bluuebunny/crossref_metadata_2025_split huggingface dataset:
Outcomes of cavotricuspid isthmus-dependent fLutter ablation: randomized study comparing single vs multiple catheter procedures. The SIMPLE study
Authors: Falasconi G , Penela D , Chauca A , Fernandez-Armenta J , Pavon R , Acosta J , Lozano J M , Soto-Iglesias D , Marti-Almor J , Bellido A , Ordonez A , Viveros D , Alderete J , Francia P , Berruezo A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Catheter ablation is recommended as first-line therapy for patients with symptomatic typical atrial flutter (AFl). Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative.

Purpose
The present study sought to compare safety, efficacy, and efficiency of single vs multi-catheter approach for AFl ablation.

Methods
In this randomized multicentre study, consecutive patients referred for AFl ablation (n= 253) were enrolled and randomized to multiple vs single-catheter approach for CTI ablation. In the single-catheter arm CTI block was confirmed analyzing PR interval (PRI) on the surface ECG as previously described by Madaffari and colleagues: briefly, PRI defined as the time between the pacing spike and the onset of the QRS complex, was measured on the surface ECG during atrial pacing (10 V, 1.5 ms) at a stable cycle length from the tip of the ablation catheter placed at 5 o’clock (medial to CTI line), 7 o’clock (lateral to CTI line), and 9 o’clock position. CTI block was assumed when: (i) the PRI at 7 o’clock was &gt;80ms longer than that at pacing sites of 5, and (ii) the PRI at 9 o’clock was shorter than the PRI at 7 o’clock (Figure 1). Procedural and follow-up data were collected and compared between the two arms.

Results
128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was singificantly shorter (37±25 vs 48±27 minutes, p=0.002), required less fluoroscopy time (430±461 vs 712±628 seconds, p&lt;0.001) and less radiofrequency time (428±316 vs 643±519 seconds, p&lt;0.001), achieving a higher first-pass CTI block rate [55 (45%) vs 37 (31%), p=0.044], compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences [5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, P=0.99]. No differences were found in arrhythmia-free survival between arms (log-rank= 0.71). Results are summarized in Figure 2.

Conclusions
Recurrence-free survival of the single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy and radiofrequency time.
National sudden cardiac death autopsy database highlighting sudden arrhythmic death and cardiomyopathies, applying diagnostic criteria and expanding the concept of the molecular autopsy
Authors: Westaby J , Zullo E , Cox S , Sheppard M N 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Other. Main funding source(s): Cardiac Risk in the Young

Background
Sudden cardiac death (SCD) is defined as natural unexpected death in witnessed cases occurring &lt;1 hour and in unwitnessed cases as last seen alive &lt;24hours. SCD due to ischaemic heart disease (IHD) is frequent in older age groups, in younger people genetic cardiac causes including channelopathies and cardiomyopathies are more frequent.

Purpose
To present the causes of SCD from a large pathology registry.

Methods
Cases were examined macroscopically and microscopically by two expert cardiac pathologists. Criteria used are presented in figure 1.

Results
The hearts from 7214 SCD cases were examined between 1994-2021. Sudden arrhythmic death syndrome (SADS), a morphologically normal heart, which can be underlain by the channelopathies, is most common (3821, 53%) followed by the cardiomyopathies (1558, 22%), then IHD (670, 9%). Valve disease (225, 3%), congenital heart disease (213, 3%) and myocarditis/sarcoidosis (206, 3%) are the next most common. Hypertensive heart disease (185, 3%), aortic disease (129, 2%), vascular disease (97, 1%) and conduction disease (40, 1%) are smaller proportions (figure 2).

Discussion
This is the largest SCD cohort with autopsy findings ever reported from one country. SADS and cardiomyopathies predominate. This study highlights the importance of the autopsy in SCD which is a significant public health concern in all age groups. Knowing the true incidence in our population will improve risk stratification and develop preventative strategies for family members. There is now a national pilot study integrating molecular autopsy into the assessment of SCD victims.
Long-term follow-up of idiopathic ventricular fibrillation: A 30-year experience from our hospital
Authors: Rattanawong P , Rayfield C , Kenyon C , Seri A , Yinadsawaphan T , Srivathsan K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background/Introduction
Idiopathic ventricular fibrillation (IVF) is responsible for 5-7% of sudden cardiac arrests in the absence of substrate for ventricular arrhythmia, structural diseases, or primary arrhythmic syndromes. The characteristics, management, and prognosis of these patients are unclear.

Purpose
To investigate the clinical features, management, and prognosis of IVF in our hospital healthcare system

Methods
Mayo Database Explorer software was used to identify IVF patients from our hospital electronic medical records between 1990 to 2022 in 5 states. The medical records were manually reviewed.

