bluuebunny/crossref_metadata_2025_split huggingface dataset:
673Bipolar radiofrequency ablation supported by non-ionic catheter irrigation
Authors: Futyma P R , Kulakowski P 
Published: June 2020

Abstract

Introduction
Bipolar radiofrequency catheter ablation (Bi-RFCA) or irrigation of ablation catheter (AC) using non-ionic coolant, such as dextrose-5 in water (D5W), are novel ways to improve lesion formation in case of arrhythmia refractoriness. Combination of these two methods has not yet been described.

Puprose
To determine feasibility and effectiveness of Bi-RFCA additionally supported by non-ionic catheter irrigation for treatment of refractory premature ventricular complexes (PVC) or ventricular tachycardia (VT).

Methods
Consecutive patients after failed extensive Bi-RFCA or D5W-irrigated ablation for symptomatic PVCs or non-sustained VT (nsVT) underwent Bi-RFCA supported with D5W coolant.

Results
We ultimately enrolled 2 patients (2 males, age 64 ± 12 years) after failed extensive ablations for the left ventricular summit PVCs and nsVT to undergo Bi-RFCA supported with D5W irrigation of both AC and intracardiac return electrode (IRE). Previous pharmacological antiarrhythmic treatment consisting of at least one drug and catheter ablation failed in both patients. Bi-RFCA was delivered between earliest activation sites located in the left/right aortic commissure and the left pulmonic cusp (Figure). Efforts were made to achieve safe distance from coronary arteries, AC, and IRE. Bipolar RFCA (35 ± 7W power, 8 ± 4 applications, 199 ± 166s RF time) led to acute elimination of PVCs in both patients. Baseline impedance oscillated around 250Ω and initial 50-70Ω impedance drop was observed during first 20s of bipolar applications, followed by impedance rise up to 350-450Ω. No steam pop occurred and there were no complications during procedures. All antiarrhythmic drugs were discontinued. Follow-up lasted 8 ± 2 months, there was no nsVT recurrence and 90,4% PVC burden reduction was achieved: from 30000 to 3100 PVC/day in patient #1 and from 39000 to 3500 PVC/day in patient #2. Both patients remained symptom-free.

Conclusion
Bi-RFCA can be additionally supported using non-ionic D5W coolant. Such approach is feasible and can be safe and effective. More data on impedance imbalance during D5W-supported bipolar RF applications is warranted.
Abstract Figure. Fluoroscopic view and 12-lead ECG
P1393Prolonged atrial electrical conduction as a predictor of atrial fibrillation after atrioventricular nodal reentrant tachycardia ablation
Authors: Marinheiro R , Parreira L , Amador P , Mesquita D , Farinha J , Fonseca M , Esteves A , Ferreira J , Lopes C , Duarte C , Venancio J , Santos B , Caria R 
Published: June 2020

Abstract

BACKGROUND
Patients (pts) with atrioventricular nodal reentrant tachycardia (AVNRT) have a higher incidence of atrial fibrillation (AF) during follow-up. Conventional risk factors can play a role in AF development, however atrial electrical conduction properties may be implicated in AF pathogenesis.

AIMS
to evaluate atrial conduction times and assess its effect on AF development during follow-up.

METHODS
We studied AVNRT pts who performed EPS and catheter ablation of the slow pathway between 2013 and 2016 in a single center. Pts with AF or valvular disease were excluded. We evaluated duration of symptoms due to AVNRT, conventional risk factors for AF (age, gender, obesity, hypertension, diabetes and structural heart disease (SHD)), left atrium (LA) enlargement and electrophysiologic study (EPS) time intervals related with atrial electrical conduction properties. We measured the time interval between: (1) the beginning of the P wave on the ECG to the A deflection in His-bundle electrogram (P-AHis); (2) the beginning of the P wave to the mid-distal coronary sinus (CS) atrial electrogram (P-CS) and (3) the beginning of the P wave to the H deflection in His-bundle electrogram (P-HHis).

