bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing conditional moment restriction models using empirical likelihood
Authors: Berger Yves G
Published: October 2021

An empirical likelihood test is proposed for parameters of models defined by conditional moment restrictions, such as models with nonlinear endogenous covariates, with and without heteroscedastic errors and non-separable transformation models. The number of empirical likelihood constraints is given by the size of the parameter, unlike alternative semi-parametric approaches. We show that the empirical likelihood ratio test is asymptotically pivotal, without explicit studentization. A simulation study shows that the observed size is close to the nominal level, unlike alternative empirical likelihood approaches. It also offers a major advantage over two-stage least-squares, because the relationship between endogenous and instrumental variables does not need to be known. An empirical likelihood model specification test is also proposed.
Emery-Dreifuss muscular dystrophy presenting as a heart rhythm disorders in children
Authors: Kovalchuk T S , Yakovleva E V , Fetisova S G , Vershinina T L , Pervunina T M , Kostareva A A , Vasichkina E S
Published: October 2021

Introduction

Emery-Dreifuss muscular dystrophy (EDMD) is an inherited muscle dystrophy often accompanied by cardiac abnormalities in the form of supraventricular arrhythmias, conduction defects, sinus node dysfunction. Cardiac phenotype typically arises years after skeletal muscle presentations, though, can be severe and life-threatening. The disease usually manifests during the third decade of life with elbow joint contractions and progressive muscle weakness and atrophy.

Objective

To present our clinical experience of diagnosis and treatment of arrhythmias in children with Emery-Dreifuss muscular dystrophy

Materials and methods

We enrolled 5 patients with different forms of EDMD (X-linked and autosomal dominant) linked to the mutations in EMD and LMNA genes, presented with early onset of cardiac abnormalities and no leading skeletal muscle phenotype. The predominant forms of cardiac pathology were atrial flutter, atrial fibrillation and conduction disturbances that progress over time.

Clinical examination included physical examination, 12-lead electrocardiography, Holter ECG monitoring (HM), transthoracic echocardiography, neurological examination and biochemical and hormone tests. Also we performed CMR, electrophysiological study (EPS), treadmill test of some patients. One patient underwent an endomyocardial biopsy to exclude inflammatory heart disease. Target sequencing was performed using a panel of 108 or 172 genes

Results

We observed five patients with EDMD and cardiac debut during first-second decades of life: 3 with 1st subtype (variants in EMD gene) and 2 with 2nd subtype (variants in LMNA gene). All patients were males. The mean age of cardiac manifestation was 13,2±3,11 (from 9 to 16 y.o.). The mean follow-up period was 7,4±2,6 years.

All patients presented with sinus node dysfunction and four out of five with AV conduction abnormalities. The leading arrhythmic phenotypes included various types of supraventricular arrhythmias: multifocal atrial tachycardia (AT) (n=4), premature atrial captures (PACs) (n=4), atrial flutter, (AF) (n=3), atrial fibrillation (AFib) (n=3) and AV nodal recurrent tachycardia (AVRNT). Heart rhythm disorders were the first manifestation in all three patients with 1st EDMD subtype. Radiofrequency ablation was performed in 2 patients, one of them received permanent pacemaker implantation.

Conclusions

In conclusion, while being the rare cases, heart rhythm disorders can represent the first and for a long time, the only clinical symptom of EDMD even in the pediatric group of patients. Therefore, thorough laboratory and neurological screening along with genetic studies, are of importance in each pediatric patient presenting with complex heart rhythm disorders of primary supraventricular origin to exclude EDMD or other neuromuscular disorders.

Funding Acknowledgement

Type of funding sources: None.
Predictors of cardiac implantable electronic device infection in the United States
Authors: Shah K , Modi V , Gandhi H , Thyagaturu H , Walker A , Shirani J
Published: October 2021

Background

Cardiac implantable electronic devices (CIED) are important tools for managing arrhythmias, improving hemodynamics, and preventing sudden cardiac death. Device infection (DI) remains a significant complication of CIED and is associated with high morbidity, mortality, and healthcare cost.

Purpose

To analyze predictors of DI and its in-hospital outcomes.

Methods

National Inpatient Sample 2011–2018 database was analyzed for admissions for CIED implantation or DI. Baseline and hospital level characteristics were derived. The Chi-square test and student t-test were used for comparison of categorical and continuous variables respectively. Variables with p<0.20 from univariate analysis were included in the multivariate logistic regression to identify independent predictors of DI.

Results

A total of 1,604,173 admissions for CIED implantations and 71,007 (4.4%) admissions for DI were reported during 2011–2018. There was no significant change in annual admissions for DI (range 8550 to 9307, p for trend=0.98). Those with DI were more likely to be male (69.3 vs 57%, p<0.001) and had higher Charlson comorbidity index score ≥3 (46.6%-vs-36.8%, p<0.001). Multivariate analysis identified post-procedural hematoma (odds ratio (OR)=3.96; 95% Confidence Interval (CI)=3.46–4.54), congestive heart failure (CHF; OR=2.80, 95% CI=2.66–2.96), age group 45–60 years (OR=2.46, 95% CI=2.30–2.63), malnutrition (OR=1.99, 95% CI=1.85–2.15), coagulopathy (OR=1.75, 95% CI=1.64–1.86), end-stage renal disease (OR=1.65, 95% CI=1.53–1.78), atrial fibrillation (OR=1.42; 95% CI=1.35–1.49), non-Hispanic race (OR=1.25; 95% CI=1.16–1.36), coronary artery disease (OR=1.21; 95% CI=1.15–1.26), and thyroid disease (OR=1.15; 95% CI=1.09–1.12) [all p<0.001] as independent predictors of DI. Prevalence of CHF, malnutrition, and atrial fibrillation increased in those admitted with DI over the observation period as shown in Figure 1 (p for trend <0.001). Prevalence of diabetes mellitus also increased during the observation period although it was not an independent predictor of DI (p for trend <0.001). Pulmonary embolism and deep vein thrombosis were most common complications in those with DI (4.1 and 3.6% respectively). Annual in-hospital mortality ranged from 3.9 to 5.7% (mean 4.4%, p for trend=0.07).

