bluuebunny/crossref_metadata_2025 huggingface dataset:
Negative SA-VA difference during entrainment of a supraventricular tachycardia: a new criterion for the diagnosis of focal atrial tachycardia
Authors: Adelino Recasens R , Bazan V , Sarrias A , Jimenez J , Rodriguez Garcia J , Bisbal F , Aranyo J , Villuendas R , Almendral J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Ventricular overdrive pacing during tachycardia is one of the most common and useful maneuvers to assess de differential diagnosis of supraventricular tachycardia (SVT). Focal atrial tachycardia (FAT) usually presents long ventriculo-atrial (VA) interval, which is a passive interval since FAT is not an atrio-ventricular reentry. Therefore, during ventricular entrainment of a FAT, the stimulus-atrial (SA) interval will depend solely on the retrograde VA conduction time, if retrograde conduction exists. This retrograde conduction time is usually shorter than the VA Interval during tachycardia, thus being able to cause a negative SA-VA difference. This does not occur in other types of SVT, where the SA-VA difference helps to differential diagnosis, but positive values have been described.

Purpose

Our aim was to analyze whether the SA-VA value discriminates FAT from the other types of SVT, in patients with SVT and VA conduction when stimulating the ventricle during tachycardia.

Methods

Multicenter data of SVT entrainment were collected retrospectively, including FAT, atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reciprocating tachycardia (AVRT). The numeric value of SA-VA difference was calculated for each case. The best SA-VA cut-off point for the diagnosis of TAF was determined, evaluating the sensitivity and specificity of this value for the diagnosis of TAF with respect to the gold standard (classical criteria).

Results

Continuous ventricular pacing during tachycardia succeeded in accelerating the atrium to the pacing rate in 80 cases out of the total studied cases: 32 (40%) AVNRT, 28 (35%) AVRT and 20 (25%) FAT. All FAT cases had a negative SA-VA value and all AVNRT and AVRT cases obtained positive SA-VA (Figure 1). SA-VA value lower than 0 ms was the best cut-off point (using ROC curve, Figure 2) with an area under the curve of 1. SA-VA difference lower than 0 ms (or negative SA-VA difference) showed 100% sensitivity and specificity for the diagnosis of FAT.

Conclusions

Negative SA-VA difference is a new and accurate criterion for the diagnosis of focal atrial tachycardia.
A novel dipole charge density mapping system integrated in robotics offers advantages for ablation of atrial tachycardias: first-in-human experience
Authors: Gagyi R , Noten AME , Wijchers S , Yap SC , Hoogendijk M , Szili-Torok T
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation (CA) for atrial tachycardia (AT) and atrial flutter (AFL) offers favorable acute and long-term outcomes. Until recently, mapping of AT/AFL was only possible with sequential mapping methods using manually controlled catheters. Even by implementing multielectrode mapping, some limitations exist during mapping of short-lived arrhythmias and ATs with unstable CL. Remote magnetic navigation (RMN) with its atraumatic catheter design has superior safety profile and excellent accuracy. Recently, a novel high-resolution mapping system (AcQMap) can be used in combination with RMN (AcQMap-RMN).

Purpose

To assess the feasibility, safety and efficacy of AcQMap-RMN guided ablation in the management of complex ATs.

Methods

All patients undergoing CA for AT/AFL using AcQMap-RMN were included. The AcQMap system utilizes two different types of mapping: Single Position Map (SMP) and SuperMap, allowing mapping of both non-sustained and sustained ATs. Procedural efficiency was characterized by procedure time, total ablation time and radiation doses. Acute success was defined by arrhythmia source elimination. Efficacy data are based on 12-month follow up and number of redo procedures. Procedural safety was evaluated by intra- and post-procedural complications.

Results

A total number of 76 patients were referred for CA with AT/AFL (mean age 59.0±13.2), including 3 patients with inappropriate sinus tachycardia and 73 patients with AT/AFL. Out of 73 patients, 8 had perinodal AT. From the remaining 65 patients, 38 had de novo, 22 had post-PVI, and 5 patients had post-MAZE AT/AFL. Twenty-nine patients had short-lived ATs and were mapped exclusively by SPM. The mean procedure time was 175.9±61.4 min, mean ablation time 964.0 (IQR 422.0-1693.0) s, and mean radiation dose was 152.0(IQR 86.7-294.0) mGy. Acute success was documented in 70 procedures (92.1%). From de novo AT/AF patients 4 (10.5%), from post-PVI and post-MAZE AT/AFL patients 3 had recurrence at the end of the follow-up period (11.1%). Four patients had redo procedure. Three patients had post-procedural complications including 2 patients with groin hematoma and 1 patient with transient ischemic attack.

Conclusion

AcQMap-RMN integration offers improved efficiency, high success and low complication rates in complex AT ablation.
Zero fluro compared to fluoroscopy guided radiofrequency ablation of typical atrial flutter
Authors: Spinthakis NS , Mclachlan FM , Hawley AH , Podd SJP , Lovell ML
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

There is growing evidence of the harm caused by radiation exposure for both patients and health professionals. Current use of electroanatomical 3D mapping systems has allowed the application of zero fluro technique in order to reduce exposure. The efficacy and accuracy of these mapping systems is becoming more apparent, reserving traditional fluoroscopic techniques for simple anatomical cases. Hence, the use of radiation with no electroanatomical mapping for the ablation of typical flutter, still remains the mainstay of treatment in most centers.