RESULTS
Fifty-two pts were evaluated during a median follow-up of 63 months (IQR 51-69): 22% male, median age 55 years (IQR 42-67). AF occurred in 9 patients (17%) (39 cases per 1000 person-years). Patients with AF were older (67 vs 53 years, p= 0.005) and had more frequently LA enlargement (33% vs 7%, p= 0.024) but they did not differ in hypertension, obesity, diabetes, SHD and duration of symptoms. EPS measured intervals P-AHis and P-HHis interval were not different between the groups (26.0 vs 22.8 ms, p = 0.89 and 151 vs 106 ms, p= 0.56, respectively) but P-CS were prolonged in patients with AF (70 vs 55 ms, p = 0.02) (figure 1). Univariate logistic analysis for AF is presented in table 1. There was no interaction between P-CS and LA enlargement (p = 0.87). In multiavariate analysis, only P-CS was independently associated with AF (table).

CONCLUSIONS
In this group of patients with AVNRT, P-CS, but not other atrial conduction intervals, was independently associated with AF development. The possible role of LA electrical conduction impairment in AVNRT pts for AF development needs further studies.
Univariate and multivariate analysis Univariate analysis Multivariate analysis OR 95% CI p-value OR 95% CI p-value Age (years) 1.10 1.02-1.19 0.016 1.10 1.00-1.21 0.051 LA enlargement 7.00 1.10-44.71 0.040 3.42 0.41-28.03 0.255 P-CS 1.07 1.021.14 0.013 1.06 1.01-1.12 0.044 OR Odds ratio. CI: confidence interval
Abstract Figure. Box-plot for the studied intervals
P1097Heart rate acceleration is a poor surrogate of complete parasympathetic denervation of sinus node during cardioneuroablation
Authors: Wichterle D , Jansova H , Stiavnicky P , Peichl P , Cihak R , Kautzner J 
Published: June 2020

Abstract

Background
Ablation of superior paraseptal ganglionic plexi is invariantly associated with the acceleration of sinus rhythm. This is considered a favourable sign during cardioneuroablation for the treatment of recurrent neurally-mediated cardioinhibitory syncope or symptomatic sinus bradycardia.

Purpose
In this retrospective study, we investigated whether the magnitude of sinus rhythm acceleration corresponds with directly assessed sinus nodal parasympathetic denervation.

Methods
The study included 48 patients (age: 39 ± 13 years, 58% males) who underwent cardioneuroablation in general anaesthesia. The procedural endpoint was non-responsiveness (i.e. loss of original cardioinhibitory response) of the sinus node to extracardiac high-frequency stimulation of the vagal nerve. The magnitude of sinus rhythm acceleration was compared between patients who reached or did not reach this endpoint.

Results
All patients had positive atropine test (baseline heart rate: 65 ± 14 bpm; post-atropine: 109 ± 22 bpm). Complete sinus nodal denervation as assessed by vagal nerve stimulation was achieved in 44/48 (92%) patients. Intraprocedurally, heart rate accelerated from 54 ± 11 to 85 ± 14 bpm (difference: 31 ± 10; median 29; interquartile range: 24–40; total range: 13–61 bpm). This change did not correlate with age and was not related to pre-procedural post-atropine sinus rhythm acceleration. There was no difference in heart rate acceleration between the patient with and without sinus nodal denervation (Figure).

Conclusions
Sinus rhythm acceleration is not reliable endpoint for cardioneuroablation. Guidance by extracardiac vagal nerve stimulation may help to tailor the procedures to increase the clinical success rate and, at the same time, to avoid patient overtreatment.
Abstract Figure.
236Automatic classification of 20 different types of atrial tachycardia using 12-lead ECG signals
Authors: Luongo G , Schuler S , Rivolta M W , Doessel O , Sassi R , Loewe A 
Published: June 2020

Abstract

Funding Acknowledgements
Supported by the European Union"s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.766082 (MY-ATRIA)

Background
Atrial Flutter (AFl) as a common reentrant atrial tachycardia is driven by self-sustainable mechanisms that cause excitation to propagate along pathways different from sinus rhythm. Intracardiac electrophysiological mapping and catheter ablation is often performed without prior knowledge of the mechanism perpetuating AFl in a given patient, likely prolonging the procedure time of these invasive interventions. We investigated the feasibility of automatically identifying 20 different AFl types based on the non-invasive 12-lead electrocardiogram (ECG) using machine learning.