Conclusion

DI is relatively common and continues to be associated with high morbidity and mortality. Prevalence of DI has not changed significantly despite technical and technological advances in device implantation. Evaluation of risk factors for DI and management of modifiable comorbidities may be needed to reduce the incidence of this important complication of CIED implantation.

Funding Acknowledgement

Type of funding sources: None.
Nationwide study of sudden cardiac death among children and young adults in Iceland
Authors: Jonsdottir V , Tryggvason T , Einarsson G O , Bjornsson J , Gunnarsson G
Published: October 2021

Introduction

Sudden cardiac death (SCD) in children and young adults is a devastating event.

Ischemic heart disease is the predominant cause of sudden cardiac death in older persons. Whereas among persons 1–35 years of age, SCD is more often caused by structural heart disease or purely arrhythmogenic causes.

In studies on SCD in the young up to 40% of all autopsies show no cardiac abnormalities. Which raises suspicion of underlying arrhythmogenic causes. Many of these arrhythmogenic causes of SCD have an underlying genetic basis and are inherited.

Purpose

In Iceland, the true impact of SCD in children and young adults is unknown. The aim of this investigation is to study the incidence and causes of SCD in persons aged 1–35 years in nationwide settings.

Methods

This is a nationwide retrospective population-based study in Iceland. All deaths in persons aged 12–35 years in 1974–2015 and all deaths in persons aged 1–12 years 2005–2015 were included. Death certificates, autopsy reports and medical records were reviewed to confirm SCD. Medical records were also reviewed for medical history and circumstances of death.

Individuals that were resuscitated after cardiac arrest but died later in hospitals were included. Individuals that fulfilled the criteria of SUDEP (sudden unexpected death in epilepsy) were excluded from the study.

Results

We found 73 (68% male) cases of SCD, of which 64 (88%) were autopsied. The most common find in autopsy was structurally normal heart (16%), myocarditis (16%), hypertrophic cardiomyopathy (16%) and ischemic heart disease (16%). Death occurred during daily activities in 36% of cases, sleep in 27% cases and physical activities in 19% of cases. Incidence rate was 1.4 per 100.000 in 1–35 years old in the years 2005–2015 and 1.6 per 100.000 for 12–35 years old in the years 1974–2015.

Conclusion

Incidence of SCD in the young in Iceland is similar as for other nations. Post-mortem diagnoses are often difficult to establish. Because of the possibility of unrecognized underlying inherited cardiac disorder it is important to consider genetic analysis as a part of the post-mortem examination.

Majority of SCD in the young occurred related to normal daily activities or during sleep or at rest. This raises many questions about the connections between any underlying cause of SCD and behaviour.

It is important to discuss and study further the connection between sudden unexplained death in epilepsy (SUDEP) and SCD. SUDEP is most often unwitnessed events with cases found deceased in bed. SUDEP is characterized by an absence of any identifiable cause of death post-mortem, which can suggest underlying arrhythmogenic cause.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2
An electrocardiographic diagnostic model for differentiating right from left ventricular outflow tract arrythmias origin
Authors: Luna R , Gonzalez-Torrecilla E , Arenal A , Atienza F , Datino T , Avila P , Soto N , Peinado R , Fernandez-Aviles F
Published: October 2021

Background/Introduction

Several ECG signs have been proposed to discern the focal origin of ventricular outflow tract arrhythmias with a transition ≥V3. Their independent predictive value is unclear.

Purpose

The aim of the study is to establish a predictive model of independent ECG parameters to obtain an acute success in right-sided catheter ablation of isolated premature ventricular contractions (PVCs) or ventricular tachycardia (VT) from the ventricular outflow tract with a transition ≥V3.

Methods

We included 122 patients (62 women, mean age 54±16 years) with documented PVCs or VT showing a lower axis and predominantly negative QRS complexes in V1 and V2 who underwent ablation between January 2014 and June 2020. The achievement of acute ablation success from right endocardial positions was assessed. We performed a predictive model by multivariate logistic regression analysis including the following ECG variables associated with a right origin of the ventricular focus in previous studies: Transitional Zone (TZ) index, V2 transition ratio, V2S / V3R index, R-wave duration index, R/S-wave amplitude index in V2, variable coupling interval, and the presence of QS morphology in lead I.

Results

Two independent predictive ECG variables were identified: the V2S / V3R index (odds ratio 1.223; 95% CI, 1.024–1.460; p=0.026) and a coupling interval variability >60 ms (odds ratio 0.307; 95% CI, 0.129 - 0.731; p=0.008). The area under the curve of this model was 0.733 (Picture 1). Arrhythmias with transition in V3 present a greater electroanatomic overlap and, therefore, a higher probability of right failure (59.3% vs 73.5% in arrhythmias with transitions after V3). In these, the V2 transition ratio is useful to predict the origin of the ectopy.

