bluuebunny/crossref_metadata_2025 huggingface dataset:
High-definition electro-anatomical mapping of Koch’s Triangle including AV node potentials recordings in consecutive AVNRT patients
Authors: Pandozi C , Botto GL , Del Giorno G , Papa AA , Castro A , Di Belardino N , Viani S , Russo M , Brasca F , Carbone A , Galeazzi M , Casale MC , Treglia S , Malacrida M , Colivicchi F
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Activation mapping of Koch’s Triangle, even when coupled with high density mapping, is incomplete without recordings of AV nodal electrical activity.

Purpose

To identify, through a highly specific methodology and high-density electro-anatomical mapping (HDM), the slow AVN potential (AVNP) and the precise activation modality of Koch’s Triangle in SR in atrio-ventricular nodal reentrant tachycardia (AVNRT) patients.

Method

The 3D KT geometry was created from the Orion mapping and the Rhythmia Mapping System. KT was divided into 8 distinct regions moving from an antero-septal to postero-septal areas and bounded by tricuspid annulus (TA) anteriorly and tendon of Todaro posteriorly. AV nodal potential activity was recorded by non-standard bipolar electrogram filtering at 0.50–300 Hz. The AVNP was defined as a slow frequency potential between atrial and ventricular EGM similar to that reported by Scherlag and Jackman, and it was confirmed by high frequency atrial pacing. The AVNP was annotated at the end of electrogram when it was followed in the same recording by a sharp potential; otherwise it was annotated at the center. Data are reported as mean±SD.

Results

Twenty successful SP ablation cases of typical AVNRT from 7 centers were included. RA acquired points during SR were 2512±1400 (123±67 acquired inside the KT, KT area of 41±64 mm2). The time of a complete RA mapping was 19.2±8 min. The AVNP was detected in all cases (n=20, 100%). At the mid-region of the KT, AVNP was identified in 20 (100%) cases; at postero-septal regions bounded anteriorly by the TA and posteriorly by the lateral wall toward the crista terminalis AVN was present in 17 (85%) cases; at mid-postero-septal regions AVN was detected in 15 (75%) cases. In all patients, the first activation in the KT was recorded in the antero-septal region at the expected site of the fast pathway; then the wavefront spread in two directions: anteriorly toward the His-bundle and posteriorly toward the base of KT colliding with the wavefront coming from the opposite direction through the slow pathway. In all patients, abolition of the SP and acute procedural success was achieved in the first procedure with 5.4±3 RF ablations. In 30 out 35 (86%) ablation sites, ablations were done at sites with concurrent detectable AVNP. No complications occurred.

Conclusions

High-density mapping using a non-standard bipolar electrograms filtering at 0.50–300 Hz showed multiple electrograms in SR including low frequency potential that may represent the electrical activity of compact node and inferior extensions.
Atypical atrial flutter in patients after cardiac surgery
Authors: Bakhytzhanuly A , Nuralinov O , Seisembekov T , Smagulova A , Abdrakhmanov A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Atypical atrial flutter (AFL) is often associated with cardiac surgery or extensive catheter ablation (CA) for the treatment of atrial fibrillation (AF) [1-2]. Therefore, the increase in the number of cardiac surgery procedures leads to the development of substrates for atypical AFL onset. Incisions after cardiac surgery are common substrates for macro re-entry tachycardia and one patient can suffer from several macro re-entry tachycardia mechanisms. Atrial flutter in this category of patients lead to heart failure.

Objective

The aim of our study was to access the effectiveness and safety of catheter ablation of atypical atrial flutter in patients after cardiac surgery.

Methods

107 adult patients with AFL after cardiac surgery and catheter ablation were included in a single-center prospective study. The patient’s mean age was 57.8±11.1 years with the prevalence of male (56%). BMI was 27,8±5 kg/m 2. All patients underwent radiofrequency ablation (RFA) of atypical AFL with 3D navigation system Carto3 using the CLOSE protocol. The patients were discharged safely and were monitored for 12 months.

Results

According to basic characteristics of patients cardiac surgery performed in 19.6% for CABG, in 9.3% for congenital heart disease and in 58.9% for valvular heart diseases. RFA for pulmonary veins isolation (PVI) for AF was performed in 15.9% and cryoballoon isolation of PVI in 19.6%. The onset of atrial events after incision or catheter ablation was 12 (Q1-14; Q3-25) months. In 8.4% of patients, ejection fraction was less than 40%. The mean RFA time was 110,8±10,4 min, mean fluoroscopy time 2.2 min. There were two re-entry mechanisms in 22.4% of patients, three and more re-entry mechanisms in 8.4% of patients. During 12 months monitoring after RFA in 2 (1.9%) patients registered AFL and in 8 (7.5%) of patients noticed non-sustained palpitations.

Conclusions

RFA of AFL with the use of ablation index and CLOSE protocol lead to the high effect and safety in patients after cardiac surgery. AFL is most frequent in patients after valvular heart surgery and usually occurs 12 months after the surgery.
Cardioneuroablation of severe neurally mediated reflex syncope: the experience of two Portuguese centres
Authors: Silva G , Cardoso F , Almeida J , Fonseca P , Ribeiro S , Oliveira M , Sanfins V , Goncalves H , Primo J , Lourenco A , Fontes-Carvalho R
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Neurocardiogenic syncope (NCS) is the most frequent aetiology of syncope in young people. Cardioinhibition with asystole and/or transitory atrio-ventricular block induced by a massive vagal reflex is commonly observed in severe cases. According to the current guidelines, cardiac pacing is indicated in patients > 40 years old with severe, recurrent syncope and documented cardioinhibitory reflex. In younger patients there is no recommendation. Although pacing therapy could be effective, complications after pacemaker implantation are commonly seen. Recently, cardioneuroablation (CNA), a technique based on radiofrequency ablation of vagal ganglia, was developed to treat NCS as an alternative to pacemaker implantation in younger patients. However, this method is still evolving, and existing data refer to a small number of patients in a limited number of centres.