Purpose

We aimed to investigate whether a zero fluro approach in typical atrial flutter ablation results in similar outcomes compared to traditional fluoroscopic techniques.

Methods

This was a single center retrospective study of (n=388) consecutive patients undergoing typical atrial flutter ablation between 2018 and 2020. Majority of cases were performed under conscious sedation (i.v. midazolam and fentanyl) with two sheaths into the right femoral vein under ultrasound guidance. A steerable Livewire™ quadripolar or an Inquiry™ deccapolar diagnostic catheter was advanced into the coronary sinus. 3D mapping was performed with Ensite Precision™ or Carto 3™. Fluoroscopy was performed in LAO 300 with ablation performed at 6 o’clock on the tricuspid annulus back to inferior vena cava. Ablation catheters used 30-60 seconds per lesion. Procedural endpoints included a bidirectional block across cavotricuspid isthmus and clinical and electrocardiographical recurrence during follow up at 3 months. Baseline characteristics were examined for confounders.

Results

Atrial flutter ablation was successful in 95% of the procedures with no difference between the two groups (p=0.07). There was a significant exposure to radiation (2.494 ± 3.596 gy/cm² vs 0.1 ± 0.7 gy/cm², p=0.001) and in total fluoroscopy time (8 ± 5.7 min vs 0 ± 0 min, p=0.001) in the fluro guided group compared to zero fluro group. Total ablation time was not significantly different between the two groups (16.1 ± 11.6 min vs 14.7 ± 10.2 min, p=0.40). Patients undergoing fluro guided ablation had a significantly longer procedure when compared to the zero fluro group (77.4 ± 44.8 min vs 66.1 ± 37.1 min, p=0.006). There was no difference in baseline characteristics or procedural complications between the two groups (table 1).

Conclusion

Ablation of typical atrial flutter can be performed safely and effectively with zero fluro techniques using only 3D anatomical mapping. This work adds to the growing body of evidence to support the use of these technologies in the management of simple cardiac arrhythmias, in order to eliminate the use of radiation and its effect in carcinogenesis, by making them current standard of care.
Long-term If current blockade increases right atrial mRNA expression of HCN4, encoding proteins for If
Authors: Scridon A , Halatiu VB , Balan AI , Cozac DA , Moldovan V , Banescu C , Serban RC
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS - UEFISCDI, within PNCDI III

Background

Numerous long-term pharmacologic manipulations of cardiac ion channels have shown potential to modify the expression of genes encoding proteins for those channels.

Purpose

We aimed to investigate whether long-term pharmacologic inhibition of the hyperpolarization-activated inward current (If) using ivabradine affects the right atrial expression of genes encoding for hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, responsible for If.

Methods

The right atrial mRNA expression of HCN1, HCN2, and HCN4, and of the neuron-specific HCN3 isoform was quantified in 6 control (Control) and 12 ivabradine-treated (IVA; 10 mg/kg, 4 weeks) adult male Wistar rats. The expression levels of the target genes were normalized with GAPDH housekeeping gene levels and compared between the two groups.

Results

Right atrial HCN1 and HCN2 expression levels were both similar (both p >0.05) between the IVA and the Control rats. There was also no significant difference in the right atrial expression of the neuron-specific HCN3 isoform between the two groups (p = 0.22). However, the right atrial expression of HCN4, the most highly expressed HCN isoform in the sinus node, was significantly higher in the ivabradine-treated compared to the non-treated rats (p = 0.02).

Conclusions

Our study shows that chronic If blockade using ivabradine significantly up-regulates right atrial HCN4 expression. Although the examined samples contained both nodal and non-nodal tissue, since HCN4 is highly expressed in the nodal pacemaker cells and only sparsely in the remaining atrial myocardium, it is likely that the HCN4 changes observed in our study reflect sinus node alterations. HCN4 and a consequent If up-regulation could render the sinus node less sensitive to acute vagal inputs and protect against excessive vagal-induced bradycardia. Further studies will have to evaluate this hypothesis.
Anatomically-guided cardioneuroablation for recurrent neurally mediated syncope
Authors: Wichterle D , Stiavnicky P , Jansova H , Stojadinovic P , Haskova J , Peichl P , Cihak R , Kautzner J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Cardioneuroablation (CNA) has been proposed as a new therapeutic approach in selected patients with recurrent neurally mediated syncope and documented cardioinhibitory component.

Purpose

We report on procedural data and clinical outcomes of consecutive patients who underwent anatomically-guided CNA at our center in the period of 2014 - 2021.