Conclusion

Two easily identifiable ECG variables (the V2S / V3R index and coupling interval variability >60 ms) predict the acute success of a right-sided approach in the ablation of focal ventricular arrhythmias with predominantly negative QRS complexes in V1 and V2.

Funding Acknowledgement

Type of funding sources: None. Predictive accuracy of the ECG model
Correlation of signal averaged electrocardiography findings with fibrosis on cardiac magnetic resonance imaging
Authors: Saad S , Ahmed J , Drutel R , Clark D , Danrad R , Lelorier P
Published: October 2021

Background

Signal averaged electrocardiogram (SAECG) is a non invasive test to record delayed depolarization of myocardium with slow conduction that can potentially be the substrate for monomorphic ventricular tachycardia in high risk patients. Cardiac magnetic resonance imaging (cMRI) techniques for fibrosis imaging using late gadolinium enhancement (LGE) and T1 mapping remain the gold standard for characterization of myocardial tissue and triaging patients for risk of ventricular arrhythmias. However, cMRI remains unavailable in some areas, is time consuming, expensive and impossible for some patients to obtain due to claustrophobia, renal impairment or implanted hardware. To date, data is lacking with regards to correlation of findings between these two modalities.

Purpose

To investigate whether late potentials identified by SAECG correlate with the presence of fibrosis seen with cMRI. If correlation is established, SAECG could potentially be used as a non-invasive, cheaper, more convenient and readily available tool for risk stratification in patients at high risk for ventricular arrhythmias.

Methods

SAECGs were obtained in 25 consecutive patients undergoing cMRI. Patients with wide QRS (>120 ms) on ECG were excluded. Positive SAECG was defined as at least 1/3 abnormal criteria. Standard criteria were used. Results of the 2 modalities were compared. Sensitivity and specificity of SAECG for diagnosing fibrosis on cMRI were calculated.

Results

The mean age of the patients was 50.3±5.8 years and the mean ejection fraction was 48.9±5.8% as determined by cMRI. Forty-eight percent of the patients had fibrosis on cMRI by either LGE, T1 mapping or both. The sensitivity and specificity of SAECG were 75% and 100%, respectively. Seven patients had history of ventricular tachycardia and 6 patients had dilated cardiomyopathy.

Conclusion

SAECG is extremely specific in identifying patients with myocardial fibrosis on cMRI. A positive test may confer a lesser indication to pursue cMRI solely for purposes of risk stratification, and may correlate with risk of ventricular arrhythmia.

Funding Acknowledgement

Type of funding sources: None.
Clinical impact of continuous electrical monitoring in patients with arrhythmic myocarditis: a prospective cohort study
Authors: Peretto G , Mazzone P , Della Bella P , Sala S
Published: October 2021

Background

Although potentially life-threatening, arrhythmias in myocarditis are under-reported.

Purpose

To assess diagnostic yield and clinical impact of continuous arrhythmia monitoring (CAM) in patients with arrhythmic myocarditis.

Methods

We enrolled consecutive adult patients (n=104; 71% males, age 47±11y, mean LVEF 50±13%) with biopsy-proven active myocarditis and de novo ventricular arrhythmias (VA). All patients underwent prospective monitoring by both sequential 24-hour Holter ECGs (4/y in the first year; 2/y in years 2–5; 1/y later) and CAM, including either ICD (n=62; 60%) or loop recorder (n=42; 40%).

Results

By 3.7±1.6 y follow-up, 45 patients (43%) had VT, 67 (64%) NSVT, and 102 (98%) premature ventricular complexes (PVC). As compared to Holter ECG (average 9.5 exams per patient), CAM identified more patients with VA (VT: 45 vs. 4; NSVT: 64 vs. 45; both p<0.001), more VA episodes (VT: 100 vs. 4%; NSVT: 91 vs. 12%), and earlier NSVT timing (median 6 vs. 24 months, p<0.001). Conversely, Holter ECG allowed VA morphology characterization and daily PVC quantification. The time to first treatment modification was 12±9 months by CAM vs. 33±16 months by Holter ECG (p<0.001), and drug withdrawal was always CAM-dependent. Guided by CAM findings, 8 patients (8%) started anticoagulants for newly-diagnosed atrial arrhythmias. Differently from ICDs, loop recorders did not interfere with the interpretation of cardiac magnetic resonance.

Conclusion

In patients with arrhythmic myocarditis, CAM allowed accurate arrhythmia detection and showed a considerable clinical impact. As a complementary exam, VA characterization and PVC burden were better assed by repeated Holter ECGs.

Funding Acknowledgement

Type of funding sources: None.
A novel machine learning algorithm has the potential to reduce by 1/3 the quantity of ILR episodes needing review
Authors: Rosier A , Crespin E , Lazarus A , Laurent G , Menet A , Gozlan A , Varma N
Published: October 2021

Background

Implantable Loop Recorders (ILRs) are increasingly used and generate a high workload for timely adjudication of ECG recordings. In particular, the excessive false positive rate leads to a significant review burden.

Purpose

A novel machine learning algorithm was developed to reclassify ILR episodes in order to decrease by 80% the False Positive rate while maintaining 99% sensitivity.

This study aims to evaluate the impact of this algorithm to reduce the number of abnormal episodes reported in Medtronic ILRs.

Methods

Among 20 European centers, all Medtronic ILR patients were enrolled during the 2nd semester of 2020. Using a remote monitoring platform, every ILR transmitted episode was collected and anonymised.