Methods
Electrophysiological fast marching computer simulations of 20 different atrial tachycardia scenarios (micro-/macro-reentry, scar-related/anatomical/functional, figure-of-eight, focal, different locations) were performed and propagated to the standard 12-lead ECG based on the Courtemanche atrial action potential model. The virtual study population comprised combinations of 8 different anatomical bi-atrial models with 2 orientational variants each and 8 different torso models yielding a total of 2512 ECGs. From each ECG, we extracted 114 features from different domains (e.g., time, frequency, entropy, wavelet, non-linear recurrence analysis). The dataset was randomly split into 1256 training samples, 628 validation samples and 628 test samples while maintaining a balanced AFl type distribution. A radial basis neural network (RBNN) was trained as a classifier after selection of the most informative features.

Results
The RBNN yielded a test set accuracy of 90% regarding the identification of the AFl mechanism using 10 features (from different domains). The most discriminative single feature was the cycle length that alone led to a test set accuracy of 74%, while the remaining feature set without cycle length (9 features) reduced the test set accuracy to 33%. The machine learning approach generalized well regarding unseen torso geometries (90% accuracy if training was performed on only 7 torso models) but rather poor regarding atrial anatomies (23% if the atrial anatomical model was not seen during training) indicating that more than the currently used 8 atrial models should be included during training to cover the relevant anatomical variability.

Conclusions
Our results show that a machine learning classifier can potentially identify a high number of different AFl types using the 12-lead ECG. This non-invasive method can aid in planning and tailoring AFl treatment for patients. Application to clinical data is necessary as a next step to pave the way for clinical translation.
Abstract Figure.
P1395The role of hyponatremia in the development of atrial fibrillation after cardiac surgery
Authors: Pavlikova A , Shevelyok A , Vatutin N 
Published: June 2020

Abstract
Background. Atrial fibrillation (AF) is one of the most common complication after cardiac surgeries. Age, valvular heart disease, heart failure, chronic obstructive pulmonary disease and a history of AF are well known risk factors for postoperative AF. On the other hand, hyponatremia is also a frequent disorder in patients undergoing cardiac surgery but its relationship with AF has not been studied.
Purpose. We evaluated the impact of hyponatremia on the incidence of postoperative AF in patients undergoing cardiac surgery with cardiopulmonary bypass.
Methods. The retrospective study included case history of 222 patients (174 men and 48 women, median age 64.5 [range 58.0; 69.0] years) who underwent cardiac surgery with cardiopulmonary bypass between January 2015 and December 2018. In all patients intraoperative sodium level was analyzed. Hyponatremia was defined as serum sodium level &lt; 135 mmol/l. Primary outcome was the episode of AF in postoperative period.
Results. The incidence of postoperative AF was 18.9% (95% confidence interval (CI) 14.1-24.3 P = 0.05). Patients with AF more often had obesity, diabetes mellitus and a history of myocardial infarction and were more likely to perform combined surgery compared to non-AF patients (all Ps &lt; 0.05). The prevalence of hyponatremia was significantly higher among AF group compared with non-AF (95.2% versus 77.8%, P = 0.017). Hyponatremia was the independent risk factors of postoperative AF in Cox regression models adjusted for covariates (odds ratio 5.31; 95% CI 1.42-18.7; P = 0.017).
Conclusion. In this analysis serum sodium level was closely associated with the risk of AF. These findings suggest that hyponatremia may cause the development of postoperative AF in patients undergoing cardiac surgery with cardiopulmonary bypass.
P1418Heart failure and atrial fibrillation: clinical, prognostic and echocardiographic outcome
Authors: La Greca C , Cirasa A , Pecora D , Sorgato A , Simoncelli U , Campana M , Cuccia C 
Published: June 2020

Abstract

Background
Catheter ablation (CA) for atrial fibrillation (AF) in heart failure (HF) patients is
associated with a lower rate of cardiac events compared to medical therapy.