Methods

A study investigated 145 otherwise healthy patients (age: 40 ± 14 years, 56% males) with recurrent reflex syncope and the physiological result of the atropine test. Biatrial radiofrequency (RF) ablation was performed under general anesthesia by irrigated-tip catheter at empirical sites of ganglionated plexi (GP) with the navigation by CARTO-3 system and intracardiac echocardiography. Anterior right GP and posteromedial left GP were always targeted to modulate the innervation of both sinoatrial (SAN) and atrioventricular (AVN) nodes, irrespective of clinical manifestation of the disease. The loss of responsiveness of both nodes to extracardiac vagus nerve stimulation was the procedural endpoint. Right vagus or bilateral vagus nerve stimulation was used in 86% and 54% of procedures, respectively.

Results

Enrolled patients had documented cardioinhibitory disorder of SAN (59%), AVN (30%), or both nodes (11%). CNA (duration: 157 ± 31 min; RF time: 15 ± 6 min; radiation dose: 84 ± 135 µGy.m²) resulted in sinus rate acceleration by 28 ± 12 bpm, shortening of AH interval by 15 ± 31 ms, an increase of Wenckebach point by 28 ± 33 bpm, shortening of AVN effective refractory period by 110 ± 115 ms, and sinus node recovery time by 508 ± 666 ms. During a median follow up of 26 (IQR: 12-39) months, CNA was repeated in 9 patients and is scheduled in 3 other (total 8%). Pacemaker was implanted only in 4 (3%) patients after single (n = 2) or repeated CNA (n = 2). Corresponding Kaplan-Meier curves are provided in the Figure. Any-syncope-free survival is comparable to that reported in active arms of historical and recent pacemaker studies.

Conclusions

CNA is a reasonably effective treatment option for patients with functional cardioinhibitory syncope. CNA can be performed by anatomically-guided ablation at empirical GP sites. Our study corroborates the clinical utility of CNA as a viable alternative to pacemaker implant in selected patients.
Improved prediction of electrical storm in patients with prior myocardial infarction and implantaImproved prediction of electrical storm in patients with prior myocardiable cardioverter defibrillator
Authors: Faga V , Anguera I , Oloriz T , Nombela-Franco L , Teruel L , Dallaglio PD , Perez Guerrero A , Gomez Hospital JA , Rodriguez Garcia J , Rodriguez Garcia MA , Adelino Recasens R , Merce J , Viedma J , Comin Colet J , Di Marco A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Aims

To evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD).

Methods

Multicenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation.

Results

During a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p<0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p=0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%).

Conclusion

In a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.
Discussions on implantable cardioverter defibrillator deactivation in patients receiving radiation therapy
Authors: Salum E , Turner S , Syeda A , Singh SM
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): University of Toronto

Background

Established guidelines discuss ICD deactivation and end of life care in ICD patients. A previous study has suggested that 45% of patients with an ICD and do not resuscitate order have not discussed ICD deactivation. In patients receiving radiation therapy for cancer ICD deactivation should be discussed given the life limiting nature of cancer, however it is unclear how frequently this topic is discussed in clinical practice.

Objectives

To report on the frequency of discussions of ICD deactivation in a population of patients receiving radiation therapy for cancer.

Methods

Our hospital is a large regional cancer and cardiac center in Canada. Consecutive patients of our institution presenting to our ICD clinic for ICD checks prior and during receipt of radiation therapy between 2005 and 2019 were included (n=43). Electronic medical records were reviewed to determine demographics, clinical characteristics, documentation of discussions on ICD deactivation, and survival at 1-year.

Results

The cohort was predominantly male (84%), with a primary prevention ICD (65%) without resynchronization capacity (74%). Discussions on ICD deactivation with subsequent deactivations occurred in 12 (28%) patients. During a median follow-up of 4 years 25 patients died, with 28% of these patients dying within 2 years of the ICD clinic encounter. Discussions on ICD deactivation were more frequent in patients who received a palliative care consultation.

Conclusions

End of life conversations regarding ICD deactivation in patients undergoing radiation therapy for cancer are rare. Collaboration with palliative care teams may facilitate conversations on ICD deactivation during this opportune time.
The prevalence of Type-1 Brugada pattern in African American: a large population study from the United States
Authors: Rattanawong P , Fatunde O , Ko Ko N , Shen W , Sorajja D
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

The prevalence of Type-1 Brugada pattern in Caucasians and Asians have been estimated to be 20 and 180 per 100,000. However, the prevalence of Type-1 Brugada pattern in African Americans has never been studied.

Purpose

This study aims to identify the prevalence of Type-1 Brugada pattern in African Americans.

Methods

Medical records of African American patients ages 18 years old or older with at least one 12-lead electrocardiogram (ECG) performed at 16 hospitals from 5 states in a single healthcare system between January 1, 2011 to December 31, 2020 were included. The search engine software was used to identify patients with keywords (Brugada pattern, Brugada ECG, Brugada Type-1, or Brugada syndrome) documented in the electronic medical record. The 12-lead ECGs were retrospectively analyzed by 2 cardiologists. Any inconsistencies were reviewed by a third cardiac electrophysiologist. Type-1 Brugada pattern was diagnosed according to the recent Heart Rhythm Society Expert Consensus Statement.