Purpose

The aim of our study was to evaluate the efficacy and safety of CNA in patients with highly symptomatic neurocardiogenic syncope.

Methods and Results

A total of 15 patients (11 male; aged 40.0 ± 13.3 years) who underwent CNA in two Portuguese centres between January 2019 and September 2021 were included. All had recurrent syncope with documented pauses at head-up tilt test, Holter or implantable loop recorder. Radiofrequency energy was applied in ganglionated plexi (GP) 1 (between the right upper pulmonary vein and the right atrium) in 14 patients, GP2 (between the superior vena cava and aortic root just above the right upper pulmonary vein) in 9 patients, GP3 (between the inferior vena cava and the right and left atrium) in 5 patients and GP4 (at the insertion of the left pulmonary veins) in 9 patients. The end point of procedure was the inhibition of the vagal response at target sites. Ablation was successfully performed in all patients. One patient had a convulsive episode after the procedure, requiring admission to intensive care but without neurological sequelae. No other major complications occurred. At a mean follow-up of 17.1 ± 12.6 months (range 3-35 months), 13 patients remained free of syncope. Other 2 patients had spontaneous recurrence of syncope (both 9 months after CNA) and underwent a new procedure. These 2 patients had a new symptomatic recurrence and a pacemaker was implanted.

Conclusion

CNA appears to be an effective and safe treatment option for patients with refractory neurocardiogenic syncope and provide a new potential approach without pacemaker implantation.
Adrenergic stimulation amplifies the difference in beat-to-beat variability between the scar border zone and remote region
Authors: Vermoortele D , Amoni M , Ingelaere S , Holemans P , Menten R , Willems R , Sipido KR , Claus P
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): KU Leuven BOF-C1 “Blood pressure induced premature ventricular beats as triggers for ventricular arrhythmia in ischemic cardiomyopathy”

Background

Myocardial infarction (MI) results in a dense scar region surrounded by a heterogeneous region of fibrosis and remodeled myocytes called the border zone (BZ). Beta-adrenergic stimulation results in increased beat-to-beat variability of repolarization (BVR) which could increase spatial heterogeneity and arrhythmia vulnerability.

Objective

To examine the effect of adrenergic stimulation on the beat-to-beat variability in the BZ, compared to the remote region, using novel methodology for determining spatially dense activation-repolarization intervals.

Methods

Anterior-septal myocardial infarction (MI) was induced in 10 domestic pigs by 120-minute occlusion of the left anterior descending artery followed by reperfusion. Electro-anatomical mapping was performed after one month. The BZ was defined using contact mapping as the region with bipolar voltage between 0.5 and1.5mV. A non-contact recording of a 64-electrode array was translated to 2048 non-contact electrograms distributed over the LV (EnSite PrecisionTM, St. Jude/Abbott Medical). Electrophysiological recordings were made during baseline and during an isoproterenol (ISO) infusion (incremental doses of 0.01µg/kg until 0.04µg/kg). In each of the 2048 points non-contact electrograms over 25 consecutive beats were processed to determine the BVR using a custom-made algorithm, validated against monophasic action potential recordings.

Results

During baseline conditions the maximal BVR was increased in the BZ compared to the remote region (BZ: 3.28±0.90 ms vs remote: 2.61±0.67 ms, P=0.002). During ISO infusion the maximal BVR was also increased in the BZ (BZ: 3.55±0.74 ms vs remote: 2.21±0.60 ms, P<0.001). During baseline the BZ exhibited a larger spatial variance of BVR than the remote region (BZ: 0.20±0.11 ms2 vs remote: 0.087±0.055 ms2, P=0.002). During ISO infusion the spatial variance of BVR was larger in the BZ (BZ: 0.23±0.12 ms2 vs remote: 0.083±0.056 ms2, P=0.001). The maximal BVR was not significantly different during baseline and ISO in the BZ, nor the remote region (P>0.05). However, the difference of the maximal BVR between BZ and remote regions was significantly increased during ISO (baseline: 0.67±0.48 ms vs ISO: 1.34±0.49ms, P=0.001).

Conclusion

The MI BZ showed increased temporal heterogeneity in repolarization that could serve as functional substrate for re-entry. Adrenergic stimulation amplified this vulnerability by increasing the difference in maximal BVR between BZ and remote regions.
Late gadolinium enhancement is a strong predictor of life threatening arrhythmias in patients with non-ischemic dilated cardiomyopathy undergoing ICD implantation for primary prevention of sudden card
Authors: Lopes Da Cunha GJ , Lopes P , Freitas PN , Matos D , Rodrigues G , Carmo J , Carvalho S , Santos PG , Costa FM , Carmo P , Cavaco D , Morgado F , Mendes M , Ferreira A , Adragao P
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

The usefulness of implantable cardioverter defibrillators (ICD) for primary prevention of arrhythmic sudden cardiac death (SCD) in patients with non-ischemic dilated cardiomyopathy (DCM) has been questioned. Efforts to improve risk stratification have included scores such as the ‘MADIT-ICD benefit score’, and the use of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

The purpose of this study was to evaluate the potential usefulness of these two tools to assess the risk of life-threatening arrhythmias in patients with non-ischemic DCM undergoing ICD implantation for primary prevention of SCD.