For every ILR detected episode with a transmitted ECG, the new algorithm reclassified it applying the same labels as the ILR (asystole, brady, AT/AF, VT, artifact, normal). We measured the number of episodes identified as false positive and reclassified as normal by the algorithm, and their proportion among all episodes.

Results

In 370 patients, ILRs recorded 3755 episodes including 305 patient-triggered and 629 with no ECG transmitted. 2821 episodes were analyzed by the novel algorithm, which reclassified 1227 episodes as normal rhythm. These reclassified episodes accounted for 43% of analyzed episodes and 32.6% of all episodes recorded.

Conclusion

A novel machine learning algorithm significantly reduces the quantity of episodes flagged as abnormal and typically reviewed by healthcare professionals.

Funding Acknowledgement

Type of funding sources: None. Figure 1. ILR episodes analysis
Features of changes in left ventricular mechanics in patients with epicardial obesity
Authors: Gritsenko O , Chumakova G
Published: October 2021

Currently, there is no single non-invasive marker that can directly assess left ventricular (LV) diastolic function. Untwist of LV contributes to diastolic suction and early filling. Speckle-tracking imaging can be used to diagnose diastolic dysfunction at the preclinical stage.

Objective

To study the features of changes in the parameters of LV mechanics and their relationship with the levels of serum markers of myocardial fibrosis in patients with epicardial obesity (EO).

Materials and methods

The study included 125 men with general obesity. All patients underwent transthoracic echocardiography (ECG) to assess the thickness of epicardial adipose tissue (tEAT) as equivalent to visceral obesity, as well as to diagnose diastolic dysfunction (DD) of left ventricle (LV). According to the results of ECG, the patients were divided into 2 groups: EO(+) with epicardial fat thickness (tEAT) ≥7 mm (n=78); EO(−) with (tEAT) <7 mm (n=40). DD LV was detected in 7 patients, who were subsequently excluded from the analysis.

Profibrotic markers in blood serum (MMP-3, collagen I, collagen III, TGF-β, VEGFA, PICP) were determined in all patients using enzyme immunoassay. Using speckle-tracking ECG, the mechanics of LV were studied (twist LV, peak twist ratio LV, time to peak twist of LV, peak untwist ratio LV, time to peak untwist of LV). The exclusion criteria were the presence of coronary pathology, arterial hypertension, and type 2 diabetes mellitus.

Results

In the group of patients with EO(+) statistically significant increase the level of all studied profibrotic markers was revealed. According to the results of speckle-tracking ECG in the EO(+) group an increase peak untwist ratio LV to −125.56 (−141.0; −117.0)deg/s (p=0.003) and an increase time to peak untwist of LV of 469.44 (509.0; 401.0) msec was determined in comparison with the EO(−) group (p=0.03). A weak statistically significant effect of tEAT on the peak untwist ratio LV in EO(+) group was revealed (r=0.28; p=0.03). In addition, there was a significant relationship between peak untwist ratio LV and markers of myocardial fibrosis MMP-3 (r=0.23; p=0.03) and collagen type III (r=0.25; p=0.04).

Conclusion

Thus, LV unwinding may be a new non-invasive marker of LV DD at the preclinical stage, since this parameter reflects the mechanical aspect of global diastolic function, especially the early phase of diastole.

Funding Acknowledgement

Type of funding sources: None.
Patients with reflex syncope have a higher prevalence of atrial fibrillation than general population which is predicted by the type of the tilt table test response
Authors: Farinha J M , Parreira L , Esteves A F , Fonseca M , Pinheiro A , Ferreira J , Coelho R , Mesquita D , Marinheiro R , Amador P , Caria R
Published: October 2021

Introduction

Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF).

Objective

The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF.

Methods

We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF.

Results

We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043).

Conclusions

Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF.

Funding Acknowledgement

Type of funding sources: None.
Nine year experience of the Northern Ireland Inherited Cardiac Conditions Service (NI ICC of slow vs. rapid ajmaline infusion protocols for the diagnosis of Brugada syndrome (BrS)
Authors: Msulaiman H , Connolly H , McOsker J , Jardine T , McCall D , McKeown P , Muir A
Published: October 2021

Background

BrS is diagnosed in patients with ST-segment elevation with type1 morphology ≥2mm in one or more leads among the right precordial leads V1 and/or V2 positioned in the second, third or fourth intercostal space, occurring either spontaneously or after provocative drug test with intravenous administration of sodium channel blockers (ie. ajmaline, flecainide, procainamide or pilsicainide). The specific protocol for Ajmaline provocation testing for diagnosis of BrS has been debated between ICC services worldwide. Concerns regarding safety and false positive rates are perceived to be associated with a more rapid infusion protocol. This retrospective observational cohort study describes the safety and positivity rates for patients undergoing ajmaline provocation challenge by both protocols over nine years.

Method

Consecutive adults undergoing ajmaline challenge test from Mach 2011 to Feb 2020 were retrospectively collected. Data on patient demographics, indication for testing, genetic information, adverse events and positivity rates were compared by test protocol used. Slow protocol was defined as total dose of 1mg/kg ajmaline capped at 100mg given at rate of 10mg/min over 10 minutes. Rapid protocol was defined as 1mg/kg ajmaline capped at 100mg given over 5 minutes.