Results

Among 43,116 African American patients, (46.9% males), 6 patients (mean age 44.8±13.9 years, 100% males) had Type-1 Brugada pattern documented on at least one 12-lead ECG. The prevalence of Type-1 Brugada pattern in this large patient population of African American was 13.9 per 100,000. None of the patients had major arrhythmic event at 6.7±4.7 years follow-up.

Conclusions

The prevalence of Type-1 Brugada pattern in African American is lower than Caucasian and Asian populations. The risk of major arrhythmic event of Type-1 Brugada pattern in African American appears to be low; however longer follow-up data is needed.
Phenotypic characteristics of patients with arrhythmogenic left ventricular cardiomyopathy and sustained ventricular tachycardias
Authors: Sanchez Munoz JJ , Munoz Esparza C , Penafiel Verdu P , Gonzalez Alarcon J , Polo Garcia LA , Gimeno Blanes JR , Garcia Alberola A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

The Padua criteria proposed for the diagnostic approach to Arrhythmogenic Cardiomyopathy (AMC) introduced new diagnostic criteria to recognize patients with a phenotype of the left ventricular variants of AMC (ALVC). Unlike ARVC, the arrhythmogenicity of this left phenotype has not yet been established.

Objectives

This study aims to analyze the phenotypic characteristics in a group of patients with ALVC and ventricular arrhythmias (VA).

Methods

Thirty-seven related patients with ALVC and VA were included and these were evaluated at the Inherited Cardiac Disease Unit of a Tertiary Hospital.

Results

Between 2000 and 2021, a total of 207 patients were diagnosed with ALVC. Thirty-seven patients (18%) presented VA; 25 ( 67%) sustained ventricular tachycardia (SVT), 10 ( 27 %) non sustained ventricular tachycardia (NSVT) and 2 ventricular fibrillation (VF). Eighteen 18/37 (49%) biventricular and 19/37 (51%) dominant . Twenty-five, 67 % male, aged 41.8 ± 13.4 years. A genetic study was performed in 36 ( 97%), and the pathogenic mutations were identified in desmoplakin in eighteen, plakophilin-2, desmoglein-2 and phospholamb in three, titin and filamine in two; desmin, plakoglobin and lamin A in one. There was one variant of uncertain significance in desmocollin-2, desmoplakin and titin. A low amplitude QRS voltages (LAQRS) in limb leads was present in 14/33 patients . Inverted T waves in right (V1-V3) in 4/33 patients and in left precordial (V4-V6) were present in 9/33 patients. The average left ventricular ejection fraction (LVEF) was 41%± 14 and myocardial fibrosis evidenced by contrast-enhanced CMR as LGE was presented in 22 patients. Ventricular arrhythmias with a right bundle branch block (RBBB) morphology were most frequent (7/12 ), denoting the origin from LV. All VT with LBBB morphology appeared in biventricular cases (5/12). Reverse pattern break was present in three patients. EAM showed bipolar or unipolar endocardial scar left ventricle in 6/10 and bipolar or unipolar endocardial scar right ventricle in 3/10 patients. Epicardial scar was present in 4 patients ( 3 LV, 2 RV). An implantable cardioverted defibrillator (ICD) therapy was performed in 25 patients for primary or secondary prevention of sudden death. Heart transplantation was carried out for three patients.

Conclusions

A substancial number of patients with ALVC have presented ventricular arrhythmias. Ventricular arrhythmias with a right bundle branch block (RBBB) morphology were the most frequent. All of VT with LBBB morphology appeared in biventricular cases. The mutation in DSP was the most prevalent in patients with ALVC and VT. Patients with ALVC and VA are characterized by a ventricular function that is not significantly impaired; however, fibrosis in LGE is widespread.
More than half of all sudden cardiac deaths occur in persons without a history of cardiovascular disease: A study of 54,028 deaths in Denmark
Authors: Lynge T , Skjelbred T , Svane J , Garcia R , Winkel BG , Tfelt-Hansen J
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Copenhagen University Hospital, Rigshospitalet

Background

Sudden cardiac death (SCD) is a major public health problem accounting for a large proportion of global mortality. Previous studies suggest that SCD often occurs in the general population in persons not previously diagnosed with cardiovascular disease. It is evidently challenging to identify high-risk persons in an overwhelmingly large population of mainly healthy individuals and studies are needed to further characterize these SCD cases.

Purpose

To estimate SCD burden in patients not previously diagnosed with cardiovascular disease and to characterize these SCD cases.

Methods

All deaths in Denmark (population of 5.5 million) in 2010 were manually reviewed case-by-case. Autopsy reports, death certificates, and information from nationwide health registries were systematically examined to identify all SCD in 2010. The Danish National Patient Register contains information on all in- and outpatient activities at Danish hospitals and emergency departments and was used to identify all SCD cases with a previous cardiovascular diagnosis.

