bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: insight from a porcine experimental study
Authors: Matsuura G , Fukaya H , Ogawa E , Kawakami S , Saito D , Sato T , Arakawa Y , Kobayashi S , Shirakawa Y , Ishizue N , Oikawa J , Kishihara J , Niwano S , Ako J 
Published: October 2021

Abstract

Background
Local impedance (LI) at a distal tip of the ablation catheter can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). LI decreases by RFCA, and a degree of LI drop is correlated with lesion size. However, data on the effects of catheter contact angle on lesion size and LI drop were scarce. This study aimed to evaluate the influence of catheter contact angle on lesion size and LI drop in a porcine experimental study.

Methods
Lesions were created on porcine myocardial left ventricles by the LI-sensing ablation catheter (IntellaNav MiFi OI®). Contact force (CF) was measured using pressure to current transducer (load cell). Radiofrequency ablation was performed with a power of 30 Watt and a duration of 30 seconds. CF (0g, 5g, 10g, 20g, and 30g) and catheter angle (30°, 45°, and 90°) were changed in each set (total 120 lesions, n=8 each). LI rise, LI drop by RF application, and lesion size (maximum lesion width, maximum surface width, and maximum lesion depth) were evaluated.

Results
There was no angular dependence in LI rise in all CF. The values of LI rise increased as CF increased. The LI drop also increased as CF increased in all contact angles. Regarding the difference of catheter angles, LI drop with 90° was lower than those with 30° and 45°in CF 10g, 20g, and 30g, respectively. Maximum lesion width and surface width were larger in 30° and 45° than those in 90°, whereas there were no differences in maximum lesion depth.

Conclusion
LI drop in 90° were significantly lower than those in 45° and 30°. Although lesion depths were not different among the three angles, the absolute values of LI drop were different. Caution should be exercised to comprehend the LI drop with catheter angles.

Funding Acknowledgement
Type of funding sources: None.
Benefits of early intervention with catheter ablation in patients with atrial fibrillation
Authors: Mohanty S , Trivedi C , Della Rocca D G , Gianni C , MacDonald B , Mayedo A , Bassiouny M , Gallinghouse G J , Burkhardt J D , Horton R , Al-Ahmad A , Di Biase L , Natale A.N.D.R.E.A 
Published: October 2021

Abstract

Background
Radiofrequency catheter ablation, a widely recognized therapeutic option for atrial fibrillation (AF) has limited success rate as it is influenced by several factors including duration of AF.

Purpose
We evaluated the ablation success in AF patients intervened early versus late in the disease course.

Methods
Consecutive AF patients undergoing their first catheter ablation in 2015–16 at our center were included in the analysis. Patients were classified into two groups based on the time to ablation after AF diagnosis; 1) early: ≤12 months and 2) late: &gt;12 months.
All received PV isolation plus isolation of posterior wall and superior vena cava. Additionally, in non-paroxysmal AF cases, non-PV triggers were identified with isoproterenol-challenge and ablated. Patients were prospectively followed up for 3 years with regular rhythm monitoring.

Results
A total of 752 and 1248 patients were included in the “early” and “late” group respectively. Baseline characteristics of the study population is provided in Table 1 A. At 4 years of follow-up, overall success rate off-antiarrhythmic drugs was significantly higher in the “early” group (65.4% vs 57%, p&lt;0.001). After stratification by AF type, “early” group was still associated with significantly higher success rate compared to the “late” group (Table 1B).

Conclusion
In this large series with standardized ablation strategy, early intervention with catheter ablation was associated with higher success rate in all AF types.

Funding Acknowledgement
Type of funding sources: None. Table 1
Utilization and complications of catheter ablation for ventricular arrhythmias in patients with mechanical valves
Authors: Rozen G , Elbaz-Greener G , Andria N , Heist E K , Ruskin J N , Wijeysundera H C , Carasso S , Birati E , Amir O , Marai I 
Published: October 2021

Abstract

Background
Catheter ablation (CA) for ventricular arrhythmias (VAs) is increasingly utilized in the recent years. Ablation for VAs in patients with mechanical valves (MVs), can be challenging due to the chronic anticoagulation therapy, limitations in accessing the cardiac chambers, the risk for entrapment of mapping or ablation catheters between the leaflets of MVs and more.