Results
A total of 132 patients were initially diagnosed with IVF. During the 9.2±6.8 years mean follow-up, 36 [27.3%] patients were later diagnosed with structural diseases or primary arrhythmic syndromes (dilated cardiomyopathy [41.7%], Long QT syndrome [27.8%], catecholaminergic polymorphic ventricular tachycardia [8.3%], Brugada syndrome [5.6%], mitral valve-related arrhythmia [5.6%], and short QT syndrome [2.8%]). Among the rest of the 96 patients with true IVF (mean age 38.4±15.7 years, male 59.4%, Caucasian 80.2%, hypertension 28.1%, diabetes 8.3%), 91 (94.8%) patients presented with out-of-hospital cardiac arrest and 88 (91.7%) patients had a history of syncope. Early repolarization and fragmented QRS were noted in 32 (33.3%) and 28 (29.1%) patients, respectively. Defibrillators were implanted in 92 (95.8%) patients. Genetic testing was performed in 35 (36.5%) patients, and possible associated mutations were found in 13 (37.1%) patients. An Electrophysiology study was conducted in 55 (57.3%) patients, and ventricular fibrillation was induced in 17 (30.9%) patients. The medical management with antiarrhythmic drugs was selected in 60 (62.5%) patients, and the catheter ablation ± anti-arrhythmic drugs was selected in 36 (37.5%) patients. The recurrence of ventricular fibrillation during 9.2±6.8 years of mean follow-up was significantly higher in the ablation strategy group (p=0.0003) (Figure 1).

Conclusions
We reported the largest cohort of IVF patients from a single healthcare system. Early repolarization and fragmented QRS were common in IVF. The possible associated mutations were found in one-third of IVF who underwent genetic testing. The ventricular fibrillation recurrences were significantly higher in the catheter ablation strategy group.
Sinus rate and QRS duration on lead V1 predict major events in Brugada syndrome
Authors: Laporte P , Vaglio M , Denjoy I , Maison-Blanche P , Badilini F , Leenhardt A , Extramiana F 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Ministère de la Santé Française

Background
Arrhythmic risk stratification remains a major challenge in asymptomatic Brugada patients. Many studies have evaluated risk stratification performance based on a single or a few ECG-derived parameters measured manually. We aimed to assess the predictive value of multi ECG parameters measured automatically in patients with Brugada syndrome.

Materials and Methods
We performed a prospective, multicenter cohort study including Brugada patients with at least one available type 1 ECG (either spontaneously or drug-induced) between January 2005 and November 2021. Paper ECG were first digitized and then automatically analyzed using the Glasgow and Bravo algorithms (included in the logiciel CalECG). Clinical data and Brugada related events at diagnosis and during follow-up were collected. Sudden cardiac death, aborted cardiac arrest and appropriate ICD therapy in the VF zone were considered as major events. The predictive value of clinical and ECG parameters for symptomatic status was assessed using uni- and multivariate Cox models.

Results
ECGs from 301 Brugada patients (77% male, mean age at diagnosis 43 years, follow-up 7±5.6 years) were analyzed. Brugada-related symptoms (cardiac syncope or major event) occurred in 23% of patients before diagnosis and 11% during follow-up (incidence: 1.57%/year).
After multivariate Cox analysis, only 2 baseline ECG (without Ajmaline) parameters were significantly associated with major events: RR interval (HR=1.01 (95%CI [1-1.01]), p=0.002) and QRS duration in lead V1 (HR=1.04 (95%CI [1-1.07]), p=0.038).
QRS prolongation in lead V1 &gt;113 ms (AUROC 0.69 (95% CI [0.58-0.8])) was associated with a 3-fold increased risk of major event (HR =3.49 (95% CI [1.72-7.09]), p=0.001).

Conclusion
Many previously described ECG parameter were not associated with major event in Brugada patients after multi-parameter evaluation. Sinus rate and QRS duration on lead V1 were independent risk factor. These results need to be validated on an external cohort. The predictive value of ECG parameters in Brugada syndrome should be assessed using automated multiparametric quantification.
Using the 3D architecture of scar to predict life-threatening ventricular arrythmias - still a long way to go
Authors: Amador R , Bello A R , Freitas P , Guerreiro S , Abecasis J , Coutinho Santos A , Saraiva C , Galvao Santos P , Moscoso Costa F , Carvalho M S , Carmo P , Cavaco D , Morgado F , Ferreira A M , Adragao P 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias.

Purpose
The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD).

Methods
We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 5 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock) or SCD.

Results
A total of 75 patients were analysed (mean age 63 ± 13 years; 83% male; mean LVEF 31 ± 13%; 50 patients with ischemic and 25 with non-ischemic cardiomyopathy; 14 patients received a device in the setting of secondary prevention). During a median follow-up of 1.4 years (IQR 0.7 – 2.4 years) there were 15 events (12 appropriate ICD therapies [8 shocks and 4 ATP] and 3 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values &gt; 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 11 patients did not show any channel. Two of these experienced an arrhythmic event, yielding a negative predictive value of 80% (95% CI 75-83%) for the absence of channels.