Results

There were 54,028 deaths in Denmark in 2010, of which 6,867 (13%) were categorized as SCD. Overall incidence rate of SCD was 124 (95%-CI: 121-127) per 100,000 person-years. Of all SCD, 59% were not diagnosed with cardiovascular disease prior to death. SCD incidence in persons with and without a history of cardiovascular disease was 790 (95%-CI: 762-820) and 78 (95%-CI: 75-80) per 100,000 person-years, respectively. This corresponds to an incidence rate ratio of 10 (95%-CI: 10-11). SCD cases with no previously diagnosed cardiovascular diseases were younger (median age 75 vs. 80 years, p<0.001), more often female (45 vs. 42%, p=0.019), and on average had a lower household income (p=0.002) (Table 1). SCD cases not diagnosed with cardiovascular disease prior to death in general had fewer comorbidities, except for psychiatric diseases, which were more common in the undiagnosed group (Table 1).

Conclusion

In this large and nationwide study of all SCD in Denmark in 2010, more than half of all SCD occurred in persons without a history of cardiovascular disease. This suggests that SCD is often first manifestation of disease. We currently do not have accurate tools for SCD risk stratification in the general population and future research is needed to identify modifiable and easily measured risk factors of SCD in the general population.
The peri-infarct gray zone of myocardial fibrosis is a better predictor of ventricular arrhythmias than dense core fibrosis in patients with previous myocardial infarction
Authors: Lopes P , Cunha G , Freitas P , Rocha B , Matos D , Rodrigues G , Carmo J , Carvalho MS , Galvao Santos P , Costa FM , Carmo P , Cavaco D , Morgado F , Ferreira A , Adragao P
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Current sudden cardiac death (SCD) risk stratification relies heavily on left ventricular ejection fraction (LVEF), but markers to refine risk assessment are needed. Dense core fibrosis (DCF) and peri-infarct "gray zone" of myocardial fibrosis (GZF) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) have been proposed as potential arrhythmogenic substrates. The aim of our study was to determine whether DCF and GZF could predict the occurrence of ventricular arrhythmias in patients with previous myocardial infarction.

Methods

We performed a single centre retrospective study enrolling consecutive patients with previous myocardial infarction undergoing CMR before implantable cardioverter-defibrillator (ICD) implantation. Areas of LGE were subdivided into "core" DCF and "peri-infarct" GZF zones based on signal intensity (>5 SD, and 2-5 SD above the mean of reference myocardium, respectively).

The primary endpoint was a composite of sudden arrhythmic death, appropriate ICD shock, ventricular fibrillation (VF), or sustained ventricular tachycardia (VT) as detected by the device.

Results

A total of 88 patients (median age 61 years [IQR 54-73], 84% male, median LVEF 30% [IQR 23-36%], 14% secondary prevention) were included. During a median follow-up of 23 months [IQR 9-38], 13 patients reached the primary endpoint (10 appropriate ICD shock, 2 sustained VT or VF, and 1 sudden arrhythmic death). Patients who attained the primary endpoint had similar DCF (30.4g ± 14.7 vs. 28.0g ± 15.3; P = 0.601) but a greater amount of GZF (18.1g ± 9.6 vs. 11.9g ± 6.7; P = 0.005). On univariate analysis, GZF was associated with the composite endpoint (HR: 1.09 per gram; 95%CI: 1.02-1.15; P = 0.006), whereas DCF was not (HR: 1.01 per gram; 95%CI: 0.98-1.05; P = 0.571). After adjustment for LVEF, GZF remained independently associated with the primary endpoint (adjusted HR: 1.06 per gram; 95% CI: 1.01-1.12; P = 0.035). Decision tree analysis identified 11.9g of GZF as the best cut-off to predict life-threatening arrhythmic events. The primary endpoint occurred in 11 out of the 35 patients (31.4%) with GZF ≥11.9g, but in only 2 of the 53 patients (3.8%) with GZF <11.9g – Figure.

Conclusions

The extent of peri-infarct GZF seems to be a better predictor of ventricular arrhythmias than DCF. This parameter may be useful to identify a subgroup of patients with previous myocardial infarction at increased risk of life-threatening arrhythmic events.
SAECG - advances in Brugada stratification
Authors: Brito J , Silverio Antonio P , Silva P , Couto Pereira S , Valente Silva B , Cunha N , Nunes-Ferreira A , Lima Da Silva G , Neves I , Cortez-Dias N , J Pinto F , Sousa J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Brugada syndrome (BrS) is a relevant cause of sudden cardiac death (SCD) in young adults. Several risk factors have been identified, but clinical decision making remains extremely challenging, particularly in asymptomatic patients.

Purpose

To explore the usefulness of the non-invasive assessment of late potentials (LPs) based signal-averaged ECG (SAECG) for risk stratification in BrS.

Methods

Prospective single-center study of patients with BrS included from 2003 to 2021. 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.

The primary endpoint was the occurrence of malignant arrhythmic events (MAEs), defined as a composite of SCD or appropriate shocks. Uni- and multivariate Cox regression survival analyses were used to identify significant prognostic predictors considering the clinical, genetic, and electrocardiographic characteristics as well as the tercile distribution of the SAECG parameters. A risk score was computed incorporating the significant LPs variables and its usefulness for prognostic stratification was explored using Kaplan Meier survival analysis.