Purpose
This study deals with the clinical, echocardiographic and prognostic outcomes in these patients.

Methods
From a single center 47 patients with AF, HF and left ventricular ejection fraction (LVEF)
&lt;50%, underwent CA. The primary endpoints were NYHA functional class, LVEF and MAGGIC
(Meta-Analysis Global Group in Chronic Heart Failure) Risk score before the procedure and after 12
months.

Results
The median age of patients was 59 years; 49% had paroxysmal AF. At 12-month a
significant improvement of NYHA class (median before II [interquartile range (IQR) II-III] vs
median after I [IQR I-II]) and of LVEF (median before 44% [IQR 37-47] vs median after 55%
[IQR49-57]) was observed (p-value 0.000). The MAGGIC 1-year and 3-year probability of death was
estimated before (mean score 13 [IQR 11-17]) and at 12-month (mean score 11 [IQR 8-13]) showing
a significant decrease in the probability of death (p-value 0.000). At 12-month patients with reduced
LVEF before the ablation had more HF hospitalizations than HF mid-range patients (p-value 0.035).
Coronary artery disease (CAD) (HR 5, p-value 0.035) and MAGGIC score (HR 1.2, p-value 0.030)
were predictors of HF hospitalization.

Conclusion
CA for AF in HF patients was associated with a significant improvement of NYHA
functional class and LVEF and a higher life expectation. CAD history, LVEF &lt;40% and MAGGIC
score before ablation were predictors of HF hospitalization at 12-month follow-up.
854Predictors of ventricular tachyarrhythmia in patients with implantable cardioverter-defibrillator and non-ischaemic systolic heart failure
Authors: Jedrzejczyk-Patej E , Mazurek M , Lazar M , Pruszkowska-Skrzep P , Podolecki T , Kowalczyk J , Kowalski O , Kalarus Z , Lenarczyk R 
Published: June 2020

Abstract

Funding Acknowledgements
none

OnBehalf
none

Background
The benefit of an implantable cardioverter-defibrillator (ICD) in patients with ischaemic heart failure (HF) has been well proven but the benefit of ICD in subjects with non-ischaemic systolic HF is less well-established. Consequently, there is very limited evidence which patients with non-ischaemic HF would benefit most from receiving an ICD.
Aim
To determine the incidence and predictors of ventricular arrhythmia in patients with ICD and non-ischaemic systolic HF.

Methods
Study population consisted of 420 consecutive patients with ICD and non-ischaemic systolic HF monitored remotely (on a daily basis) between 2010 and 2017 in tertiary care university hospital, in a densely inhabited, urban region of Poland. Sixty-six percentage of patients had cardiac resynchronization therapy with defibrillator (CRT-D).

Results
During the median follow-up of 1645 days (range: 507-3515) sustained ventricular arrhythmia occurred in 100 patients (23.8%). Of those, ventricular fibrillation (VF), ventricular tachycardia (VT) or VT/VF (combined) occurred in 10 (10.0%), 77 (77.0%) and 13 (13.0%) patients, respectively. Patients with versus without ventricular arrhythmia did differ with respect to baseline variables such as: left ventricular end diastolic diameter (LVEDD) - median of 67 mm [49-82] vs 62 mm [46-78]; post-inflammatory HF (17 vs 9.7%, P = 0.045); atrial fibrillation/atrial flutter - AF/AFL (57 vs. 38.1%, P = 0.0009); supraventricular arrhythmia (SVT) - any supraventricular arrythmia &gt;100/min other than AF/AFL (27 vs. 15.9%, P = 0.01); and left ventricular ejection fraction - EF (25 vs. 28%, P = 0.01). No differences were observed for age, sex, NYHA class, mitral regurgitation, common comorbidities (including diabetes and chronic renal disease) or concomitant medications. On multivariable regression analysis, LVEDD (HR 1.05, 95% CI 1.004-1.09, P = 0.03), AF/AFL (HR 1.81, 95% CI 1.21-2.72, P = 0.004) and SVT (HR 1.91, 95% CI 1.21-3.01, P = 0.006) were identified as independent predictors of sustained ventricular arrhythmia in patients with ICD and non-ischaemic HF. All-cause mortality in patients with VT/VF was significantly higher than in subjects without sustained ventricular arrhythmias (33% vs. 20%, P = 0.03).