Methods

We conducted a single-center retrospective study of consecutive patients who underwent contrast-enhanced CMR before ICD implantation for primary prevention of SCD. Patients with ischemic cardiomyopathy were used as reference. Patients with non-dilated cardiomyopathies were excluded.

The arrhythmic component of the MADIT-ICD benefit score (VT/VF score) was calculated for each patient, and considered high if ≥ 7, as recommended.

The primary endpoint was the occurrence of SCD or life-threatening arrhythmias (VF or VT >200 bpm). Follow-up was performed by device interrogation in all patients except those who suffered SCD.

Results

A total of 151 patients (93 ischemic, mean age 62±13 years, 75% male) with mean left ventricular ejection fraction (LVEF) of 27±8% were included. Overall, 72% (n=67) ischemic and 45% (n=26) non-ischemic patients had scores ≥ 7 and were considered high-risk. LGE was present in all patients with ischemic cardiomyopathy, and in 76% (n=44) of patients with non-ischemic DCM.

During a median follow-up of 21 (8-38) months, 21 patients (13.9%, 11 ischemic and 10 non-ischemic) met the primary endpoint.

Overall, the event-free survival of non-ischemic patients was similar to that of ischemic patients (log rank p=0.269) – Fig 1A. In patients with non-ischemic DCM, there were 7 arrhythmic events (26.9%) in those with MADIT-ICD VT/VF scores ≥7, and 3 events (9.4%) in those with scores <7 (log rank p= 0.104) – Fig 1B.

In the same population, there were 10 arrhythmic events (23%) in patients with LGE, but no events in patients without LGE (log rank p=0.036) – Fig 1C.

LVEF was similar in patients with and without arrhythmic events (26±8% vs. 27±7%, p=0.717), and in those with and without LGE (26±7% vs. 28±9%, p=0.342).

Conclusion

The presence of LGE is a strong predictor of life threatening arrhythmias in patients in non-ischemic DCM undergoing ICD implantation for primary prevention, seemingly outperforming the clinical MADIT-ICD benefit score.
Clinical risk factors associated with ventricular fibrillation during first ST-elevation myocardial infarction
Authors: Warming PE , Glinge C , Jabbari R , Stampe NK , Dusi V , Tan HL , Bezzina CR , Crotti L , De Ferrari GM , Engstrom T , Schwartz PJ , Wilde AAM , Tfelt-Hansen J
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union’s Horizon 2020 research and innovation programme under acronym ESCAPE-NET, registered under grant agreement No 733381

Introduction

Sudden cardiac death (SCD) remains a major public health issue. Most cases in the general population are caused by ischemic heart disease, and often occur in patients without known ischemic heart disease. The assessment of risk factors may point to novel causal pathways or new targets for intervention and risk prediction of SCD.

Objective

The aim of this study was to evaluate the effect of family history of sudden death, prior history of atrial fibrillation (AF), and anterior infarct location on ECG on the development of ventricular fibrillation (VF) during first ST-elevation myocardial infarction (STEMI).

Methods

We performed individual participant data meta-analyses of three European case-control studies including first STEMI patients (aged 18-80 years) with VF (cases) and without VF (controls) before revascularization (GEVAMI, AGNES, and PREDESTINATION). Analyses were done using fixed-effect, inverse variance weighted meta-analysis and multivariable logistic regression. Potential confounding variables were identified using causal diagrams and missing data were handled with multiple imputation for each cohort separately.

Results

We included 1664 cases and 2497 controls (median age (IQR) = 59 (51-67) years, 20% females) in the analyses. After adjusting for potential confounding, we found an independent and additive association between the three exposures and VF (see picture): for family history of sudden death odds ratio (OR) 1.59 (95% confidence interval: 1.37-1.85), for AF OR 2.41 (1.49-3.89), and for anterior myocardial infarction OR 1.50 (1.32-1.71). Further investigation indicated increased effect of family history with multiple sudden deaths in the family, a stronger effect of AF on VF developing within the first minutes of symptoms, and the effect of anterior infarctions being modified by enzymatically determined infarct size. The three risk factors showed an additive effect: with one factor present OR 1.59 (1.38-1.84), two factors OR 2.41 (1.95-2.99), and all three factors OR 5.49 (1.43-21.1). Complete case analysis gave similar results for all analyses.

Conclusions

Family history of sudden death, history of AF, and anterior infarct location with significant interaction with enzymatic infarct size were all independently and additively associated with an increased risk of VF in patients with a first STEMI.
Automated detection of scar-related ventricular tachycardia origins from implanted device electrograms: a combined computational-AI platform
Authors: Monaci S , Qian S , Gillette K , Puyol-Anton E , Rajani R , Plank G , King A , Bishop MJ
Published: May 2022

Funding Acknowledgements

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

Background

Existing strategies that identify ventricular tachycardia (VT) ablation targets either employ invasive and time-consuming electrophysiological (EP) mapping, or non-invasive modalities that utilise standard electrocardiogram (ECG) signals. Success of these pre-procedure ablation approaches in localising re-entrant VTs often relies on VT induction, which could be avoided by utilising recordings of clinical VT episodes stored as electrograms (EGMs) in implanted devices. Such a non-invasive approach that localises VT substrates from EGMs may aid ablation planning, enhancing safety and speed.

