bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical and genetic characteristics and course of congenital long QT syndrome: A ten-year single center experience
Authors: Blich M , Kchoury A , Darawsha W , Eyal A , Suleiman M , Gepstein L , Boulos M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Long QT syndrome (LQTS) is an inherited primary arrhythmia syndrome associated with life-threatening ventricular arrhythmia.

Objective
To report the clinical and genetic characteristics and outcome of LQTS patients in single center inherited arrhythmia clinic.

Methods
Retrospective review of patients diagnosed LQTS and evaluated by ECG, 12 lead holter, exercise test and genetic testing in inherited arrhythmia clinic from January 212 to January 2022.

Results
101 patients (32 families) were included, mean age 24.3± 17 years. Thirteen patients (12.8%) were diagnosed after previous cardiac arrest and six patients (6%) had syncope. Seventy (69.3%) were identified as having LQTS during family screening. 97 patients (97%) were confirmed to have a pathogenic mutation for LQTS genes. Beta blockers were recommended to 74 patients (73%), flecainide to 20 (19.8%). Nine patients (8.9%) received an ICD for secondary prevention and one patient (1%) for primary prevention. During 5.8 ± 2.7 years, dose of beta-blockers increased from propranolol 70 ±42 mg to 105 ±60.3 mg (p= 0.0004), QTC shortening (479 ± 36.9 to 466 ±30.1 msec, p=0.01) in ECG and maximal QTC measured in 12 lead holter (521± 43.9 to 505± 37.8 msec, p=0.01). Maximal heart rates measured in 12 lead holter and exercise test were reduced ( 130± 24.5 to 116 ± 20.2 beats/min p=0.0001 and 152.6±22 to 145± 20.58 beats/min, p=0.043). Seven patients (6.9%) experienced ventricular arrhythmia, five received appropriate ICD shock and two patients that declined beta blockers experienced syncope due to polymorphic ventricular tachycardia and cardiac arrest. The one patient that had the ICD for primary prevention, experienced polymorphic ventricular tachycardia that was successfully treated by the ICD.

Conclusions
Intensive clinical follow up and an optimal medical therapy in a specialized arrhythmia clinic is associated with a relatively low incidence of sudden cardiac death and a low rate of ICD utilization in LQTS patients.
Risk stratification of severe ventricular arrhythmias in Brugada syndrome
Authors: Nguyen Khiem T H A O , Truong Thanh V I E N , Pham Thanh B I N H , Phan Nhu N G O C , Vu Xuan Q U A N G , Vu Tran Dinh H U Y , Ngo N M T A M , Mazur W , Chung E U G E N E , Ton That M I N H 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Predicting likelihood of severe ventricular arrhythmias in Brugada syndrome (BrS) patients is challenging due to conflicting evidence.

Objectives
The goal of this study was to construct a prediction model of severe ventricular arrhythmias (VAs) for BrS patients.

Methods
Two hundred forty-two BrS patients were enrolled from 2008 to 2019 in a single-center cohort study. Those patients were followed up until December 2021. Clinical data and multiple ECG markers were collected and analyzed to determine the risk factors of severe VAs and sudden cardiac death (SCD). Multivariate logistic regression analysis was then used to develop a risk prediction model for adverse arrhythmic outcomes in BrS patients.

Results
During the follow-up (90.1 ± 45.8 months) of 242 BrS patients (mean age 42.3 ± 12 years; 94.6% male), 49 (20.2%) patients had syncope/pre-syncope due to VAs and 7 (2.9%) patients had aborted cardiac arrest. In multivariable analysis, epsilon wave, early repolarization sign, S wave duration in lead I, QRS duration in V2 and Tp-e duration were significant associated with adverse arrhythmic outcomes. A clinical model including these five significant predictors had a good performance to predict outcomes with balanced accuracy of 0.86 and area under curve of 0.93 (95% CI, 0.89-0.96, p &lt; 0.001) indicating a good discriminative ability. Furthermore, the Hosmer–Lemeshow test and the calibration plot showed a good fit between the predicted and observed probabilities of the predictive model.