Conclusions
Ventricular arrhythmia occurred in 23.8% of patients with systolic non-ischaemic HF during 4.5 years of observation and was associated with significantly worse prognosis compared with subjects free of VT/VF. Left ventricular dimension, atrial fibrillation/atrial flutter and supraventricular tachycardia were identified as independent predictors for ventricular arrhythmia.
739SERCA2 Cys674 modification lead to ventricular arrhythmia due to impaired sarcoplasmic reticulum Ca2+ handling
Authors: Ito K , Yada H , Toya T , Osaki A , Kagami K , Yumita Y , Ido Y , Takase B , Adachi T 
Published: June 2020

Abstract

Background
Sarcoplasmic reticulum Ca2+-ATPase2 (SERCA2) plays an important role in intracellular Ca2+ handling. Under pathological conditions, oxidative stress leads to irreversible oxidation of Cys674 on SERCA2 which causes intracellular Ca2+ overload. Intracellular Ca2+ overload is known as the cause of ventricular arrhythmia, but the relation between SERCA2 function and ventricular arrhythmia remains unclear.

Purpose
To investigate the role of Cys674 on SERCA2 in the intracellular Ca2+ handling and the induction of ventricular arrhythmia.

Methods
We employed SERCA2 Cys674Ser heterozygote knock-in mice (SKI) which mimics oxidative modification of Cys674 on SERCA2. Continuous infusion of angiotensin (ANG) (3mg/kg/day) or distilled water were performed both in wild type mice (WT) and SKI for a week. After 1 week, electrophysiological study and intracellular Ca2+ transient measurement were performed.

Results
ANG elevated blood pressure and represented cardiac hypertrophy with fibrosis similarly both in WT and SKI. The mRNA expression of calcium/calmodulin-dependent protein kinase-II (CaMKII), ryanodine receptor (RyR) and sodium-calcium exchanger (NCX) was increased in SKI heart compared with WT. QTc interval was prolonged in SKI compared with WT, which was markedly prolonged with ANG infusion. Under programmed electrical stimulation, only SKI with ANG showed high incidence of pacing induced ventricular arrhythmia (0/11 in WT/SKI control, 0/14 in WT with ANG vs. 8/14 in SKI with ANG, P &lt; 0.01). In Ca2+ transient measurement, the peak Ca2+ transient amplitude (F/F0) was decreased (WT: 1.81 vs. SKI: 1.46, P &lt; 0.01) and the time to 50% of cytosolic Ca2+ extrusion (T50) was prolonged (WT: 152.6ms vs. SKI: 202.3ms, P &lt; 0.05) in SKI with ANG, suggesting decreased sarcoplasmic reticulum Ca2+ content and impaired SERCA2 activity in SKI with ANG. Intraperitoneal administration of dantrolene sodium (DAN) which inhibit Ca2+ leakage from RyR receptor normalized decreased F/F0 and prolonged T50 in SKI with ANG (Fig. 1 A, B). DAN also prevented QTc prolongation and decreased the incidence of ventricular arrhythmia in SKI with ANG (8/14 in SKI with ANG vs. 2/13 in SKI with ANG + DAN, P &lt; 0.05) (Fig. 2).