Results

Our cohort consisted of 117 patients (mean age: 47±13 years, 33% male), including 75 (65%) with type 1 spontaneous pattern and 92 (79%) asymptomatic individuals. Symptoms at presentation included syncope in 16 pts (14%) and polymorphic VT/cardiac arrest in 4 (3.4%).

During a median follow-up of 4.1±0.3 years, 8 pts (6.8%) suffered MAEs: 3 (2.6%) with SCD and 5 (4.3%) with appropriate shocks.

The risk of events differed in relation to the several SAECG parameters (Table 1), increasing linearly with the fQRS duration determined either in the conventional (HR 1.03, 95% CI 1.01-1.06, p=0.008) or modified leads (HR: 1.03, 95% CI 1.01- 1.05, p=0.003). The SAECG score incorporated as risk markers a fQRS ≥113ms and a RMS40 <13 μV. Patients with both risk markers presented a 7-fold increased risk (HR 7.17, 95% CI 1.29-40, p = 0.025), independently of the baseline symptomatic status and ECG pattern.

Conclusion

This study shows that the non-invasive assessment of LPs based on SAECG is useful for prognostic stratification of BrS. It was possible to identify a subset of patients presenting a high risk of events who may deserve individualized preventive strategies.
PVC ablation without fluoroscopy
Authors: Pena Mellado J , Sanchez Millan P , Gutierrez Ballesteros G , Tercedor L , Alvarez Lopez M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Premature ventricular complex(PVC) catheter ablation is required in a wide spectrum of the population.Ionizing radiation exposure in this procedure carries health risks, especially in young patients.

Purpose

In this prospective observational study we describe our experience in PVC ablation without fluoroscopy

Methods

26 patients were included, submitted to PVC ablation without fluoroscopy between October 2018 and November 2021, in our center. Baseline characteristics of the population, acute success and complications derived from the procedure were evaluated, as well as recurrence rate during follow-up.

Results

Mean age was 45.5± 16.3 years old, with a 46.2% of men. Most often cause of ablation were palpitations(73.1%),followed by reduced LVEF(19.2%). Mean LVEF by transtoracic echocardiography was 52.4 ± 11%. 38.5% had a cardiopathy, among them the most common was tachycardiomyopathy(49.9%).Mean PVC burden pre-ablation was 23.6±11.5%. 65% of patients were taking beta blockers. The most frequent PVC origin was the right ventricle outflow tract(RVOT), with a 65.4% prevalence, followed by the left ventricle outflow tract(LVOT) with 15.4%.We used a 3D electroanatomical navigation system in all cases,while intracardiac echocardiography was used in 88.5% and a contact force catheter for mapping(57.7%) and ablation(92.3%).The mean maximum radiofrequency power applied was 34 ±5.8W, with a median time of 240 seconds. Median number of applications was 6 and mean total time of procedure was 210 ±67,5 minutes. 28ms median best prematurity.

Suppression of PVC was achieved in 88.5%. There was only two complications(7.6%): pericardial effusion without the need for pericardiocentesis and right brunch block.Median follow-up of 3 months, with 23% of recurrences. Most of patients(57.7%) did not require antiarrhythmics drugs during it.

Conclusions

Zero fluoroscopy PVC ablation is a safe procedure with no major complications and good rates of success and recurrence in our experience
Sinus rhythm endocardial mapping for channels identification in ischemic ventricular tachycardia using a modified electrophysiological triad
Authors: Adragao P , Nascimento Matos D , Galvao Santos P , Costa FM , Rodrigues G , Carmo J , Salome Carvalho M , Carmo P , Cavaco D , Morgado F , Mendes M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

In a previous study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients. This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps.

Purpose

This study aimed to prospectively assess the ability of a modified electrophysiological triad to identify and localize the ventricular tachycardia’s (VT) channels and entrance zones during sinus rhythm mapping.

Methods

Prospective analysis of a unicentric registry of individuals who underwent ischemic VT ablation with Carto® EAM, all in sinus rhythm. All patients with non-ischemic etiology, lack of high-density EAM or lack of mapping in any of the left ventricle walls or structures were excluded. Areas of late potentials and possible channels of re-entry were compared to a modified electrophysiological triad constituted by: areas of low-voltage (<0.5mV), a site of deep histogram valley (LAT-Valley) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the total activation time mapped. We also assessed the relationship between the pre-valley bar (the LAT histogram bar immediately before the prolonged LAT-Valley) and the channel entrances.

Results

A total of 14 patients (14 men, median age 70 IQR 64-78 years) were included. All patients presented with ischemic VT and 86% had a previous inferior myocardial infarction. The median number of collected points were 1733 (IQR 1363─2729). All sinus rhythm maps presented with at least 1 LAT-Valley in the analysed histograms. All arrhythmias were effectively treated after undergoing radiofrequency in the LAT-Valley location, either by blocking the channel entrances or scar homogenization ablation strategy. Also, the pre-valley bar in the histogram marked all the channel entrances in the scar borders. No patient had relapse after a clinical follow up of over 6 months.