Conclusions
This study constructed a risk prediction model for severe VAs in BrS patients with a high predictive accuracy.
Interim evaluation of insertable cardiac monitor signal quality in the LUX-Dx PERFORM study
Authors: Richards M , Mahajan D , Simon T , Kupfer M , Rajan A , Herrmann K , Rogers J D , Garner J , Pokorney S 
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. Although follow-up is ongoing, enrollment is complete, and at least half of the patients have completed 180 days of follow-up. The visibility (or absence) of P-waves in the ICM-recorded S-ECG is an important feature in the diagnosis of atrial arrhythmias.

Objective
Evaluate the visibility of P-waves in patients enrolled in the LUX-Dx PERFORM study.

Methods
P-wave visibility was evaluated from the first 356 patients enrolled in the LUX-Dx PERFORM study. The daily presenting S-ECGs (10 second rhythm) nearest to Day 7 (+/- 1) and Day 180 (+/- 7) after implant were blindly adjudicated by independent electrophysiologists to calculate the percentage of beats with clearly visible P-waves.

Results
Of 636 reviewed S-ECGs, 24 (3.7%) were excluded from analysis for presence of AF rhythm (11), or unavailable data (8 with insufficient adjudication and 5 with no detected R-waves from which to calculate the percentage of beats with visible P-waves). Figure 1 shows an example of a presenting S-ECG rhythm with clearly visible P-waves from the patient management system LATITUDE Clarity. The P-waves were found to be clearly visible in 89.1% of the total heart cycles (Day 7: 90.4%, Day 180: 87.8%). The average difference in percent visibility between Day 7 and Day 180 was approximately 2.2% (p=.248). At a patient level, 88% of patients had visible P-waves in at least one presenting ECG for more than 90% of beats, as shown in Figure 2. In addition, 69% of patients had visible P-waves in both presenting ECGs (Day 7 and Day 180) for at least 90% of beats.

Conclusion
The LUX-Dx showed consistent visibility of P-waves in the first half of patients enrolled in the LUX-Dx PERFORM study, which represents a general patient population. Adequate P-wave visibility is an important clinical feature in diagnosing atrial arrhythmias and may aid in analysis and clinic workflow efficiency.
Heart rate variability according to electrolyte changes during hemodialysis in patients with chronic kidney disease
Authors: Im S I , Shin H S 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Autonomic neuropathy commonly arises as a long-term complication in chronic kidney disease (CKD) and can be diagnosed from heart rate variability (HRV), calculated from electrocardiogram (ECG) recordings.

Purpose
There is limited data about HRV using real-time ECG according to electrolyte levels during hemodialysis (HD) in patients with CKD.

Methods
Total of 50 patients (62.1±10.7 years) with CKD underwent continuous real-time ECG monitor (237.4±15.3 mins) during HD for HRV using remote monitoring system and checked electrolyte levels before/after HD. And we compared HRV according to electrolyte levels.

Results
During the monitor, we checked total 2374 times of ECG and electrolyte level simultaneously of all patients. Both time and frequency domain HRV were higher when the patients had lower K+ level change before/after HD (&lt;0.5mEq/L) as compared with those with higher K+ level change (&gt;0.5mEq/L) in Table. In addition, there were higher incidence of arrhythmic events including atrial/ventricular premature complexes, even though no difference of mean heart rate in patients with lower K+ level change group (P&lt;0.001).

Conclusions
Poor controlled K+ level during hemodialysis was independently associated with higher HRV in patients with CKD. This is further substantiated by independent continuous associations between real-time measures of K+ level and higher HRV. These data strongly suggest that cardiac autonomic dysfunction can be caused by lower change before/after hemodialysis alone.
Late potentials assessment - an useful tool for Brugada Syndrome risk stratification
Authors: Brito J , Silverio Antonio P , Nunes Ferreira A , Lima Da Silva G , Ricardo I , Neves I , Cortez-Dias N , J Pinto F , Sousa J 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Brugada syndrome (BrS) is a channelopathy confining an increased risk of sudden cardiac death (SCD). Asymptomatic patients (pts) management remains challenging enhancing the necessity for additionally stratification tools.