Results

A total of 350 ajmaline challenges were included (275 (73%) slow vs. 75 (27%) rapid protocol) [Mean age 40±15 years; 53% male]. Indication for conducting the test was a) Family history of Brugada syndrome 164 (43%) b) Family history of SADS/SUD 103 (28%), c) OOHCA 22 (6%) d) abnormal ECG 39 (11%) and e) syncope 22 (6%). Among the positive test group, average time for test positivity is 5.92 minutes and average dose was 55mgs (p<0.05). There were no differences between positivity rate between the two protocols, group A vs. group B, p=0.45, ns. Comparison between all patients with positive vs. negative results regardless of the protocol, showed no statistical differences. Predominantly male in both groups (p=0.71, ns) and mean age of patients in their 40's (p=0.93, ns). There is a trend that positive patients likely to have family history of BrS p=0.08, ns). 2 patients had experience jaundice at later stage which resolved.

Conclusion

In NI ICC service to date, we have performed 350 Ajmaline test over the last nine years. Our positivity rate was 21% (75/350). We did not identify any significant evidence of ventricular dysrhythmia (0) or QRS broadening (2) that resulting in early termination of the protocol. Abnormal ECG with absence of symptoms yields low. Therefore we will continue fast protocol in our service for efficiency in our unit.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Belfast Health and Social Care TrustCormac Felowship
Prognostic implication of left atrial strain in patients undergoing totally thoracoscopic ablation of atrial fibrillation
Authors: Kim J K
Published: October 2021

Background

Atrial fibrillation (AF) is a common form of arrhythmia and associated with poor quality of life. Totally thoracoscopic ablation (TTA) is a novel minimally invasive strategy for symptomatic atrial fibrillation (AF) refractory to other therapy. However, some of patients undergoing TTA are still exposed to a risk of AF recurrence.

Purpose

The aim of this study is to investigate prognostic factors related with AF recurrence after TTA, and to determine the prognostic implication of left atrial (LA) strain in this population.

Methods

This was a prospective observational study. Between February 2012 and March 2015, left atrial appendage (LAA) was harvested from patients who underwent TTA in our Medical Center. Degree of LAA fibrosis was expressed as the percentage of area of positive collagen staining in the total area of the image of specimen. All echocardiographic parameters were measured in preoperative echocardiography. The primary outcome was any recurrence of AF detected in 12- lead electrocardiogram or holter monitoring during 5 years of follow-up.

Results

Out of 150 patients who underwent TTA during the study period, 129 were eligible for analysis with appropriate surgery, LAA specimen, and echocardiographic images. A mean age was 54.4±8.8 years, and 123 patients (95.3%) were male. Twenty four patients (18.6%) had paroxysmal AF and a mean CHA2DS2 VASc score was 1.1±1.2. A median value of peak longitudinal LA strain (reservoir strain) was 15.2% (IQR 12.1–19.2), and the median value of LAA fibrosis was 38.5% (IQR 33.0–44.7). Among clinical and echocardiographic variables, peak longitudinal LA strain (p<0.001) and left ventricular ejection fraction (p=0.044) were significantly associated with degree of LAA fibrosis (Figure). Of 129 patients, 47 (36.4%) experienced recurrent AF during the median 3.9 years of follow-up. In a multivariable Cox regression analysis using clinical, echocardiographic and operative parameters, peak longitudinal LA stain was the only predictor of recurrent AF (adjusted HR 0.89, 95% CI 0.81–0.98, p=0.024; Table).

Conclusions

Peak longitudinal LA strain was associated with LAA fibrosis, and was a significant predictor of recurrent AF after TTA

Funding Acknowledgement

Type of funding sources: None.
Is there an antiarrhythmic benefit from switching to sacubitril/valsartan therapy? A systematic review and meta-analysis
Authors: Anagnostopoulos I , Kousta M , Kossyvakis C , Lakka E , Paraskevaidis N T , Schizas N , Giannopoulos G
Published: October 2021

Background

Sacubitril/valsartan through reverse structural remodeling and neurohormonal inhibition could play an antiarrhythmic role.

Purpose

This systematic review and meta-analysis was performed to explore the arrhythmiologic effects of switching patients with heart failure with reduced ejection fraction (HFrEF) from angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) to sacubitril/valsartan.

Methods

We searched major databases for studies comparing device-detected, incident atrial and ventricular arrhythmias in patients with HFrEF while on ACEi/ARBs versus while on sacubitril/valsartan. For pooling the primary outcome of interest, we calculated the risk difference (RD) with the corresponding 95% confidence interval (CI) in the probability of experiencing each arrhythmic event while on ACEi/ARBs and while on sacubitril/valsartan. A random effects (DerSimonian-Laird) model was adopted.

Results

We analyzed 4 eligible studies, resulting in 497 patients with a pooled mean age of 67.8±10.36. 64% had ischemic cardiomyopathy while 98% had either an implantable cardioverter defribrillator or a cardiac resynchronization therapy device. Main comorbidities were hypertension (68.7%) and dyslipidemia (59.6%). Almost all (96.3%) patients were treated with b-blockers and 23.7% were also receiving anti-arrhythmic drugs, mainly amiodarone. After switching to sacubitril/valsartan there was a trend towards reduced risk for sustained ventricular tachycardia/fibrillation and non-sustained ventricular tachycardias (RD: −0.04, 95% CI: −0.09–0.02, I2: 65.7% and −0.06, 95% CI: −0.19–0.07, I2: 85%; respectively). Meta-regression analysis showed that patients with ischemic cardiomyopathy experience greater benefit. Incident paroxysmal atrial fibrillation/tachycardia was significantly reduced (RD: −0.09 95% CI: −0.14 to −0.03, I2: 0%), while favorable effects were noticed for the risk of appropriate shock delivery and inadequate biventricular pacing (RD: −0.06, 95% CI: −0.09 to −0.03, I2: 0% and −0.06, 95% CI: −0.11 to 0.00, I2: 35.55%, respectively). All results seem to suffer from publication bias.