Conclusions
The loss of thiol on Cys674 under pathological condition resulted in impaired Ca2+ handling and high incidence of ventricular arrhythmia which were ameliorated by inhibition of Ca2+ leakage through RyR. Oxidative modification of Cys674 on SERCA2 might contribute to Ca2+ mishandling and arrhythmogenesis.
Abstract Figure.
P1011Cryptogenic stoke and asymptomatic atrial fibrillation in a real world population: a single centre, implantable loop recorder study
Authors: Faustino M , Di Stefano V , Franciotti R , Furia N , Di Girolamo E , Bonanni L , Onofrj M , De Angelis M V 
Published: June 2020

Abstract

Funding Acknowledgements
None

Background
The incidence of atrial fibrillation (AF) in cryptogenic stroke (CS) patients has been studied in carefully controlled clinical trials, but real-world data are limited.

Purpose
Aim of this study was to investigated the incidence of AF in clinical practice among CS patients with an implantable cardiac monitor (ICM) recommended (IIA) for AF detection.

Methods
Patients with CS admitted to our Stroke Unit were included in the study. Patiens received an ICM and were monitored for up to 2 years for AF detection (in-hospital clinic and remote monitoring). All detected AF episodes (≥30 sec) were considered.

Results
From March 2016 to March 2019, 58 patients (mean age 68 ±12 years, 67% male) received an ICM to detect AF after a CS. No patients were lost during follow-up.
AF was detected in 23 patients (40% overall; AF group mean age 72 ± 11 years; 65% male) after a mean time of 6 months from ICM implantation (ranging from 2 days up to 2 years) and 8 months after CS (ranging from 1 month up to 2 years). In these AF patients anticoagulant treatment was prescribed, and no further stroke was reported.

Conclusions
AF episodes were detected via continuous monitoring with ICMs in 40% of implanted CS patients. AF after CS was asymptomatic and thus unlikely to be detected by strategies based on intermittent short-term recordings. Therefore, ICMs should be considered as part of daily practice in the evaluation of CS patients.
Abstract Figure 1. Detection rate over time
P1157Defibrillation threshold with subcutaneous implantable-cardioverter defibrillator implanted using an intermuscular 2-incision approach
Authors: Biffi M , Ziacchi M , Martignani C , Lavalle C , Piro A , Diemberger I 
Published: June 2020

Abstract

Funding Acknowledgements
NO FUNDING

OnBehalf
Rhythm Detect Registry

Background
Current subcutaneous implantable cardioverter–defibrillators (S-ICD) deliver 80J, and the conversion test is usually conducted by delivering shock energy of 65 J to ensure a safety defibrillation margin of at least 15 J. However, little is known about the real safety margin in real life clinical practice.

Purpose
To determine the defibrillation threshold (DFT) with S-ICD and to investigate its association with clinical characteristics.

Methods
De novo S-ICD patients were consecutively enrolled and DFT was evaluated using a pre-specified step-up protocol at implantation.

Results
35 patients, BMI 25 ± 4 kg/m2, left ventricular ejection fraction (LVEF) 48 ± 19%, underwent S-ICD implantation. The generator was positioned in an intermuscular pocket and a 2-incision technique was applied in all patients. The mean DFT was 30 ± 10J and the DFT was &gt;30J in 7 (20%) patients. A single patient had a &gt;40J DFT. The time to shock was 11 ± 3 seconds and the shock impedance was 67 ±21 Ohm at the lowest effective energy. The DFT was comparable in patients with LVEF ≤35% (33 ± 15J) versus &gt;35% (29 ± 5J, p = 0.278), and in patients with BMI ≤25 kg/m2 (30 ± 5J) versus &gt;25kg/m2 (31 ± 14J, p = 0.864).

Conclusions
We observed low DFT and low shock impedance in patients who received S-ICD with an intermuscular 2-incision approach. The S-ICD defibrillation success rate at ≤30J was 80%, while 97% of patients were defibrillated at ≤ 40J. We found no difference in DFT according to the LVEF or the BMI.