Purpose

Our goal is to automate scar-related VT localisation by utilising EGM recordings of VT episodes from implanted devices. To achieve this, deep-learning algorithms will be trained on computational data to return VT sites of origin from implanted device EGMs. Ultimately, we intend to utilise this computational-artificial intelligence (AI) framework to detect ablation targets of clinical VT episodes and guide pre-procedure ablation planning non-invasively.

Methods

A comprehensive library of ECGs and EGMs from simulated paced beats (~15000) and scar-related VTs (500) was generated across five detailed torso models within a fast EP computational environment, combining reaction-eikonal and lead field methods. ECG (or EGM) traces from simulated paced beats were used to initially pre-train two convolutional neural network (CNN) long short-term (LSTM) attention-based architectures. Subsequently, signals of the in-silico, re-entrant VTs were used to re-train the networks to output the sites of origin of these episodes in a standardised ventricular coordinate space. Finally, the retrained CNN architectures were tested on re-entrant VTs of unseen models, and median localisation errors (LEs) were estimated against known VT origins from simulations.

Results

The performance of the networks to localise scar-related VT episodes was asserted for each torso model. When a torso model was only seen during initial training on simulated paced beats, implanted device EGMs and ECGs successfully localised VT sources with LEs 10.04 – 16.36 mm and 10.05 – 12.79 mm, respectively. When a torso model was not seen during pacing or VT training, recreating potential clinical application settings where ECGs or EGMs of clinical VTs would be the only inputs to the networks, LEs ranged 12.42 - 22.79 mm and 12.41 - 19.68 mm for EGM and ECG-based testing, respectively.

Conclusions

Our study successfully detected VT ablation substrates with accuracy that could be beneficial in clinical ablation settings. The proposed computational-AI framework may be used to automate the localisation of scar-related VTs from clinical ECGs or EGM recordings from implanted devices, ultimately aiding ablation planning.
Ganglion stellate blockade in the treatment algorithm of the malignant electric storm: one center, five years and 72 procedures in 59 patients
Authors: Jiravsky O , Spacek R , Chovancik J , Hudec M , Miklik R , Sknouril L , Stepanova R , Fiala M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Malignant electric storm (ES) is a life-threatening condition with a high mortality rate. With years of increasing numbers of implanted ICDs, we witness increasing numbers of patients treated for ES. The role of local suppression of sympathetic nerve activity using ultrasound-guided anesthetic ganglion stellate blockade (GSB) is still under investigation with the first favorable published data from prospective cohorts.

Objective

To present data from a cohort of consecutive patients treated for ES at our cardiac center using a two-stage algorithm including GSB.

Method and Cohort

Between 2017 and 2021, 59 patients were treated using the two-stage algorithm ( when the first stage of standard procedures failed - ions, antiarrhythmic drugs, ischemia correction, heart rate modification, sedation, and GSB was performed as the second stage of the algorithm when ventricular arrhythmia recurred) in 72 GSB procedures.

57 GSB in men (79.2%)/15 GSB (20.8%) in women. Mean age 68.1 +/- 12.1 years. Mean LV EF 29.6 +/- 8.9%. 22 GSB in diabetic patients (30.6%). Ischemic etiology of ES in 41 cases (56.9%). Monomorphic ventricular tachycardia dominated among arrhythmias with 53 cases ( 73.6%). Betablocker and amiodarone were administered in 67 and 56 cases, respectively ( 93.1 and 77.8%).

A statistically significant decrease of 87.7% in ventricular arrhythmias treated with shock ICD or ATP was seen ( decrease from 57.2 to 1.43 episodes 48 hours before vs. 48 hours after GSB, p<.0001) (Table 1).

Hemodynamically unstable patients on continuous catecholamines responded significantly less to the two-step algorithm, including GSB. Horner’s syndrome and other demographic and medication parameters did not appear to predict a better response to GSB (Table 2 ). No serious adverse events were observed. In one case, intermittent ( couple hours) vocal chord paresis after bilateral GSB has been observed.

Conclusion

The two-stage algorithm for the treatment of ES, including ganglion stellate blockade, has shown stable high efficacy over the years with exceptional safety. However, the actual efficacy must be proven in a double-blinded study to allow the widespread method to the clinical practice.
Integration of structural and functional data in VT ablation -- SENSE2 protocol mapping
Authors: Collinson J , Bangash F , Dungu J , Gedela S , Westwood M , Manisty C , Farwell D , Tan S , Savage H , Vlachos K , Schilling R , Hunter R , Srinivasan N
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

We have previously developed the sense protocol functional substrate mapping technique for VT ablation(1). However, functional substrate characterizaiton can involve protracted mapping time.

Purpose

We incorporated the integration of MRI data using ADAS-3D software into the mapping workflow, to integrate structural mapping information into the functional mapping substrate characterization, in order to improve procedural efficiency.

Methods

CMRs were performed in 20 patients with ischemic related VT and VT therapy in the previous 6 months. These were processed with the ADAS-3D software to characterize the extent of ventricular scars and also ADAS corridors which may correlate with VT channels. Focused substrate maps were then performed in patients, guided by the extent of ADAS scar and corridors, looking at the scar substrate in intrinsic rhythm and then functional channels using single extra pacing from the RV at 20ms above ERP (SENSE2 Protocol). Specifically healthy areas 2cm beyond the scar borderzone based on ADAS were not mapped, in order to reduce substrate mapping time and complete geometries were not created. Following delineation of functional channels pacemapping and entrainment mapping were used to confirm targets for ablation.

The ADAS 3D MRI was integrated into the into the VT substrate map on Ensite-Precision with alignment to the aorta, RV and PA (Figure 1). We compared our data with previous functional mapping data without the integration of MRI.