Conclusion

Limited data support that switching to sacubitril/valsartan seems to be associated with reduced risk for both ventricular and atrial arrhythmias. More studies are needed to clarify the potential anti-arrhythmic role of this drug. Whether patients with frequent arrhythmias or at high arrhythmic risk may benefit from early switch is a matter of further investigation.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2
Ongoing antiarrhythmic drug therapy type does not affect the rate of first-pass pulmonary vein isolation: data from a multicenter registry
Authors: Gasimova N , Kropotkin E , Ivanitsky E , Kolunin G , Nechepurenko A , Shavshin D , Antolic B , Kovalev K , Mikhaylov E , Lebedev D
Published: October 2021

Background

It is well-known that antiarrhythmic drugs (AAD) change the electrophysiological properties of the atrium mostly by increasing the atrial refractory period and wavelength for reentry. Frequently, atrial fibrillation (AF) catheter ablation is being performed with AAD interruption. However, the information on the impact of AAD on AF ablation performance is lacking, and AAD interruption is not desirable in highly symptomatic patients with persistent arrhythmia.

Purpose

We sought to study potential differences in achieving first-pass pulmonary vein isolation (FPI) during AF ablation in patients receiving different classes of ongoing AADs.

Methods

This was a prospective observational multicenter registry. All centers were invited to participate in the registry voluntarily. Data on demographic, clinical, and procedure characteristics were derived from a web-based system. All catheter ablation procedures were performed according to local practices. A total of 450 patients were enrolled, 408 of them underwent first-time AF ablation. Data on AAD characteristics were available in 350 patients (mean age 61±9 years, 195 (56%) males, 270 (77%) had paroxysmal AF). All patients were divided into three groups: ongoing I class AAD treatment (propafenone, ethacyzin, allapinin, n=76), ongoing II class AAD (beta-blockers, n=60), and ongoing III class AAD (amiodarone, sotalol, n=214).

Results

Baseline clinical and procedural characteristics between AAD groups are summarized in Table. Patients in the I class AAD group were younger, likely had paroxysmal AF, and a smaller mean left atrial diameter. Procedures in the III class AAD group were performed with a higher median target ablation index on the posterior left atrial wall. But the percentage of first-pass isolation was distributed equally between groups (60%, 68%, 61%, p=0.56). The correlation matrix revealed no significant associations between FPI and clinical and procedural variables (r=0.02–0.09; p>0.05 for all).

Conclusion(s)

Our real-life multicenter data demonstrate no difference in FPI achievement between patients receiving different AADs. We suggest that highly symptomatic patients may continue pharmacological treatment during AF ablation without compromising acute ablation success.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Higher Education grant (Russian Federation President Grant) Table 1. Clinical and procedural parameter
Amiodarone and amplitude spectral area of ventricular fibrillation in patients with out-of-hospital cardiac arrest
Authors: Gentile F R , Compagnoni S , Baldi E , Aramendi E , Primi R , Bendotti S , Currao A , Contri E , Palo A , Savastano S
Published: October 2021

Background

Ventricular fibrillation is the most common cause of out-of-hospital cardiac arrest (OHCA) and the use of antiarrhythmic drug therapy is usually recommended in addition to defibrillation. The role of the amplitude spectral area (AMSA) of ventricular fibrillation as a predictor of defibrillation efficacy has been established, while the existing data in favour of the use of amiodarone has been assessed with poor evidence and controversy.

Purpose

The aim of our study is to evaluate whether the administration of amiodarone during resuscitation could affect AMSA values.

Materials

All the OHCAs with a shockable presenting rhythm and attempted resuscitation which occurred from January 2015 to June 2019 in the province of Pavia were considered. Both the end-tidal CO2 (ETCO2) and AMSA values were calculated by retrospectively analyzing the data collected by the Corpuls 3 monitors/defibrillators (Corpuls, Kaufering, Germany) used in the territory and by considering a pre-shock interval of 2 seconds.

Results

Among a total of 3413 OHCAs, resuscitation was attempted in 2195 cases (64%), 377 (17%) had a shockable presenting rhythm and in 112 cases (3.4%) it was possible to obtain the values of ETCO2 and AMSA for a total of 391 shocks. Among these, 301 shocks (77%) were delivered to patients who received amiodarone during resuscitation. The success rate of each single shock was similar in the two groups but with an unfavorable trend for amiodarone (amiodarone 43.5% vs no amiodarone 54.4%, p=0.07). AMSA was significantly lower in patients treated with amiodarone (7.9 mV·Hz, IQR 5.4–12.2 vs 10.6 mV·Hz, IQR 7.1–14.1; p<0.001). According to a multivariate analysis, the administration of amiodarone and the time to shock were independent predictors of AMSA values. Lastly, on a sample of 124 shocks, homogeneous for age, sex, ETCO2, outcome of resuscitation and randomly matched, the AMSA of patients who received amiodarone was significantly lower (7.2 mV·Hz, IQR 7.2–11.7 vs 9.7 mV·Hz, IQR 6.7–12.5; p=0.02).

Conclusions

Our results indicate that amiodarone administration is associated with lower values of AMSA. Since higher AMSA values are known to be associated with a higher probability of shock rate success, this could help to better clarify the controversial role of amiodarone administration in patients with OHCA.