Conclusion

In a prospective analysis, a modified electrophysiological triad was able to identify the scar channels in sinus rhythm in all patients. The pre-valley bar in the histogram disclosed the channel entrances. Further studies are needed to assess the usefulness of this algorithm to simplify catheter ablation and improve clinical outcomes.
Non-ischemic cardiomyopathy: what predicts survival and ICD shocks after ventricular tachycardia ablation?
Authors: Oliveira C , Silverio Antonio P , Couto Pereira S , Valente Silva B , Brito J , Alves Da Silva P , Martins AM , Garcia B , Azaredo Raposo M , Nunes Ferreira A , Lima Da Silva G , Carpinteiro L , Cortez-Dias N , J Pinto F , Sousa J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Patients (pts) with non-ischemic cardiomyopathy (NICM) present an increased morbidity and mortality from sustained monomorphic ventricular tachycardia (VT). Implantable cardiac defibrillators effectively terminate VT, but ablation is usually required to prevent recurrences and appropriate shocks. Although several risk factors have been pointed out, clear prognostic predictors need to be established and addressed.

Purpose

To evaluate risk factors associated with all-cause mortality and ICD shocks in NICM pts submitted to VT ablation.

Methods

Prospective, observational, single-centre study of pts with NICM submitted to VT ablation using high density mapping tools.The primary outcome was all-cause death or VT recurrence terminated with appropriate ICD shock during long-term follow up. Kaplan-Meier analysis was used to estimate the long-term event-free survival. Uni and multivariate Cox regression analyses were used to determine relevant prognostic predictors.

Results

A total of 27 consecutive pts with NICM were referred for a first-ever VT ablation procedure between June 2015 and June 2021 (males: 93%; mean age: 61±12 years). The mean left ventricular ejection fraction (LVEF) was 35±12% and 70% of pts had NYHA class I or II.

During a mean follow-up of 29 ± 19 months, VT recurrences requiring ICD shocks occurred in 25.9% of pts. VT ablation success and the risk of ICD shocks were not associated with any of the clinical characteristics. Long-term all-cause mortality was 37%. In univariate analysis, LVEF <30%, NT-proBNP, NYHA classification III-IV, chronic kidney disease (CKD), ICD for secondary prevention and prior VT ablation (p=0.08) were associated with reduced survival. On multivariate analysis, CKD was identified as the strongest independent survival predictor (HR 6.9; CI95%: 1.5-23-2, p=0.010)

Conclusions

In pts with NIDM, VT ablation may be successful even in pts with advanced heart disease. However, long-term survival will depend mostly on the stage of disease progression and is strongly associated with the clinical markers of end-stage heart failure. Therefore, a timely referral is crucial to derive the best clinical benefit from VT ablation in this population.
Initial experience of left bundle branch area pacing using stylet-driven pacing leads: a multicenter study
Authors: De Pooter J , Ozpak E , Calle S , Peytchev P , Heggermont W , Marchandise S , Provenier F , Francois BART , Anne W , Barbaud C , Gillis K , Vanheuverswyn F , Tung R , Wauters A , Le Olain De Waroux JB
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Left bundle branch area pacing (LBBAP) has been performed exclusively using lumen-less pacing leads (LLL) with fixed helix design. This study is the first to explore in a multicenter population the safety and feasibility of LBBAP using stylet-driven leads (SDL) with extendable helix design.

Methods

This study prospectively enrolled all consecutive patients who underwent LBBAP for anti-bradycardia pacing or heart failure indications at 8 Belgian hospitals. LBBAP was attempted either using SDL or LLL delivered through dedicated delivery sheaths. Implant success, complications, procedural and pacing characteristics were recorded at implant and follow-up.

Results

The study enrolled 412 patients (mean age 74 ± 38 years, 44% female). LBBAP with SDL and LLL was successful in 334/353 (94%) and 52/59 (88%) respectively (p=0.058). Implant success for LBBAP using SDL varied from 93 to 100% among centers. Mean paced QRS duration and stimulus to left ventricular activation time were comparable for SDL and LLL (126 ± 21ms versus 125 ± 22ms, p=0.861 and 74 ± 17 and 75 ± 21ms, p=0.756). SDL LBBAP resulted in low pacing thresholds (0.6 ± 0.4V at 0.4ms), which remained stable at 1, 6 and 12 months of follow-up. Lead revisions for SDL LBBAP occurred in 5(1.4%) patients: 2 dislodgements at day 1, 1 late septal perforation at week 3, 1 Twiddler’s syndrome at 5 months, 1 lead fracture at 6 months.

Conclusion

This multicenter study confirms the safety and feasibility of LBBAP using SDL, which is characterized by high implant success, low complication rate and low and stable pacing thresholds.
Conduction system pacing in paediatric patients: a single centre experience
Authors: Zizek D , Topalovic M , Stublar J , Mrak M , Jan M , Weiss M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Paediatric patients with conduction abnormalities are generally exposed to life-long dyssynchronous pacing from a very early age. Thus, preservation of cardiac function during chronic ventricular pacing is important. Conduction system pacing (CSP) with His bundle pacing (HBP) or left bundle branch pacing (LBBP) is an alternative method to standard right ventricular (RV) pacing that may preserve physiological ventricular activation and avoid potential pacing-induced cardiomyopathy (1). However, data on feasibility and safety of various CSP approaches in paediatric patients with or without congenital heart disease (CHD) is scarce and mainly relies on case studies (2-4).