Results

20 patients (age 70 years; 19 male subjects) underwent ablation. Mean EF 28%. Median procedure time was 161 minutes compared with 246 minutes (in our previous study)(p=<0.001) Mean substrate mapping time was 32 mins vs 63 mins (p=<0.001). Mean ablation time was 22 mins vs 32 mins (p=0.11). 85% (17 of 20) patients were free from symptomatic VT/ anti-tachycardia pacing or implantable cardioverter defibrillator shocks at a median follow-up of 171 days. The mean VT burden was reduced from 22 events per patient in the 6 months’ pre-ablation to 1 event per patient in the median follow up period of 171 days post ablation (p=0.02). Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same time period(p=0.03).

Conclusion

The SENSE2 protocol involves the integration of structural and functional data into the VT workflow for substrate characterization. It enables focused substrate maps to be performed without the need for complete geometry to be created in large ventricles. Outcomes compare favourably with our previous data but with significantly shorter procedure times. This streamlined workflow has the potential to improve care in VT ablation by shortening procedure times with similar outcomes which may reduce risks for the patient.

Figure 1: Comparison of Voltage Map with MRI scar & corridors using ADAS
Efficacy and safety of VT ablation of electrical storm
Authors: Mueller J , Nentwich K , Berkovitz A , Halbfass P , Ene E , Sonne K , Simu GR , Chakarov I , Deneke T
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Data about VT ablation in patients with electrical storm (ES) is limited. This study sought to compare the prognostic outcome of patients with ES to those with ventricular tachyarrhythmias but without ES undergoing VT ablation on mortality, VT recurrence rates, rehospitalization rates and major adverse cardiac events (MACE).

Methods

In this large single-centre study patients presenting with ES and undergoing VT ablation from June 2018 to April 2021 were compared to patients undergoing VT ablation due to ventricular tachyarrhythmias but without ES. The primary prognostic outcome was cardiovascular mortality, secondary endpoints were VT recurrence rates, rehospitalization rates and MACE all after a median follow-up of 22 months.

Results

A total of 311 patients underwent a first VT ablation due to ventricular tachyarrhythmias and were included (63 ± 14 years; 86% male). Of them 108 presented with ES. In the ES cohort dilated cardiomyopathy as underlying heart disease was significantly increased (p=0.008), whereas all other cardiomyopathies were equally distributed. Major complications were equal among both groups (p>0.05). Ablation of the clinical VT was achieved in 95% of all patients without ES and in 94% of all patients with ES (p>0.05). Noninducibility of any VT was achieved in 91% without ES and in 76% with ES (p=0.001). This was also reflected in higher VT induction rates in non-invasive programmed stimulation before hospital discharge among ES patients (40% vs. 19%; p=0.031). After a median of 22 months of follow-up, patients with ES revealed slightly increased cardiovascular mortality rates (17% vs. 9%; log-rank p=0.061; HR 1.902; CI 95% 0.961 – 3.765; p=0.061). Furthermore, ES patients suffered from increased VT recurrence rates (59% vs. 40%; log rank p=0.006), rehospitalization rates (73% vs. 49%; log rank p=0.001) and MACE (71% vs. 45%; log rank p=0.001). ES patients displayed a 1.7-fold increased risk for VT recurrence (HR 1.701; CI 95% 1.160 – 2.493; p=0.006), a 1.9-fold increase for rehospitalization (HR 1.885; CI 95% 1.366 – 2.600; p=0.001) and a 1.9-fold increase for occurrence of MACE (HR 1.935; CI 95% 1.398 – 2.679; p=0.001). Presence of ES was the only independent predictors of VT recurrence and occurrence of MACE, whereas ES and decreased LVEF were independent predictors of rehospitalization.

Conclusions

VT ablation in patients with ES is challenging and these patients reveal highest risk for recurrent VTs, rehospitalization and MACE. These patients need close follow-ups and optimal guideline-directed therapy.
Prognosis of patients with and without septal substrate after VT ablation due to electrical storm
Authors: Mueller J , Nentwich K , Berkovitz A , Halbfass P , Ene E , Sonne K , Simu GR , Chakarov I , Deneke T
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Data about VT ablation in patients with electrical storm (ES) is limited. This study sought to compare the prognostic outcome of patients undergoing VT ablation after electrical storm with and without a septal substrate on mortality, VT recurrence rates, rehospitalization rates and major adverse cardiac events (MACE).

Methods

In this large single-centre study patients presenting with ES and undergoing VT ablation were included from June 2018 to April 2021. Patients with septal substrate were compared to patients without septal substrate. The primary prognostic outcome was cardiovascular mortality, secondary endpoints were VT recurrence rates, rehospitalization rates and MACE all after a median follow-up of 22 months.

Results

A total of 108 patients underwent a first VT ablation due to electrical storm and were included (65 ± 13 years; 86% male; 45% ischemic cardiomyopathy). Cardiovascular risk factors were equally distributed among both groups (all p>0.05). Major complications occurred in 11% of all patients with increased postinterventional third degree AV blocks among patients with septal substrate (9% vs 0%; p=0.062). Noninducibility of the clinical VT was achieved in 98% of all patients without a septal substrate and in 91% of all patients with a septal substrate (p=0.136). Noninducibility of any VT was achieved in 88% without a septal substrate and in 66% with a septal substrate (p=0.011). However, in non-invasive programmed stimulation before hospital discharge VT inducibility did not differ among both groups (p>0.05). After 1 year and a median of 22 months follow-up, patients with septal substrate died significantly more often due to cardiovascular causes (25% vs. 7%; log-rank p=0.021). In univariate analysis cardiovascular mortality for ES patients with septal substrate was 3.9 fold higher (HR 3.979; CI 95% 1.124 – 14.092; p=0.032). Independent predictors of adverse outcome in multivariable regression analysis were presence of septal substrate (HR 4.836; p=0.026) and increased numbers of VTs inducible during VT ablation (HR 1.635; p=0.007). VT recurrence during follow-up was 59% and equally distributed among both groups (log rank p=0.911). Rehospitalization rates (log rank p=0.532) and rates of MACE (log rank p=0.463) were equal.