Funding Acknowledgement

Type of funding sources: None.
Significance of mitral L wave to predict late recurrence of atrial fibrillation after radiofrequency catheter ablation
Authors: Wada R , Shinohara M , Yao S , Yano K , Akitsu K , Koike H , Kinoshita T , Yuzawa H , Nakanishi R , Fujino T , Ikeda T
Published: October 2021

Background

Mitral L wave, prominent mid-diastolic filling wave in echocardiographic examinations, is associated with severe left ventricular diastolic dysfunction, and that has been reported to predict recurrent atrial fibrillation (AF) after cardioversion. However, association between mitral L wave and the outcome of AF after radiofrequency catheter ablation (RFCA) has not been established.

Objective

The aim of this study is to evaluate the predictive value of mitral L wave on AF recurrence after RFCA.

Methods

250 patients including 164 paroxysmal AF (65.6%) and 86 non-paroxysmal AF (34.4%) who received RFCA in single center from January 2015 to December 2016 were enrolled consecutively. Echocardiographic examinations before RFCA were recorded, and the mitral L wave was defined as a distinct mid-diastolic flow velocity with a peak velocity ≥20 cm/s following the E wave. Systematic follow-up was conducted after RFCA. Univariate and multivariate analyses were carried out to determine the factors predicting late recurrence of AF (LRAF) which means AF recurrence after 3 months. Enrolled patients were divided into groups with the L wave (L-group; n=57) or without the L wave (NL-group; n=193) based on the findings of echocardiographic examinations.

Results

During a follow-up of 35.0±17.6 months, the ratio of LRAF in the L-group was significantly higher than that in the NL-group (32 (56.1%) vs. 41 (21.2%), Hazard ratio [HR]: 3.55, 95% confidence interval [CI]: 2.33 - 5.42, p<0.001). Among the clinical factors, presence of mitral L wave, BNP value, non-paroxysmal AF and moderate-severe mitral regurgitation were related to LRAF. A multivariate analysis using a Cox proportional hazard model found that presence of mitral L wave (HR: 2.67, 95% CI: 1.30 - 5.48, p=0.007) was significantly associated with LRAF.

Conclusion

This study revealed that mitral L wave predicts late recurrence of AF after RFCA.

Funding Acknowledgement

Type of funding sources: None.
Atrial functional mitral regurgitation in patients qualified for pulmonary vein isolation: a negative prognostic factor for catheter ablation efficacy
Authors: Cichon M , Wybraniec M , Mizia-Szubryt M , Mizia-Stec K
Published: October 2021

Background

Atrial functional mitral regurgitation (AF-MR) related to atrial fibrillation (AF) could affect the effectiveness of the sinus rhythm restoring procedures.

Purpose

The aim of the study was to evaluate the impact of AF-MR on pulmonary vein isolation (PVI) efficacy.

Methods

One hundred thirty-six patients (65.4% males; mean age 56±11 years) with symptomatic paroxysmal or persistent AF qualified for PVI were enrolled into the study. AF-MR assessment was performed in transthoracic (TTE) and transesophageal (TEE) echocardiography before PVI procedure. PVI efficacy was evaluated in 3-month and long-term follow-up.

Results

AF-MR was diagnosed in 74.3% patient in transthoracic echocardiography (TTE) (trace: 26.5%, mild: 43.4%, moderate: 3.7%, severe 0.7%) and 94.9% in transesophageal echocardiography (TEE) (trace: 17.6%, mild: 59.6%, moderate: 16.2%, severe: 1.5%). PVI 3-month efficacy was 75.7% in 3-month and 64% in the long-term observation.

Severe AF-MR in TEE at baseline was associated with lower 3-month PVI efficacy (P=0.012) while moderate to severe AF MR in TEE was related to inefficient PVI assessed in long-term follow-up (P=0.041). In Kaplan- Meier analysis only moderate to severe AF-MR diagnosed in TEE had an impact on long-term procedure outcome (P=0.048).

Conclusions

Significant AF-MR confirmed by TEE predicts 3-month as well as long-term PVI efficacy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The institutional budget of the First Department of Cardiology, Medical University of Silesia, Katowice, Poland
Initial clinical experience of pulmonary vein isolation using the novel ultra-low temperature cryoablation catheter for patients with atrial fibrillation
Authors: Tohoku S , Bordignon S , Chen S , Schmidt B , Chun K R J
Published: October 2021

Background

The high cooling power and ultra-low temperature cryoablation (ULTC) catheter called “Adagio” has been recently launched. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation applicable not only for atrial fibrillation (AF) but also for other tachyarrhythmia by optimizing catheter shape. The exclusive esophageal warming balloon in order to preserve esophageal temperature is encouraged to prevent the potential risk of esophageal complication during procedure.

Aim

To assess the initial clinical data on pulmonary vein (PV) isolation for patients with AF using the novel ULTC catheter.

Methods

Consecutive patients who underwent AF ablation using ULTC in our center were enrolled. We assessed the acute procedural data focusing on procedural feasibility and safety comprising “first-pass isolation” defined as successful PV isolation after the initial application.

Results

A total of 16 AF patients (53% male, age 67 years, 59% paroxysmal AF) were analyzed. Sixty-six out of 67 PVs (98.5%) were isolated with ULTC. The mean number of applications per PV was 2.3 1.1. Touch-up catheter was needed in one case at left inferior PV. The mean total procedure and fluoroscopy times were 79±30 and 14±7 mins, respectively. First-pass isolation was achieved in 34 PVs (50.7%) varying across PVs from left superior PV (43.8%) to right superior PV (58.8%). In none of the patients an acute thromboembolic event (stroke or transient ischemic attack), a pericardial effusion/tamponade and postprocedural esophageal complication occurred. A single transient phrenic nerve weakening was observed at right superior PV.