Conclusion
In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.
Clinical significance of conduction velocity orientation vectors on cardiac mapping surfaces
Authors: Rodriguez Padilla J , Anderson R , Joens C , Masse S , Bhaskaran A , Niri A , Lai P , Ali Azam M , Lee G , Vigmond E , Nanthakumar K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): This work was supported by the Lefoulon Delalande Foundation

OBJECTIVE
Electroanatomical maps using automated conduction velocity (CV) algorithms are now being calculated using 2D mapping tools. The basis of substrate-based functional assessment is to detect slow zones or slow CV of which isochronal late activation mapping (ILAM) is now commonly performed. We studied the accuracy of mapping surface 2D CV, compared to the 3D vectors, and the influence of mapping resolution in non-scarred animal and human heart models.

Methods
Two models were used: a healthy porcine Langendorff model with transmural needle electrodes and a computer stimulation model of the ventricles built from an MRI-segmented, excised human heart. Local activation times (LAT) within the 3D volume of the mesh were used to calculate true 3D CVs (direction and velocity) for different pixel resolutions ranging between 500 mm – 4 mm (3D CVs). CV was also calculated for endocardial surface-only LATs (2D CV).

Results
In the experimental model, surface (2D) CV was faster on the epicardium (0.509 m/s) compared to the endocardium (0.262 m/s, Figure 1). In stimulation models, 2D CV significantly exceeded 3D CVs across all mapping resolutions and increased as resolution decreased (Figure 2). 3D and 2D left ventricle CV at 500mm resolution increased from 429.2±189.3 mm/s to 527.7±253.8 mm/s (P&lt;0.01), respectively with modest correlation (R=0.64). Decreasing the resolution to 4mm significantly increased 2D CV and weakened the correlation (R=0.46). The majority of CV vectors were not parallel (&lt;30°) to the mapping surface providing a potential mechanistic explanation for erroneous LAT-based CV over-estimation.

Conclusion
Ventricular CV is overestimated when using 2D LAT-based CV calculation of the mapping surface and is significantly compounded by mapping resolution. These findings have implications for the current methodology of functional substrate assessment with ILAM and surface CV assessment.
Clinical trial report: the electrocardiographic response to ajmaline provocation in healthy subjects
Authors: Ensam B , Scrocco C , Batchvarov V , Behr E 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation
The Robert Lancaster Memorial Fund sponsored by McColl’s Research Group

Background
The electrocardiographic (ECG) response to diagnostic ajmaline provocation (AP) testing has been studied extensively in clinical cohorts. However, the healthy ECG response has not been described. We undertook a trial examining ECG changes in response to AP in a cohort of systematically recruited asymptomatic Caucasian healthy subjects with no family history of sudden death and normal baseline ECG and echocardiogram.

Methods
Applicants responded to a national recruitment advertisement and completed an online medical questionnaire. Those fulfilling inclusion criteria were invited to undergo further evaluation with eligible subjects undergoing a diagnostic ajmaline challenge (1mg/kg, max. 100mg over 5 minutes). A continuous ECG was recorded in the standard and high right precordial lead (HRPL) position. Automated analysis of conventional and novel ECG measurements were made at baseline and at peak drug effect, which was defined as the point of maximum QRS duration (excluding precordial leads).

Results
One hundred healthy Caucasian subjects underwent AP. The mean age was 26.84 years (SD ± 8.01 years) and 52% were male. A drug induced type 1 Brugada pattern (DI-T1BP) was observed in 3/100 (3%) of the cohort. We performed a paired comparison of ECG measures at baseline versus peak drug effect (Table 1).
AP had a similar effect on global QRS duration and global PR interval, with both increasing by 28%, mean ∆ 25.66ms and mean ∆ 43.36ms respectively. Changes in S wave parameters in lead II were pronounced, with a 97% increase in S wave duration and a 101% increase in S wave negative amplitude. ST-J point elevation in the anterior, inferior, and lateral regions was comparable, with a 57%, 51% and 57% increase in ST-J amplitude respectively.
AP had a greater effect on cardiac conduction in females compared to males (Table 2). In contrast, changes in STJ point amplitude and combined and segmented QRST segment area were greater in males.