Conclusions

Presence of a septal substrate is associated with adverse long-term cardiovascular mortality in patients admitted for VT ablation after electrical storm. Despite decreased ablation success in these patients VT recurrence rates were not increased during follow-up.
Fast high-resolution late gadolinium enhancement magnetic resonance imaging for an accurate detection of myocardial radiofrequency catheter ablation lesions
Authors: Sridi S , Stuber M , Jais P , Cochet H , Bustin A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Whole- heart high-resolution free-breathing late gadolinium enhancement (HR-LGE) is a key sequence for detecting radiofrequency catheter ablation (RFCA) lesions. However, long acquisition time is the main limitation especially for dyspneic and claustrophobic patients.

Purpose

We aimed to introduce an accelerated HR-LGE technique for the detection of myocardial RFCA lesions.

Method

An under sampled (3-fold) navigator-gated whole- heart HR-LGE (acquired resolution of 1.25 mm3) sequence combined with advanced patch-based low-rank reconstruction was implemented on a 1.5 CMR scanner. Three sheep prospectively underwent radiofrequency ablation at multiple endocardial and epicardial sites. The animals were imaged 3 months later using conventional post-contrast LGE (PSIR, voxel size 1.8x1.4x6mm) and the proposed sequence. A reader graded image quality and diagnostic value of both LGE imaging.

Results

The acceleration allowed for acquisition times of 3 min 22s ± 20 s at 1.25 mm resolution. Compared with 2D PSIR, HR-LGE showed comparable image quality (P= 0.03). All LGE- positive segments on 2D PSIR in LV myocardium were also detected on HR-LGE (6 segments). Two additional enhanced segments were only visible on HR-LGE (8 segments). LGE-positive segments in RV myocardium were detected on HR-LGE (4 segments) while 2D PSIR was either definitely negative (2 segments) or uncertain (2 segments).

Conclusion

Accelerated whole-heart HR- LGE allows an accurate detection of left and right myocardial RFCA lesions.
The outcome spectrum for Dilated Cardiomyopathy and Ventricular Tachycardia: results from the prospective, multicenter, DCM-VT ablation study
Authors: Zeppenfeld K , Wijnmaalen AP , Ebert M , Baldinger SH , Vaseghi M , De Riva Silva M , Gaspar T , Tedrow U , Deneke T , Soejima K , Shivkumar K , Carbucicchio C , Berruezo A , Hindricks G , Stevenson WG
Published: May 2022

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The study was partially supported by an investigator initiated grant from Biosense Webster (a Johnson & Johnson company)

Background

Recurrent sustained ventricular tachycardia (VT) due to nonischemic dilated cardiomyopathy (DCM) is difficult to treat and long-term outcome data are limited.

Objective

We aimed to identify predictors for mortality or heart transplantation (MHT) and VT recurrence.

Methods

Consecutive DCM patients accepted for VT catheter ablation (RFCA) in 9 centers were prospectively enrolled and followed.

Results

Of 281 consecutive patients (age 60±13yrs, 85% men, LVEF 36±12%) 35% had VT storm, 20% incessant VT, and 68% failed amiodarone. During a median follow-up of 21 (IQR 6-30) months after RFCA (epicardial in 58%, no RFCA due to inaccessible target in 6.4%), 67(24%) patients died/underwent HT and 138(49%) had VT recurrence (45 within 30 days defined as early); the cumulative 4-year rate of VT or MHT was 70% and of MHT 38%.

In multivariable analysis predictors of MHT were early VT recurrence (HR 2.92 (CI1.37-6.21), p<0.01), amiodarone at discharge (HR 3.23 (CI1.43-7.33, p<0.01), renal dysfunction (HR 1.92 (CI1.01-3.64), p=0.046), and LVEF (HR 1.36 (CI 1.0-1.84), p=0.052). A LVEF ≤32% was the optimal threshold to identify patients at risk for MHT (AUC 0.75).

MHT per 100 person-years was 40.4 after early VT recurrence and significantly higher, compared to 14.2 after later VT recurrence and to 8.5 after RFCA with no VT recurrence (both p<0.01). Mortality rates for patients with VT recurrence after 30 days were not significantly higher than for patients with no VT recurrences

Patients with early recurrence and LVEF≤32% had a 1-year MHT rate of 55% (figure). VT recurrence was predicted by prior ICD shocks, basal antero-septal VT origin, and procedural failure but not LVEF.

Conclusion

DCM patients needing RFCA for VT are a high-risk group. Following RFCA half remain free of VT recurrences. Early VT recurrence with LVEF<0.32 identifies those with a very high risk and screening for mechanical support/ HT should be considered. Late VT recurrence after RFCA does not predict worse outcome.
High power bipolar ablation of a thick myocardium: ex-vivo study using externally-irrigated large-tip ablation catheters
Authors: Futyma P , Zarebski L , Burbelka A , Pawlik A , Futyma M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Bipolar radiofrequency catheter ablation (Bi-RFCA) can overcome some challenges related with treatment of intramural ventricular arrhythmias. However, there’s no data if Bi-RFCA can be effective in the setting of a thick myocardium.