Conclusion

Sequential PV isolation using the novel ULTC catheter was achieved feasibly without compromising safety. First-pass isolation was accomplished about in a half of PVs.

Funding Acknowledgement

Type of funding sources: None.
Myocardial injury after pulmonary vein isolation: fire versus ice
Authors: Morgado Gomes A R , Antonio N S C , Silva S , Madeira M , Sousa P , Elvas L , Goncalves L
Published: October 2021

Introduction

The cornerstone of atrial fibrillation (AF) catheter ablation is pulmonary vein isolation (PVI), either using point-by-point radiofrequency ablation (RF) or single-shot ablation devices, such as cryoballoon ablation (CB). However, achieving permanent transmural lesions is difficult and pulmonary vein (PV) reconnection is common. Elevation of high-sensitivity Troponin I (hsTnI) may be used as a surrogate marker for transmural lesions. Still, data regarding the comparison of hsTnI increase after PVI with RF or cryo-energy is controversial.

Purpose

The aim of this study is to compare the magnitude of hsTnI elevation after PVI with CB versus RF using ablation index guidance.

Methods

Prospective study of 60 patients admitted for first ablation procedure of paroxysmal or persistent AF in a single tertiary Cardiology Department. Thirty patients were submitted to PVI using CB and 30 patients were submitted to RF, using CARTO® mapping system and ablation index guidance. Patients with atrial flutter were excluded. Baseline characteristics were compared between groups, as well as hsTnI before and after the procedure.

Results

Mean age was 57.9±12.3 years old, 62% of patients were male and 77% had paroxysmal AF. There were no significant differences between groups regarding gender, age, prevalence of hypertension, dyslipidaemia, diabetes, obesity or AF type. There was also no significant difference in electrical cardioversion need during the procedure. HsTnI median value before ablation was 1.90±1.98 ng/dL. Postprocedural hsTnI was significantly higher in CB-group (6562.7±4756.2 ng/dL versus 1564.3±830.7 ng/dL in RF-group; P=0.001). Regarding periprocedural complications, there was only one case of mild pericardial effusion in RF-group associated with postablation hsTnI of 1180.0 ng/dL.

Conclusions

High-sensitivity Troponin I was significantly elevated after PVI, irrespective of the ablation technique. In CB-group, hsTnI elevation was significantly higher than in RF-group. This disparity may reflect more extensive lesions with cryoablation, without compromising safety. Longterm studies are needed to understand whether this hsTnI elevation is predictive of a lower AF recurrence rate.

Funding Acknowledgement

Type of funding sources: None.
Ejection fraction basal strain ratio (EFBSR), a new accurate echocardiographic deformation parameter to screen cardiac amyloidosis among hypertrophic cardiopathies
Authors: Rique A , Martel H , Piazzai C , Mancini J , Gravier R , Arregle F , Dernys A , Gardenat A , Casalta A C , Renard S , Hubert S , N'guyen K , Habib G
Published: October 2021

Background

Early diagnosis of cardiac amyloidosis (CA) is challenging. Several echocardiographic (echo) parameters have been proposed to differentiate CA from hypertrophic cardiomyopathy (HCM), but their respective value is debated. CA is known to be characterized by a more severe decline in longitudinal deformation parameters as compared with radial function parameters (LVEF). This characteristic justified the use of the ejection fraction strain ratio (EFSR) in these patients. However, since longitudinal dysfunction usually predominates in basal segments (apical sparing), we postulated that a new parameter focusing on LVEF and basal LV deformation (EFBSR: ejection fraction basal strain ratio) will even better discriminate patients with CA from HCM than EFSR and other echo or strain parameters.

Purpose

To compare the accuracy of deformation-based echocardiographic parameters for detecting CA in a population with different causes of LV hypertrophy.

Methods and results

We included 237 subjects, of which 89 patients with CA (77±10.7 years, 72% male, EF: 56.2±12.8%, and mean interventricular septum: 18.3±3.5 mm), 137 patients with hypertrophic cardiomyopathies (HCM), 52 patients with severe aortic stenosis with myocardial remodeling, 20 patients with arterial hypertension, and 20 control patients. Conventional echocardiographic parameters and strain-derived ratios (Relative apical sparing (RELAPS), Ejection Fraction Strain Ratio (EFSR) and EFBSR) were analyzed.

EFBSR and RELAPS presented with the best performance to discriminate CA from other causes of hypertrophy (Area Under the Curve (AUC): 0.880; 95% CI: 0.830–0.929 and 0.903; 95% CI: 0.863–0.943 respectively) (p-value=0.3). In our study, among all the parameters, RELAPS had the best specificity (89.8% vs 88.3% for EFBSR), whereas EFBSR had the best sensitivity (78.7% vs 76.4% for RELAPS). EFBSR ranged from 35.25 to 1.83 and the cutoff value to differentiate CA from other hypertrophic cardiopathy was an EFBSR >7.75.

Conclusions

Our study demonstrates that in patients with LV hypertrophy, a new deformation parameter, the ejection fraction basal strain ratio (EFBSR) can accurately differentiate CA from other causes of myocardial thickening and can be used in routine practice for screening.

Funding Acknowledgement

Type of funding sources: None.