Purpose
To evaluate the role of the non-invasive assessment of late potentials (LP) based on SA-ECG as stratification tools in a BrS cohort.

Methods
Prospective, observational single-center study of pts with BrS with the following criteria (1) Type 1 Brugada ECG pattern, either spontaneous or drug induced; (2) SA-ECG performed before anti-arrhythmic treatment; (3) minimum follow up duration of 12 months. LPs were evaluated by SA-ECG with determination of the total filtered QRS duration (fQRS); root mean square voltage of the 40ms terminal portion of the QRS (RMS40) and duration of the low amplitude electric potential component of the terminal portion of the QRS (LAS40) in conventional and modified right precordial leads. Malignant arrhythmic events (MAEs) were defined as a composite event of SCD or appropriate ICD shocks. Association of relevant risk factors and MAE was conducted with Univariate Cox regression analysis, as well as SA-ECG evaluated as a continuous and categorical divided on standard cut-offs (fQRS &gt;114ms, RMS40&lt;20µV, LAS40&gt;38ms). A risk score for predicting MAE was computed incorporating the significant LPs variables.

Results
A total of 106 pts fulfilled the inclusion criteria (mean age: 48 ± 12 years, 67.9% male), 52 (49.1%) with type 1 spontaneous pattern. The majority were asymptomatic at baseline (81.1%) while 13 presented with syncope and 3 with polymorphic VT/cardiac arrest. A total of 10 (7.1%) pts MAEs were documented during a mean 4.7 years - 4 with SCD and 6 with appropriate ICD shocks. Clinical presentation with a polymorphic VT/cardiac arrest (p &lt;0.001) and LP evaluated on SA-ECG were significant predictors of MAE on univariate analysis, except for RMS40 on conventional leads. Neither of the common risk factors (male gender, spontaneous type 1 pattern at baseline, previous syncope or the presence of a pathogenic SCN5A mutation) were predictors of MAE during follow-up– figure 1. Positive LPs defined by standard cut-offs, in all variables and leads, were significantly associated with an increased risk of MAE during follow-up – figure 2. A LP score was computed incorporating the standard cut-offs on conventional leads. The presence of 2 and 3 positive LP represented an additionally 4.7-fold increased risk of MAE during follow-up (HR 4.693, 95% CI 1.506-14.624, p = 0.008) – figure 2.

Conclusion
LPs based on noninvasive assessment SAECG represent an useful prognostic stratification tool in BrS. A LP score based on standard cut-offs identified a subset of pts at a higher risk of events and who may deserve individualized preventive strategies.
Sex-specific differences in infranodal conduction properties in patients undergoing transcatheter aortic valve replacement
Authors: Serban T , Knecht S , Mannhart M , Nestelberger T , Kaiser C , Leibundgut G , Bischof M , Sticherling C , Kuehne M , Badertscher P 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Electrophysiological (EP) testing has been proposed for risk stratification of patients with left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR). A uniform cut-off of 70ms for the His-Ventricular (HV) interval has been proposed to trigger pacemaker implantation. However, sex-specific periprocedural data regarding infranodal conduction properties are lacking.

Purpose
We aimed to compare the HV interval in men and women undergoing TAVR.

Methods
We analyzed consecutive prospectively included patients undergoing TAVR between June 2020 and June 2021 at a tertiary referral center. EP testing was performed in all patients pre- and post-valve deployment and in the case of LBBB additionally for a third time the following day.