Aim

To estimate safety and efficacy of high-power long-duration Bi-RFCA in the setting of a thick myocardium and to demonstrate feasibility of external irrigation for large-tip ablation catheters (AC).

Methods

The study was performed in a saline bath containing a fresh bovine heart. Bi-RFCA of the left ventricular (LV) and right free wall, interventricular septum, papillary muscle and LV summit at power settings of 70W was performed using two solid-tip 8mm AC in a parallel orientation. Irrigation using normal saline of each AC was provided from a long sheath advanced to the level of 2nd (distal irrigation – DI) or 3rd (proximal irrigation – PI) AC electrode. Post-Bi-RFCA lesions were evaluated macroscopically.

Results

Mean intercatheter distance was 28±11 mm, range 12-50 mm and a total number of 12 high-power Bi-RFCA lesions were performed. Mean Bi-RFCA time was 108±42s. Complete transmurality was achieved in 4 (33%) of lesions (mean 17±3 mm thickness, range 12-20 mm) whereas borderline transmurality was observed in further 2 (17%) lesions (mean 23±0,5 mm thickness, range 22-23 mm). No transmurality was present in the remaining 6 (50%) lesions (mean 38±7 mm thickness, range 30-50 mm). Steam pops occurred in 25% of Bi-RFCA applications. Temperature drop during external irrigation was significantly higher in the DG group vs PG 15°C vs 7°C, p=0,0046).

Conclusions

Bi-RFCA of a myocardial thickness above >30mm is challenging. High-power (70W) long-duration Bi-RFCA is associated with substantial incidence of steam pops. Further histopathological studies should evaluate levels of transmurality using high power Bi-RFCA at muscle thickness between 20-30mm. External irrigation of solid-tip large AC is feasible and can significantly reduce AC tip temperature.
Nationwide study of sudden cardiac death in young persons diagnosed with chronic kidney disease
Authors: Svane J , Nielsen JL , Feldt-Rasmussen B , Garcia R , Risgaard B , Gislason GH , Winkel BG , Lynge TH , Tfelt-Hansen J
Published: May 2022

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): This work was supported by Novo Nordisk Foundation, Copenhagen, Denmark.

Background

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular morbidity and mortality. The increased cardiovascular mortality is partly explained by an increased risk of sudden cardiac death (SCD) among patients with CKD.

Purpose

The purpose of this study was to compare short- and long-term risk of SCD in individuals with and without CKD aged 18-49 years.

Methods & Results

Using the Danish nationwide health registries, all persons aged 18-49 years diagnosed with non-failure stage CKD or kidney failure from 1st of July 1995 through 2009 were identified. Non-exposed subjects matched on sex and birth-year were included 50:1. All SCD in the Danish population aged 18-49 years in 2000-2009 have previously been identified by thoroughly examining the Danish Registries, the Danish death certificates, autopsy reports and discharge summaries. In total, 9,476 incident cases of non-failure stage CKD and 1,283 incident cases of kidney failure were included.

For patients with non-failure stage CKD and kidney failure, the absolute risk of all-cause mortality 10-year after diagnosis was 8.7% and 23.6%, respectively. Among patients with non-failure stage CKD, the absolute risk of SCD 1, 5 and 10 years after diagnosis was 0.14%, 0.37%, and 0.68%, respectively. Compared with age- and sex matched subjects the corresponding relative risk was 20 (95%-CI 8.4-48.8), 7.1 (95%-CI 4.2-12.0), and 6.1 (95%-CI 3.8-9.7), respectively. Among patients with kidney failure, the absolute 1, 5, and 10 year risk of SCD was 0.17%, 0.56% and 2.07%, respectively. The corresponding relative risk was 12.5 (95%-CI 1.4-111.6), 7.9 (95%-CI 2.3-27.0) and 10.1 (95%-CI 4.5-22.6), respectively.

Conclusions

Persons with non-failure stage CKD and kidney failure had increased risk of SCD compared with the background population with a 20- and 13-fold increased risk one year after diagnosis, respectively. These findings underline the importance of early cardiovascular risk monitoring and assessment in persons with CKD.
Failed shocks in hypertrophic cardiomyopathy patients: prevalence, predictors and outcome
Authors: Segev A , Fishman B , Wasserstrum Y , Beinart R , Arad M , Sabbag A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

An implantable cardioverter-defibrillator (ICD) is used in selected high-risk hypertrophic cardiomyopathy (HCM) patients in order to prevent sudden arrhythmic death. The unique features of this population raise concerns regarding the reliability of successful defibrillation.

Purpose

To describe the rate and discover potential predictors of failed shocks in HCM patients.

Methods

We retrospectively evaluated all HCM patients with an ICD from a single tertiary medical center. Clinical, electrocardiographic and echocardiographic data were collected and compared among patients with and without failed shocks.