Purpose
To investigate the nationwide trends in utilization and complications of CA for VAs in patients with prior MVs.

Methods
We drew data from the US National Inpatient Sample database to identify cases of VA ablations, including premature ventricular contraction (PVC) and ventricular tachycardia (VT) ablations, in patients with MVs between 2003 and 2015. Sociodemographic and clinical data were collected, and incidence of catheter ablation complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity matched cohort of patients without prior valve surgery.

Results
The study population included a weighted total of 647 CA cases in patients with prior MVs. The annual number of ablations almost doubled, from 34 ablations on average during the “early years” (2003–2008) to 64 annual ablation procedures on average during the “late years” (2009–2015) of the study (p=0.001). Length of stay at the hospital did not differ significantly between patients with MVs and 649 matched patients without prior MVs (5.4±0.4, 4.7±0.3 days respectively, p=0.12). The incidence of complications was higher among patients with and without MVs (12.6% vs. 7.5% respectively, p=0.14), however, not reaching statistical significance. Moreover, the data revealed a trend toward higher mortality among patients with MVs undergoing CA compared to matched control patients without MVs (3.7% vs. 0.7% respectively, p=0.087).

Conclusion
The utilization of catheter ablations for ventricular arrhythmias in patients with mechanical valves increased substantially over the years. The data show a trend towards increased incidence of morality and complications in the study population, requiring further investigation in larger population cohort.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Padeh Medical Center Research Fund
Utility of left atrial strain imaging for the determination of diastolic dysfunction in patients with STEMI
Authors: Ohtaroglu Tokdil K , Ongen Z , Ikitimur B , Durmaz E , Tokdil H , Koca D , Raimoglu U , Incesu G , Pirdal B Z , Verdiyev H , Gulfidan A , Karpuz H 
Published: October 2021

Abstract

Introduction
Since echocardiographic parameters indicating increased left ventricular filling pressure were validated in patients with stable coronary artery disease and patients with acute coronary syndrome were excluded, the utility of these parameters in ACS patients is not clarified. Recent studies suggest that left atrial strain imaging is a reliable method for the assessment of left ventricular diastolic dysfunction.

Purpose
In this study, we aimed to investigate the clinical utility of left atrial strain imaging for the detection of increased LVFP.

Methods
We prospectively included patients diagnosed with ST-segment elevation myocardial infarction who were treated with primary percutaneous intervention (pPCI). Left ventricular end-diastolic pressure was measured following the procedure. Comprehensive echocardiographic evaluation was performed within 24 hours of pPCI. Patients with atrial fibrillation and severe valvular heart disease were excluded. Normal LV end-diastolic pressure was accepted as &lt;18 mmHg.

Results
76 patients were enrolled. Patients were divided into two groups according to LVEDP value. Group 1 patients included patients with normal LVEDP (42 patients) and the rest of the patients included into group 2 (27 patients). Comorbidities including hypertension (p: 0.408), diabetes (p: 0.696) and dyslipidaemia (p: 0.336) were similar between groups. Anterior myocardial infarction was more prevalent in group 2 patients (p: 0.012). Troponin and pro-BNP values were significantly higher in group 2 patients (p: 0.001 and p: 0.03 respectively). Left ventricular ejection fraction and left ventricular global strain values were significantly lower in group 2 patients (p: 0.048 and p: 0.025 respectively). Table 1 represents the comparison of strain values between groups. Left atrial reservoir strain rates were lower in group 2 patients (p: 0.09). Correlation analyses revealed that there is a statistically significant relationship between left atrial strain values and LVEDP (p: 0.003 and r: 0.238).