Results
127 patients were included (81 ± 7 years, 46% female). Median HV interval pre-valve deployment was 43 [37-50] ms vs 46 [42-53] ms in women and men, respectively (p=0.016). Nine patients underwent peri-procedural pacemaker (PM) implantation for third-degree AV-block. The median HV interval post-valve deployment was 54 [42-59] ms in women and 56 [51-61] ms in men (p=0.038). The median HV interval the day following TAVR in patients with LBBB was 45 [41-49] ms in women and 50 [48-62] ms in men (p=0.048). An HV interval ≥ 55 ms and ≥70 ms was present the day following TAVR in seven patients (24%, two females) and three patients (10%, one female). (Figure)

Conclusion
Women have shorter HV intervals pre-and post-valve-deployment as well as the day following TAVR compared to men. Further studies evaluating sex-specific cut-offs for the HV interval are warranted.
Pitfalls and limitations in the assessment of the HV interval in a transcatheter aortic valve replacement population. A prospective analysis
Authors: Teres C , Haddad C , Pagnoni M , Le Bloa M , Herrera-Siklody C , Domenichini G , Porretta A , Pruvot E , Pascale P 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
identification of patients with new-onset conduction disturbances at risk of AV-block remains a major unmet challenge in Transcatheter Aortic Valve Replacement (TAVR). His-Ventricular interval (HVI) measurement has been proposed in patients at risk. However, the HVI assessment is often overlooked, performed as a single assessment without active mapping, and even single-catheter assessment is sometimes performed.

Purpose
To systematically evaluate HVI measurements in a post TAVR population, in search of methodological pitfalls as related to outcomes

Methods
Consecutive patients who underwent HVI assessment post-TAVR between June 2014 and December 2021. HV interval was classified as normal (&lt;55), intermediate (55-70) and abnormal (&gt;70 ms). Incremental atrial pacing was performed whenever possible. All tracings were reviewed by two blinded operators. Pitfalls in the assessment of atrioventricular conduction were categorized into types 1 to 5, as reported in Table 1. In sinus rhythm, only proximal HVI were considered defined as the concomitant recording of a near-field atrial signal.

Results
90 cases were analyzed; median age 81 years1 [76 – 86] years; 37 (41%) male. The median HV interval was 54 [50 – 65] ms. An abnormal HV interval, exceeding the 55 and 70ms cut-off values, was found in 41 (45.9%) and 13 (14.8%) patients, respectively. At least one pitfall was found in 15 patients (16%). Short-term AV block occurred in 3 patients in sinus rhythm in whom no incremental pacing was performed, and in 2 patients with AF despite normal or borderline HVI in both groups.

Conclusions
Pitfalls in the assessment of the HVI are often observed after TAVR. Identification of infra- and especially intra-His disorders requires careful mapping and must be an active process on behalf of the operator. Our results call into question the value of the HV assessment using a single catheter or in patients with atrial fibrillation, considering the value of incremental atrial pacing and the inherent limitations in AF to assess the most proximal His or intraHis block.
Association between different catheter designs for the characterization of the left atrial substrate
Authors: Knecht S , Schlageter V , Badertscher P , Krisai P , Schaer B , Jousset F , Spies F , Osswald S , Sticherling C , Kuhne M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): The study was supported by an investigator sponsored grant (Boston Scientific).

Background
Bipolar voltage electrograms (BVE) for left atrial (LA) substrate characterization strongly depend on the catheter design and electrode configuration.

Purpose
The aim of the study was to compare bipolar voltage electrograms (BVE) obtained from the left atrium using four different established mapping catheters and to deduce the individual catheter-specific cut-offs for scar and healthy myocardial tissue.