Conclusion
The healthy ECG response to AP elicits a pronounced effect on cardiac conduction, more so in females compared to males, whilst changes in STJ point amplitude and QRST area were greater in male subjects. The DI-T1BP is part of the healthy response to AP.
Noninvasive stratification of ventricular substrate by electrocardiographic imaging
Authors: Reventos-Presmanes J , Hernandez-Romero I , Invers-Rubio E , Ferro E , Garre P , Borras R , Tolosana J M , Guasch E , Arbelo E , Porta-Sanchez A , Vazquez S , Guichard J B , Climent A M , Mont L , Roca-Luque I 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Abnormalities of cardiac activation and conduction velocity (CV) are known pro-arrhythmogenic factors. Electrocardiographic imaging (ECGI) is presented as a non-invasive tool for arrhythmogenic substrate analysis. However, electrocardiographic features such propagation activation patterns, and CV are unknown in healthy subjects. In this study, ECGI technology has been evaluated for ventricular tissue stratification in patients with and without structural heart disease.

Methods
Nineteen patients were included in the study. The healthy ventricles group (Panel A) included 10 patients (8 males, 57 ± 6 years, NYHA = I and LVEF 61 ± 5 %) with normal baseline QRS and normal values of ventricular morphology, function and perfusion assessed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). The structural heart disease group (Panel B) included 9 patients (9 males, 66±6 years, NYHA 2±1 and LVEF 26±5%) with ischemic cardiomyopathy (ICM) confirmed by LGE-CMR and indication for ablation due to ventricular tachycardia. For each patient, fibrotic areas were identified by ventricular segmentation of the LGE-CMR and ventricles were regionalized in 16 regions. Epicardial electrograms were noninvasively reconstructed by ECGI, late activation time (LAT) and CV maps were calculated to study electrocardiographic features.

Results
– Ventricles with fibrosis secondary to ICM revealed heterogenous activation patters and higher activation time distribution compared to healthy ventricles (120 ms vs 80 ms; p&lt;0.01). Density distribution of CV was evaluated in the 0-200 cm/s interval, patients with healthy ventricular tissue showed homogenous CV distribution whereas ICM patients presented higher concentration in the slow CV region with a maximum peak around 75 cm/s. Moreover, CV values were significantly lower in fibrotic myocardium present in patients with structural heart disease compared to healthy myocardium (77 ± 40 cm/s vs 114 ± 46 cm/s; p&lt;0.01), Panel C anterior view. Non-fibrotic regions in the ischemic ventricle group, Panel C inferior view, presented similar CV distributions to healthy ventricular tissue (114 ± 46 cm/s vs 120 ± 48 cm/s; p = 0.14).

Conclusions
ECGI can noninvasively identify fibrotic tissue by analysing ventricular activation and CV patterns. ECGI could be a potential early tool to identify patients at risk of sudden cardiac death.
Impact of cardiac magnetic resonance channels to localize deceleration zones during VT ablation
Authors: Vazquez-Calvo S , Garre P , Ferro E , Guichard J B , Falzone P , Arbelo E , Tolosana J M , Guasch E , Mont L , Porta-Sanchez A , Brugada J , Ortiz-Perez J T , Roca-Luque I 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Cardiac magnetic resonance has demonstrated to accurately identify voltage conduction channels and it is nowadays an important tool to analyze the arrhythmic substrate, to predict ventricular tachycardia (VT) events and to aid VT ablation. The characteristics of CMR channels (CMR-CCs) that predicts the presence of deceleration zone (DZ) have not been explored.

Methods
Forty-four consecutive patients with scar-related VT undergoing ablation after CMR (October 2018-July 2021) were included (medium age 64.8±11.6 years; 95.5% male; 70.5% ischemic heart disease, mean ejection fraction of 32.3±7.8). Characteristics of CMR-CCs were analyzed and correlation with DZs both in baseline maps and remaps were performed. Patients were prospectively followed for VT recurrence for one year.

Results
Overall, 129 automatically detected CMR-CCs were analyzed (2.89±1.83 per patient; length: 52.72±65.44mm (0.18–376.73), CC mass: 1.76±2.46grams (0.01–14.59); protectedness 19.02±24.51% (0.01–143.51)). Overall, 73.6% of CMR-CCs were associated with a DZ: 58.1% CMR-CCs in baseline map and 15.5% with a DZs not observed initially but in remaps. The univariate analysis showed that channels associated with DZs were longer (61.83±73.43 vs. 29.96±32.55, OR 1.01, p0.004), with higher border zone mass (2.02±2.75 vs. 1.09±1.44, OR 1.28, p0.031) and more protectedness (21.90±27.23 vs. 11.46±14.20, OR1.02, p0.036). VT recurrence after one-year follow up was 21.95%.

Conclusions
Pre ablation CMR can accurately identify channels that correlates with DZs that could be targets for ablation, especially those CMR-CCs with higher length, border zone mass and protectedness. Additionally, some channels not related with DZ in the first map have a clear DZ after abolishing the first region of slow conduction, suggesting a very useful role of CMR to detect potential DZs.