Conclusion
In conclusion, our study has demonstrated that left atrial strain imaging is a useful non-invasive method for the assessment of increased LVEDP in patients with STEMI.

Funding Acknowledgement
Type of funding sources: None. Echocardiographic variables
Feasibility and efficacy using the KODEX-EPD imaging system in right atrial flutter ablation: a single center experience
Authors: Schillaci V , Stabile G , Shopova G , Arestia A , Agresta A , Salito A , Solimene F 
Published: October 2021

Abstract

Background
Isthmus-dependent right atrial flutter is the most frequently encountered atrial flutter in clinical practice (80–90% of atrial flutters).

Purpose
The aim of our study was to assess as first experience the feasibility and safety of radiofrequency catheter ablation (RFCA) of cavo-tricuspid isthmus (CTI) guided by KODEX-EPD imaging system in patients presenting with typical atrial flutter (AFL).

Methods
16 consecutive patients (mean age 68,46±7,8 years, 80% males) with diagnosis of AFL underwent RFCA guided by KODEX-EPD imaging system. In 15 patients the analysis performed during tachycardia showed a counter-clockwise activation. In 1 patient no tachycardia could be induced and the ablation was performed in sinus rhythm with fixed pacing from the coronary sinus. The KODEX-EPD imaging system was also used to guide ablation and to confirm persistent bidirectional block after ablation.

Results
Mean procedural time was 37,6±8,2 min, mean radiofrequency ablation time was 7,8±3,4 min, and mean fluoroscopy time was 2,1±1,2 min. All procedures were acutely successful with interruption of AFL during RFCA along the inferior CTI in 15 patients and achievement of the bidirectional conduction block in 16 patients proven by atrial pacing medial and lateral to the ablation line. There were no major procedural and 30-day complications. Over a mean follow-up of 18 months, we observed no recurrence of arrhythmia and no complications.

Conclusions
Our study shows that RFCA for AFL using the KODEX-EPD imaging system is feasible, safe, and effective.

Funding Acknowledgement
Type of funding sources: None.
Left atrial appendage size is a marker of atrial fibrillation recurrence after radiofrequency catheter ablation in patients with persistent atrial fibrillation
Authors: Simon J , Mahdiui M E , Smit J M , Szaraz L , Herczeg S Z , Van Rosendael A R , Zsarnoczay E , Nagy A I , Kolossvary M , Szilveszter B , Szegedi N , Geller L , Bax J J , Maurovich-Horvat P , Merkely B 
Published: October 2021

Abstract

Background
Catheter ablation is an established therapy for rhythm control in patients with drug-refractory atrial fibrillation (AF), however, recurrence is frequent particularly in persistent AF. There are no consistently confirmed predictors of AF recurrence after catheter ablation. The left atrial appendage (LAA) potentially plays an important role in AF recurrence, although the exact mechanism and pathophysiology are still unclear.

Purpose
We aimed to study whether LAA volume (LAAV) and function influence the long-term recurrence of AF after point-by-point radiofrequency catheter ablation, depending on AF type.

Methods
AF patients who underwent point-by-point radiofrequency catheter ablation after preprocedural cardiac computed tomography (CT) and transthoracic and transesophageal echocardiography (TEE) were included in this retrospective analysis. LAAV and LAA orifice area were measured by CT and LAA flow velocity assessed by TEE and was used as a surrogate marker of LAA function. Uni- and multivariable Cox proportional hazard regression models were performed to determine the predictors of AF recurrence.

Results
In total, 561 AF patients (61.9±10.2 years, 34.9% females) were included in the study. Recurrence of AF was detected in 40.8% of the cases (34.6% in patients with paroxysmal and 53.5% in those with persistent AF) with a median recurrence-free time of 22.7 [9.3–43.1] months. Patients with AF recurrence had significantly higher body surface area-indexed left atrial volume (iLAV), LAAV and LAA orifice area, as compared to those without recurrence. Moreover, patients with persistent AF had significantly higher iLAV, LAAV, LAA orifice area and lower LAA flow velocity, than those with paroxysmal AF. After adjustment for the main cardiovascular risk factors and comorbidities left ventricular ejection fraction (LVEF) &lt;50% (HR=2.17; 95% CI=1.38–3.43; p&lt;0.001) and LAAV (HR=1.06; 95% CI=1.01–1.12; p=0.029) were independently associated with AF recurrence in persistent AF, while no independent predictors could be identified in paroxysmal AF.

