing atrial substrate and conduction properties is crucial to treat complex arrhythmias during catheter ablations. Unipolar and bipolar electrogram signals are routinely used with significant limits due to low detailed mapping, the impact of poor contact and far-field electrical signals. Moreover, signals morphology is dependent on the relative orientation of the catheter inter-electrode axis to the direction of activation. Omnipolar signals try to overcome this direction-dependence by using three adjacent electrodes to infer directional information about the local electric field.

Purpose
We compared omnipolar mapping (OM) signals with the traditional high-density bipolar mapping (BM) ones.

Methods
All the procedures were performed using a high-density grid-designed mapping catheter. The atypical left atrial flutters were mapped using both OM and BM configuration. All the analysis about voltage and potential duration are related to the entire left atrial surface excluding pulmonary veins.

Results
Ten atypical atrial flutters were mapped in the left atrium in seven patients (median age 70 y, 5 males). OM identified 7 double loops and 3 triple loops while BM identified 7 double loops, 2 triple loops and 1 single loop, missing 2 critical circuits (an example is shown in figure 1) Significant differences were present also in potentials amplitude (peak-to-peak voltage amplitude) in the critical isthmus with OM higher than BM (OM median 0.22 mV IQR [0.16 – 0.30] vs BM median 0.19 mV IQR [0.13 – 0.24], P= 0.002). Dense scar area (defined as voltage amplitude &lt;0.05 mV) identified with OM was smaller compared to BM (1.3 cm2 IQR [0.13-1.73] vs 1.7 cm2 IQR [0.23-3.10]; P= 0.06). OM showed longer signal duration (+10.1%) compared to BM in the entire left atrium and in particular the mean signal duration in the critical isthmus (OM median 79.1 ms IQR [70.7 – 88.9] vs BM median 62.5 ms IQR [55.2 – 85.2], P= 0.006). Percentage of tachycardia cycle lenght (TCL) mapped at the critical isthmus (maximum signal duration at the isthmus/ TCL) was greater with OM than BM (OM mean 60% ± 11%, BM mean 54% ± 12% (P= 0.02)(a summary of the results are shown in table 1).

Conclusions
OM identifies higher amplitude and longer signal duration especially in the critical isthmus region also reducing the extension of dense scar area. This finding may be crucial in the definition of complex and localized reentrant activities, leading to a faster and more precise catheter ablation.
A novel method to define critical isthmus of left atrial tachycardia; late potential mapping during sinus rhythm
Authors: Coteli C , Kilic S , Sezenoz B , Ates A , Yorgun H , Aytemir K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Atrial tachycardia (AT) is a commonly encountered rhythm disorder in patients with underlying atrial scar. The role of late potential (LP) based mapping in the detection of AT critical isthmus has yet to be systematically evaluated.

Purpose
We aimed to investigate the relationship between the atrial LPs (ALP) localization in sinus rhythm and the critical isthmus of re-entrant ATs in patients with underlying atrial low-voltage areas.

Methods
Thirty-five symptomatic patients [mean age: 62 ±9, gender: 25 (71.4%) female] with left AT, who had undergone catheter ablation, were enrolled. Voltage and LP mapping were performed in sinus rhythm in both atriums. Low voltage areas and signals with continuous-fragmented morphology were tagged. Isochronal late activation mapping (ILAM) was also performed in all procedures. After induction of AT, activation mapping was performed during tachycardia in all patients to detect critical sites of the tachycardia.

Results
Activation mapping indicated single re-entry in 30 patients and ≥1 re-entry in 5 patients. Localized re-entry was observed in 20 (51.2%) patients, macro re-entry in 18 (46.1%), and biatrial re-entry in 1(2.5%). The mean fractionated electrogram duration in the AT termination site was calculated at 134.3±46.7 ms and the mean bipolar voltage at 0.17±0.12 mV. The ALPs were tagged in 25 (64.1%) patients on the anterior wall, 12 (34.3%) on the roof, 5 (12.8%) on the septal wall and 2 (5.7%) in the Bachmann’s Bundle region. All ALPs were in the latest activated zones of ILAM in patients with localized re-entry and predicted successful ablation sites to terminate the AT. Freedom from atrial tachyarrhythmias (ATAs) was 78.7% at six months during a mean follow-up duration of 338 ±226 days.