Purpose

To assess feasibility and outcomes of different CSP techniques in paediatric patients.

Methods

Consecutive paediatric patients in whom CSP was attempted in our centre between November 2019 and December 2021 were analysed. Acute implant success rate, complications, fluoroscopy times, and CSP pacing parameters during follow-up were assessed.

To reduce radiation exposure, minimal fluoroscopy technique with three-dimensional (3D) electro-anatomical mapping (EAM) was also used in some cases. Geometry of right atrium and RV, along with mapping of His signal for HBP and potential LBBP sites in the RV septum were created using a decapolar catheter from the right femoral vein. Once relevant anatomy was obtained, HBP or LBBP was attempted using commercially available CSP tools. The pacing lead tip was visualised using the 3D EAM system. Transient fluoroscopy was used only for perpendicular placement of the sheath to the RV septum during LBBP, sheath removal, lead loop assessment to allow linear growth, and atrial lead placement.

Results

Six patients (100% female, age 9.3 ± 3.9 years, weight 41.8 ± 22.9 kg, baseline QRS 111.5 ± 6.3ms, CHD 50%, previous device 33%) with congenital complete AV block received CSP. One patient received HBP and 5 LBBP. The procedure was acutely successful in all patients (100%), pacing thresholds were low (0.56 ± 0.18V at 0.5ms) and there were no perioperative complications. During mean follow-up of 11.8 ± 7.8 months pacing parameters remained stable. However, significant rise of the pacing threshold (> 2.5V) was registered in the HBP patient, in whom lead revision was performed. Three-dimensional EAM was utilised in 3 patients (1 HBP, 2 LBBP). The use of minimal fluoroscopy technique with 3D EAM reduced fluoroscopy time (4.0, 3.2, 4.5 min vs. 9.5, 11.0, 8.0 min) without increasing procedural time (80, 70, 50 min vs. 110, 60, 75 min) compared to standard fluoroscopy technique.

Conclusion

Conduction system pacing is feasible and safe in paediatric patients with or without CHD. Additional utilisation of 3D EAM could reduce radiation exposure, without increasing procedural time. Future long-term studies should be considered to provide the ground for wider clinical adoption of CSP in paediatric population.
Short term outcomes of distal (ventricular) His bundle pacing: A single centre retrospective study
Authors: Vali Z , Ebeid A , Man S , Abuelmagd K , Dhutia H , Somani R , Ng GA , Ibrahim M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Chronic right ventricular apical pacing can lead to pacing induced cardiomyopathy in a significant proportion of patients. Conduction system pacing may restore more physiological activation of the heart, and has recently been shown to have favourable outcomes in clinical trials. However there remains concern regarding the long-term outcomes due to lead displacement and high pacing thresholds. The most widely used technique in current practice is to pace the His bundle proximal to the tricuspid valve. Distal His bundle pacing has a number of advantages over proximal His pacing, including, lower capture thresholds, a more stable lead position, less far field atrial sensing and better spacing from the AV node in case ablation of this is required for AF rate control. Despite these, outcomes of distal His bundle pacing from the ventricular aspect are less well defined.

Methods

We performed a retrospective review of patients who underwent conduction system pacing between January 2020 and October 2021 at our centre. During this period all procedures were performed employing a distal His bundle pacing approach with the lead placed on the ventricular aspect of the tricuspid annulus. Data was collected at implant, follow-up at 1 month and then every 6 months.

Results

Out of 35 patients, 33 underwent successful His bundle pacing (acute success rate of 94%), 1 patient had left bundle branch pacing and another patient had an unsuccessful procedure. Mean age was 74 years, median LVEF 45% and median pre-implant QRS was 108ms. 80% of the cohort had a history of AF. The indications for pacing were as follows: AF - for pace & ablate (60%); high grade AV block with narrow QRS and mild LVSD (17%); failed LV lead (14%); and other 9%. Mean procedure duration and fluoroscopy time were 78 minutes and 12.05 minutes, respectively. Median threshold at implant was 1.00V (IQR 0.719V). Selective His bundle pacing was achieved in 60% and non-selective in 34%. Mean follow-up duration was 150 days with median threshold at last f/up of 0.75V (IQR 0.750V). There were no acute procedural complications. 1 patient had a significant rise in threshold at follow-up and therefore required upgrade to CRT-P.

Discussion

Our data shows that distal His bundle pacing is a safe and effective technique for conduction system pacing. Thresholds appear stable at follow-up and failure rate was found to be comparable to biventricular pacing. We noted an initial learning curve for both implanter and physiologists with relatively poorer outcomes for the earlier cases. Longer term follow-up is ongoing, including functional assessment and follow-up to assess for remodelling with echocardiography. Prospective randomised trials are needed to compare conduction system pacing vs RV pacing in AF patients with HFpEF or mild LVSD undergoing AVN ablation, and vs biventricular pacing in the severe LVSD population.