Conclusions
The current study demonstrates that beyond left ventricular systolic dysfunction, LAA enlargement is associated with higher rate of AF recurrence after catheter ablation in persistent AF, but not in patients with paroxysmal AF. Our results suggest that preprocedural assessment of LVEF and LAAV might contribute to optimal patient selection and aid to improve long-term results of ablation procedures in patients with persistent AF.

Funding Acknowledgement
Type of funding sources: None.
Accuracy comparison of the new and previous Kodex occlusion tool software versions to assess pulmonary vein occlusion in atrial fibrillation cryoablation
Authors: Cauti F M , Rossi P , Iaia L , Polselli M , Pecere A , Bianchi S 
Published: October 2021

Abstract

Background
Atrial fibrillation (AF) is the most frequent sustained arrhythmia worldwide and Cryoballoon ablation (CB) has become a consolidated alternative to the radiofrequency pulmonary vein (PV) isolation. However, CB requires fluoroscopy and dye injections to verify the occlusion grade. The accuracy of the earlier version of the Kodex Occlusion Tool software has been studied.

Purpose
The purpose of this study was to verify the accuracy of the second generation Kodex Occlusion Tool Software of a new dielectric system imaging compared to its first generation to detect PV occlusion during CB ablation in patients with AF.

Methods
15 consecutive patients with paroxysmal AF were enrolled in the study and underwent the procedure with the guidance of the first generation version (1.4.6) of the Kodex Occlusion Tool software. The Kodex recorded procedural data were used to replay the case using the Kodex second generation version (1.4.7) of the Occlusion Tool software when clinically available. After transseptal access, a detailed image reconstruction of left atrium and PVs was achieved with an octa-polar circular mapping catheter, PV occlusion was assessed with the Occlusion Tool Software and compared with standard dye injection and angiography, the cryoablation was then performed with a cryoballoon catheter.

Results
A total of 74 PVs CB occlusions were tested. The old version showed 90.7% sensitivity and 74.2% specificity in assessing a complete PV occlusion verified with contrast medium injection. The positive predictive value was 82.9%, and the negative predictive value was 85.2%. The new version showed 94.8% sensitivity and 93.7% specificity in assessing a complete PV occlusion verified with same contrast medium injection data. The positive predictive value was 98.2%, and the negative predictive value was 93.7%. Acute isolation was achieved in all PVs and no 30-day complication was observed.

Conclusion
This study demonstrates an increased accuracy of new Occlusion Tool software of the Kodex dielectric imaging system to assess the degree of PV occlusion during a CB ablation.

Funding Acknowledgement
Type of funding sources: None.
Long-term implications of pacemaker insertion in younger adults: a single centre experience
Authors: Shirwaiker A , William J , Mariani J , Kistler P , Patel H , Voskoboinik A 
Published: October 2021

Abstract

Background
The long-term implications of pacemaker insertion in younger adults are poorly described in the literature.

Methods
We performed a retrospective analysis of consecutive younger adult patients (18–50 years) undergoing pacemaker implantation at a quaternary hospital between 1986–2020. Defibrillators and cardiac resynchronisation therapy devices were excluded. All clinical records, pacemaker checks and echocardiograms were reviewed.