Conclusion
Our findings demonstrated the utility of ALPs during sinus rhythm to predict the successful termination sites for left ATs. These areas displayed continuous-fragmented signal morphology during sinus/paced rhythm in correlation with the critical isthmus of AT detected during activation mapping.
Local impedance changes are a suitable real time surrogate for lesion formation in RF-ablation
Authors: Bahlke F , Wachter A , Krafft H , Popa M , Erhard N , Englert F , Telishevska M , Lengauer S , Lennerz C , Reents T , Risse E , Hessling G , Deisenhofer I , Bourier F 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Radiofrequency current remains one of the most important techniques for catheter ablation. Creating durable lesions is key for sufficient and safe procedures. Several possibilities were tested for estimating the progress of lesion formation. For instance, force-time-integral, ablation index and lesion size index are used to assess quality of RF-application and, therefore, lesion size and durability. Nevertheless, recovered conduction after acute conduction block remains an issue in RF-ablation. The aim of this study was to evaluate local impedance (LI) changes as real time surrogate for lesion formation.

Methods
RF-lesions were created using an ex vivo porcine cardiac model and a force and local impedance sensing catheter. The experimental setup consisted of a saline-filled container, a dispersive electrode, a heated thermostat and a circulation pump to imitate in vivo conditions. Global impedance was kept at 120 Ohm as well as the temperature at 37°C. RF-lesions were created using identic values of RF duration and contact force. RF power (20W, 30W, 40W, 50W) and level of electrode-tissue-coupling were also systematically varied between minor and full coupling. In minor ETC-level, only the distal end of the catheter is in contact with the tissue. In full ETC-level, the whole catheter tip is in contact with the tissue.
All parameters (power, temperature, global and local impedance, contact force, ETC, lesion size) were measured constantly during application of RF-current, enabling real-time correlation of RF parameters and lesion size. In case of an audible steam pop, RF application was stopped.

Results
Including a total of 8654 measurements into the analysis, maximum diameter and depth were 9.51 ± 1.91 mm and 7.29 ± 2.50 mm in average. Local impedance correlated well with lesion depth (r= 0,78, p&lt;0,001), as well as lesion diameter (r=0,652, p&lt;0,001, Figure 1).
After significant declines of LI at the beginning of RF-application, it slowly approximates a minimum. Lesion size on the other hand, rises exponentially in first seconds and gets closer to a maximum after more than 25 seconds. This relationship is illustrated in Figure 2. With decreasing lesion growth at the end of RF-application, LI changes decrease to low level (Figure 3).

Conclusion
Lesion formation in RF-ablation is not linear during application of RF current. Local impedance changes seem to be a suitable real-time surrogate for assessing changes in lesion size during ablation.
Prevalence of concealed arrhythmogenic substrate for sudden cardiac arrest in the general population
Authors: Chugh H , Kransdorf E , Chugh S 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): US National Heart Lung and Blood institute National Institute of Health.

Background
Individuals who present with SCA as the first manifestation of heart disease (Concealed Substrate) present the greatest challenge for clinical risk stratification but population-based information in the current era is lacking. We hypothesized that improved awareness and access to health care has resulted in a reduction in prevalence of Concealed Substrate.

Purpose
We compared the overall prevalence, secular trends and SCA etiologies of Concealed Substrate in two geographically distinct US populations.

Methods
Consecutive cases of SCA were ascertained prospectively from 2 large ongoing US studies, the Population Cohort A (PopulationCohortA, 2002-2018) and Population Cohort B (PopulationCohortB, 2015-2022), total population 1.85 million residents. All out-of-hospital SCA events attended by emergency medical services were determined following an established multi-source ascertainment and adjudication process, and detailed lifetime clinical record evaluation conducted for each individual. This included the comprehensive electronic health record, evaluation of SCA survivors as well as all available autopsy information. Concealed Substrate cases were defined as SCA with no prior heart disease diagnosis.