Methods
We prospectively included 25 consecutive patients referred for catheter ablation for atrial fibrillation recurrence after index PVI. The pipeline of the analysis leading to the individual cut-off for every catheter based on a reference catheter value is shown in the figure. In detail, consecutive high-resolution electroanatomic mapping was performed using a multipolar catheter (Orion), a duo-decapolar variable circular mapping catheter (Lasso), an irrigated ablation catheter with micro electrodes (MIFI) and a 4.5 mm tip-size irrigated ablation catheter (Nav). BVEs for the four catheters were compared in voxels with a size of 3x3x3mm^3 (Figure, top left). Total least squares regression was performed for every patient to investigate the logarithmic relationship between the BVE measured by two different catheter types (Figure, top right). The mean equivalent BVE cut-off over all patients for every catheter was calculated for the reference cut-offs of 0.1 mV, 0.2 mV, 0.5 mV, 1.0 mV, and 1.5 mV (Figure, bottom left).

Results
Correlation between the four different BVE maps for the 25 patients showed a slight individual variation between the patients. Compared to the BVE cut-offs from the standard Nav catheter with a 4.5 mm tip, the scar cut-off using the Orion catheter must be lowered to 0.034 mV for a 0.1 mV cut-off, to 0.09 mV for a 0.2 mV cut-off, and to 0.35 mV for the 0.5 mV cut-off (Figure). Similar values hold true for a Lasso map as comparator (Figure). For healthy tissue above 1 mV, similar cut-offs to the reference values might be advisable.

Conclusion
In contrast to the established Nav or Lasso catheter, the scar voltage cut-off for the Orion catheter needs to be lowered to 0.1 mV instead of the 0.2 mV cut-off and approx. 0.35 mV for a 0.5 mV cut-off. At lower voltages the difference between the catheters increases. The presented connective table enables to transfer the studies of left atrial substrate characterizations using different catheter types.
Role of the implantable loop recorder in clinical practice: insights on indications, diagnostic yield and therapeutic implications from a single, high volume, tertiary care centre experience
Authors: Castagno D , Ferraris F , Anselmino M , Millesimo M , Saglietto A , Matta M , Verna D , Donadoni M , Ruffini S , Giustetto C , De Ferrari G M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Besides the established class I indication for the evaluation of patients with recurrent syncope of uncertain origin, implantable loop recorders (ILRs) have been increasingly used for other diagnostic purposes (e.g. detection of atrial fibrillation (AF) following cryptogenic stroke).

Purpose
To describe the main indications to ILR and to investigate procedural parameters, outcomes and diagnostic yield of ILR in a single, high-volume tertiary care centre.

Methods
All patients undergoing ILR implantation between November 2007 and April 2022 were consecutively enrolled in this study. Clinical characteristics of patients, procedural data and outcomes were collected. The indications to ILR implantation were divided into four categories: 1) AF detection in patients with recent cryptogenic stroke or peripheral thromboembolism [CRYSP], 2) recurrent syncope of uncertain origin [RSUO], 3) monitoring of ventricular arrhythmic events [VAE] in patients with predisposing cardiomyopathy/channelopathy, 4) monitoring of AF burden or relapse [AFB]. The main endpoint of the study was the diagnostic yield (number of definitive diagnoses made) and the time to diagnosis following ILR implantation. The occurrence of acute or subacute complications was used as a secondary safety endpoint.

Results
Overall, 1442 patients underwent ILR implantation (mean age 65 years, 43% female). The two main indications to ILR were AF detection following CRYSP and RSUO (42% and 34% of all implantations respectively, table 1). The commonest site of implantation was the left parasternal position (902 patients, 63%), median procedural time was 20 minutes (IQR 15-25). During a median follow-up of 397 days (134-1094), infections requiring ILR extraction or pocket revision occurred in 13 patients (0.9%). A definitive diagnosis was achieved in 500 (35%) patients after a median time of 206 days (IQR 60-533) [table 1 shows details and action taken following diagnosis for each indication subgroup]. At multivariable analysis, age and PR interval duration were significantly associated with the need for PM/ICD implantation among patients receiving ILR for RSUO whilst age was associated with AF detection among those with CRYSP (table 2).

Conclusions
In this cohort of patients use of ILR was associated with a good diagnostic yield regardless of the initial indication, triggered timely therapeutic actions and was overall safe.