Results
81 patients (39.5±9.6 years, 53% male) underwent pacemaker implantation. Indications were complete heart block (41%), sinus node dysfunction (33%), high grade AV block (11%) and tachycardia-bradycardia syndrome (7%). During a median 7.6 (IQR=0.6–14.8) years follow-up, 9 patients (11%) developed 13 late device-related complications (generator or lead malfunction requiring reoperation (n=11), device infection (n=1) and pocket revision (n=1)). Five of these patients were &lt;40 years old at time of pacemaker insertion. At long-term follow-up, a further 9 patients (11%) experienced significant symptoms from inadequate lead performance managed with device reprogramming. Sustained ventricular tachycardia was detected in 2 patients (2%). Deterioration in ventricular function (LVEF decline &gt;10%) was observed in 14 patients (17%) and 7 of these patients required subsequent biventricular upgrade. Furthermore, 4 patients (5%) developed new tricuspid regurgitation (≥ moderate-severe). Of 69 patients with available long-term pacing data, minimal pacemaker utilisation (pacing &lt;5% at all checks) was observed in 13 (19%) patients.

Conclusions
Pacemaker insertion in younger adults has significant long-term implications. Clinicians should carefully consider pacemaker insertion in this cohort given risk of device-related complications, potential for device under-utilisation and issues related to lead longevity. In addition, patients require close follow-up for development of structural abnormalities and arrhythmias.

Funding Acknowledgement
Type of funding sources: None.
Subcutaneous ICD combined with VT ablation for the secondary prevention of sudden cardiac death: pilot data from the prospective multinational SICD-VTAbl study
Authors: Goldenberg I , Maury P , Sacher F , Clementy N , Huang D T , Mulpuru S , Friedman P , Meyer C , Benshushan A D , Tiefenbrun N L , Nof E ,   The SICD-VTAbl Investigators
Published: October 2021

Abstract

Background
The aim of the Subcutaneous ICD Combined with Ventricular Tachycardia Ablation (SICD-VTAbl) Study is to provide preliminary data on the safety and efficacy of a management strategy that incorporates S-ICD implantation and VT ablation among patients with a secondary prevention indication for an ICD. We hypothesize that VT ablation for the prevention of monomorphic VT recurrence combined with S-ICD implantation for termination of life-threatening VT/VF is safe, while reducing the need for device interventions and systemic complications associated with conventional transvenous ICD implantation for secondary prevention.

Methods
SICD-VTAbl is an uncontrolled, prospective, multinational observational study, conducted in France, Germany, US (Rochester NY, and Rochester MN) and coordinated in Israel. We aim to prospectively enroll 30 patients presenting with scar-related VT/VF who will undergo VT ablation/substrate modification followed by S-ICD implantation. The primary endpoint is the first occurrence of S-ICD therapy (appropriate and inappropriate). Secondary endpoints include separate occurrence of appropriate and inappropriate ICD therapies, peri-procedural complications, and adverse clinical outcomes.

Results
We provide clinical, arrhythmia, and outcome data on the first 15 patients enrolled in the SICD-VTAbl Study through February 2021. Mean age was 59±12 years, 78% were males, 60% had New York Heart Association (NYHA) Class ≥II symptoms, 20% had renal insufficiency, and 33% were treated with an antiarrhythmic medication (all amiodarone). Periprocedural, arrhythmia, and long-term outcome data are provided in Table 1. There were no major complications associated with the VT ablation and the S-ICD implantation procedures. During a median follow-up of 6 months (interquartile range: 2–12 months), 2 patients (13%) received S-ICD therapy: one patient (7%) experienced VF terminated by the S-ICD and one patient experienced a single episode of inappropriate S-ICD therapy. Adverse events during follow-up, unrelated to study procedures, occurred in 3 patients (20%): hospitalization for heart failure exacerbation (N=1) and non-cardiovascular hospitalizations (N=2). None of the patients died during follow-up (Table 1).

Conclusions
Our preliminary data from the SICD-VTAbl Study suggest that a management approach that incorporates VT ablation followed by S-ICD implantation is safe and may lead to improved arrhythmia and clinical outcomes in patients presenting with a secondary prevention indication for an ICD.

Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): Research grant to Sheba Medical Center from Boston Scientific