Results

A total of 99 patients (77% male, 45±17 years old) were analyzed. Over a median follow up of 6.3 years (IQR 2.6-10.7), 20 patients developed sustained ventricular arrhythmia (VTA). Of those, 18 patients received appropriate shocks from their ICD. VTA was associated with younger age at diagnosis, history of syncope and thicker maximal LV width. Six patients experienced at least one failed shock. The likelihood of failed shocks was similar when single or dual coil electrodes were used (dual coils in 67% of patients with failed shocks and 50% in those without), and the only predictor was increased wall thickness [OR 1.2 (1.07-1.38) per 1 mm]. All-cause mortality was low and similar in patients with an without failed shocks (0% vs 8%, P=0.5)

Conclusions

Failed shocks are a rare entity in HCM patients. Increased maximal LV width was the only predictor of those events. Our findings support avoiding defibrillation threshold testing routinely, but may indicate its need in patients with extreme LV wall thickening (≥23 mm).
Very low event rate and few device implants in drug-induced brugada. A seven-year experience of ajmaline challenge at a district general hospital
Authors: Brown S , Furniss G , Dayer M , Bailey J , Kemp J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with a drug-induced Brugada electrocardiogram (ECG) are thought to have a lower risk of sudden cardiac death than those with a spontaneous type 1 ECG. Despite having a Brugada ECG, most patients do not need an implantable cardioverter defibrillator (ICD).

Purpose

To report a district general hospital experience on referral and outcomes of ajmaline challenge (AC) with medium term follow up.

Methods

92 consecutive patients (50 males, mean age 41 ±17) had an AC in a single centre from 2014-2021. High ventricular leads were used from 2015. Ajmaline (1m/kg) was administered intravenously over 10-minutes. Data were collected from the electronic health record.

Results

The AC was positive in 18 (20%) patients. The yield from high leads was higher (7% vs 22%) p=0.28) but not statistically significant. There were no deaths or documented ventricular arrhythmias (VA) in AC positive patients during a median follow up of 3.2 years (1.7-4.9).

The resting ECG was normal in 46.7%. A type 1 pattern had been provoked by fever or electrolyte derangements in 3.3%, type 2 pattern in 8.7% and a type 3 pattern in 5.4%. An RSR pattern (not in keeping with a BrS ECG) was seen in 26.4%. The test was stopped prematurely due to QRS widening >150ms in 1 patient. No adverse arrhythmic events occurred (table 1).

In our cohort, positive AC patients were older (48y vs 37y p= 0.05) and more likely to have a type 2 (28% vs 4% p=0.007) or type 3 ECG (17% vs 3% p=0.05). Asymptomatic patients were more likely to have a normal ECG (22% vs 78% p=0.05)

Of those with a positive AC, nine patients had symptoms of palpitations or syncope (table 2). A subcutaneous ICD (S-ICD) was implanted for syncope in two patients. No device therapies have occurred during a follow up of 2.5 years and 3.9 years respectively. Of those with a positive AC but asymptomatic, one S-ICD was initially implanted due to patient preference. A second S-ICD was implanted in a patient who experienced a collapse and brief seizure in the context of modest alcohol consumption.

In seven positive patients (39%) and 18 negative patients (23%) an ILR was implanted. 1 episode of complete heart block was detected in an ajmaline negative patient during a median follow up of 2.7 years (1.7-3.9).

There were no device related complications or adverse events.

Conclusion

AC is safe with a low number of device implants and ICD shocks. The yield from ILR implants was very low. A single patient had a potentially adverse outcome after consuming alcohol, a known trigger for VA in BrS. Our findings are in keeping with contemporary evidence that suggests the risk of adverse cardiac events in drug-induced BrS is low. However, time to first ICD shock may occur after ten years or more from diagnosis so long term follow up is required.
Access site bleeding complications comparing oral anticoagulation therapy with NOACs and VKAs in patients with atrial fibrillation undergoing cardiac implantable device intervention
Authors: Spinoni E , Ghiglieno C , Costantino S , Battistini E , Dell’era G , Porcellini S , Santagostino M , De Vecchi F , Patti G
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation is frequent in patients undergoing cardiac implantable electronic device (CIED) intervention. Such population require oral anticoagulation therapy, which increases risk of procedure related bleeding. There is a lack on data on procedure-related bleeding outcome with non-vitamin K antagonist anticoagulants (NOACs) vs vitamin K antagonist anticoagulants (VKAs) in patients with AF undergoing CIED intervention.

Study purpose

Aim of the present stud was to evaluate whether NOACs have a safety benefit compared to VKAs in terms of fewer hemorrhagic complications at the site of CIED implant.

Methods

Consecutive AF patients receiving NOACs or VKAs at the time of CIED procedure were included in this observational, retrospective, monocentric investigation. Primary endpoint was the incidence of post-intervention clinically significant pocket hematoma. Multivariate analysis was performed to investigate the association between covariates and the primary endpoint.

Results

A total of 311 patients were enrolled, 146 on NOACs and 165 on VKAs. The incidence of pocket hematoma was 3.4% in the NOAC vs 13.3% in the VKA group (p=0.002) (Figure 1). Primary outcome-free survival at 30-days was 96.6 % in patients on NOACs and 86.0% in those on VKAs (p=0.019) (Figure 2). Multivariate analysis, adjusted by propensity-score calculation of inverse-probability-weighting, showed a significantly lower occurrence of pocket hematoma in patients receiving NOACs vs VKAs (HR 0.35, 95% CI 0.13-0.96, p=0.042). Such NOACs benefit was confirmed vs patients on VKAs without peri-procedural bridging with low-molecular weight heparin (HR 0.34, 95% CI 0.11-0.99, p=0.048). The incidence of pocket infection, surgical pocket evacuation, ischemic events and major bleeding complications at 30 days (secondary endpoints) was similar in the two groups.

Conclusion

Among patients with AF undergoing implantable cardiac defibrillator or pace-maker intervention, the use of NOACs vs VKAs is associated with significant reduction of post-procedural pocket hematoma, regardless of bridging with low molecular-weight heparin in the VKA group.