Results
From a total of 5708 SCA cases (age 66.5 ± 18.2, female 35%), n=3390 (age 64.3 ± 18.8, female 34%) were identified in PopulationCohortA and n=2318 (age 71.6 ± 15.7, female 36%) in PopulationCohortB. In PopulationCohortA, prevalence of Concealed Substrate was 39% (n=1282, age 58.6 ± 21.7, 32% female) and decreased modestly over time (Figure; 37% in 2002-06 vs. to 33% in 2014-18; p=0.001). In PopulationCohortB, overall prevalence of Concealed Substrate was 41% (n=949, age 68.3 ± 17.6, 33% female) and did not change significantly over time (Figure; 2015-2022; p=0.06). Etiology of SCA was determined in a subgroup of overall cases (n=3210, 56%) of which n=2727 (85%) were ischemic SCA and n=483 (15%) non-ischemic SCA. Non-ischemic SCA was more commonly identified in Concealed Substrate (29% vs. 11%; p&lt;0001) and ischemic SCA was more common in Revealed Substrate (89% vs. 72%; p&lt;0.0001).

Conclusion
There was a modest reduction in prevalence over time, 33-41% of individuals continued to present with Concealed Substrate, with higher likelihood of non-ischemic SCA. These findings suggest that widely available and inexpensive tests such as the 12-lead ECG warrant further evaluation as a pre-screening method in the general population.
Relative tachycardia at admission as a predictor of mortality in severe and critical COVID-19, a tertiary centre study
Authors: Bistrovic P , Lucijanic M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Relative tachycardia is the phenomenon of disproportionate tachycardia in response to fever, originally described in the context of systemic inflammatory response syndrome (SIRS) (1). Systemic COVID-19 has shown similarities to SIRS, as well as arrhythmogenic effects and other cardiovascular complications. Relative tachycardia is associated with increased mortality in SIRS, however currently there is no data on effects of relative tachycardia in COVID-19.

Purpose
Our goal was to determine whether relative tachycardia impacted clinical outcomes of COVID-19 patients.

Methods
We retrospectively analyzed data on 3490 COVID patients hospitalized at our institution from March 2020 to June 2021. Inclusion criteria were age over 18 and positive polymerase chain reaction test to SARS-CoV-2 virus. Exclusion criteria were beta blocker use and atrial fibrillation. We stratified our patients into four quartiles according to their heart rate to body temperature ratio at admission. We defined the fourth quartile as relative tachycardia.

Results
Most patients were male (57.5%), median age was 69 years, median Charlson comorbidity index was 3, 69% had severe COVID and 15% had critical COVID at admission. Median heart rate was 90 beats per minute, median body temperature was 38 degrees Celsius and median pulse-to-temperature radio was 2.36 at admission. Patients whose heart rate-to-fever ratio at admission indicated relative tachycardia were significantly more likely to require mechanical ventilation (OR 1.48, CI 1,22-1,80), be transferred to an intensive care unit (OR 1.62, CI 1.36 to 1.93), to experience venous thromboembolisms (OR 1.50, CI 1.12-1.99) and increased intrahospital mortality (OR 1.63, CI 1.39-1.92) compared to those in first three quartiles. After adjustment for age (OR 1.04, CI 1.03-1.05), sex (OR 1.36, CI 1.14-1.61), Charlson comorbidity index (OR 1.24, CI 1.19-1.29) and COVID severity (OR 28.81, CI 14.68-56.55), death during hospitalization was significantly higher in the relative tachycardia group (OR 1.86, CI 1.47-2.35).

Conclusions
COVID patients with excessive tachycardic response to fever at admission seem to have lower chances of survival. Further research is necessary to establish a cut-off value for this easily measured clinical parameter.